When allocating the memory for i2c busses, the code checked the wrong
variable and thus never detected if there was a memory error.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org
Signed-off-by: Jean Delvare <khali@linux-fr.org>

The code instantiating an i2c-mux-gpio platform device doesn't
necessarily know in advance the GPIO pin numbers it wants to use. If
pins are on a GPIO device which gets its base GPIO number assigned
dynamically at run-time, the values can't be hard-coded.

In that case, let the caller tell i2c-mux-gpio the name of the GPIO
chip and the (relative) GPIO pin numbers to use. At probe time, the
i2c-mux-gpio driver will look for the chip and apply the proper offset
to turn relative GPIO pin numbers to absolute GPIO pin numbers.

The same could be (and was so far) done on the caller's end, however
doing it in i2c-mux-gpio has two benefits:
* It avoids duplicating the code on every caller's side (about 30
  lines of code.)
* It allows for deferred probing for the muxed part of the I2C bus
  only. If finding the GPIO chip is the caller's responsibility, then
  deferred probing (if the GPIO chip isn't there yet) will not only
  affect the mux and the I2C bus segments behind it, but also the I2C
  bus trunk.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Peter Korsgaard <peter.korsgaard@barco.com>

Use the devm_kzalloc managed function to stripdown the error and remove
code.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Let I2C bus segments behind multiplexers have a class. This allows for
device auto-detection on these segments. As long as parent segments
don't share the same class, it should be fine.

I implemented support in drivers i2c-mux-gpio and i2c-mux-pca954x. I
left i2c-mux-pca9541 and i2c-mux-pinctrl alone for the moment as I
don't know if this feature makes sense for the use cases of these
drivers.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Peter Korsgaard <peter.korsgaard@barco.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Michael Lawnick <ml.lawnick@gmx.de>
Cc: Rodolfo Giometti <giometti@linux.it>

My old e-mail address won't be valid for much longer. Time to update it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

This is useful for SoCs whose I2C module's signals can be routed to
different sets of pins at run-time, using the pinctrl API.

                                 +-----+  +-----+
                                 | dev |  | dev |
    +------------------------+   +-----+  +-----+
    | SoC                    |      |        |
    |                   /----|------+--------+
    |   +---+   +------+     | child bus A, on first set of pins
    |   |I2C|---|Pinmux|     |
    |   +---+   +------+     | child bus B, on second set of pins
    |                   \----|------+--------+--------+
    |                        |      |        |        |
    +------------------------+  +-----+  +-----+  +-----+
                                | dev |  | dev |  | dev |
                                +-----+  +-----+  +-----+

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Update the MAINTAINERS entry and all other references accordingly.

Based on an original patch by Wolfram Sang.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com>

[wsa: fixed merge conflict due to rework in i2c_add_mux_adapter()]

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

Apply a naming pattern like in the rest of the subsystem to a first set
of mux drivers. Those drivers are the low-hanging fruit; we want to pick
them to motivate upcoming drivers to follow the new pattern. The missing
GPIO driver will be converted in a later patch.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com> (pca9541)
Acked-by: Jean Delvare <khali@linux-fr.org>

And adjust all callers.

The new device parameter is used in the next patch to initialize the
mux's of_node so that its children may be automatically populated.

Signed-off-by: David Daney <david.daney@cavium.com>
Tested-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

This patch converts the drivers in drivers/i2c/muxes/* to use the
module_i2c_driver() macro which makes the code smaller and a bit simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Michael Lawnick <ml.lawnick@gmx.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>