diff options
| -rw-r--r-- | doc/README.nand | 62 | ||||
| -rw-r--r-- | drivers/mtd/nand/nand.c | 96 | ||||
| -rw-r--r-- | include/nand.h | 5 |
3 files changed, 126 insertions, 37 deletions
diff --git a/doc/README.nand b/doc/README.nand index 023740e1d..04a87c991 100644 --- a/doc/README.nand +++ b/doc/README.nand @@ -120,6 +120,68 @@ Configuration Options: CONFIG_SYS_NAND_MAX_CHIPS The maximum number of NAND chips per device to be supported. + CONFIG_SYS_NAND_SELF_INIT + Traditionally, glue code in drivers/mtd/nand/nand.c has driven + the initialization process -- it provides the mtd and nand + structs, calls a board init function for a specific device, + calls nand_scan(), and registers with mtd. + + This arrangement does not provide drivers with the flexibility to + run code between nand_scan_ident() and nand_scan_tail(), or other + deviations from the "normal" flow. + + If a board defines CONFIG_SYS_NAND_SELF_INIT, drivers/mtd/nand/nand.c + will make one call to board_nand_init(), with no arguments. That + function is responsible for calling a driver init function for + each NAND device on the board, that performs all initialization + tasks except setting mtd->name, and registering with the rest of + U-Boot. Those last tasks are accomplished by calling nand_register() + on the new mtd device. + + Example of new init to be added to the end of an existing driver + init: + + /* + * devnum is the device number to be used in nand commands + * and in mtd->name. Must be less than + * CONFIG_SYS_NAND_MAX_DEVICE. + */ + mtd = &nand_info[devnum]; + + /* chip is struct nand_chip, and is now provided by the driver. */ + mtd->priv = &chip; + + /* + * Fill in appropriate values if this driver uses these fields, + * or uses the standard read_byte/write_buf/etc. functions from + * nand_base.c that use these fields. + */ + chip.IO_ADDR_R = ...; + chip.IO_ADDR_W = ...; + + if (nand_scan_ident(mtd, CONFIG_SYS_MAX_NAND_CHIPS, NULL)) + error out + + /* + * Insert here any code you wish to run after the chip has been + * identified, but before any other I/O is done. + */ + + if (nand_scan_tail(mtd)) + error out + + if (nand_register(devnum)) + error out + + In addition to providing more flexibility to the driver, it reduces + the difference between a U-Boot driver and its Linux counterpart. + nand_init() is now reduced to calling board_nand_init() once, and + printing a size summary. This should also make it easier to + transition to delayed NAND initialization. + + Please convert your driver even if you don't need the extra + flexibility, so that one day we can eliminate the old mechanism. + NOTE: ===== diff --git a/drivers/mtd/nand/nand.c b/drivers/mtd/nand/nand.c index d987f4c85..4cf4c1c70 100644 --- a/drivers/mtd/nand/nand.c +++ b/drivers/mtd/nand/nand.c @@ -23,6 +23,7 @@ #include <common.h> #include <nand.h> +#include <errno.h> #ifndef CONFIG_SYS_NAND_BASE_LIST #define CONFIG_SYS_NAND_BASE_LIST { CONFIG_SYS_NAND_BASE } @@ -31,63 +32,84 @@ DECLARE_GLOBAL_DATA_PTR; int nand_curr_device = -1; + + nand_info_t nand_info[CONFIG_SYS_MAX_NAND_DEVICE]; +#ifndef CONFIG_SYS_NAND_SELF_INIT static struct nand_chip nand_chip[CONFIG_SYS_MAX_NAND_DEVICE]; static ulong base_address[CONFIG_SYS_MAX_NAND_DEVICE] = CONFIG_SYS_NAND_BASE_LIST; +#endif + +static char dev_name[CONFIG_SYS_MAX_NAND_DEVICE][8]; + +static unsigned long total_nand_size; /* in kiB */ + +/* Register an initialized NAND mtd device with the U-Boot NAND command. */ +int nand_register(int devnum) +{ + struct mtd_info *mtd; + + if (devnum >= CONFIG_SYS_MAX_NAND_DEVICE) + return -EINVAL; + + mtd = &nand_info[devnum]; + + sprintf(dev_name[devnum], "nand%d", devnum); + mtd->name = dev_name[devnum]; + +#ifdef CONFIG_MTD_DEVICE + /* + * Add MTD device so that we can reference it later + * via the mtdcore infrastructure (e.g. ubi). + */ + add_mtd_device(mtd); +#endif + + total_nand_size += mtd->size / 1024; -static const char default_nand_name[] = "nand"; -static __attribute__((unused)) char dev_name[CONFIG_SYS_MAX_NAND_DEVICE][8]; + if (nand_curr_device == -1) + nand_curr_device = devnum; + + return 0; +} -static void nand_init_chip(struct mtd_info *mtd, struct nand_chip *nand, - ulong base_addr) +#ifndef CONFIG_SYS_NAND_SELF_INIT +static void nand_init_chip(int i) { + struct mtd_info *mtd = &nand_info[i]; + struct nand_chip *nand = &nand_chip[i]; + ulong base_addr = base_address[i]; int maxchips = CONFIG_SYS_NAND_MAX_CHIPS; - static int __attribute__((unused)) i = 0; if (maxchips < 1) maxchips = 1; - mtd->priv = nand; + mtd->priv = nand; nand->IO_ADDR_R = nand->IO_ADDR_W = (void __iomem *)base_addr; - if (board_nand_init(nand) == 0) { - if (nand_scan(mtd, maxchips) == 0) { - if (!mtd->name) - mtd->name = (char *)default_nand_name; -#ifdef CONFIG_NEEDS_MANUAL_RELOC - else - mtd->name += gd->reloc_off; -#endif -#ifdef CONFIG_MTD_DEVICE - /* - * Add MTD device so that we can reference it later - * via the mtdcore infrastructure (e.g. ubi). - */ - sprintf(dev_name[i], "nand%d", i); - mtd->name = dev_name[i++]; - add_mtd_device(mtd); -#endif - } else - mtd->name = NULL; - } else { - mtd->name = NULL; - mtd->size = 0; - } + if (board_nand_init(nand)) + return; + if (nand_scan(mtd, maxchips)) + return; + + nand_register(i); } +#endif void nand_init(void) { +#ifdef CONFIG_SYS_NAND_SELF_INIT + board_nand_init(); +#else int i; - unsigned int size = 0; - for (i = 0; i < CONFIG_SYS_MAX_NAND_DEVICE; i++) { - nand_init_chip(&nand_info[i], &nand_chip[i], base_address[i]); - size += nand_info[i].size / 1024; - if (nand_curr_device == -1) - nand_curr_device = i; - } - printf("%u MiB\n", size / 1024); + + for (i = 0; i < CONFIG_SYS_MAX_NAND_DEVICE; i++) + nand_init_chip(i); +#endif + + printf("%lu MiB\n", total_nand_size / 1024); #ifdef CONFIG_SYS_NAND_SELECT_DEVICE /* diff --git a/include/nand.h b/include/nand.h index d444ddcef..5dd1710eb 100644 --- a/include/nand.h +++ b/include/nand.h @@ -30,7 +30,12 @@ extern void nand_init(void); #include <linux/mtd/mtd.h> #include <linux/mtd/nand.h> +#ifdef CONFIG_SYS_NAND_SELF_INIT +void board_nand_init(void); +int nand_register(int devnum); +#else extern int board_nand_init(struct nand_chip *nand); +#endif typedef struct mtd_info nand_info_t; |