Reading the register (if allowed) after writing is to ensure writing
is completed on a posted bus. The endianness of reading doesn't matter.
Signed-off-by: NYork Sun <yorksun@freescale.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

With CONFIG_OF=n, the following warnings occur when compiling
drivers/i2c/muxes/i2c-mux-reg.c:

  CC      drivers/i2c/muxes/i2c-mux-reg.o
drivers/i2c/muxes/i2c-mux-reg.c:170:13: warning: ‘struct gpiomux’ declared inside parameter list [enabled by default]
      struct platform_device *pdev)
             ^
drivers/i2c/muxes/i2c-mux-reg.c:170:13: warning: its scope
is only this definition or declaration, which is probably not what you want [enabled by default]
drivers/i2c/muxes/i2c-mux-reg.c: In function ‘i2c_mux_reg_probe’:
drivers/i2c/muxes/i2c-mux-reg.c:201:3: warning: passing argument 1 of ‘i2c_mux_reg_probe_dt’ from incompatible pointer type [enabled by default]
   ret = i2c_mux_reg_probe_dt(mux, pdev);
   ^
Signed-off-by: NMike Rapoport <mike.rapoport@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Checking was done at three different locations, just do it once and
properly at probing time.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Tested-by: NYork Sun <yorksun@freescale.com>

Every call of of_parse_phandle() increments user count of found device
node, if OF_DYNAMIC is enabled.

The change fixes all similar addressed cases in drivers/i2c.
Signed-off-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Based on i2c-mux-gpio driver, similarly the register-based mux
switch from one bus to another by setting a single register.
The register can be on PCIe bus, local bus, or any memory-mapped
address. The endianness of such register can be specified in device
tree if used, or in platform data.
Signed-off-by: NYork Sun <yorksun@freescale.com>
Acked-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This change is needed to properly lock I2C parent bus driver.

Prior to this change i2c_put_adapter() is misused, which may lead
to an overflow over zero of I2C bus driver user counter.
Signed-off-by: NVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

i2c_driver does not need to set an owner because i2c_register_driver()
will set it.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

pca9541 and pca954x are calling master_xfer() of the parent adapter directly
thus bypassing the quirks checks of the adapter. Use __i2c_transfer() instead.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: NŁukasz Gemborowski <lukasz.gemborowski@nokia.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NJisheng Zhang <jszhang@marvell.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Fixes: b7f62584 ("i2c: add quirk checks to core")

The GPIO subsystem provides dummy GPIO consumer functions if GPIOLIB is
not enabled. Hence drivers that depend on GPIOLIB, but use GPIO consumer
functionality only, can still be compiled if GPIOLIB is not enabled.

Relax the dependency on GPIOLIB if COMPILE_TEST is enabled, where
appropriate.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Probe deferral is not an error case. It happens only when
the necessary dependencies are not there yet.

The driver core is already printing a message when a driver
requests probe deferral, so this can be traced in the logs
without these error prints.

This patch removes the error messages for these deferral cases.
Signed-off-by: NIonut Nicu <ioan.nicu.ext@nokia.com>
Acked-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Acked-by: NPeter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Add i2c-mux-idle-disconnect device tree property to PCA954x mux driver. The new
property forces the multiplexer to disconnect child buses in idle state. This is
used, for example, when there are several multiplexers on the same bus and the
devices on the underlying buses might have same I2C addresses.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nsn.com>
[wsa: added a newline]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

pca954x may be power lost during suspend, so after resume we also suffer
the issue fixed by commit cd823db8,

 "pca954x power-on default is channel 0 connected. If multiple pca954x
 muxes are connected to the same physical I2C bus, the parent bus will
 see channel 0 devices behind both muxes by default."

What's more, when resume bootloader may also operate the mux, so the
the channel connected after that may not be the one driver thought.

We fix this problem by putting the mux to disconnected state and
clearing last_chan in the resume hook.
Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Reviewed-by: NJean Delvare <jdelvare@suse.de>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This driver causes the following randconfig build error:

drivers/i2c/muxes/i2c-mux-pca954x.c: In function ‘pca954x_probe’:
drivers/i2c/muxes/i2c-mux-pca954x.c:204:2: error: implicit declaration
of function ‘devm_gpiod_get’ [-Werror=implicit-function-declaration]
  gpio = devm_gpiod_get(&client->dev, "reset");
  ^
drivers/i2c/muxes/i2c-mux-pca954x.c:204:7: warning: assignment makes
pointer from integer without a cast [enabled by default]
  gpio = devm_gpiod_get(&client->dev, "reset");
       ^
drivers/i2c/muxes/i2c-mux-pca954x.c:206:3: error: implicit declaration
of function ‘gpiod_direction_output’
[-Werror=implicit-function-declaration]
   gpiod_direction_output(gpio, 0);
   ^
cc1: some warnings being treated as errors
make[3]: *** [drivers/i2c/muxes/i2c-mux-pca954x.o] Error 1

This is because it is getting compiled without gpiolib, so
introduce an explicit dependency.
Reported-by: NJim Davis <jim.epost@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The pca954x driver recently switched to the GPIO descriptor API without
including the correct <linux/gpio/consumer.h> header. This breaks
compilation without CONFIG_GPIOLIB.

drivers/i2c/muxes/i2c-mux-pca954x.c: In function ‘pca954x_probe’:
drivers/i2c/muxes/i2c-mux-pca954x.c:204:2: error: implicit declaration
of function ‘devm_gpiod_get’ [-Werror=implicit-function-declaration]
  gpio = devm_gpiod_get(&client->dev, "reset");
  ^
drivers/i2c/muxes/i2c-mux-pca954x.c:204:7: warning: assignment makes
pointer from integer without a cast [enabled by default]
  gpio = devm_gpiod_get(&client->dev, "reset");
       ^
drivers/i2c/muxes/i2c-mux-pca954x.c:206:3: error: implicit declaration
of function ‘gpiod_direction_output’
[-Werror=implicit-function-declaration]
   gpiod_direction_output(gpio, 0);
   ^
cc1: some warnings being treated as errors
make[3]: *** [drivers/i2c/muxes/i2c-mux-pca954x.o] Error 1

Fix it by including the right header.
Reported-by: NJim Davis <jim.epost@gmail.com>
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The ID-based GPIO API pushes handling of GPIO polarity to drivers.
Simplify the driver by switching to the descriptor-based GPIO API.

This also fixes a mismatch between the pca954x DT bindings that document
a "reset-gpios" property and the driver that requests a "reset-gpio"
property.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Signed-off-by: NJean Delvare <khali@linux-fr.org>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

If a reset GPIO support is specified, request the GPIO and get the chip
out of reset at probe time.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This simplifies error and removal paths.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

This helps avoiding duplicate includes.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The i2c-mux driver requires that the chan_id parameter
passed to the i2c_add_mux_adapter() function is equal
to the reg value for that adapter:

for_each_child_of_node(mux_dev->of_node, child) {
	ret = of_property_read_u32(child, "reg", &reg);
	if (ret)
		continue;
	if (chan_id == reg) {
		priv->adap.dev.of_node = child;
		break;
	}
}

The i2c-mux-gpio driver uses an internal logical index
for chan_id when calling i2c_add_mux_adapter() instead
of using the reg value.

Because of this, there will problems in selecting the
right adapter when the i2c-mux-gpio's index into
mux->data.values doesn't match the reg value.

An example of such a case:

mux->data.values = { 1, 0 }

For chan_id = 0, i2c-mux will bind the adapter to the
of_node with reg = <0>, but when it will call the
select() callback with chan_id set to 0, the i2c-mux-gpio
will use it as an index into mux->data.values and it will
actually select the bus with reg = <1>.
Signed-off-by: NIonut Nicu <ioan.nicu.ext@nsn.com>
Acked-by: NAlexander Sverdlin <alexander.sverdlin@nsn.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

Some gpio chips may have get/set operations that
can sleep. gpio_set_value() only works for chips
which do not sleep, for the others we will get a
kernel warning. Using gpio_set_value_cansleep()
will work for both chips that do sleep and those
who don't.
Signed-off-by: NIonut Nicu <ioan.nicu.ext@nsn.com>
Acked-by: NPeter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

'of_match_ptr' is defined in linux/of.h. Include it explicitly to
avoid build breakage in the future.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

If it is not there yet, it might appear later.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

If it is not there yet, it might appear later.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

If the i2c-parent bus driver is not loaded, returning
-ENODEV will force people to unload and then reload the
module again to get it working.
Signed-off-by: NIonut Nicu <ioan.nicu.ext@nsn.com>
Acked-by: NPeter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

of_get_named_gpio could return -E_PROBE_DEFER or another
error code. This error should be passed further instead
of being ignored.
Signed-off-by: NIonut Nicu <ioan.nicu.ext@nsn.com>
Acked-by: NPeter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

I2C of helpers used to live in of_i2c.c but experience (from SPI) shows
that it is much cleaner to have this in the core. This also removes a
circular dependency between the helpers and the core, and so we can
finally register child nodes in the core instead of doing this manually
in each driver. So, fix the drivers and documentation, too.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

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: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NNaveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NWolfram 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: NAlexandre Courbot <acourbot@nvidia.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>

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: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

gpio_direction_output() may fail, check for that and deal with it
appropriately. Also log an error message if gpio_request() fails.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NPeter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

My old e-mail address is no longer working.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

There is simply no reason to be manually setting the private driver
data to NULL in the remove/fail to probe cases.  This is just extra
cruft code that can be removed.

A few notes:
* Nothing relies on drvdata being set to NULL.
* The __device_release_driver() function eventually calls
  dev_set_drvdata(dev, NULL) anyway, so there's no need to do it
  twice.
* I verified that there were no cases where xxx_get_drvdata() was
  being called in these drivers and checking for / relying on the NULL
  return value.

This could be cleaned up kernel-wide but for now just take the baby
step and remove from the i2c subsystem.
Reported-by: NWolfram Sang <wsa@the-dreams.de>
Reported-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NWolfram Sang <wolfram@the-dreams.de>

sizeof when applied to a pointer typed expression gives the size of
the pointer

The semantic patch that makes this output is available
in scripts/coccinelle/misc/noderef.cocci.

More information about semantic patching is available at
http://coccinelle.lip6.fr/Signed-off-by: NLaurent Navet <laurent.navet@gmail.com>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

CC: Stephen Warren <swarren@nvidia.com>
CC: Peter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NPeter Korsgaard <peter.korsgaard@barco.com>