It is a bit subtle when to correctly increase the buffer index when
reading. Make this clearer by adding some more comments and pointers to
the docs.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

After more discussion, brave users, and additional datasheet evaluation,
some API updates for the new I2C slave framework became imminent. The
slave events now get some easier to understand naming. Also, the event
handling has been simplified to only need a single call to the slave
callback when an action by the backend is required.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

The CX92755 is an SoC in the Conexant Digicolor series. The devicetree binding
document describes the I2C controller on the CX92755 SoC, that is also shared
by some other SoCs in the Digicolor series. The driver adds support.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
[wsa: fixed spaces around operators]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Make sure dynamic ids do not interfere with fixed ones and let them
start after the highest fixed id. This patch might cause different
bus-numbers than before for dynamic ids, however it fixes a bug. Assume:

- fixed id0 defers probe
- fixed id1 succeeds and registers a muxed bus with dynamic id
- muxed bus gets id0
- fixed id0 wants to probe again, but its fixed id is gone now
- fixed id0 probe fails

With this patch, the fixed ids are always reserved in the DT case.
For legacy board init, we already have a mechanism like this in
i2c_register_board_info().
Reported-by: Bob Feretich <bob.feretich@rafresearch.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

I2C supports adding adapters using either a dynamic or fixed id. The
latter is provided by aliases in the DT case. To prevent id collisions
of those two types, install this function which gives us the highest
fixed id, so we can then let the dynamically created ones come after
this highest number.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

With -EPROBE_DEFER, this message is confusing and we hope for a
centralized printout in the future anyhow.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Christian Ruppert <christian.ruppert@alitech.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

For the 85xx platforms, the source clock for the i2c-mpc can change from
one SoC to another. This is documented in the AN2919 "Determining the
I2C Frequency Divider Ratio for SCL" by Freescale. Not taking this into
account can lead to the output SCL frequency to by off by an offset. It
was observed on the P2041 from the QorIQ family.

This patch fixes this problem by setting the prescaler value to the
appropriate value when required. The SoCs that required a different
prescaler than 1 are identified by reading out the SVR as discussed in
http://thread.gmane.org/gmane.linux.drivers.devicetree/94247/focus=20556Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Return type of wait_for_completion_timeout is unsigned long not int.
Appropriately typed/named variable are added and assignment fixed up.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Return type of wait_for_completion_timeout is unsigned long not int. This
patch adds a timeout variable of appropriate type and fixes up the assignment.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of wait_for_completion_timeout is unsigned long not int. The
return variable is renamed to reflect its use and the type adjusted to
unsigned long.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of read_i2c() is int not u32. As the assignments to status
are consistent with int here its type is changed to int.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of wait_for_completion_timeout is unsigned long not int. as
timeout is used for wait_for_completion_timeout exclusively here its
type is simply changed to unsigned long.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of wait_for_completion_timeout is unsigned long not int.
An appropriate variable of type unsigned long is introduced and the
assignments fixed up.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of wait_for_completion_timeout is unsigned long not int. As
ret is in used for other calls a new appropriately typed variable timeout
is added to handle wait_for_completion_timeout
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of wait_for_completion_timeout is unsigned long not int. as
wait_result is only used for wait_for_completion_timeout here the type
is simply changed to unsigned long.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of wait_for_completion_timeout is unsigned long not int. as
time_left is used for wait_for_completion_timeout exclusively here its
type is simply changed to unsigned long.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of wait_for_completion_timeout is unsigned long not int, rather
than introducing a new variable the wait_for_completion_timeout is moved
into the if condition as the return value is only used to detect timeout.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of wait_for_completion_timeout is unsigned long not int. The
return variable is renamed to make the timeout condition clearly readable
and the type adjusted to unsigned long.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

This is only an API consolidation and should make things more readable
it replaces var * HZ / 1000 by msecs_to_jiffies(var).
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

return type of wait_for_completion_timeout is unsigned long not int. As ret
was only used for wait_for_completion_timeout here it is renamed to time_left
the type changed to unsigned long and references fixed up.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Return type of wait_for_completion_timeout is unsigned long not int.
An appropriately named unsigned long is added and the assignment fixed up.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Hardware can do write-then-anything. Activate that.
Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
[wsa: cosmetic updates]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Ray Jui <rjui@broadcom.com>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-By: Ludovic Desroches <ludovic.desroches@atmel.com>

Let the core do the checks if HW quirks prevent a transfer. Saves code
from drivers and adds consistency.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Ray Jui <rjui@broadcom.com>
Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Tested-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Tested-By: Ludovic Desroches <ludovic.desroches@atmel.com>

The number of I2C adapters which are not fully I2C compatible is rising,
sadly. Drivers usually do handle the flaws, still the user receives only
some errno for a transfer which normally can be expected to work. This
patch introduces a formal description of flaws. One advantage is that
the core can check before the actual transfer if the messages could be
transferred at all. This is done in the next patch. Another advantage is
that we can pass this information to the user so the restrictions are
exactly known and further actions can be based on that. This will be
done later after some stabilization period for this description.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Ray Jui <rjui@broadcom.com>
Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Tested-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Tested-By: Ludovic Desroches <ludovic.desroches@atmel.com>

Since 39b2bbe3 (gpio: add flags argument to gpiod_get*() functions)
which appeared in v3.17-rc1, the gpiod_get* functions take an additional
parameter that allows to specify direction and initial value for
outputs.

Also there is an *_optional variant that serves well here.  The sematics
is slightly changed here by using it. Now if a reset gpio is specified
and getting hold on it fails, pca954x_probe fails, too.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Simplifies the code a bit and makes easier to disable PCI device on driver
detach by removing the pcim_pin_device() call in the future if needed.

Reason why i2c-i801.c doesn't ever call pci_disable_device() was because it
made some systems to hang during power-off. See commit d6fcb3b9
("[PATCH] i2c-i801.c: don't pci_disable_device() after it was just enabled")
and
http://marc.info/?l=linux-kernel&m=115160053309535&w=2Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Since pci_disable_device() is not called from i801_suspend() and power
state is set already it means that subsequent pci_enable_device() calls do
practically nothing but monotonically increase struct pci_dev enable_cnt.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>