On the SIMATIC, IOT2040 only a single pin is exportable as GPIO, the
rest is required to operate the UART. To allow modeling this case,
expand the platform device data structure to specify a (consecutive) pin
subset for exporting by the gpio-exar driver.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>

Set the parent of the exar gpiochip to its platform device, like other
gpiochips are doing it. In order to keep the relationship discoverable
for ACPI systems, set the platform device companion to the PCI device.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

The UART driver already maps the resource for us. Trying to do this here
only fails and leaves us with a non-working device.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

Commtech adapters need the MPIOs for internal purposes, and the
gpio-exar driver already refused to pick them up. But there is actually
no point in even creating the underlying platform device.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

First, the logic for translating a register bit to the return code of
exar_get_direction and exar_get_value were wrong. And second, there was
a flip regarding the register bank in exar_get_direction.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Do not allocate resources on behalf of the parent device but on our own.
Otherwise, cleanup does not properly work if gpio-exar is removed but
not the parent device.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This fixes reloading of the GPIO driver for the same platform device
instance as created by the exar UART driver: First of all, the driver
sets drvdata to its own value during probing and does not restore the
original value on exit. But this won't help anyway as the core clears
drvdata after the driver left.

Set the platform device parent instead.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Current code does not set output level in exar_direction_output, fix it.
Also move the direction_output/direction_input code block to avoid forward
declaration for exar_set_value().
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Exar XR17V352/354/358 chips have 16 multi-purpose inputs/outputs which
can be controlled using gpio interface.

Add the gpio specific code.
Signed-off-by: NSudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>