| Age | Commit message (Collapse) | Author |
|---|
|
interrupts from the fuel gauge while charging.
Change-Id: I6a004c9d6ae9f47eae69387f27534f63c77ebfcf
|
|
Such a long timeout of 1s for a transfer to finish or wait for the
bus to become free causes an i2c client to become blocked for at
least 2s, if the attached slave is misbehaving. This timeout can
be reduced to 500ms; 500ms is plenty long enough for a single i2c
transfer to finish even in clock stretching cases.
Also, after an i2c transfer is complete, there's no benefit in
waiting for the bus to become ready, since the check will be done
again just before the next transfer.
Finally, in case the bus never gets freed, let's return an error
immediately after clearing the bus, regardless if the recovery
was successful. This will allow the i2c client to try the transfer
again on its own terms, instead of having the i2c driver attempt
to proceed with the transfer immediately after the recovery.
Change-Id: I6bc950948bd012aae4c3029b9c00603354a938fa
Signed-off-by: Mohsan Habibi <mohsan@motorola.com>
|
|
The I2C driver uses a threaded interrupt, which results in over 100us
of extra cpu activity. Update the omap i2c driver to not use a
threaded interrupt on single core processors. This reduces the i2c
latency from about 150us to 30us at 1.2GHz.
Change-Id: I4ee424d2dac4ea3ea03d7e414224b764d5c11648
Signed-off-by: Jim Wylder <jwylder@motorola.com>
|
|
Interrupts should be enabled only during a transfer for several
reasons:
- During bus busy recovery (omap_bus_clear), the recovery mechanism
might generate spurious and unexpected interrupts, which won't be
handled properly.
- Inside omap_i2c_xfer, there is a race condition where an interrupt
could trigger while calling pm_runtime_put, which would schedule
the ISR thread, but the clocks would be disabled before the thread
gets a chance to run.
- Prevent a misbehaving slave from causing unexpected interrupts if
it starts driving the lines in an incorrect way.
Additionally, move the recovery procedure to its own bus_clear function
for clarity, and also perform a reset after the recovery to ensure the
module is in a defined state.
Change-Id: I9b78884e7ad5407c2c09bc6af0fa982d7e7b2158
Signed-off-by: Mohsan Habibi <mohsan@motorola.com>
|
|
Using msleep for low values such as 1ms will often sleep longer than
~20ms, which is a unnecessarily high delay time, especially in
situations such as waiting for the bus to become free where we want
to resume i2c as soon as it is ready, not 20ms later.
Change-Id: If1f32c3ed3b6c3c109c85392442babc3c95ce030
Signed-off-by: Mohsan Habibi <mohsan@motorola.com>
|
|
Currently, the driver uses pm_runtime_put_autosuspend with a large
timeout to place the device in low power mode. However, this is not
necessary and the driver can instead use pm_runtime_put_sync instead
since the i2c module is inactive anytime we're not in a transfer.
Change-Id: I3148e34c3ee5cf64dd5e4b56d61e2a0c497f7e9c
Signed-off-by: Mohsan Habibi <mohsan@motorola.com>
|
|
results in over 100us of extra cpu activity"
This reverts commit 3c092304e321a2c569d4965ddb99487da4b4c3c9.
|
|
over 100us of extra cpu activity
Update the omap i2c driver to not use a threaded interrupt on single core processors. This
reduces the i2c latency from about 150us to 30us at 1.2GHz.
Change-Id: I0de708e98d5ebf39d14b181c91c06ca6ec772983
|
|
In case a peripheral is holding the DATA bus low, provide a 400Khz
constant clock output using the TEST register.
Also soft reset the I2C controller so that there is no stale state
left in the HW state machine.
A WARN_ON() will be generated when a BB timeout happens.
A timeout on a wait for bus no longer busy means that something
catatrosphic has happened either with the i2c module or one of the
slaves. When this happens, all subsequent i2c transfers will be
broken, so this recovery mechanism provides so hope that the bus
will come back up.
Change-Id: Ie921651d8fec77690fe9e02249f9d9ad70cf5ca9
Signed-off-by: Mohsan Habibi <mohsan@motorola.com>
|
|
Convert the driver from the outdated omap_pm_set_max_mpu_wakeup_lat
API to the new PM QoS API.
Since the constraint is on the MPU subsystem, use the PM_QOS_CPU_DMA_LATENCY
class of PM QoS. The resulting MPU constraints are used by cpuidle to
decide the next power state of the MPU subsystem.
The I2C device latency timing is derived from the FIFO size and the
clock speed and so is applicable to all OMAP SoCs.
Based on: 671d9f5 OMAP: convert I2C driver to PM QoS for latency
constraints
Change-Id: Iea5ac78d89019ed6e8888a0d6489057186748bfa
Signed-off-by: Mohsan Habibi <mohsan@motorola.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c bugfixes from Wolfram Sang:
"These should have been in rc2 but I missed it due to working on devm
longer than expected.
There is one ID addition, since we are touching the driver anyhow.
And the feature bit documentation is one outcome of a debug session
and will make it easier for users to work around problems. The rest
is typical driver bugfixes."
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: suppress lockdep warning on delete_device
i2c: mv64xxx: work around signals causing I2C transactions to be aborted
i2c: i801: Document feature bits in modinfo
i2c: designware: add Intel BayTrail ACPI ID
i2c: designware: always clear interrupts before enabling them
i2c: designware: fix RX FIFO overrun
|
|
devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Barry Song <Baohua.Song@csr.com>
|
|
i2c: suppress lockdep warning on delete_device
Since commit 846f99749ab68bbc7f75c74fec305de675b1a1bf the following lockdep
warning is thrown in case i2c device is removed (via delete_device sysfs
attribute) which contains subdevices (e.g. i2c multiplexer):
=============================================
[ INFO: possible recursive locking detected ]
3.8.7-0-sampleversion-fct #8 Tainted: G O
---------------------------------------------
bash/3743 is trying to acquire lock:
(s_active#110){++++.+}, at: [<ffffffff802b3048>] sysfs_hash_and_remove+0x58/0xc8
but task is already holding lock:
(s_active#110){++++.+}, at: [<ffffffff802b3cb8>] sysfs_write_file+0xc8/0x208
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(s_active#110);
lock(s_active#110);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by bash/3743:
#0: (&buffer->mutex){+.+.+.}, at: [<ffffffff802b3c3c>] sysfs_write_file+0x4c/0x208
#1: (s_active#110){++++.+}, at: [<ffffffff802b3cb8>] sysfs_write_file+0xc8/0x208
#2: (&adap->userspace_clients_lock/1){+.+.+.}, at: [<ffffffff80454a18>] i2c_sysfs_delete_device+0x90/0x238
#3: (&__lockdep_no_validate__){......}, at: [<ffffffff803dcc24>] device_release_driver+0x24/0x48
stack backtrace:
Call Trace:
[<ffffffff80575cc8>] dump_stack+0x8/0x34
[<ffffffff801b50fc>] __lock_acquire+0x161c/0x2110
[<ffffffff801b5c3c>] lock_acquire+0x4c/0x70
[<ffffffff802b60cc>] sysfs_addrm_finish+0x19c/0x1e0
[<ffffffff802b3048>] sysfs_hash_and_remove+0x58/0xc8
[<ffffffff802b7d8c>] sysfs_remove_group+0x64/0x148
[<ffffffff803d990c>] device_remove_attrs+0x9c/0x1a8
[<ffffffff803d9b1c>] device_del+0x104/0x1d8
[<ffffffff803d9c18>] device_unregister+0x28/0x70
[<ffffffff8045505c>] i2c_del_adapter+0x1cc/0x328
[<ffffffff8045802c>] i2c_del_mux_adapter+0x14/0x38
[<ffffffffc025c108>] pca954x_remove+0x90/0xe0 [pca954x]
[<ffffffff804542f8>] i2c_device_remove+0x80/0xe8
[<ffffffff803dca9c>] __device_release_driver+0x74/0xf8
[<ffffffff803dcc2c>] device_release_driver+0x2c/0x48
[<ffffffff803dbc14>] bus_remove_device+0x13c/0x1d8
[<ffffffff803d9b24>] device_del+0x10c/0x1d8
[<ffffffff803d9c18>] device_unregister+0x28/0x70
[<ffffffff80454b08>] i2c_sysfs_delete_device+0x180/0x238
[<ffffffff802b3cd4>] sysfs_write_file+0xe4/0x208
[<ffffffff8023ddc4>] vfs_write+0xbc/0x160
[<ffffffff8023df6c>] SyS_write+0x54/0xd8
[<ffffffff8013d424>] handle_sys64+0x44/0x64
The problem is already known for USB and PCI subsystems. The reason is that
delete_device attribute is defined statically in i2c-core.c and used for all
devices in i2c subsystem.
Discussion of original USB problem:
http://lkml.indiana.edu/hypermail/linux/kernel/1204.3/01160.html
Commit 356c05d58af05d582e634b54b40050c73609617b introduced new macro to suppress
lockdep warnings for this special case and included workaround for USB code.
LKML discussion of the workaround:
http://lkml.indiana.edu/hypermail/linux/kernel/1205.1/03634.html
As i2c case is in principle the same, the same workaround could be used here.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nsn.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
Do not use interruptible waits in an I2C driver; if a process uses
signals (eg, Xorg uses SIGALRM and SIGPIPE) then these signals can
cause the I2C driver to abort a transaction in progress by another
driver, which can cause that driver to fail. I2C drivers are not
expected to abort transactions on signals.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
Duplicate the feature bits documentation in modinfo, as not every user
will read the driver's source code or documentation file.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
This is the same controller as on Intel Lynxpoint but the ACPI ID is
different (8086F41). Add support for this.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
If the I2C bus is put to a low power state by an ACPI method it might pull
the SDA line low (as its power is removed). Once the bus is put to full
power state again, the SDA line is pulled back to high. This transition
looks like a STOP condition from the controller point-of-view which sets
STOP detected bit in its status register causing the driver to fail
subsequent transfers.
Fix this by always clearing all interrupts before we start a transfer.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
|
|
i2c_dw_xfer_msg() pushes a number of bytes to transmit/receive
to/from the bus into the TX FIFO.
For master-rx transactions, the maximum amount of data that can be
received is calculated depending solely on TX and RX FIFO load.
This is racy - TX FIFO may contain master-rx data yet to be
processed, which will eventually land into the RX FIFO. This
data is not taken into account and the function may request more
data than the controller is actually capable of storing.
This patch ensures the driver takes into account the outstanding
master-rx data in TX FIFO to prevent RX FIFO overrun.
Signed-off-by: Josef Ahmad <josef.ahmad@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
|
|
Pull removal of GENERIC_GPIO from Grant Likely:
"GENERIC_GPIO now synonymous with GPIOLIB. There are no longer any
valid cases for enableing GENERIC_GPIO without GPIOLIB, even though it
is possible to do so which has been causing confusion and breakage.
This branch does the work to completely eliminate GENERIC_GPIO."
* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux:
gpio: update gpio Chinese documentation
Remove GENERIC_GPIO config option
Convert selectors of GENERIC_GPIO to GPIOLIB
blackfin: force use of gpiolib
m68k: coldfire: use gpiolib
mips: pnx833x: remove requirement for GENERIC_GPIO
openrisc: default GENERIC_GPIO to false
avr32: default GENERIC_GPIO to false
xtensa: remove explicit selection of GENERIC_GPIO
sh: replace CONFIG_GENERIC_GPIO by CONFIG_GPIOLIB
powerpc: remove redundant GENERIC_GPIO selection
unicore32: default GENERIC_GPIO to false
unicore32: remove unneeded select GENERIC_GPIO
arm: plat-orion: use GPIO driver on CONFIG_GPIOLIB
arm: remove redundant GENERIC_GPIO selection
mips: alchemy: require gpiolib
mips: txx9: change GENERIC_GPIO to GPIOLIB
mips: loongson: use GPIO driver on CONFIG_GPIOLIB
mips: remove redundant GENERIC_GPIO select
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC device tree updates (part 2) from Arnd Bergmann:
"These are mostly new device tree bindings for existing drivers, as
well as changes to the device tree source files to add support for
those devices, and a couple of new boards, most notably Samsung's
Exynos5 based Chromebook.
The changes depend on earlier platform specific updates and touch the
usual platforms: omap, exynos, tegra, mxs, mvebu and davinci."
* tag 'dt-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (169 commits)
ARM: exynos: dts: cros5250: add EC device
ARM: dts: Add sbs-battery for exynos5250-snow
ARM: dts: Add i2c-arbitrator bus for exynos5250-snow
ARM: dts: add mshc controller node for Exynos4x12 SoCs
ARM: dts: Add chip-id controller node on Exynos4/5 SoC
ARM: EXYNOS: Create virtual I/O mapping for Chip-ID controller using device tree
ARM: davinci: da850-evm: add SPI flash support
ARM: davinci: da850: override SPI DT node device name
ARM: davinci: da850: add SPI1 DT node
spi/davinci: add DT binding documentation
spi/davinci: no wildcards in DT compatible property
ARM: dts: mvebu: Convert mvebu device tree files to 64 bits
ARM: dts: mvebu: introduce internal-regs node
ARM: dts: mvebu: Convert all the mvebu files to use the range property
ARM: dts: mvebu: move all peripherals inside soc
ARM: dts: mvebu: fix cpus section indentation
ARM: davinci: da850: add EHRPWM & ECAP DT node
ARM/dts: OMAP3: fix pinctrl-single configuration
ARM: dts: Add OMAP3430 SDP NOR flash memory binding
ARM: dts: Add NOR flash bindings for OMAP2420 H4
...
|
|
This is support for the ARM Chromebook, originally scheduled
as a "late" pull request. Since it's already late now, we
can combine this into the existing next/dt2 branch.
* late/dt:
ARM: exynos: dts: cros5250: add EC device
ARM: dts: Add sbs-battery for exynos5250-snow
ARM: dts: Add i2c-arbitrator bus for exynos5250-snow
ARM: dts: Add chip-id controller node on Exynos4/5 SoC
ARM: EXYNOS: Create virtual I/O mapping for Chip-ID controller using device tree
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c changes from Wolfram Sang:
- an arbitration driver. While the driver is quite simple, it caused
discussion if we need additional arbitration on top of the one
specified in the I2C standard. Conclusion is that I accept a few
generic mechanisms, but not very specific ones.
- the core lost the detach_adapter() call. It has no users anymore and
was in the way for other cleanups. attach_adapter() is sadly still
there since there are users waiting to be converted.
- the core gained a bus recovery infrastructure. I2C defines a way to
recover if the data line is stalled. This mechanism is now in the
core and drivers can now pass some data to make use of it.
- bigger driver cleanups for designware, s3c2410
- removing superfluous refcounting from drivers
- removing Ben Dooks as second maintainer due to inactivity. Thanks
for all your work so far, Ben!
- bugfixes, feature additions, devicetree fixups, simplifications...
* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (38 commits)
i2c: xiic: must always write 16-bit words to TX_FIFO
i2c: octeon: use HZ in timeout value
i2c: octeon: Fix i2c fail problem when a process is terminated by a signal
i2c: designware-pci: drop superfluous {get|put}_device
i2c: designware-plat: drop superfluous {get|put}_device
i2c: davinci: drop superfluous {get|put}_device
MAINTAINERS: Ben Dooks is inactive regarding I2C
i2c: mux: Add i2c-arb-gpio-challenge 'mux' driver
i2c: at91: convert to dma_request_slave_channel_compat()
i2c: mxs: do error checking and handling in PIO mode
i2c: mxs: remove races in PIO code
i2c-designware: switch to use runtime PM autosuspend
i2c-designware: use usleep_range() in the busy-loop
i2c-designware: enable/disable the controller properly
i2c-designware: use dynamic adapter numbering on Lynxpoint
i2c-designware-pci: use managed functions pcim_* and devm_*
i2c-designware-pci: use dev_err() instead of printk()
i2c-designware: move to managed functions (devm_*)
i2c: remove CONFIG_HOTPLUG ifdefs
i2c: s3c2410: Add SMBus emulation for block read
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
"Usual stuff, mostly comment fixes, typo fixes, printk fixes and small
code cleanups"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (45 commits)
mm: Convert print_symbol to %pSR
gfs2: Convert print_symbol to %pSR
m32r: Convert print_symbol to %pSR
iostats.txt: add easy-to-find description for field 6
x86 cmpxchg.h: fix wrong comment
treewide: Fix typo in printk and comments
doc: devicetree: Fix various typos
docbook: fix 8250 naming in device-drivers
pata_pdc2027x: Fix compiler warning
treewide: Fix typo in printks
mei: Fix comments in drivers/misc/mei
treewide: Fix typos in kernel messages
pm44xx: Fix comment for "CONFIG_CPU_IDLE"
doc: Fix typo "CONFIG_CGROUP_CGROUP_MEMCG_SWAP"
mmzone: correct "pags" to "pages" in comment.
kernel-parameters: remove outdated 'noresidual' parameter
Remove spurious _H suffixes from ifdef comments
sound: Remove stray pluses from Kconfig file
radio-shark: Fix printk "CONFIG_LED_CLASS"
doc: put proper reference to CONFIG_MODULE_SIG_ENFORCE
...
|
|
The TX_FIFO register is 10 bits wide. The lower 8 bits are the data to be
written, while the upper two bits are flags to indicate stop/start.
The driver apparently attempted to optimize write access, by only writing a
byte in those cases where the stop/start bits are zero. However, we have
seen cases where the lower byte is duplicated onto the upper byte by the
hardware, which causes inadvertent stop/starts.
This patch changes the write access to the transmit FIFO to always be 16 bits
wide.
Signed off by: Steven A. Falco <sfalco@harris.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
|
|
HZ based value is better than a magic number.
Signed-off-by: Eunbong Song <eunb.song@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
I've been debugging the abnormal operation of i2c on octeon. If a process is
terminated by signal in the middle of i2c operation, next i2c read operation
which is done by another process was failed. So i changed to ignore signal in
the middle of i2c operation. After that the problem was not reproduced.
Signed-off-by: Eunbong Song <eunb.song@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
|
|
Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
|
|
Driver core already takes care of refcounting, no need to do this on
driver level again.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Sekhar Nori <nsekhar@ti.com>
|
|
The i2c-arb-gpio-challenge driver implements an I2C arbitration scheme
where masters need to claim the bus with a GPIO before they can start
a transaction. This should generally only be used when standard I2C
multimaster isn't appropriate for some reason (errata/bugs).
This driver is based on code that Simon Glass added to the i2c-s3c2410
driver in the Chrome OS kernel 3.4 tree. The current incarnation as a
mux driver is as suggested by Grant Likely. See
<https://patchwork.kernel.org/patch/1877311/> for some history.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
GENERIC_GPIO is now equivalent to GPIOLIB and features that depended on
GENERIC_GPIO can now depend on GPIOLIB to allow removal of this option.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
|
|
Use generic DMA DT helper. Platforms booting with or without DT populated are
both supported.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
In PIO mode we can end up with the same errors as in DMA mode, but as IRQs
are disabled there we have to check for them manually after each command.
Also don't use the big controller reset hammer when receiving a NAK from a
slave. It's sufficient to tell the controller to continue at a clean state.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
This commit fixes the three following races in PIO code:
- The CTRL0 register is racy in itself, when programming transfer state and
run bit in the same cycle the hardware sometimes ends up using the state
from the last transfer. Fix this by programming state in one cycle, make
sure the write is flushed down APBX bus by reading back the reg and only
then trigger the run bit.
- Only clear the DMAREQ bit in DEBUG0 after the read/write to the data reg
happened. Otherwise we are racing with the hardware about who touches
the data reg first.
- When checking for completion of a transfer it's not sufficient to check
if the data engine finished, but also a check for i2c bus idle is needed.
In PIO mode we are really fast to program the next transfer after a finished
one, so the controller possibly tries to start a new transfer while the
clkgen engine is still busy writing the NAK/STOP from the last transfer to
the bus.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
Using autosuspend helps to reduce the resume latency in situations where
another I2C message is going to be started soon. For example with HID over
I2C touch panels we get several messages in a short period of time while
the touch panel is in use.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
This is not an atomic context so there is no need to use mdelay() but
instead use usleep_range().
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
The correct way to disable or enable the controller is to wait until the
DW_IC_ENABLE_STATUS register bit matches the bit we program into DW_IC_ENABLE
register. This procedure is described in the DesignWare I2C databook.
By doing this we can be sure that the controller is in correct state once
the function returns.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
It is not good idea to mix static and dynamic I2C adapter numbering. In
this particular case on Lynxpoint we had graphics I2C adapter which took
the first numbers preventing the designware I2C driver from using the
adapter numbers it preferred.
Since Lynxpoint support was just introduced and there is no hardware available
outside Intel we can fix this by switching to use dynamic adapter numbering
instead of static.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
This makes the error handling much more simpler than open-coding everything
and in addition makes the probe function smaller an tidier.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
With dev_err() we can get the device instance printed as well and is pretty
much standard to use dev_* macros in the drivers anyway. In addition
correct the indentation of probe() arguments.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
This makes the error handling much more simpler than open-coding everything
and in addition makes the probe function smaller and tidier.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
CONFIG_HOTPLUG is going away as an option, cleanup CONFIG_HOTPLUG
ifdefs in i2c files.
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
SMBus read and write are supported by the emulation layer of i2c
framework if the controller doesn't have SMBus features.
I2C_M_RECV_LEN flag is used to let i2c drivers know rx length is not
yet determined but will be read to the first byte in rx buffer.
s3c2410 doesn't handle this flag. So only one byte is read from slave.
There fore following two features are added to the driver code.
1. skip rx length check if I2C_M_RECV_LEN is set and the length is 1.
2. add actual bytes to the rx length after reading first bytes if
I2C_M_RECV_LEN.
I2C_M_RECV_LEN is only set for SMBus command. So this code does not
affect legacy codes which only use i2c command for s3c2410.
Signed-off-by: Jaemin Yoo <jmin.yoo@samsung.com>
Tested-by: Prasanna Kumar <prasanna.ps@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
With the generic DMA device tree helper supported by mxs-dma driver,
client devices only need to call dma_request_slave_channel() for
requesting a DMA channel from dmaengine.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
|
|
The ACPI handle of struct i2c_adapter's dev member should not be
set, because this causes that struct i2c_adapter to be associated
with the ACPI device node corresponding to its parent as the
second "physical_device", which is incorrect (this happens during
the registration of struct i2c_adapter). Consequently,
acpi_i2c_register_devices() should use the ACPI handle of the
parent of the struct i2c_adapter it is called for rather than the
struct i2c_adapter's ACPI handle (which should be NULL).
Make that happen and modify the i2c-designware-platdrv driver,
which currently is the only driver for ACPI-enumerated I2C
controller chips, not to set the ACPI handle for the
struct i2c_adapter it creates.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
|
|
i2c_del_mux_adapter always returns 0 and none of it current users check its
return value anyway. It is also an essential requirement of the Linux device
driver model, that functions which may be called from a device's remove callback
to free resources provided by the device, are not allowed to fail. This is the
case for i2c_del_mux_adapter(), so make its return type void to make the
fact that it won't fail explicit.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
i2c_del_mux_adapter() always returns 0. So all checks testing whether it will be
non zero will always evaluate to false and the conditional code is dead code.
This patch updates all callers of i2c_del_mux_adapter() to ignore its return
value and assume that it will always succeed (which it will). A subsequent
patch will make the return type of i2c_del_mux_adapter() void.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
i2c_del_adapter() is usually called from a drivers remove callback. The Linux
device driver model does not allow the remove callback to fail and all resources
allocated in the probe callback need to be freed, as well as all resources which
have been provided to the rest of the kernel(for example a I2C adapter) need to
be revoked. So any function revoking such resources isn't allowed to fail
either. i2c_del_adapter() adheres to this requirement and will never fail. But
i2c_del_adapter()'s return type is int, which may cause driver authors to think
that it can fail. This led to code constructs like:
ret = i2c_del_adapter(...);
BUG_ON(ret);
Since i2c_del_adapter() always returns 0 the BUG_ON is never hit and essentially
becomes dead code, which means it can be removed. Making the return type of
i2c_del_adapter() void makes it explicit that the function will never fail and
should prevent constructs like the above from re-appearing in the kernel code.
All callers of i2c_del_adapter() have already been updated in a previous patch
to ignore the return value, so the conversion of the return type from int to
void can be done without causing any build failures.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
i2c_del_adapter() always returns 0. So all checks testing whether it will be
non zero will always evaluate to false and the conditional code is dead code.
This patch updates all callers of i2c_del_mux_adapter() to ignore the return
value and assume that it will always succeed (which it will). In a subsequent
patch the return type of i2c_del_adapter() will be made void.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
|
Currently i2c_del_adapter() returns -EINVAL when it gets an adapter which is not
registered. But none of the users of i2c_del_adapter() depend on this behavior,
so for the sake of being able to sanitize the return type of i2c_del_adapter
argue, that the purpose of i2c_del_adapter() is to remove an I2C adapter from
the system. If the adapter is not registered in the first place this becomes a
no-op. So we can return success without having to do anything.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
|
