The i2c_imx_trx_complete() function is using
wait_event_interruptible_timeout() to wait for the I2C controller to
signal that it has completed an I2C bus operation. If the process that
causes the I2C operation receives a signal, the wait will be
interrupted, returning an error. It is better to let the I2C operation
finished before handling the signal (i.e. returning into userspace).
It is safe to use wait_event_timeout() instead, because the timeout
will allow the process to exit if the I2C bus hangs. It's also better
to allow the I2C operation to finish, because unacknowledged I2C
operations can cause the I2C bus to hang.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This patch is an improvement to 4bba0fd8d1
which got to mainline a little early.
Sudhakar Rajashekhara explains that at least OMAP-L138 requires MDR mode
settings before DXR for correct behaviour, so load MDR first with
STT cleared and later load again with STT set.
Tested on DM355 connected to Techwell TW2836 and Wolfson WM8985
Signed-off-by: Jon Povey <jon.povey@racelogic.co.uk>
Acked-by: Troy Kisky <troy.kisky@boundarydevices.com>
Tested-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
of/i2c: Fix module load order issue caused by of_i2c.c
i2c: Fix checks which cause legacy suspend to never get called
i2c-pca: Fix waitforcompletion() return value
i2c: Fix for suspend/resume issue
i2c: Remove obsolete cleanup for clientdata
S3C2440 style I2C controller uses PCLK to calculate the SDA line delay.
The driver wrongly assumed that this delay is calculated from the
frequency that the controller is operating on. This patch fixes this
issue.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Commit 959e85f7, "i2c: add OF-style registration and binding" caused a
module dependency loop where of_i2c.c calls functions in i2c-core, and
i2c-core calls of_i2c_register_devices() in of_i2c. This means that
when i2c support is built as a module when CONFIG_OF is set, then
neither i2c_core nor of_i2c are able to be loaded.
This patch fixes the problem by moving the of_i2c_register_devices()
calls back into the device drivers. Device drivers already
specifically request the core code to parse the device tree for
devices anyway by setting the of_node pointer, so it isn't a big
deal to also call the registration function. The drivers just become
slightly more verbose.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
For devices which are not adapted to runtime PM a call to
pm_runtime_suspended always returns true.
Hence the pm_runtime_suspended checks below prevent legacy
suspend from getting called.
So do a pm_runtime_suspended check only for devices with a
dev_pm_ops populated (which hence do not rely on the legacy
suspend.)
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
ret is still -1, if during the polling read_byte() returns at once
with I2C_PCA_CON_SI set. So ret > 0 would lead *_waitforcompletion()
to return 0, in spite of the proper behavior.
The routine was rewritten, so that ret has always a proper value,
before returning.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: stable@kernel.org
Signed-off-by: Jean Delvare <khali@linux-fr.org>
In current i2c core driver, call to pm_runtime_set_active from
i2c_device_pm_resume will unconditionally enable i2c module and
increment child count of the parent. Because of this, in CPU Idle
path, i2c does not idle, preventing Core to enter retention. Also i2c
module will not be suspended upon system suspend as
pm_runtime_set_suspended is not called from i2c_device_pm_suspend.
This issue is fixed by removing pm_runtime_set_active call from resume
path which is not necessary.
This fix has been tested on OMAP4430.
Signed-off-by: Partha Basak <p-basak2@ti.com>
Signed-off-by: Vishwanath BS <vishwanath.bs@ti.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
When setting up to transmit, a race exists between the ISR and
i2c_davinci_xfer_msg() trying to load the first byte and adjust counters.
This is mostly visible for transmits > 1 byte long.
The hardware starts sending immediately that MDR is loaded. IMR trickery
doesn't work because if we start sending, finish the first byte and an
XRDY event occurs before we load IMR to unmask it, we never get an
interrupt, and we timeout.
Move the MDR load after DXR,IMR loads to avoid this race without locking.
Tested on DM355 connected to Techwell TW2836 and Wolfson WM8985
Signed-off-by: Jon Povey <jon.povey@racelogic.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
It doesn't make sense to set result to -ETIMEDOUT but return 0 (success)
afterwards. Since there's code in octeon_i2c_start() to handle the
error, it should be called.
Signed-off-by: Bernhard Walle <walle@corscience.de>
Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
If the i2c bus receives an interrupt with both BB (bus busy) and
ARDY (register access ready) statuses set during the tranfer of the last message
the bus was put to idle while still busy.
This caused bus to timeout.
Signed-off-by: Mathias Nyman <mathias.nyman@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
* 'for-linus/i2c-2636' of git://git.fluff.org/bjdooks/linux:
i2c/nuc900: add i2c driver support for nuc900
i2c: Enable NXP LPC support in Kconfig
i2c-pxa: fix compiler warning, due to missing const
i2c: davinci: bus recovery procedure to clear the bus
i2c: davinci: Add cpufreq support
i2c: davinci: Add suspend/resume support
i2c: davinci: Add helper functions for power management
i2c: davinci: misc. cleanups: remove MOD_REG_BIT and IO_ADDRESS usage
i2c: davinci: Fix smbus Oops with AIC33 usage
* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
i2c: I2C bus multiplexer driver pca954x
i2c: Multiplexed I2C bus core support
i2c: Use a separate mutex for userspace client lists
i2c: Make i2c_default_probe self-sufficient
i2c: Drop dummy variable
i2c: Move adapter locking helpers to i2c-core
V4L/DVB: Use custom I2C probing function mechanism
i2c: Add support for custom probe function
i2c-dev: Use memdup_user
i2c-dev: Remove unnecessary kmalloc casts
Add multiplexed bus core support. I2C multiplexer and switches
like pca954x get instantiated as new adapters per port.
Signed-off-by: Michael Lawnick <ml.lawnick@gmx.de>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Moving userspace-instantiated clients to separate lists wasn't nearly
enough to avoid deadlocks in multiplexed bus cases. We also want to
have a dedicated mutex to protect each list.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Lawnick <ml.lawnick@gmx.de>
Make i2c_default_probe self-sufficient, so that callers don't have to
do functionality checks themselves. This ensures everything is and
will stay consistent.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Now that bus_for_each_drv() is no longer __must_check, we can drop the
dummy variable that was used to store the returned value.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Justin P. Mattock <justinmattock@gmail.com>
Uninline i2c adapter locking helper functions, move them to i2c-core,
and use them in i2c-core itself. The functions are still exported for
external users. This makes future updates to the locking model (which
will be needed for multiplexing support) possible and transparent.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Lawnick <ml.lawnick@gmx.de>
Now that i2c-core offers the possibility to provide custom probing
function for I2C devices, let's make use of it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
The probe method used by i2c_new_probed_device() may not be suitable
for all cases. Let the caller provide its own, optional probe
function.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Use memdup_user when user data is immediately copied into the allocated
region. Note that in the second case, the ++i is no longer necessary, as
the last value is already freed if needed by the call to memdup_user.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression from,to,size,flag;
position p;
identifier l1,l2;
@@
- to = \(kmalloc@p\|kzalloc@p\)(size,flag);
+ to = memdup_user(from,size);
if (
- to==NULL
+ IS_ERR(to)
|| ...) {
<+... when != goto l1;
- -ENOMEM
+ PTR_ERR(to)
...+>
}
- if (copy_from_user(to, from, size) != 0) {
- <+... when != goto l2;
- -EFAULT
- ...+>
- }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Marc Kleine-Budde
Jon Povey
Linus Torvalds
MyungJoo Ham
Grant Likely
Rajendra Nayak
Yegor Yefremov
Vishwanath BS
Bernhard Walle
Mathias Nyman
Michael Lawnick
Jean Delvare
Julia Lawall
Joe Perches
Ben Dooks