diff options
Diffstat (limited to 'doc/driver-model')
| -rw-r--r-- | doc/driver-model/UDM-block.txt | 279 | ||||
| -rw-r--r-- | doc/driver-model/UDM-cores.txt | 126 | ||||
| -rw-r--r-- | doc/driver-model/UDM-design.txt | 315 | ||||
| -rw-r--r-- | doc/driver-model/UDM-fpga.txt | 115 | ||||
| -rw-r--r-- | doc/driver-model/UDM-gpio.txt | 106 | ||||
| -rw-r--r-- | doc/driver-model/UDM-hwmon.txt | 118 | ||||
| -rw-r--r-- | doc/driver-model/UDM-keyboard.txt | 47 | ||||
| -rw-r--r-- | doc/driver-model/UDM-mmc.txt | 319 | ||||
| -rw-r--r-- | doc/driver-model/UDM-net.txt | 434 | ||||
| -rw-r--r-- | doc/driver-model/UDM-pci.txt | 265 | ||||
| -rw-r--r-- | doc/driver-model/UDM-pcmcia.txt | 78 | ||||
| -rw-r--r-- | doc/driver-model/UDM-power.txt | 88 | ||||
| -rw-r--r-- | doc/driver-model/UDM-rtc.txt | 258 | ||||
| -rw-r--r-- | doc/driver-model/UDM-serial.txt | 191 | ||||
| -rw-r--r-- | doc/driver-model/UDM-spi.txt | 200 | ||||
| -rw-r--r-- | doc/driver-model/UDM-stdio.txt | 191 | ||||
| -rw-r--r-- | doc/driver-model/UDM-tpm.txt | 48 | ||||
| -rw-r--r-- | doc/driver-model/UDM-twserial.txt | 47 | ||||
| -rw-r--r-- | doc/driver-model/UDM-usb.txt | 94 | ||||
| -rw-r--r-- | doc/driver-model/UDM-video.txt | 74 | ||||
| -rw-r--r-- | doc/driver-model/UDM-watchdog.txt | 334 |
21 files changed, 3727 insertions, 0 deletions
diff --git a/doc/driver-model/UDM-block.txt b/doc/driver-model/UDM-block.txt new file mode 100644 index 000000000..5d5c77601 --- /dev/null +++ b/doc/driver-model/UDM-block.txt @@ -0,0 +1,279 @@ +The U-Boot Driver Model Project +=============================== +Block device subsystem analysis +=============================== + +Pavel Herrmann <morpheus.ibis@gmail.com> +2012-03-08 + +I) Overview +----------- + + U-Boot currently implements several distinct APIs for block devices - some + drivers use the SATA API, some drivers use the IDE API, sym53c8xx and + AHCI use the SCSI API, mg_disk has a separate API, and systemace also has a + separate API. There are also MMC and USB APIs used outside of drivers/block, + those will be detailed in their specific documents. + + Block devices are described by block_dev_desc structure, that holds, among + other things, the read/write/erase callbacks. Block device structures are + stored in any way depending on the API, but can be accessed by + + block_dev_desc_t * $api_get_dev(int dev) + + function, as seen in disk/part.c. + + 1) SATA interface + ----------------- + + The SATA interface drivers implement the following functions: + + int init_sata(int dev) + int scan_sata(int dev) + ulong sata_read(int dev, ulong blknr, ulong blkcnt, void *buffer) + ulong sata_write(int dev, ulong blknr, ulong blkcnt, const void *buffer) + + Block devices are kept in sata_dev_desc[], which is prefilled with values + common to all SATA devices in cmd_sata.c, and then modified in init_sata + function in the drivers. Callbacks of the block device use SATA API + directly. The sata_get_dev function is defined in cmd_sata.c. + + 2) SCSI interface + ----------------- + + The SCSI interface drivers implement the following functions: + + void scsi_print_error(ccb *pccb) + int scsi_exec(ccb *pccb) + void scsi_bus_reset(void) + void scsi_low_level_init(int busdevfunc) + + The SCSI API works through the scsi_exec function, the actual operation + requested is found in the ccb structure. + + Block devices are kept in scsi_dev_desc[], which lives only in cmd_scsi.c. + Callbacks of the block device use functions from cmd_scsi.c, which in turn + call scsi_exec of the controller. The scsi_get_dev function is also defined + in cmd_scsi.c. + + 3) mg_disk interface + -------------------- + + The mg_disk interface drivers implement the following functions: + + struct mg_drv_data* mg_get_drv_data (void) + uint mg_disk_init (void) + uint mg_disk_read (u32 addr, u8 *buff, u32 len) + uint mg_disk_write(u32 addr, u8 *buff, u32 len) + uint mg_disk_write_sects(void *buff, u32 sect_num, u32 sect_cnt) + uint mg_disk_read_sects(void *buff, u32 sect_num, u32 sect_cnt) + + The mg_get_drv_data function is to be overridden per-board, but there are no + board in-tree that do this. + + Only one driver for this API exists, and it only supports one block device. + Callbacks for this device are implemented in mg_disk.c and call the mg_disk + API. The mg_disk_get_dev function is defined in mg_disk.c and ignores the + device number, always returning the same device. + + 4) systemace interface + ---------------------- + + The systemace interface does not define any driver API, and has no command + itself. The single defined function is systemace_get_devs() from + systemace.c, which returns a single static structure for the only supported + block device. Callbacks for this device are also implemented in systemace.c. + + 5) IDE interface + ---------------- + + The IDE interface drivers implement the following functions, but only if + CONFIG_IDE_AHB is set: + + uchar ide_read_register(int dev, unsigned int port); + void ide_write_register(int dev, unsigned int port, unsigned char val); + void ide_read_data(int dev, ulong *sect_buf, int words); + void ide_write_data(int dev, ulong *sect_buf, int words); + + The first two functions are called from ide_inb()/ide_outb(), and will + default to direct memory access if CONFIG_IDE_AHB is not set, or + ide_inb()/ide_outb() functions will get overridden by the board altogether. + + The second two functions are called from input_data()/output_data() + functions, and also default to direct memory access, but cannot be + overridden by the board. + + One function shared by IDE drivers (but not defined in ide.h) is + int ide_preinit(void) + This function gets called from ide_init in cmd_ide.c if CONFIG_IDE_PREINIT + is defined, and will do the driver-specific initialization of the device. + + Block devices are kept in ide_dev_desc[], which is filled in cmd_ide.c. + Callbacks of the block device are defined in cmd_ide.c, and use the + ide_inb()/ide_outb()/input_data()/output_data() functions mentioned above. + The ide_get_dev function is defined in cmd_ide.c. + +II) Approach +------------ + + A new block controller core and an associated API will be created to mimic the + current SATA API, its drivers will have the following ops: + + struct block_ctrl_ops { + int scan(instance *i); + int reset(instance *i, int port); + lbaint_t read(instance *i, int port, lbaint_t start, lbatin_t length, + void *buffer); + lbaint_t write(instance *i, int port, lbaint_t start, lbatin_t length, + void*buffer); + } + + The current sata_init() function will be changed into the driver probe() + function. The read() and write() functions should never be called directly, + instead they should be called by block device driver for disks. + + Other block APIs would either be transformed into this API, or be kept as + legacy for old drivers, or be dropped altogether. + + Legacy driver APIs will each have its own driver core that will contain the + shared logic, which is currently located mostly in cmd_* files. Callbacks for + block device drivers will then probably be implemented as a part of the core + logic, and will use the driver ops (which will copy current state of + respective APIs) to do the work. + + All drivers will be cleaned up, most ifdefs should be converted into + platform_data, to enable support for multiple devices with different settings. + + A new block device core will also be created, and will keep track of all + block devices on all interfaces. + + Current block_dev_desc structure will be changed to fit the driver model, all + identification and configuration will be placed in private data, and + a single accessor and modifier will be defined, to accommodate the need for + different sets of options for different interfaces, while keeping the + structure small. The new block device drivers will have the following ops + structure (lbaint_t is either 32bit or 64bit unsigned, depending on + CONFIG_LBA48): + + struct blockdev_ops { + lbaint_t (*block_read)(struct instance *i, lbaint_t start, lbaint_t blkcnt, + void *buffer); + lbaint_t (*block_write)(struct instance *i, lbaint_t start, lbaint_t blkcnt, + void *buffer); + lbaint_t (*block_erase)(struct instance *i, lbaint_t start, lbaint_t blkcnt + ); + int (*get_option)(struct instance *i, enum blockdev_option_code op, + struct option *res); + int (*set_option)(struct instance *i, enum blockdev_option_code op, + struct option *val); + } + + struct option { + uint32_t flags + union data { + uint64_t data_u; + char* data_s; + void* data_p; + } + } + + enum blockdev_option_code { + BLKD_OPT_IFTYPE=0, + BLKD_OPT_TYPE, + BLKD_OPT_BLOCKSIZE, + BLKD_OPT_BLOCKCOUNT, + BLKD_OPT_REMOVABLE, + BLKD_OPT_LBA48, + BLKD_OPT_VENDOR, + BLKD_OPT_PRODICT, + BLKD_OPT_REVISION, + BLKD_OPT_SCSILUN, + BLKD_OPT_SCSITARGET, + BLKD_OPT_OFFSET + } + + Flags in option above will contain the type of returned data (which should be + checked against what is expected, even though the option requested should + specify it), and a flag to indicate whether the returned pointer needs to be + free()'d. + + The block device core will contain the logic now located in disk/part.c and + related files, and will be used to forward requests to block devices. The API + for the block device core will copy the ops of a block device (with a string + identifier instead of instance pointer). This means that partitions will also + be handled by the block device core, and exported as block devices, making + them transparent to the rest of the code. + + Sadly, this will change how file systems can access the devices, and thus will + affect a lot of places. However, these changes should be localized and easy to + implement. + + AHCI driver will be rewritten to fit the new unified block controller API, + making SCSI API easy to merge with sym53c8xx, or remove it once the device + driver has died. + + Optionally, IDE core may be changed into one driver with unified block + controller API, as most of it is already in one place and device drivers are + just sets of hooks. Additionally, mg_disk driver is unused and may be removed + in near future. + + + +III) Analysis of in-tree drivers +-------------------------------- + + 1) ahci.c + --------- + SCSI API, will be rewritten for a different API. + + 2) ata_piix.c + ------------- + SATA API, easy to port. + + 3) fsl_sata.c + ------------- + SATA API, few CONFIG macros, easy to port. + + 4) ftide020.c + ------------- + IDE API, defines CONFIG_IDE_AHB and ide_preinit hook functions. + + 5) mg_disk.c + ------------ + Single driver with mg_disk API, not much to change, easy to port. + + 6) mvsata_ide.c + --------------- + IDE API, only defines ide_preinit hook function. + + 7) mxc_ata.c + ------------ + IDE API, only defines ide_preinit hook function. + + 8) pata_bfin.c + -------------- + SATA API, easy to port. + + 9) sata_dwc.c + ------------- + SATA API, easy to port. + + 10) sata_sil3114.c + ------------------ + SATA API, easy to port. + + 11) sata_sil.c + -------------- + SATA API, easy to port. + + 12) sil680.c + ------------ + IDE API, only defines ide_preinit hook function. + + 13) sym53c8xx.c + --------------- + SCSI API, may be merged with code from cmd_scsi. + + 14) systemace.c + --------------- + Single driver with systemace API, not much to change, easy to port. diff --git a/doc/driver-model/UDM-cores.txt b/doc/driver-model/UDM-cores.txt new file mode 100644 index 000000000..4e1318871 --- /dev/null +++ b/doc/driver-model/UDM-cores.txt @@ -0,0 +1,126 @@ +The U-Boot Driver Model Project +=============================== +Driver cores API document +========================= + +Pavel Herrmann <morpheus.ibis@gmail.com> + +1) Overview +----------- + Driver cores will be used as a wrapper for devices of the same type, and as + an abstraction for device driver APIs. For each driver API (which roughly + correspond to device types), there will be one driver core. Each driver core + will implement three APIs - a driver API (which will be the same as API of + drivers the core wraps around), a core API (which will be implemented by all + cores) and a command API (core-specific API which will be exposed to + commands). + + A) Command API + The command API will provide access to shared functionality for a specific + device, which is currently located mostly in commands. Commands will be + rewritten to be more lightweight by using this API. As this API will be + different for each core, it is out of scope of this document. + + B) Driver API + The driver API will act as a wrapper around actual device drivers, + providing a single entrypoint for device access. All functions in this API + have an instance* argument (probably called "this" or "i"), which will be + examined by the core, and a correct function for the specified driver will + get called. + + If the core gets called with a group instance pointer (as discussed in + design), it will automatically select the instance that is associated + with this core, and use it as target of the call. if the group contains + multiple instances of a single type, the caller must explicitly use an + accessor to select the correct instance. + + This accessor will look like: + struct instance *get_instance_from_group(struct instance *group, int i) + + When called with a non-group instance, it will simply return the instance. + + C) Core API + The core API will be implemented by all cores, and will provide + functionality for getting driver instances from non-driver code. This API + will consist of following functions: + + int get_count(struct instance *core); + struct instance* get_instance(struct instance *core, int index); + int init(struct instance *core); + int bind(struct instance *core, struct instance *dev, void *ops, + void *hint); + int unbind(struct instance *core, instance *dev); + int replace(struct instance *core, struct_instance *new_dev, + struct instance *old_dev); + int destroy(struct instance *core); + int reloc(struct instance *new_core, struct instance *old_core); + + The 'hint' parameter of bind() serves for additional data a driver can + pass to the core, to help it create the correct internal state for this + instance. the replace() function will get called during instance + relocation, and will replace the old instance with the new one, keeping + the internal state untouched. + + +2) Lifetime of a driver core +---------------------------- + Driver cores will be initialized at runtime, to limit memory footprint in + early-init stage, when we have to fit into ~1KB of memory. All active cores + will be stored in a tree structure (referenced as "Core tree") in global data, + which provides good tradeoff between size and access time. + Every core will have a number constant associated with it, which will be used + to find the instance in Core tree, and to refer to the core in all calls + working with the Core tree. + The Core Tree should be implemented using B-tree (or a similar structure) + to guarantee acceptable time overhead in all cases. + + Code for working with the core (i2c in this example) follows: + + core_init(CORE_I2C); + This will check whether we already have a i2c core, and if not it creates + a new instance and adds it into the Core tree. This will not be exported, + all code should depend on get_core_instance to init the core when + necessary. + + get_core_instance(CORE_I2C); + This is an accessor into the Core tree, which will return the instance + of i2c core, creating it if necessary + + core_bind(CORE_I2C, instance, driver_ops); + This will get called in bind() function of a driver, and will add the + instance into cores internal list of devices. If the core is not found, it + will get created. + + driver_activate(instance *inst); + This call will recursively activate all devices necessary for using the + specified device. the code could be simplified as: + { + if (is_activated(inst)) + return; + driver_activate(inst->bus); + get_driver(inst)->probe(inst); + } + + The case with multiple parents will need to be handled here as well. + get_driver is an accessor to available drivers, which will get struct + driver based on a name in the instance. + + i2c_write(instance *inst, ...); + An actual call to some method of the driver. This code will look like: + { + driver_activate(inst); + struct instance *core = get_core_instance(CORE_I2C); + device_ops = get_ops(inst); + device_ops->write(...); + } + + get_ops will not be an exported function, it will be internal and specific + to the core, as it needs to know how are the ops stored, and what type + they are. + + Please note that above examples represent the algorithm, not the actual code, + as they are missing checks for validity of return values. + + core_init() function will get called the first time the core is requested, + either by core_link() or core_get_instance(). This way, the cores will get + created only when they are necessary, which will reduce our memory footprint. diff --git a/doc/driver-model/UDM-design.txt b/doc/driver-model/UDM-design.txt new file mode 100644 index 000000000..185f477b0 --- /dev/null +++ b/doc/driver-model/UDM-design.txt @@ -0,0 +1,315 @@ +The U-Boot Driver Model Project +=============================== +Design document +=============== +Marek Vasut <marek.vasut@gmail.com> +Pavel Herrmann <morpheus.ibis@gmail.com> +2012-05-17 + +I) The modular concept +---------------------- + +The driver core design is done with modularity in mind. The long-term plan is to +extend this modularity to allow loading not only drivers, but various other +objects into U-Boot at runtime -- like commands, support for other boards etc. + +II) Driver core initialization stages +------------------------------------- + +The drivers have to be initialized in two stages, since the U-Boot bootloader +runs in two stages itself. The first stage is the one which is executed before +the bootloader itself is relocated. The second stage then happens after +relocation. + + 1) First stage + -------------- + + The first stage runs after the bootloader did very basic hardware init. This + means the stack pointer was configured, caches disabled and that's about it. + The problem with this part is the memory management isn't running at all. To + make things even worse, at this point, the RAM is still likely uninitialized + and therefore unavailable. + + 2) Second stage + --------------- + + At this stage, the bootloader has initialized RAM and is running from it's + final location. Dynamic memory allocations are working at this point. Most of + the driver initialization is executed here. + +III) The drivers +---------------- + + 1) The structure of a driver + ---------------------------- + + The driver will contain a structure located in a separate section, which + will allow linker to create a list of compiled-in drivers at compile time. + Let's call this list "driver_list". + + struct driver __attribute__((section(driver_list))) { + /* The name of the driver */ + char name[STATIC_CONFIG_DRIVER_NAME_LENGTH]; + + /* + * This function should connect this driver with cores it depends on and + * with other drivers, likely bus drivers + */ + int (*bind)(struct instance *i); + + /* This function actually initializes the hardware. */ + int (*probe)(struct instance *i); + + /* + * The function of the driver called when U-Boot finished relocation. + * This is particularly important to eg. move pointers to DMA buffers + * and such from the location before relocation to their final location. + */ + int (*reloc)(struct instance *i); + + /* + * This is called when the driver is shuting down, to deinitialize the + * hardware. + */ + int (*remove)(struct instance *i); + + /* This is called to remove the driver from the driver tree */ + int (*unbind)(struct instance *i); + + /* This is a list of cores this driver depends on */ + struct driver *cores[]; + }; + + The cores[] array in here is very important. It allows u-boot to figure out, + in compile-time, which possible cores can be activated at runtime. Therefore + if there are cores that won't be ever activated, GCC LTO might remove them + from the final binary. Actually, this information might be used to drive build + of the cores. + + FIXME: Should *cores[] be really struct driver, pointing to drivers that + represent the cores? Shouldn't it be core instance pointer? + + 2) Instantiation of a driver + ---------------------------- + + The driver is instantiated by calling: + + driver_bind(struct instance *bus, const struct driver_info *di) + + The "struct instance *bus" is a pointer to a bus with which this driver should + be registered with. The "root" bus pointer is supplied to the board init + functions. + + FIXME: We need some functions that will return list of busses of certain type + registered with the system so the user can find proper instance even if + he has no bus pointer (this will come handy if the user isn't + registering the driver from board init function, but somewhere else). + + The "const struct driver_info *di" pointer points to a structure defining the + driver to be registered. The structure is defined as follows: + + struct driver_info { + char name[STATIC_CONFIG_DRIVER_NAME_LENGTH]; + void *platform_data; + } + + The instantiation of a driver by calling driver_bind() creates an instance + of the driver by allocating "struct driver_instance". Note that only struct + instance is passed to the driver. The wrapping struct driver_instance is there + for purposes of the driver core: + + struct driver_instance { + uint32_t flags; + struct instance i; + }; + + struct instance { + /* Pointer to a driver information passed by driver_register() */ + const struct driver_info *info; + /* Pointer to a bus this driver is bound with */ + struct instance *bus; + /* Pointer to this driver's own private data */ + void *private_data; + /* Pointer to the first block of successor nodes (optional) */ + struct successor_block *succ; + } + + The instantiation of a driver does not mean the hardware is initialized. The + driver_bind() call only creates the instance of the driver, fills in the "bus" + pointer and calls the drivers' .bind() function. The .bind() function of the + driver should hook the driver with the remaining cores and/or drivers it + depends on. + + It's important to note here, that in case the driver instance has multiple + parents, such parent can be connected with this instance by calling: + + driver_link(struct instance *parent, struct instance *dev); + + This will connect the other parent driver with the newly instantiated driver. + Note that this must be called after driver_bind() and before driver_acticate() + (driver_activate() will be explained below). To allow struct instance to have + multiple parent pointer, the struct instance *bus will utilize it's last bit + to indicate if this is a pointer to struct instance or to an array if + instances, struct successor block. The approach is similar as the approach to + *succ in struct instance, described in the following paragraph. + + The last pointer of the struct instance, the pointer to successor nodes, is + used only in case of a bus driver. Otherwise the pointer contains NULL value. + The last bit of this field indicates if this is a bus having a single child + node (so the last bit is 0) or if this bus has multiple child nodes (the last + bit is 1). In the former case, the driver core should clear the last bit and + this pointer points directly to the child node. In the later case of a bus + driver, the pointer points to an instance of structure: + + struct successor_block { + /* Array of pointers to instances of devices attached to this bus */ + struct instance *dev[BLOCKING_FACTOR]; + /* Pointer to next block of successors */ + struct successor_block *next; + } + + Some of the *dev[] array members might be NULL in case there are no more + devices attached. The *next is NULL in case the list of attached devices + doesn't continue anymore. The BLOCKING_FACTOR is used to allocate multiple + slots for successor devices at once to avoid fragmentation of memory. + + 3) The bind() function of a driver + ---------------------------------- + + The bind function of a driver connects the driver with various cores the + driver provides functions for. The driver model related part will look like + the following example for a bus driver: + + int driver_bind(struct instance *in) + { + ... + core_bind(&core_i2c_static_instance, in, i2c_bus_funcs); + ... + } + + FIXME: What if we need to run-time determine, depending on some hardware + register, what kind of i2c_bus_funcs to pass? + + This makes the i2c core aware of a new bus. The i2c_bus_funcs is a constant + structure of functions any i2c bus driver must provide to work. This will + allow the i2c command operate with the bus. The core_i2c_static_instance is + the pointer to the instance of a core this driver provides function to. + + FIXME: Maybe replace "core-i2c" with CORE_I2C global pointer to an instance of + the core? + + 4) The instantiation of a core driver + ------------------------------------- + + The core driver is special in the way that it's single-instance driver. It is + always present in the system, though it might not be activated. The fact that + it's single instance allows it to be instantiated at compile time. + + Therefore, all possible structures of this driver can be in read-only memory, + especially struct driver and struct driver_instance. But the successor list, + which needs special treatment. + + To solve the problem with a successor list and the core driver flags, a new + entry in struct gd (global data) will be introduced. This entry will point to + runtime allocated array of struct driver_instance. It will be possible to + allocate the exact amount of struct driver_instance necessary, as the number + of cores that might be activated will be known at compile time. The cores will + then behave like any usual driver. + + Pointers to the struct instance of cores can be computed at compile time, + therefore allowing the resulting u-boot binary to save some overhead. + + 5) The probe() function of a driver + ----------------------------------- + + The probe function of a driver allocates necessary resources and does required + initialization of the hardware itself. This is usually called only when the + driver is needed, as a part of the defered probe mechanism. + + The driver core should implement a function called + + int driver_activate(struct instance *in); + + which should call the .probe() function of the driver and then configure the + state of the driver instance to "ACTIVATED". This state of a driver instance + should be stored in a wrap-around structure for the structure instance, the + struct driver_instance. + + 6) The command side interface to a driver + ----------------------------------------- + + The U-Boot command shall communicate only with the specific driver core. The + driver core in turn exports necessary API towards the command. + + 7) Demonstration imaginary board + -------------------------------- + + Consider the following computer: + + * + | + +-- System power management logic + | + +-- CPU clock controlling logc + | + +-- NAND controller + | | + | +-- NAND flash chip + | + +-- 128MB of DDR DRAM + | + +-- I2C bus #0 + | | + | +-- RTC + | | + | +-- EEPROM #0 + | | + | +-- EEPROM #1 + | + +-- USB host-only IP core + | | + | +-- USB storage device + | + +-- USB OTG-capable IP core + | | + | +-- connection to the host PC + | + +-- GPIO + | | + | +-- User LED #0 + | | + | +-- User LED #1 + | + +-- UART0 + | + +-- UART1 + | + +-- Ethernet controller #0 + | + +-- Ethernet controller #1 + | + +-- Audio codec + | + +-- PCI bridge + | | + | +-- Ethernet controller #2 + | | + | +-- SPI host card + | | | + | | +-- Audio amplifier (must be operational before codec) + | | + | +-- GPIO host card + | | + | +-- User LED #2 + | + +-- LCD controller + | + +-- PWM controller (must be enabled after LCD controller) + | + +-- SPI host controller + | | + | +-- SD/MMC connected via SPI + | | + | +-- SPI flash + | + +-- CPLD/FPGA with stored configuration of the board diff --git a/doc/driver-model/UDM-fpga.txt b/doc/driver-model/UDM-fpga.txt new file mode 100644 index 000000000..4f9df940e --- /dev/null +++ b/doc/driver-model/UDM-fpga.txt @@ -0,0 +1,115 @@ +The U-Boot Driver Model Project +=============================== +I/O system analysis +=================== +Marek Vasut <marek.vasut@gmail.com> +2012-02-21 + +I) Overview +----------- + +The current FPGA implementation is handled by command "fpga". This command in +turn calls the following functions: + +fpga_info() +fpga_load() +fpga_dump() + +These functions are implemented by what appears to be FPGA multiplexer, located +in drivers/fpga/fpga.c . This code determines which device to operate with +depending on the device ID. + +The fpga_info() function is multiplexer of the functions providing information +about the particular FPGA device. These functions are implemented in the drivers +for the particular FPGA device: + +xilinx_info() +altera_info() +lattice_info() + +Similar approach is used for fpga_load(), which multiplexes "xilinx_load()", +"altera_load()" and "lattice_load()" and is used to load firmware into the FPGA +device. + +The fpga_dump() function, which prints the contents of the FPGA device, is no +different either, by multiplexing "xilinx_dump()", "altera_dump()" and +"lattice_dump()" functions. + +Finally, each new FPGA device is registered by calling "fpga_add()" function. +This function takes two arguments, the second one being particularly important, +because it's basically what will become platform_data. Currently, it's data that +are passed to the driver from the board/platform code. + +II) Approach +------------ + +The path to conversion of the FPGA subsystem will be very straightforward, since +the FPGA subsystem is already quite dynamic. Multiple things will need to be +modified though. + +First is the registration of the new FPGA device towards the FPGA core. This +will be achieved by calling: + + fpga_device_register(struct instance *i, const struct fpga_ops *ops); + +The particularly interesting part is the struct fpga_ops, which contains +operations supported by the FPGA device. These are basically the already used +calls in the current implementation: + +struct fpga_ops { + int info(struct instance *i); + int load(struct instance *i, const char *buf, size_t size); + int dump(struct instance *i, const char *buf, size_t size); +} + +The other piece that'll have to be modified is how the devices are tracked. +It'll be necessary to introduce a linked list of devices within the FPGA core +instead of tracking them by ID number. + +Next, the "Xilinx_desc", "Lattice_desc" and "Altera_desc" structures will have +to be moved to driver's private_data. Finally, structures passed from the board +and/or platform files, like "Xilinx_Virtex2_Slave_SelectMap_fns" would be passed +via platform_data to the driver. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) Altera driver + ---------------- + The driver is realized using the following files: + + drivers/fpga/altera.c + drivers/fpga/ACEX1K.c + drivers/fpga/cyclon2.c + drivers/fpga/stratixII.c + + All of the sub-drivers implement basically the same info-load-dump interface + and there's no expected problem during the conversion. The driver itself will + be realised by altera.c and all the sub-drivers will be linked in. The + distinction will be done by passing different platform data. + + 2) Lattice driver + ----------------- + The driver is realized using the following files: + + drivers/fpga/lattice.c + drivers/fpga/ivm_core.c + + This driver also implements the standard interface, but to realise the + operations with the FPGA device, uses functions from "ivm_core.c" file. This + file implements the main communications logic and has to be linked in together + with "lattice.c". No problem converting is expected here. + + 3) Xilinx driver + ---------------- + The driver is realized using the following files: + + drivers/fpga/xilinx.c + drivers/fpga/spartan2.c + drivers/fpga/spartan3.c + drivers/fpga/virtex2.c + + This set of sub-drivers is special by defining a big set of macros in + "include/spartan3.h" and similar files. These macros would need to be either + rewritten or replaced. Otherwise, there are no problems expected during the + conversion process. diff --git a/doc/driver-model/UDM-gpio.txt b/doc/driver-model/UDM-gpio.txt new file mode 100644 index 000000000..8ff0a965c --- /dev/null +++ b/doc/driver-model/UDM-gpio.txt @@ -0,0 +1,106 @@ +The U-Boot Driver Model Project +=============================== +GPIO analysis +============= +Viktor Krivak <viktor.krivak@gmail.com> +2012-02-24 + +I) Overview +----------- + + At this moment U-Boot provides standard API that consists of 7 functions. + + int gpio_request(unsigned gpio, const char *label) + int gpio_free(unsigned gpio) + int gpio_direction_input(unsigned gpio) + int gpio_direction_output(unsigned gpio, int value) + int gpio_get_value(unsigned gpio) + void gpio_set_value(unsigned gpio, int value) + + Methods "gpio_request()" and "gpio_free()" are used for claiming and releasing + GPIOs. First one should check if the desired pin exists and if the pin wasn't + requested already elsewhere. The method also has a label argument that can be + used for debug purposes. The label argument should be copied into the internal + memory, but only if the DEBUG macro is set. The "gpio_free()" is the exact + opposite. It releases the particular pin. Other methods are used for setting + input or output direction and obtaining or setting values of the pins. + +II) Approach +------------ + + 1) Request and free GPIO + ------------------------ + + The "gpio_request()" implementation is basically the same for all boards. + The function checks if the particular GPIO is correct and checks if the + GPIO pin is still free. If the conditions are met, the method marks the + GPIO claimed in it's internal structure. If macro DEBUG is defined, the + function also copies the label argument to the structure. If the pin is + already locked, the function returns -1 and if DEBUG is defined, certain + debug output is generated, including the contents of the label argument. + The "gpio_free()" function releases the lock and eventually deallocates + data used by the copied label argument. + + 2) Internal data + ---------------- + + Internal data are driver specific. They have to contain some mechanism to + realise the locking though. This can be done for example using a bit field. + + 3) Operations provided by the driver + ------------------------------------ + + The driver operations basically meet API that is already defined and used. + Except for "gpio_request()" and "gpio_free()", all methods can be converted in + a simple manner. The driver provides the following structure: + + struct gpio_driver_ops { + int (*gpio_request)(struct instance *i, unsigned gpio, + const char *label); + int (*gpio_free)(struct instance *i, unsigned gpio); + int (*gpio_direction_input)(struct instance *i, unsigned gpio); + int (*gpio_direction_output)(struct instance *i, unsigned gpio, + int value); + int (*gpio_get_value)(struct instance *i, unsigned gpio); + void (*gpio_set_value)(struct instance *i, unsigned gpio, int value); + } + +III) Analysis of in-tree drivers +-------------------------------- + + 1) altera_pio.c + --------------- + Meets standard API. Implements gpio_request() properly. Simple conversion + possible. + + 2) at91_gpio.c + -------------- + Don't meet standard API. Need some other methods to implement. + + 3) da8xx_gpio.c + --------------- + Meets standard API. Implements gpio_request() properly. Simple conversion + possible. + + 4) kw_gpio.c + ------------ + Doesn't meet standard API. Needs some other methods to implement and move some + methods to another file. + + 5) mpc83xx_gpio.c + ----------------- + Meets standard API. Doesn't implement gpio_request() properly (only checks + if the pin is valid). Simple conversion possible. + + 6) mvgpio.c + ----------- + Meets standard API. Doesn't implement gpio_request() properly (only checks + if the pin is valid). Simple conversion possible. + + 7) mvgpio.h + ----------- + Wrong placement. Will be moved to another location. + + 8) mvmfp.c + ---------- + Wrong placement. Will be moved to another location. diff --git a/doc/driver-model/UDM-hwmon.txt b/doc/driver-model/UDM-hwmon.txt new file mode 100644 index 000000000..cc5d529c3 --- /dev/null +++ b/doc/driver-model/UDM-hwmon.txt @@ -0,0 +1,118 @@ +The U-Boot Driver Model Project +=============================== +Hwmon device subsystem analysis +=============================== + +Tomas Hlavacek <tmshlvck@gmail.com> +2012-03-02 + +I) Overview +----------- + +U-Boot currently implements one API for HW monitoring devices. The +interface is defined in include/dtt.h and comprises of functions: + + void dtt_init(void); + int dtt_init_one(int); + int dtt_read(int sensor, int reg); + int dtt_write(int sensor, int reg, int val); + int dtt_get_temp(int sensor); + +The functions are implemented by a proper device driver in drivers/hwmon +directory and the driver to be compiled in is selected in a Makefile. +Drivers are mutually exclusive. + +Drivers depends on I2O code and naturally on board specific data. There are +few ad-hoc constants put in dtt.h file and driver headers and code. This +has to be consolidated into board specific data or driver headers if those +constants makes sense globally. + + +II) Approach +------------ + + 1) New API + ---------- + In the UDM each hwmon driver would register itself by a function + + int hwmon_device_register(struct instance *i, + struct hwmon_device_ops *o); + + The structure being defined as follows: + + struct hwmon_device_ops { + int (*read)(struct instance *i, int sensor, int reg); + int (*write)(struct instance *i, int sensor, int reg, + int val); + int (*get_temp)(struct instance *i, int sensor); + }; + + + 2) Conversion thougths + ---------------------- + U-Boot hwmon drivers exports virtually the same functions (with exceptions) + and we are considering low number of drivers and code anyway. The interface + is already similar and unified by the interface defined in dtt.h. + Current initialization functions dtt_init() and dtt_init_one() will be + converted into probe() and hwmon_device_register(), so the funcionality will + be kept in more proper places. Besides implementing core registration and + initialization we need to do code cleanup, especially separate + driver-specific and HW specific constants. + + 3) Special consideration due to early initialization + ---------------------------------------------------- + The dtt_init() function call is used during early initialization in + board/gdsys/405ex/io64.c for starting up fans. The dtt code is perfectly + usable in the early stage because it uses only local variables and no heap + memory is required at this level. However the underlying code of I2C has to + keep the same properties with regard to possibility of running in early + initialization stage. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) drivers/hwmon/lm81.c + ----------------------- + The driver is standard dtt. Simple conversion is possible. + + + 2) drivers/hwmon/ds1722.c + ------------------------- + The driver is not standard dtt, but interface is similar to dtt. + The interface has to be changed in order to comply to above mentioned + specification. + + + 3) drivers/hwmon/ds1775.c + ------------------------- + The driver is standard dtt. Simple conversion is possible. + + + 4) drivers/hwmon/lm73.c + ----------------------- + The driver is standard dtt. Simple conversion is possible. + + + 5) drivers/hwmon/lm63.c + ----------------------- + The driver is standard dtt. Simple conversion is possible. + + + 6) drivers/hwmon/adt7460.c + -------------------------- + The driver is standard dtt. Simple conversion is possible. + + + 7) drivers/hwmon/lm75.c + ----------------------- + The driver is standard dtt. Simple conversion is possible. + + + 8) drivers/hwmon/ds1621.c + ------------------------- + The driver is standard dtt. Simple conversion is possible. + + + 9) drivers/hwmon/adm1021.c + -------------------------- + The driver is standard dtt. Simple conversion is possible. diff --git a/doc/driver-model/UDM-keyboard.txt b/doc/driver-model/UDM-keyboard.txt new file mode 100644 index 000000000..ef3761dc2 --- /dev/null +++ b/doc/driver-model/UDM-keyboard.txt @@ -0,0 +1,47 @@ +The U-Boot Driver Model Project +=============================== +Keyboard input analysis +======================= +Marek Vasut <marek.vasut@gmail.com> +2012-02-20 + +I) Overview +----------- + +The keyboard drivers are most often registered with STDIO subsystem. There are +components of the keyboard drivers though, which operate in severe ad-hoc +manner, often being related to interrupt-driven keypress reception. This +components will require the most sanitization of all parts of keyboard input +subsystem. + +Otherwise, the keyboard is no different from other standard input but with the +necessity to decode scancodes. These are decoded using tables provided by +keyboard drivers. These tables are often driver specific. + +II) Approach +------------ + +The most problematic part is the interrupt driven keypress reception. For this, +the buffers that are currently shared throughout the whole U-Boot would need to +be converted into driver's private data. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) board/mpl/common/kbd.c + ------------------------- + This driver is a classic STDIO driver, no problem with conversion is expected. + Only necessary change will be to move this driver to a proper location. + + 2) board/rbc823/kbd.c + --------------------- + This driver is a classic STDIO driver, no problem with conversion is expected. + Only necessary change will be to move this driver to a proper location. + + 3) drivers/input/keyboard.c + --------------------------- + This driver is special in many ways. Firstly because this is a universal stub + driver for converting scancodes from i8042 and the likes. Secondly because the + buffer is filled by various other ad-hoc implementations of keyboard input by + using this buffer as an extern. This will need to be fixed by allowing drivers + to pass certain routines to this driver via platform data. diff --git a/doc/driver-model/UDM-mmc.txt b/doc/driver-model/UDM-mmc.txt new file mode 100644 index 000000000..bed430643 --- /dev/null +++ b/doc/driver-model/UDM-mmc.txt @@ -0,0 +1,319 @@ +The U-Boot Driver Model Project +=============================== +MMC system analysis +=================== +Marek Vasut <marek.vasut@gmail.com> +2012-02-25 + +I) Overview +----------- + +The MMC subsystem is already quite dynamic in it's nature. It's only necessary +to flip the subsystem to properly defined API. + +The probing process of MMC drivers start by calling "mmc_initialize()", +implemented by MMC framework, from the architecture initialization file. The +"mmc_initialize()" function in turn calls "board_mmc_init()" function and if +this doesn't succeed, "cpu_mmc_init()" function is called. It is important to +note that both of the "*_mmc_init()" functions have weak aliases to functions +which automatically fail. + +Both of the "*_mmc_init()" functions though serve only one purpose. To call +driver specific probe function, which in turn actually registers the driver with +MMC subsystem. Each of the driver specific probe functions is currently done in +very ad-hoc manner. + +The registration with the MMC subsystem is done by calling "mmc_register()", +whose argument is a runtime configured structure of information about the MMC +driver. Currently, the information structure is intermixed with driver's internal +data. The description of the structure follows: + +struct mmc { + /* + * API: Allows this driver to be a member of the linked list of all MMC drivers + * registered with MMC subsystem + */ + struct list_head link; + + /* DRIVER: Name of the registered driver */ + char name[32]; + + /* DRIVER: Driver's private data */ + void *priv; + + /* DRIVER: Voltages the host bus can provide */ + uint voltages; + + /* API: Version of the card */ + uint version; + + /* API: Test if the driver was already initialized */ + uint has_init; + + /* DRIVER: Minimum frequency the host bus can provide */ + uint f_min; + + /* DRIVER: Maximum frequency the host bus can provide */ + uint f_max; + + /* API: Is the card SDHC */ + int high_capacity; + + /* API: Actual width of the bus used by the current card */ + uint bus_width; + + /* + * DRIVER: Clock frequency to be configured on the host bus, this is read-only + * for the driver. + */ + uint clock; + + /* API: Capabilities of the card */ + uint card_caps; + + /* DRIVER: MMC bus capabilities */ + uint host_caps; + + /* API: Configuration and ID data retrieved from the card */ + uint ocr; + uint scr[2]; + uint csd[4]; + uint cid[4]; + ushort rca; + + /* API: Partition configuration */ + char part_config; + + /* API: Number of partitions */ + char part_num; + + /* API: Transmission speed */ + uint tran_speed; + + /* API: Read block length */ + uint read_bl_len; + + /* API: Write block length */ + uint write_bl_len; + + /* API: Erase group size */ + uint erase_grp_size; + + /* API: Capacity of the card */ + u64 capacity; + + /* API: Descriptor of this block device */ + block_dev_desc_t block_dev; + + /* DRIVER: Function used to submit command to the card */ + int (*send_cmd)(struct mmc *mmc, + struct mmc_cmd *cmd, struct mmc_data *data); + + /* DRIVER: Function used to configure the host */ + void (*set_ios)(struct mmc *mmc); + + /* DRIVER: Function used to initialize the host */ + int (*init)(struct mmc *mmc); + + /* DRIVER: Function used to report the status of Card Detect pin */ + int (*getcd)(struct mmc *mmc); + + /* + * DRIVER: Maximum amount of blocks sent during multiblock xfer, + * set to 0 to autodetect. + */ + uint b_max; +}; + +The API above is the new API used by most of the drivers. There're still drivers +in the tree that use old, legacy API though. + +2) Approach +----------- + +To convert the MMC subsystem to a proper driver model, the "struct mmc" +structure will have to be properly split in the first place. The result will +consist of multiple parts, first will be the structure defining operations +provided by the MMC driver: + +struct mmc_driver_ops { + /* Function used to submit command to the card */ + int (*send_cmd)(struct mmc *mmc, + struct mmc_cmd *cmd, struct mmc_data *data); + /* DRIVER: Function used to configure the host */ + void (*set_ios)(struct mmc *mmc); + /* Function used to initialize the host */ + int (*init)(struct mmc *mmc); + /* Function used to report the status of Card Detect pin */ + int (*getcd)(struct mmc *mmc); +} + +The second part will define the parameters of the MMC driver: + +struct mmc_driver_params { + /* Voltages the host bus can provide */ + uint32_t voltages; + /* Minimum frequency the host bus can provide */ + uint32_t f_min; + /* Maximum frequency the host bus can provide */ + uint32_t f_max; + /* MMC bus capabilities */ + uint32_t host_caps; + /* + * Maximum amount of blocks sent during multiblock xfer, + * set to 0 to autodetect. + */ + uint32_t b_max; +} + +And finally, the internal per-card data of the MMC subsystem core: + +struct mmc_card_props { + /* Version of the card */ + uint32_t version; + /* Test if the driver was already initializes */ + bool has_init; + /* Is the card SDHC */ + bool high_capacity; + /* Actual width of the bus used by the current card */ + uint8_t bus_width; + /* Capabilities of the card */ + uint32_t card_caps; + /* Configuration and ID data retrieved from the card */ + uint32_t ocr; + uint32_t scr[2]; + uint32_t csd[4]; + uint32_t cid[4]; + uint16_t rca; + /* Partition configuration */ + uint8_t part_config; + /* Number of partitions */ + uint8_t part_num; + /* Transmission speed */ + uint32_t tran_speed; + /* Read block length */ + uint32_t read_bl_len; + /* Write block length */ + uint32_t write_bl_len; + /* Erase group size */ + uint32_t erase_grp_size; + /* Capacity of the card */ + uint64_t capacity; + /* Descriptor of this block device */ + block_dev_desc_t block_dev; +} + +The probe() function will then register the MMC driver by calling: + + mmc_device_register(struct instance *i, struct mmc_driver_ops *o, + struct mmc_driver_params *p); + +The struct mmc_driver_params will have to be dynamic in some cases, but the +driver shouldn't modify it's contents elsewhere than in probe() call. + +Next, since the MMC drivers will now be consistently registered into the driver +tree from board file, the functions "board_mmc_init()" and "cpu_mmc_init()" will +disappear altogether. + +As for the legacy drivers, these will either be converted or removed altogether. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) arm_pl180_mmci.c + ------------------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 2) atmel_mci.c + -------------- + This driver uses the legacy API and should be removed unless converted. It is + probably possbible to replace this driver with gen_atmel_mci.c . No conversion + will be done on this driver. + + 3) bfin_sdh.c + ------------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 4) davinci_mmc.c + ---------------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 5) fsl_esdhc.c + -------------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple, unless some problem appears due to the FDT + component of the driver. + + 6) ftsdc010_esdhc.c + ------------------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 7) gen_atmel_mci.c + ------------------ + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 8) mmc_spi.c + ------------ + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 9) mv_sdhci.c + ------------- + This is a component of the SDHCI support, allowing it to run on Marvell + Kirkwood chip. It is probable the SDHCI support will have to be modified to + allow calling functions from this file based on information passed via + platform_data. + + 10) mxcmmc.c + ------------ + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 11) mxsmmc.c + ------------ + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 12) omap_hsmmc.c + ---------------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 13) pxa_mmc.c + ------------- + This driver uses the legacy API and is written in a severely ad-hoc manner. + This driver will be removed in favor of pxa_mmc_gen.c, which is proved to work + better and is already well tested. No conversion will be done on this driver + anymore. + + 14) pxa_mmc_gen.c + ----------------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 15) s5p_mmc.c + ------------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 16) sdhci.c + ----------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple, though it'd be necessary to modify this driver + to also support the Kirkwood series and probably also Tegra series of CPUs. + See the respective parts of this section for details. + + 17) sh_mmcif.c + -------------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. + + 18) tegra2_mmc.c + ---------------- + Follows the new API and also has a good encapsulation of the whole driver. The + conversion here will be simple. diff --git a/doc/driver-model/UDM-net.txt b/doc/driver-model/UDM-net.txt new file mode 100644 index 000000000..e2ea8f5a6 --- /dev/null +++ b/doc/driver-model/UDM-net.txt @@ -0,0 +1,434 @@ +The U-Boot Driver Model Project +=============================== +Net system analysis +=================== +Marek Vasut <marek.vasut@gmail.com> +2012-03-03 + +I) Overview +----------- + +The networking subsystem already supports multiple devices. Therefore the +conversion shall not be very hard. + +The network subsystem is operated from net/eth.c, which tracks all registered +ethernet interfaces and calls their particular functions registered via +eth_register(). + +The eth_register() is called from the network driver initialization function, +which in turn is called most often either from "board_net_init()" or +"cpu_net_init()". This function has one important argument, which is the +"struct eth_device", defined at include/net.h: + +struct eth_device { + /* DRIVER: Name of the device */ + char name[NAMESIZE]; + /* DRIVER: MAC address */ + unsigned char enetaddr[6]; + /* DRIVER: Register base address */ + int iobase; + /* CORE: state of the device */ + int state; + + /* DRIVER: Device initialization function */ + int (*init) (struct eth_device*, bd_t*); + /* DRIVER: Function for sending packets */ + int (*send) (struct eth_device*, volatile void* packet, int length); + /* DRIVER: Function for receiving packets */ + int (*recv) (struct eth_device*); + /* DRIVER: Function to cease operation of the device */ + void (*halt) (struct eth_device*); + /* DRIVER: Function to send multicast packet (OPTIONAL) */ + int (*mcast) (struct eth_device*, u32 ip, u8 set); + /* DRIVER: Function to change ethernet MAC address */ + int (*write_hwaddr) (struct eth_device*); + /* CORE: Next device in the linked list of devices managed by net core */ + struct eth_device *next; + /* CORE: Device index */ + int index; + /* DRIVER: Driver's private data */ + void *priv; +}; + +This structure defines the particular driver, though also contains elements that +should not be exposed to the driver, like core state. + +Small, but important part of the networking subsystem is the PHY management +layer, whose drivers are contained in drivers/net/phy. These drivers register in +a very similar manner to network drivers, by calling "phy_register()" with the +argument of "struct phy_driver": + +struct phy_driver { + /* DRIVER: Name of the PHY driver */ + char *name; + /* DRIVER: UID of the PHY driver */ + unsigned int uid; + /* DRIVER: Mask for UID of the PHY driver */ + unsigned int mask; + /* DRIVER: MMDS of the PHY driver */ + unsigned int mmds; + /* DRIVER: Features the PHY driver supports */ + u32 features; + /* DRIVER: Initialize the PHY hardware */ + int (*probe)(struct phy_device *phydev); + /* DRIVER: Reconfigure the PHY hardware */ + int (*config)(struct phy_device *phydev); + /* DRIVER: Turn on the PHY hardware, allow it to send/receive */ + int (*startup)(struct phy_device *phydev); + /* DRIVER: Turn off the PHY hardware */ + int (*shutdown)(struct phy_device *phydev); + /* CORE: Allows this driver to be part of list of drivers */ + struct list_head list; +}; + +II) Approach +------------ + +To convert the elements of network subsystem to proper driver model method, the +"struct eth_device" will have to be split into multiple components. The first +will be a structure defining the driver operations: + +struct eth_driver_ops { + int (*init)(struct instance*, bd_t*); + int (*send)(struct instance*, void *packet, int length); + int (*recv)(struct instance*); + void (*halt)(struct instance*); + int (*mcast)(struct instance*, u32 ip, u8 set); + int (*write_hwaddr)(struct instance*); +}; + +Next, there'll be platform data which will be per-driver and will replace the +"priv" part of "struct eth_device". Last part will be the per-device core state. + +With regards to the PHY part of the API, the "struct phy_driver" is almost ready +to be used with the new driver model approach. The only change will be the +replacement of per-driver initialization functions and removal of +"phy_register()" function in favor or driver model approach. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) drivers/net/4xx_enet.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 2) drivers/net/altera_tse.c + --------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 3) drivers/net/armada100_fec.c + ------------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 4) drivers/net/at91_emac.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 5) drivers/net/ax88180.c + ------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 6) drivers/net/ax88796.c + ------------------------ + + This file contains a components of the NE2000 driver, implementing only + different parts on the NE2000 clone AX88796. This being no standalone driver, + no conversion will be done here. + + 7) drivers/net/bfin_mac.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 8) drivers/net/calxedaxgmac.c + ----------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 9) drivers/net/cs8900.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 10) drivers/net/davinci_emac.c + ------------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 11) drivers/net/dc2114x.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 12) drivers/net/designware.c + ---------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 13) drivers/net/dm9000x.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 14) drivers/net/dnet.c + ---------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 15) drivers/net/e1000.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 16) drivers/net/e1000_spi.c + --------------------------- + + Driver for the SPI bus integrated on the Intel E1000. This is not part of the + network stack. + + 17) drivers/net/eepro100.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 18) drivers/net/enc28j60.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 19) drivers/net/ep93xx_eth.c + ---------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 20) drivers/net/ethoc.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 21) drivers/net/fec_mxc.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 22) drivers/net/fsl_mcdmafec.c + ------------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 23) drivers/net/fsl_mdio.c + -------------------------- + + This file contains driver for FSL MDIO interface, which is not part of the + networking stack. + + 24) drivers/net/ftgmac100.c + --------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 25) drivers/net/ftmac100.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 26) drivers/net/greth.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 27) drivers/net/inca-ip_sw.c + ---------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 28) drivers/net/ks8695eth.c + --------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 29) drivers/net/lan91c96.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 30) drivers/net/macb.c + ---------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 31) drivers/net/mcffec.c + ------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 32) drivers/net/mcfmii.c + ------------------------ + + This file contains MII interface driver for MCF FEC. + + 33) drivers/net/mpc512x_fec.c + ----------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 34) drivers/net/mpc5xxx_fec.c + ----------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 35) drivers/net/mvgbe.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 36) drivers/net/natsemi.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 37) drivers/net/ne2000_base.c + ----------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. This driver contains the core + implementation of NE2000, which needs a few external functions, implemented by + AX88796, NE2000 etc. + + 38) drivers/net/ne2000.c + ------------------------ + + This file implements external functions necessary for native NE2000 compatible + networking card to work. + + 39) drivers/net/netarm_eth.c + ---------------------------- + + This driver uses the old, legacy, network API and will either have to be + converted or removed. + + 40) drivers/net/netconsole.c + ---------------------------- + + This is actually an STDIO driver. + + 41) drivers/net/ns8382x.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 42) drivers/net/pcnet.c + ----------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 43) drivers/net/plb2800_eth.c + ----------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 44) drivers/net/rtl8139.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 45) drivers/net/rtl8169.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 46) drivers/net/sh_eth.c + ------------------------ + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 47) drivers/net/smc91111.c + -------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 48) drivers/net/smc911x.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 49) drivers/net/tsec.c + ---------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 50) drivers/net/tsi108_eth.c + ---------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 51) drivers/net/uli526x.c + ------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 52) drivers/net/vsc7385.c + ------------------------- + + This is a driver that only uploads firmware to a switch. This is not subject + of conversion. + + 53) drivers/net/xilinx_axi_emac.c + --------------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. + + 54) drivers/net/xilinx_emaclite.c + --------------------------------- + + This driver uses the standard new networking API, therefore there should be no + obstacles throughout the conversion process. diff --git a/doc/driver-model/UDM-pci.txt b/doc/driver-model/UDM-pci.txt new file mode 100644 index 000000000..b65e9ea73 --- /dev/null +++ b/doc/driver-model/UDM-pci.txt @@ -0,0 +1,265 @@ +The U-Boot Driver Model Project +=============================== +PCI subsystem analysis +====================== + +Pavel Herrmann <morpheus.ibis@gmail.com> +2012-03-17 + +I) Overview +----------- + + U-Boot already supports multiple PCI busses, stored in a linked-list of + pci_controller structures. This structure contains generic driver data, bus + interface operations and private data for the driver. + + Bus interface operations for PCI are (names are self-explanatory): + + read_byte() + read_word() + read_dword() + write_byte() + write_word() + write_dword() + + Each driver has to implement dword operations, and either implement word and + byte operations, or use shared $operation_config_$type_via_dword (eg. + read_config_byte_via_dword and similar) function. These functions are used + for config space I/O (read_config_dword and similar functions of the PCI + subsystem), which is used to configure the connected devices for standard MMIO + operations. All data transfers by respective device drivers are then done by + MMIO + + Each driver also defines a separate init function, which has unique symbol + name, and thus more drivers can be compiled in without colliding. This init + function is typically called from pci_init_board(), different for each + particular board. + + Some boards also define a function called fixup_irq, which gets called after + scanning the PCI bus for devices, and should dismiss any interrupts. + + Several drivers are also located in arch/ and should be moved to drivers/pci. + +II) Approach +------------ + + The pci_controller structure needs to be broken down to fit the new driver + model. Due to a large number of members, this will be done through three + distinct accessors, one for memory regions, one for config table and one for + everything else. That will make the pci_ops structure look like this: + + struct pci_ops { + int (*read_byte)(struct instance *bus, pci_dev_t *dev, int addr, + u8 *buf); + int (*read_word)(struct instance *bus, pci_dev_t *dev, int addr, + u16 *buf); + int (*read_dword)(struct instance *bus, pci_dev_t *dev, int addr, + u32 *buf); + int (*write_byte)(struct instance *bus, pci_dev_t *dev, int addr, + u8 val); + int (*write_byte)(struct instance *bus, pci_dev_t *dev, int addr, + u8 val); + int (*write_dword)(struct instance *bus, pci_dev_t *dev, int addr, + u32 val); + void (*fixup_irq)(struct instance *bus, pci_dev_t *dev); + struct pci_region* (*get_region)(struct instance *, uint num); + struct pci_config_table* (*get_cfg_table)(struct instance *bus); + uint (*get_option)(struct instance * bus, enum pci_option_code op); + } + + enum pci_option_code { + PCI_OPT_BUS_NUMBER=0, + PCI_OPT_REGION_COUNT, + PCI_OPT_INDIRECT_TYPE, + PCI_OPT_AUTO_MEM, + PCI_OPT_AUTO_IO, + PCI_OPT_AUTO_PREFETCH, + PCI_OPT_AUTO_FB, + PCI_OPT_CURRENT_BUS, + PCI_OPT_CFG_ADDR, + } + + The return value for get_option will be an unsigned integer value for any + option code. If the option currently is a pointer to pci_region, it will + return an index for get_region function. Special case has to be made for + PCI_OPT_CFG_ADDR, which should be interpreted as a pointer, but it is only + used for equality in find_hose_by_cfg_addr, and thus can be returned as an + uint. Other function using cfg_addr value are read/write functions for + specific drivers (especially ops for indirect bridges), and thus have access + to private_data of the driver instance. + + The config table accessor will return a pointer to a NULL-terminated array of + pci_config_table, which is supplied by the board in platform_data, or NULL if + the board didn't specify one. This table is used to override PnP + auto-initialization, or to specific initialization functions for non-PNP + devices. + + Transparent PCI-PCI bridges will get their own driver, and will forward all + operations to operations of their parent bus. This however makes it + impossible to use instances to identify devices, as not all devices will be + directly visible to the respective bus driver. + + Init functions of controller drivers will be moved to their respective + probe() functions, in accordance to the driver model. + + The PCI core will handle all mapping functions currently found in pci.c, as + well as proxy functions for read/write operations of the drivers. The PCI + core will also handle bus scanning and device configuration. + + The PnP helper functions currently in pci_auto.c will also be a part of PCI + core, but they will be exposed only to PCI controller drivers, not to other + device drivers. + + The PCI API for device drivers will remain largely unchanged, most drivers + will require no changes at all, and all modifications will be limited to + changing the pci_controlle into instance*. + +III) Analysis of in-tree drivers +-------------------------------- + + A) drivers in drivers/pci/ + -------------------------- + + 1) pci_indirect.c + ----------------- + Shared driver for indirect PCI bridges, several CONFIG macros - will + require significant cleanup. + + 2) pci_ixp.c + ------------ + Standard driver, specifies all read/write functions separately. + + 3) pci_sh4.c + ------------ + Shared init function for SH4 drivers, uses dword for read/write ops. + + 4) pci_sh7751.c + --------------- + Standard driver, uses SH4 shared init. + + 5) pci_sh7780.c + --------------- + Standard driver, uses SH4 shared init. + + 6) tsi108_pci.c + --------------- + Standard driver, uses dword for read/write ops. + + 7) fsl_pci_init.c + ----------------- + Driver for PCI and PCI-e, uses indirect functions. + + 8) pci_ftpci100.c + ----------------- + Standard driver, uses indirect functions, has separate scan/setup + functions. + + B) driver in arch/ + ------------------ + + 1) x86/lib/pci_type1.c + ---------------------- + Standard driver, specifies all read/write functions separately. + + 2) m68k/cpu/mcf5445x/pci.c + -------------------------- + Standard driver, specifies all read/write functions separately. + + 3) m68k/cpu/mcf547x_8x/pci.c + ---------------------------- + Standard driver, specifies all read/write functions separately. + + 4) powerpc/cpu/mpc824x/pci.c + ---------------------------- + Standard driver, uses indirect functions, does not setup HW. + + 5) powerpc/cpu/mpc8260/pci.c + ---------------------------- + Standard driver, uses indirect functions. + + 6) powerpc/cpu/ppc4xx/4xx_pci.c + ------------------------------- + Standard driver, uses indirect functions. + + 7) powerpc/cpu/ppc4xx/4xx_pcie.c + -------------------------------- + PCI-e driver, specifies all read/write functions separately. + + 8) powerpc/cpu/mpc83xx/pci.c + ---------------------------- + Standard driver, uses indirect functions. + + 9) powerpc/cpu/mpc83xx/pcie.c + ----------------------------- + PCI-e driver, specifies all read/write functions separately. + + 10) powerpc/cpu/mpc5xxx/pci_mpc5200.c + ------------------------------------- + Standard driver, uses dword for read/write ops. + + 11) powerpc/cpu/mpc512x/pci.c + ----------------------------- + Standard driver, uses indirect functions. + + 12) powerpc/cpu/mpc8220/pci.c + ----------------------------- + Standard driver, specifies all read/write functions separately. + + 13) powerpc/cpu/mpc85xx/pci.c + ----------------------------- + Standard driver, uses indirect functions, has two busses. + + C) drivers in board/ + -------------------- + + 1) eltec/elppc/pci.c + -------------------- + Standard driver, uses indirect functions. + + 2) amirix/ap1000/pci.c + ---------------------- + Standard driver, specifies all read/write functions separately. + + 3) prodrive/p3mx/pci.c + ---------------------- + Standard driver, uses dword for read/write ops, has two busses. + + 4) esd/cpci750/pci.c + -------------------- + Standard driver, uses dword for read/write ops, has two busses. + + 5) esd/common/pci.c + ------------------- + Standard driver, uses dword for read/write ops. + + 6) dave/common/pci.c + -------------------- + Standard driver, uses dword for read/write ops. + + 7) ppmc7xx/pci.c + ---------------- + Standard driver, uses indirect functions. + + 8) pcippc2/cpc710_pci.c + ----------------------- + Standard driver, uses indirect functions, has two busses. + + 9) Marvell/db64360/pci.c + ------------------------ + Standard driver, uses dword for read/write ops, has two busses. + + 10) Marvell/db64460/pci.c + ------------------------- + Standard driver, uses dword for read/write ops, has two busses. + + 11) evb64260/pci.c + ------------------ + Standard driver, uses dword for read/write ops, has two busses. + + 12) armltd/integrator/pci.c + --------------------------- + Standard driver, specifies all read/write functions separately. + + All drivers will be moved to drivers/pci. Several drivers seem + similar/identical, especially those located under board, and may be merged + into one. diff --git a/doc/driver-model/UDM-pcmcia.txt b/doc/driver-model/UDM-pcmcia.txt new file mode 100644 index 000000000..fc31461ca --- /dev/null +++ b/doc/driver-model/UDM-pcmcia.txt @@ -0,0 +1,78 @@ +The U-Boot Driver Model Project +=============================== +PCMCIA analysis +=============== +Viktor Krivak <viktor.krivak@gmail.com> +2012-03-17 + +I) Overview +----------- + + U-boot implements only 2 methods to interoperate with pcmcia. One to turn + device on and other to turn device off. Names of these methods are usually + pcmcia_on() and pcmcia_off() without any parameters. Some files in driver + directory implements only internal API. These methods aren't used outside + driver directory and they are not converted to new driver model. + +II) Approach +----------- + + 1) New API + ---------- + + Current API is preserved and all internal methods are hiden. + + struct ops { + void (*pcmcia_on)(struct instance *i); + void (*pcmcia_off)(struct instance *i); + } + + 2) Conversion + ------------- + + In header file pcmcia.h are some other variables which are used for + additional configuration. But all have to be moved to platform data or to + specific driver implementation. + + 3) Platform data + ---------------- + + Many boards have custom implementation of internal API. Pointers to these + methods are stored in platform_data. But the most implementations for Intel + 82365 and compatible PC Card controllers and Yenta-compatible + PCI-to-CardBus controllers implement whole API per board. In these cases + pcmcia_on() and pcmcia_off() behave only as wrappers and call specific + board methods. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) i82365.c + ----------- + Driver methods have different name i82365_init() and i82365_exit but + all functionality is the same. Board files board/atc/ti113x.c and + board/cpc45/pd67290.c use their own implementation of these method. + In this case all methods in driver behave only as wrappers. + + 2) marubun_pcmcia.c + ------------------- + Meets standard API behaviour. Simple conversion. + + 3) mpc8xx_pcmcia.c + ------------------ + Meets standard API behaviour. Simple conversion. + + 4) rpx_pcmcia.c + --------------- + Implements only internal API used in other drivers. Non of methods + implemented here are used outside driver model. + + 5) ti_pci1410a.c + ---------------- + Has different API but methods in this file are never called. Probably + dead code. + + 6)tqm8xx_pcmcia.c + ----------------- + Implements only internal API used in other drivers. Non of methods + implemented here are used outside driver model. diff --git a/doc/driver-model/UDM-power.txt b/doc/driver-model/UDM-power.txt new file mode 100644 index 000000000..9ac1a5fbb --- /dev/null +++ b/doc/driver-model/UDM-power.txt @@ -0,0 +1,88 @@ +The U-Boot Driver Model Project +=============================== +POWER analysis +============== +Viktor Krivak <viktor.krivak@gmail.com> +2012-03-09 + +I) Overview +----------- + + 1) Actual state + --------------- + + At this moment power doesn't contain API. There are many methods for + initialization of some board specific functions but only few does what is + expected. Basically only one file contains something meaningful for this + driver. + + 2) Current implementation + ------------------------- + + In file twl6030.c are methods twl6030_stop_usb_charging() and + twl6030_start_usb_charging() for start and stop charging from USB. There are + also methods to get information about battery state and initialization of + battery charging. Only these methods are used in converted API. + + +II) Approach +------------ + + 1) New API + ---------- + + New API implements only functions specific for managing power. All board + specific init methods are moved to other files. Name of methods are + self-explanatory. + + struct ops { + void (*start_usb_charging)(struct instance *i); + void (*stop_usb_charging)(struct instance *i); + int (*get_battery_current)(struct instance *i); + int (*get_battery_voltage)(struct instance *i); + void (*init_battery_charging)(struct instance *i); + } + + 2) Conversions of other methods + ------------------------------- + + Methods that can't be converted to new API are moved to board file or to + special file for board hacks. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) ftpmu010.c + ------------- + All methods of this file are moved to another location. + void ftpmu010_32768osc_enable(void): Move to boards hacks + void ftpmu010_mfpsr_select_dev(unsigned int dev): Move to board file + arch/nds32/lib/board.c + void ftpmu010_mfpsr_diselect_dev(unsigned int dev): Dead code + void ftpmu010_dlldis_disable(void): Dead code + void ftpmu010_sdram_clk_disable(unsigned int cr0): Move to board file + arch/nds32/lib/board.c + void ftpmu010_sdramhtc_set(unsigned int val): Move to board file + arch/nds32/lib/board.c + + 2) twl4030.c + ------------ + All methods of this file are moved to another location. + void twl4030_power_reset_init(void): Move to board hacks + void twl4030_pmrecv_vsel_cfg(u8 vsel_reg, u8 vsel_val, u8 dev_grp, + u8 dev_grp_sel): Move to board hacks + void twl4030_power_init(void): Move to board hacks + void twl4030_power_mmc_init(void): Move to board hacks + + 3) twl6030.c + ------------ + Some methods are converted to new API and rest are moved to another location. + void twl6030_stop_usb_charging(void): Convert to new API + void twl6030_start_usb_charging(void): Convert to new API + int twl6030_get_battery_current(void): Convert to new API + int twl6030_get_battery_voltage(void): Convert to new API + void twl6030_init_battery_charging(void): Convert to new API + void twl6030_power_mmc_init(): Move to board file + drivers/mmc/omap_hsmmc.c + void twl6030_usb_device_settings(): Move to board file + drivers/usb/musb/omap3.c diff --git a/doc/driver-model/UDM-rtc.txt b/doc/driver-model/UDM-rtc.txt new file mode 100644 index 000000000..5d9fb333b --- /dev/null +++ b/doc/driver-model/UDM-rtc.txt @@ -0,0 +1,258 @@ +============================= +RTC device subsystem analysis +============================= + +Tomas Hlavacek <tmshlvck@gmail.com> +2012-03-10 + +I) Overview +----------- + +U-Boot currently implements one common API for RTC devices. The interface +is defined in include/rtc.h and comprises of functions and structures: + + struct rtc_time { + int tm_sec; + int tm_min; + int tm_hour; + int tm_mday; + int tm_mon; + int tm_year; + int tm_wday; + int tm_yday; + int tm_isdst; + }; + + int rtc_get (struct rtc_time *); + int rtc_set (struct rtc_time *); + void rtc_reset (void); + +The functions are implemented by a proper device driver in drivers/rtc +directory and the driver to be compiled in is selected in a Makefile. +Drivers are mutually exclusive. + +Drivers depends on date code in drivers/rtc/date.c and naturally on board +specific data. + +II) Approach +------------ + + 1) New API + ---------- + In the UDM each rtc driver would register itself by a function + + int rtc_device_register(struct instance *i, + struct rtc_device_ops *o); + + The structure being defined as follows: + + struct rtc_device_ops { + int (*get_time)(struct instance *i, struct rtc_time *t); + int (*set_time)(struct instance *i, struct rtc_time *t); + int (*reset)(struct instance *i); + }; + + + 2) Conversion thougths + ---------------------- + U-Boot RTC drivers exports the same functions and therefore the conversion + of the drivers is straight-forward. There is no initialization needed. + + +III) Analysis of in-tree drivers +-------------------------------- + + 1) drivers/rtc/rv3029.c + ----------------------- + The driver is standard rtc. Simple conversion is possible. + + + 2) drivers/rtc/s3c24x0_rtc.c + ---------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 3) drivers/rtc/pt7c4338.c + ------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 4) drivers/rtc/mvrtc.c + ---------------------- + The driver is standard rtc. Simple conversion is possible. + + + 5) drivers/rtc/ftrtc010.c + ------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 6) drivers/rtc/mpc5xxx.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 7) drivers/rtc/ds164x.c + ----------------------- + The driver is standard rtc. Simple conversion is possible. + + + 8) drivers/rtc/rs5c372.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 9) drivers/rtc/m41t94.c + ----------------------- + The driver is standard rtc. Simple conversion is possible. + + + 10) drivers/rtc/mc13xxx-rtc.c + ----------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 11) drivers/rtc/mcfrtc.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 12) drivers/rtc/davinci.c + ------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 13) drivers/rtc/rx8025.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 14) drivers/rtc/bfin_rtc.c + -------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 15) drivers/rtc/m41t62.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 16) drivers/rtc/ds1306.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 17) drivers/rtc/mpc8xx.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 18) drivers/rtc/ds3231.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 19) drivers/rtc/ds12887.c + ------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 20) drivers/rtc/ds1302.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 21) drivers/rtc/ds1374.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 22) drivers/rtc/ds174x.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 23) drivers/rtc/m41t60.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 24) drivers/rtc/m48t35ax.c + -------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 25) drivers/rtc/pl031.c + ----------------------- + The driver is standard rtc. Simple conversion is possible. + + + 26) drivers/rtc/x1205.c + ----------------------- + The driver is standard rtc. Simple conversion is possible. + + + 27) drivers/rtc/m41t11.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 28) drivers/rtc/pcf8563.c + ------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 29) drivers/rtc/mk48t59.c + ------------------------- + Macros needs cleanup. Besides that the driver is standard rtc. + Simple conversion is possible. + + + 30) drivers/rtc/mxsrtc.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 31) drivers/rtc/ds1307.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 32) drivers/rtc/ds1556.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 33) drivers/rtc/rtc4543.c + ------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 34) drivers/rtc/s3c44b0_rtc.c + ----------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 35) drivers/rtc/ds1337.c + ------------------------ + The driver is standard rtc. Simple conversion is possible. + + + 36) drivers/rtc/isl1208.c + ------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 37) drivers/rtc/max6900.c + ------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 38) drivers/rtc/mc146818.c + -------------------------- + The driver is standard rtc. Simple conversion is possible. + + + 39) drivers/rtc/at91sam9_rtt.c + ------------------------------ + The driver is standard rtc. Simple conversion is possible. diff --git a/doc/driver-model/UDM-serial.txt b/doc/driver-model/UDM-serial.txt new file mode 100644 index 000000000..e9c274d45 --- /dev/null +++ b/doc/driver-model/UDM-serial.txt @@ -0,0 +1,191 @@ +The U-Boot Driver Model Project +=============================== +Serial I/O analysis +=================== +Marek Vasut <marek.vasut@gmail.com> +2012-02-20 + +I) Overview +----------- + +The serial port support currently requires the driver to export the following +functions: + + serial_putc() ...... Output a character + serial_puts() ...... Output string, often done using serial_putc() + serial_tstc() ...... Test if incoming character is in a buffer + serial_getc() ...... Retrieve incoming character + serial_setbrg() .... Configure port options + serial_init() ...... Initialize the hardware + +The simpliest implementation, supporting only one port, simply defines these six +functions and calls them. Such calls are scattered all around U-Boot, especiall +serial_putc(), serial_puts(), serial_tstc() and serial_getc(). The serial_init() +and serial_setbrg() are often called from platform-dependent places. + +It's important to consider current implementation of CONFIG_SERIAL_MULTI though. +This resides in common/serial.c and behaves as a multiplexer for serial ports. +This, by calling serial_assign(), allows user to switch I/O from one serial port +to another. Though the environmental variables "stdin", "stdout", "stderr" +remain set to "serial". + +These variables are managed by the IOMUX. This resides in common/iomux.c and +manages all console input/output from U-Boot. For serial port, only one IOMUX is +always registered, called "serial" and the switching of different serial ports +is done by code in common/serial.c. + +On a final note, it's important to mention function default_serial_console(), +which is platform specific and reports the default serial console for the +platform, unless proper environment variable overrides this. + +II) Approach +------------ + +Drivers not using CONFIG_SERIAL_MULTI already will have to be converted to +similar approach. The probe() function of a driver will call a function +registering the driver with a STDIO subsystem core, stdio_device_register(). + +The serial_init() function will now be replaced by probe() function of the +driver, the rest of the components of the driver will be converted to standard +STDIO driver calls. See [ UDM-stdio.txt ] for details. + +The serial_setbrg() function depends on global data pointer. This is wrong, +since there is likely to be user willing to configure different baudrate on two +different serial ports. The function will be replaced with STDIO's "conf()" +call, with STDIO_CONFIG_SERIAL_BAUDRATE argument. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) altera_jtag_uart.c + --------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 2) altera_uart.c + ---------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 3) arm_dcc.c + ------------ + No support for CONFIG_SERIAL_MULTI. Simple conversion possible, unless used + with CONFIG_ARM_DCC_MULTI. Then it registers another separate IOMUX. + + 4) atmel_usart.c + ---------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 5) mcfuart.c + ------------ + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 6) ns16550.c + ------------ + This driver seems complicated and certain consideration will need to be made + during conversion. This driver is implemented in very universal manner, + therefore it'll be necessary to properly design it's platform_data. + + 7) ns9750_serial.c + ------------------ + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 8) opencores_yanu.c + ------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 9) s3c4510b_uart.c + ------------------ + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 10) s3c64xx.c + ------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 11) sandbox.c + ------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 12) serial.c + ------------ + This is a complementary part of NS16550 UART driver, see above. + + 13) serial_clps7111.c + --------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 14) serial_imx.c + ---------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. This driver + might be removed in favor of serial_mxc.c . + + 15) serial_ixp.c + ---------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 16) serial_ks8695.c + ------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 17) serial_lh7a40x.c + -------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 18) serial_lpc2292.c + -------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 19) serial_max3100.c + -------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 20) serial_mxc.c + ---------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 21) serial_netarm.c + ------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 22) serial_pl01x.c + ------------------ + No support for CONFIG_SERIAL_MULTI. Simple conversion possible, though this + driver in fact contains two drivers in total. + + 23) serial_pxa.c + ---------------- + This driver is a bit complicated, but due to clean support for + CONFIG_SERIAL_MULTI, there are no expected obstructions throughout the + conversion process. + + 24) serial_s3c24x0.c + -------------------- + This driver, being quite ad-hoc might need some work to bring back to shape. + + 25) serial_s3c44b0.c + -------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 26) serial_s5p.c + ---------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 27) serial_sa1100.c + ------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 28) serial_sh.c + --------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 29) serial_xuartlite.c + ---------------------- + No support for CONFIG_SERIAL_MULTI. Simple conversion possible. + + 30) usbtty.c + ------------ + This driver seems very complicated and entangled with USB framework. The + conversion might be complicated here. + + 31) arch/powerpc/cpu/mpc512x/serial.c + ------------------------------------- + This driver supports CONFIG_SERIAL_MULTI. This driver will need to be moved to + proper place. diff --git a/doc/driver-model/UDM-spi.txt b/doc/driver-model/UDM-spi.txt new file mode 100644 index 000000000..7442a32bd --- /dev/null +++ b/doc/driver-model/UDM-spi.txt @@ -0,0 +1,200 @@ +The U-Boot Driver Model Project +=============================== +SPI analysis +============ +Viktor Krivak <viktor.krivak@gmail.com> +2012-03-03 + +I) Overview +----------- + + 1) The SPI driver + ----------------- + + At this moment U-Boot provides standard API that consist of 7 functions: + + void spi_init(void); + struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode); + void spi_free_slave(struct spi_slave *slave); + int spi_claim_bus(struct spi_slave *slave); + void spi_release_bus(struct spi_slave *slave); + int spi_xfer(struct spi_slave *slave, unsigned int bitlen, + const void *dout, void *din, unsigned long flags); + int spi_cs_is_valid(unsigned int bus, unsigned int cs); + void spi_cs_activate(struct spi_slave *slave); + void spi_cs_deactivate(struct spi_slave *slave); + void spi_set_speed(struct spi_slave *slave, uint hz); + + Method spi_init() is usually empty. All necessary configuration are sets by + spi_setup_slave(). But this configuration is usually stored only in memory. + No real hardware sets are made. All hardware settings are provided by method + spi_claim_bus(). This method claims the bus and it can't be claimed again + until it's release. That's mean all calls of method spi_claim_bus() will + fail. But lots of cpu implementation don't meet this behaviour. + Method spi_release_bus() does exact opposite. It release bus directly by + some hardware sets. spi_free_slave() only free memory allocated by + spi_setup_slave(). Method spi_xfer() do actually read and write operation + throw specified bus and cs. Other methods are self explanatory. + + 2) Current limitations + ---------------------- + + Theoretically at this moment api allows use more then one bus per device at + the time. But in real this can be achieved only when all buses have their + own base addresses in memory. + + +II) Approach +------------ + + 1) Claiming bus + --------------- + + The current api cannot be used because struct spi_slave have to be in + private data. In that case user are prohibited to use different bus on one + device at same time. But when base memory address for bus are different. + It's possible make more instance of this driver. Otherwise it can't can be + done because of hardware limitation. + + 2) API change + ------------- + + Method spi_init() is moved to probe. Methods spi_setup_slave() and + spi_claim_bus() are joined to one method. This method checks if desired bus + exists and is available then configure necessary hardware and claims bus. + Method spi_release_bus() and spi_free_slave() are also joined to meet this + new approach. Other function remain same. Only struct spi_slave was change + to instance. + + struct ops { + int (*spi_request_bus)(struct instance *i, unsigned int bus, + unsigned int cs, unsigned int max_hz, + unsigned int mode); + void (*spi_release_bus)(struct instance *i); + int (*spi_xfer) (struct instance *i, unsigned int bitlen, + const void *dout, void *din, unsigned long flags); + int (*spi_cs_is_valid)(struct instance *i, unsigned int bus, + unsigned int cs); + void (*spi_cs_activate)(struct instance *i); + void (*spi_cs_deactivate)(struct instance *i); + void (*spi_set_speed)(struct instance *i, uint hz); + } + + 3) Legacy API + ------------- + + To easy conversion of the whole driver. Original and new api can exist next + to each other. New API is designed to be only a wrapper that extracts + necessary information from private_data and use old api. When driver can + use more than one bus at the time. New API require multiple instance. One + for each bus. In this case spi_slave have to be copied in each instance. + + 4) Conversion TIME-LINE + ----------------------- + + To prevent build corruption api conversion have to be processed in several + independent steps. In first step all old API methods are renamed. After that + new API and core function are implemented. Next step is conversion of all + board init methods to set platform data. After all these steps it is possible + to start conversion of all remaining calls. This procedure guarantees that + build procedure and binaries are never broken. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) altera_spi.c + --------------- + All methods have designated structure. Simple conversion possible. + + 2) andes_spi.c + -------------- + All methods have designated structure. Simple conversion possible. + + 3) andes_spi.h + -------------- + Support file for andes_spi.c. No conversion is needed. + + 4) armada100_spi.c + ------------------ + All methods have designated structure. Simple conversion possible. + + 5) atmel_dataflash_spi.c + ------------------------ + Wrong placement. Will be moved to another location. + + 6) atmel_spi.c + -------------- + Supports more than one bus. Need some minor change. + + 7) atmel_spi.h + -------------- + Support file for andes_spi.c. No conversion is needed. + + 8) bfin_spi.c + ------------- + Supports more than one bus. Need some minor change. + + 9) cf_spi.c + ----------- + Cooperate with some cpu specific methods from other files. Hard conversion. + + 10) davinci_spi.c + ----------------- + All methods have designated structure. Simple conversion possible. + + 11) davinci_spi.h + ----------------- + Support file for davinci_spi.h. No conversion is needed. + + 12) fsl_espi.c + -------------- + All methods have designated structure. Simple conversion possible. + + 13) kirkwood_spi.c + ------------------ + All methods have designated structure. Simple conversion possible. + + 14) mpc8xxx_spi.c + ----------------- + All methods have designated structure. Simple conversion possible. + + 15) mpc52xx_spi.c + ----------------- + All methods have designated structure. Simple conversion possible. + + 16) mxc_spi.c + ------------- + All methods have designated structure. Simple conversion possible. + + 17) mxs_spi.c + ------------- + All methods have designated structure. Simple conversion possible. + + 18) oc_tiny_spi.c + ----------------- + Supports more than one bus. Need some minor change. + + 19) omap3_spi.c + --------------- + Supports more than one bus. Need some minor change. + + 20) omap3_spi.h + --------------- + Support file for omap3_spi.c. No conversion is needed. + + 21) sh_spi.c + ------------ + All methods have designated structure. Simple conversion possible. + + 22) sh_spi.h + ------------ + Support file for sh_spi.h. No conversion is needed. + + 23) soft_spi.c + -------------- + Use many board specific method linked from other files. Need careful debugging. + + 24) tegra2_spi.c + ---------------- + Some hardware specific problem when releasing bus. diff --git a/doc/driver-model/UDM-stdio.txt b/doc/driver-model/UDM-stdio.txt new file mode 100644 index 000000000..a6c484f37 --- /dev/null +++ b/doc/driver-model/UDM-stdio.txt @@ -0,0 +1,191 @@ +The U-Boot Driver Model Project +=============================== +I/O system analysis +=================== +Marek Vasut <marek.vasut@gmail.com> +2012-02-20 + +I) Overview +----------- + +The console input and output is currently done using the STDIO subsystem in +U-Boot. The design of this subsystem is already flexible enough to be easily +converted to new driver model approach. Minor changes will need to be done +though. + +Each device that wants to register with STDIO subsystem has to define struct +stdio_dev, defined in include/stdio_dev.h and containing the following fields: + +struct stdio_dev { + int flags; /* Device flags: input/output/system */ + int ext; /* Supported extensions */ + char name[16]; /* Device name */ + +/* GENERAL functions */ + + int (*start) (void); /* To start the device */ + int (*stop) (void); /* To stop the device */ + +/* OUTPUT functions */ + + void (*putc) (const char c); /* To put a char */ + void (*puts) (const char *s); /* To put a string (accelerator) */ + +/* INPUT functions */ + + int (*tstc) (void); /* To test if a char is ready... */ + int (*getc) (void); /* To get that char */ + +/* Other functions */ + + void *priv; /* Private extensions */ + struct list_head list; +}; + +Currently used flags are DEV_FLAGS_INPUT, DEV_FLAGS_OUTPUT and DEV_FLAGS_SYSTEM, +extensions being only one, the DEV_EXT_VIDEO. + +The private extensions are now used as a per-device carrier of private data and +finally list allows this structure to be a member of linked list of STDIO +devices. + +The STDIN, STDOUT and STDERR routing is handled by environment variables +"stdin", "stdout" and "stderr". By configuring the variable to the name of a +driver, functions of such driver are called to execute that particular +operation. + +II) Approach +------------ + + 1) Similarity of serial, video and keyboard drivers + --------------------------------------------------- + + All of these drivers can be unified under the STDIO subsystem if modified + slightly. The serial drivers basically define both input and output functions + and need function to configure baudrate. The keyboard drivers provide only + input. On the other hand, video drivers provide output, but need to be + configured in certain way. This configuration might be dynamic, therefore the + STDIO has to be modified to provide such flexibility. + + 2) Unification of serial, video and keyboard drivers + ---------------------------------------------------- + + Every STDIO device would register a structure containing operation it supports + with the STDIO core by calling: + + int stdio_device_register(struct instance *i, struct stdio_device_ops *o); + + The structure being defined as follows: + + struct stdio_device_ops { + void (*putc)(struct instance *i, const char c); + void (*puts)(struct instance *i, const char *s); /* OPTIONAL */ + + int (*tstc)(struct instance *i); + int (*getc)(struct instance *i); + + int (*init)(struct instance *i); + int (*exit)(struct instance *i); + int (*conf)(struct instance *i, enum stdio_config c, const void *data); + }; + + The "putc()" function will emit a character, the "puts()" function will emit a + string. If both of these are set to NULL, the device is considered STDIN only, + aka input only device. + + The "getc()" retrieves a character from a STDIN device, while "tstc()" tests + if there is a character in the buffer of STDIN device. In case these two are + set to NULL, this device is STDOUT / STDERR device. + + Setting all "putc()", "puts()", "getc()" and "tstc()" calls to NULL isn't an + error condition, though such device does nothing. By instroducing tests for + these functions being NULL, the "flags" and "ext" fields from original struct + stdio_dev can be eliminated. + + The "init()" and "exit()" calls are replacement for "start()" and "exit()" + calls in the old approach. The "priv" part of the old struct stdio_dev will be + replaced by common private data in the driver model and the struct list_head + list will be eliminated by introducing common STDIO core, that tracks all the + STDIO devices. + + Lastly, the "conf()" call will allow the user to configure various options of + the driver. The enum stdio_config contains all possible configuration options + available to the STDIO devices, const void *data being the argument to be + configured. Currently, the enum stdio_config will contain at least the + following options: + + enum stdio_config { + STDIO_CONFIG_SERIAL_BAUDRATE, + }; + + 3) Transformation of stdio routing + ---------------------------------- + + By allowing multiple instances of drivers, the environment variables "stdin", + "stdout" and "stderr" can no longer be set to the name of the driver. + Therefore the STDIO core, tracking all of the STDIO devices in the system will + need to have a small amount of internal data for each device: + + struct stdio_device_node { + struct instance *i; + struct stdio_device_ops *ops; + uint8_t id; + uint8_t flags; + struct list_head list; + } + + The "id" is the order of the instance of the same driver. The "flags" variable + allows multiple drivers to be used at the same time and even for different + purpose. The following flags will be defined: + + STDIO_FLG_STDIN ..... This device will be used as an input device. All input + from all devices with this flag set will be received + and passed to the upper layers. + STDIO_FLG_STDOUT .... This device will be used as an output device. All + output sent to stdout will be routed to all devices + with this flag set. + STDIO_FLG_STDERR .... This device will be used as an standard error output + device. All output sent to stderr will be routed to + all devices with this flag set. + + The "list" member of this structure allows to have a linked list of all + registered STDIO devices. + +III) Analysis of in-tree drivers +-------------------------------- + +For in-depth analysis of serial port drivers, refer to [ UDM-serial.txt ]. +For in-depth analysis of keyboard drivers, refer to [ UDM-keyboard.txt ]. +For in-depth analysis of video drivers, refer to [ UDM-video.txt ]. + + 1) arch/blackfin/cpu/jtag-console.c + ----------------------------------- + This driver is a classic STDIO driver, no problem with conversion is expected. + + 2) board/mpl/pati/pati.c + ------------------------ + This driver registers with the STDIO framework, though it uses a lot of ad-hoc + stuff which will need to be sorted out. + + 3) board/netphone/phone_console.c + --------------------------------- + This driver is a classic STDIO driver, no problem with conversion is expected. + + 4) drivers/net/netconsole.c + --------------------------- + This driver is a classic STDIO driver, no problem with conversion is expected. + +IV) Other involved files (To be removed) +---------------------------------------- + +common/cmd_console.c +common/cmd_log.c +common/cmd_terminal.c +common/console.c +common/fdt_support.c +common/iomux.c +common/lcd.c +common/serial.c +common/stdio.c +common/usb_kbd.c +doc/README.iomux diff --git a/doc/driver-model/UDM-tpm.txt b/doc/driver-model/UDM-tpm.txt new file mode 100644 index 000000000..91a953a72 --- /dev/null +++ b/doc/driver-model/UDM-tpm.txt @@ -0,0 +1,48 @@ +The U-Boot Driver Model Project +=============================== +TPM system analysis +=================== +Marek Vasut <marek.vasut@gmail.com> +2012-02-23 + +I) Overview +----------- + +There is currently only one TPM chip driver available and therefore the API +controlling it is very much based on this. The API is very simple: + + int tis_open(void); + int tis_close(void); + int tis_sendrecv(const u8 *sendbuf, size_t send_size, + u8 *recvbuf, size_t *recv_len); + +The command operating the TPM chip only provides operations to send and receive +bytes from the chip. + +II) Approach +------------ + +The API can't be generalised too much considering there's only one TPM chip +supported. But it's a good idea to split the tis_sendrecv() function in two +functions. Therefore the new API will use register the TPM chip by calling: + + tpm_device_register(struct instance *i, const struct tpm_ops *ops); + +And the struct tpm_ops will contain the following members: + + struct tpm_ops { + int (*tpm_open)(struct instance *i); + int (*tpm_close)(struct instance *i); + int (*tpm_send)(const uint8_t *buf, const size_t size); + int (*tpm_recv)(uint8_t *buf, size_t *size); + }; + +The behaviour of "tpm_open()" and "tpm_close()" will basically copy the +behaviour of "tis_open()" and "tis_close()". The "tpm_send()" will be based on +the "tis_senddata()" and "tis_recv()" will be based on "tis_readresponse()". + +III) Analysis of in-tree drivers +-------------------------------- + +There is only one in-tree driver present, the "drivers/tpm/generic_lpc_tpm.c", +which will be simply converted as outlined in previous chapter. diff --git a/doc/driver-model/UDM-twserial.txt b/doc/driver-model/UDM-twserial.txt new file mode 100644 index 000000000..289416acd --- /dev/null +++ b/doc/driver-model/UDM-twserial.txt @@ -0,0 +1,47 @@ +================================== +TWserial device subsystem analysis +================================== + +Tomas Hlavacek<tmshlvck@gmail.com> +2012-03-21 + +I) Overview +----------- + +U-Boot currently implements one common API for TWSerial devices. The interface +is defined in include/tws.h and comprises of functions: + + int tws_read(uchar *buffer, int len); + int tws_write(uchar *buffer, int len); + +The functions are implemented by a proper device driver in drivers/twserial +directory and the driver to be compiled in is selected in a Makefile. There is +only one driver present now. + +The driver depends on ad-hoc code in board specific data, namely functions: + + void tws_ce(unsigned bit); + void tws_wr(unsigned bit); + void tws_clk(unsigned bit); + void tws_data(unsigned bit); + unsigned tws_data_read(void); + void tws_data_config_output(unsigned output); + +implemented in include/configs/inka4x0.h . + +II) Approach +------------ + + U-Boot TWserial drivers exports two simple functions and therefore the conversion + of the driver and creating a core for it is not needed. It should be consolidated + with include/configs/inka4x0.h and taken to the misc/ dir. + + +III) Analysis of in-tree drivers +-------------------------------- + + 1) drivers/twserial/soft_tws.c + ------------------------------ + The driver is the only TWserial driver. The ad-hoc part in + include/configs/inka4x0.h and the core soft_tws driver should be consolidated + to one compact driver and moved to misc/ . diff --git a/doc/driver-model/UDM-usb.txt b/doc/driver-model/UDM-usb.txt new file mode 100644 index 000000000..5ce85b5d6 --- /dev/null +++ b/doc/driver-model/UDM-usb.txt @@ -0,0 +1,94 @@ +The U-Boot Driver Model Project +=============================== +USB analysis +============ +Marek Vasut <marek.vasut@gmail.com> +2012-02-16 + +I) Overview +----------- + + 1) The USB Host driver + ---------------------- + There are basically four or five USB host drivers. All such drivers currently + provide at least the following fuctions: + + usb_lowlevel_init() ... Do the initialization of the USB controller hardware + usb_lowlevel_stop() ... Do the shutdown of the USB controller hardware + + usb_event_poll() ...... Poll interrupt from USB device, often used by KBD + + submit_control_msg() .. Submit message via Control endpoint + submit_int_msg() ...... Submit message via Interrupt endpoint + submit_bulk_msg() ..... Submit message via Bulk endpoint + + + This allows for the host driver to be easily abstracted. + + 2) The USB hierarchy + -------------------- + + In the current implementation, the USB Host driver provides operations to + communicate via the USB bus. This is realised by providing access to a USB + root port to which an USB root hub is attached. The USB bus is scanned and for + each newly found device, a struct usb_device is allocated. See common/usb.c + and include/usb.h for details. + +II) Approach +------------ + + 1) The USB Host driver + ---------------------- + + Converting the host driver will follow the classic driver model consideration. + Though, the host driver will have to call a function that registers a root + port with the USB core in it's probe() function, let's call this function + + usb_register_root_port(&ops); + + This will allow the USB core to track all available root ports. The ops + parameter will contain structure describing operations supported by the root + port: + + struct usb_port_ops { + void (*usb_event_poll)(); + int (*submit_control_msg)(); + int (*submit_int_msg)(); + int (*submit_bulk_msg)(); + } + + 2) The USB hierarchy and hub drivers + ------------------------------------ + + Converting the USB heirarchy should be fairy simple, considering the already + dynamic nature of the implementation. The current usb_hub_device structure + will have to be converted to a struct instance. Every such instance will + contain components of struct usb_device and struct usb_hub_device in it's + private data, providing only accessors in order to properly encapsulate the + driver. + + By registering the root port, the USB framework will instantiate a USB hub + driver, which is always present, the root hub. The root hub and any subsequent + hub instance is represented by struct instance and it's private data contain + amongst others common bits from struct usb_device. + + Note the USB hub driver is partly defying the usual method of registering a + set of callbacks to a particular core driver. Instead, a static set of + functions is defined and the USB hub instance is passed to those. This creates + certain restrictions as of how the USB hub driver looks, but considering the + specification for USB hub is given and a different type of USB hub won't ever + exist, this approach is ok: + + - Report how many ports does this hub have: + uint get_nr_ports(struct instance *hub); + - Get pointer to device connected to a port: + struct instance *(*get_child)(struct instance *hub, int port); + - Instantiate and configure device on port: + struct instance *(*enum_dev_on_port)(struct instance *hub, int port); + + 3) USB device drivers + --------------------- + + The USB device driver, in turn, will have to register various ops structures + with certain cores. For example, USB disc driver will have to register it's + ops with core handling USB discs etc. diff --git a/doc/driver-model/UDM-video.txt b/doc/driver-model/UDM-video.txt new file mode 100644 index 000000000..342aeee48 --- /dev/null +++ b/doc/driver-model/UDM-video.txt @@ -0,0 +1,74 @@ +The U-Boot Driver Model Project +=============================== +Video output analysis +===================== +Marek Vasut <marek.vasut@gmail.com> +2012-02-20 + +I) Overview +----------- + +The video drivers are most often registered with video subsystem. This subsystem +often expects to be allowed access to framebuffer of certain parameters. This +subsystem also provides calls for STDIO subsystem to allow it to output +characters on the screen. For this part, see [ UDM-stdio.txt ]. + +Therefore the API has two parts, the video driver part and the part where the +video driver core registers with STDIO API. + +The video driver part will follow the current cfb_console approach, though +allowing it to be more dynamic. + +II) Approach +------------ + +Registering the video driver into the video driver core is done by calling the +following function from the driver probe() function: + + video_device_register(struct instance *i, GraphicDevice *gd); + +Because the video driver core is in charge or rendering characters as well as +bitmaps on the screen, it will in turn call stdio_device_register(i, so), where +"i" is the same instance as the video driver's one. But "so" will be special +static struct stdio_device_ops handling the character output. + + +III) Analysis of in-tree drivers +-------------------------------- + + 1) arch/powerpc/cpu/mpc8xx/video.c + ---------------------------------- + This driver copies the cfb_console [ see drivers/video/cfb_console.c ] + approach and acts only as a STDIO device. Therefore there are currently two + possible approaches, first being the conversion of this driver to usual STDIO + device and second, long-term one, being conversion of this driver to video + driver that provides console. + + 2) arch/x86/lib/video.c + ----------------------- + This driver registers two separate STDIO devices and should be therefore + converted as such. + + 3) board/bf527-ezkit/video.c + ---------------------------- + This driver seems bogus as it behaves as STDIO device, but provides no input + or output capabilities. It relies on DEV_EXT_VIDEO, which is no longer in use + or present otherwise than as a dead code/define. + + 4) board/bf533-stamp/video.c + ---------------------------- + This driver seems bogus as it behaves as STDIO device, but provides no input + or output capabilities. It relies on DEV_EXT_VIDEO, which is no longer in use + or present otherwise than as a dead code/define. + + 5) board/bf548-ezkit/video.c + ---------------------------- + This driver seems bogus as it behaves as STDIO device, but provides no input + or output capabilities. It relies on DEV_EXT_VIDEO, which is no longer in use + or present otherwise than as a dead code/define. + + 6) board/cm-bf548/video.c + ---------------------------- + This driver seems bogus as it behaves as STDIO device, but provides no input + or output capabilities. It relies on DEV_EXT_VIDEO, which is no longer in use + or present otherwise than as a dead code/define. diff --git a/doc/driver-model/UDM-watchdog.txt b/doc/driver-model/UDM-watchdog.txt new file mode 100644 index 000000000..271bd2633 --- /dev/null +++ b/doc/driver-model/UDM-watchdog.txt @@ -0,0 +1,334 @@ +The U-Boot Driver Model Project +=============================== +Watchdog device subsystem analysis +================================== + +Tomas Hlavacek <tmshlvck@gmail.com> +2012-03-09 + +I) Overview +----------- + +U-Boot currently implements an API for HW watchdog devices as explicit drivers +in drivers/watchdog directory. There are also drivers for both hardware and +software watchdog on particular CPUs implemented in arch/*/cpu/*/cpu.c. There +are macros in include/watchdog.h that selects between SW and HW watchdog and +assembly SW implementation. + +The current common interface comprises of one set out of these two possible +variants: + + 1) + void watchdog_reset(void); + int watchdog_disable(void); + int watchdog_init(void); + + 2) + void hw_watchdog_reset(void); + void hw_watchdog_init(void); + +The watchdog implementations are also spread through board/*/*.c that in +some cases. The API and semantics is in most cases same as the above +mentioned common functions. + + +II) Approach +------------ + + 1) New API + ---------- + + In the UDM each watchdog driver would register itself by a function + + int watchdog_device_register(struct instance *i, + const struct watchdog_device_ops *o); + + The structure being defined as follows: + + struct watchdog_device_ops { + int (*disable)(struct instance *i); + void (*reset)(struct instance *i); + }; + + The watchdog_init() function will be dissolved into probe() function. + + 2) Conversion thougths + ---------------------- + + Conversion of watchdog implementations to a new API could be divided + to three subsections: a) HW implementations, which are mostly compliant + to the above mentioned API; b) SW implementations, which are compliant + to the above mentioned API and c) SW implementations that are not compliant + to the API and has to be rectified or partially rewritten. + +III) Analysis of in-tree drivers +-------------------------------- + + 1) drivers/watchdog/at91sam9_wdt.c + ---------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 2) drivers/watchdog/ftwdt010_wdt.c + ---------------------------------- + The driver is ad-hoc HW watchdog. Conversion has to take into account + driver parts spread in include/faraday/*. Restructuring the driver and + code cleanup has to be considered. + + + 3) arch/arm/cpu/arm1136/mx31/timer.c + ------------------------------------ + The driver is semi-standard ad-hoc HW watchdog. Conversion has to take + into account driver parts spread in the timer.c file. + + + 4) arch/arm/cpu/arm926ejs/davinci/timer.c + ----------------------------------------- + The driver is ad-hoc semi-standard HW watchdog. Conversion has to take + into account driver parts spread in the timer.c file. + + + 5) arch/arm/cpu/armv7/omap-common/hwinit-common.c + ------------------------------------------------- + The driver is non-standard ad-hoc HW watchdog. Conversion is possible + but functions has to be renamed and constants moved to another places. + + + 6) arch/arm/cpu/armv7/omap3/board.c + ----------------------------------- + The driver is non-standard ad-hoc HW watchdog. Conversion is possible + but functions has to be renamed and constants moved to another places. + + + 7) arch/blackfin/cpu/watchdog.c + ------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 8) arch/m68k/cpu/mcf523x/cpu.c + ------------------------------ + The driver is standard HW watchdog. Simple conversion is possible. + + + 9) arch/m68k/cpu/mcf52x2/cpu.c + ------------------------------ + The driver is standard HW watchdog. Simple conversion is possible. + + + 10) arch/m68k/cpu/mcf532x/cpu.c + ------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 11) arch/m68k/cpu/mcf547x_8x/cpu.c + ---------------------------------- + The driver is standard HW watchdog (there is slight naming convention + violation that has to be rectified). Simple conversion is possible. + + + 12) arch/powerpc/cpu/74xx_7xx/cpu.c + ----------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 13) arch/powerpc/cpu/mpc512x/cpu.c + ---------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 14) arch/powerpc/cpu/mpc5xx/cpu.c + --------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 15) arch/powerpc/cpu/mpc5xxx/cpu.c + ---------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 16) arch/powerpc/cpu/mpc8260/cpu.c + ---------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 17) arch/powerpc/cpu/mpc83xx/cpu.c + ---------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 18) arch/powerpc/cpu/mpc85xx/cpu.c + ---------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 19) arch/powerpc/cpu/mpc86xx/cpu.c + ---------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 20) arch/powerpc/cpu/mpc8xx/cpu.c + + The driver is standard HW watchdog. Simple conversion is possible. + + + 21) arch/powerpc/cpu/ppc4xx/cpu.c + --------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 22) arch/sh/cpu/sh2/watchdog.c + ------------------------------ + The driver is standard HW watchdog. Simple conversion is possible. + + + 23) arch/sh/cpu/sh3/watchdog.c + ------------------------------ + The driver is standard HW watchdog. Simple conversion is possible. + + + 24) arch/sh/cpu/sh4/watchdog.c + ------------------------------ + The driver is standard HW watchdog. Simple conversion is possible. + + + 25) board/amcc/luan/luan.c + -------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 26) board/amcc/yosemite/yosemite.c + ---------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 27) board/apollon/apollon.c + --------------------------- + The driver is standard HW watchdog however the watchdog_init() + function is called in early initialization. Simple conversion is possible. + + + 28) board/bmw/m48t59y.c + ----------------------- + Special watchdog driver. Dead code. To be removed. + + + 29) board/davedenx/qong/qong.c + ------------------------------ + The driver is standard HW watchdog. Simple conversion is possible. + + + 30) board/dvlhost/watchdog.c + ---------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 31) board/eNET/eNET.c + --------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 32) board/eltec/elppc/elppc.c + ----------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 33) board/enbw/enbw_cmc/enbw_cmc.c + ---------------------------------- + Only function proxy call. Code cleanup needed. + + + 34) board/freescale/mx31pdk/mx31pdk.c + ------------------------------------- + Only function proxy call. Code cleanup needed. + + + 35) board/gth2/gth2.c + --------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 36) board/lwmon5/lwmon5.c + ------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 37) board/manroland/mucmc52/mucmc52.c + ------------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 38) board/manroland/uc101/uc101.c + --------------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 39) board/mousse/m48t59y.c + -------------------------- + Special watchdog driver. Dead code. To be removed. + + + 40) board/mvblue/mvblue.c + ------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 41) board/netphone/netphone.c + ----------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 42) board/netta/netta.c + ----------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 43) board/netta2/netta2.c + ------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 44) board/omicron/calimain/calimain.c + ------------------------------------- + Only function proxy call. Code cleanup needed. + + + 45) board/pcippc2/pcippc2.c + --------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 46) board/pcs440ep/pcs440ep.c + ----------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 47) board/stx/stxxtc/stxxtc.c + ----------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 48) board/ti/omap2420h4/omap2420h4.c + ------------------------------------ + The driver is standard HW watchdog. Simple conversion is possible. + + + 49) board/ttcontrol/vision2/vision2.c + ------------------------------------- + The driver is standard HW watchdog but namespace is polluted by + non-standard macros. Simple conversion is possible, code cleanup + needed. + + + 50) board/v38b/v38b.c + --------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 51) board/ve8313/ve8313.c + ------------------------- + The driver is standard HW watchdog. Simple conversion is possible. + + + 52) board/w7o/watchdog.c + ------------------------ + The driver is standard HW watchdog. Simple conversion is possible. |