gpiolib: Introduce gpio_find_by_label() ...

Introduce gpio_find_by_label() in order to allow manipulating GPIOs by
the labels assigned to them via DT or board/driver code.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gpio: fix missing includes for bool and struct list_head ...

Signed-off-by: Roland Hieber <r.hieber@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gpio: move active state function stubs to GPIOLIB ...

Those are only implemented by GPIOLIB, not by GENERIC_GPIO.
Fixes like failure on old platforms, that aren't converted to
gpiolib, yet.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

gpiolib: Add code to support "active low" GPIOs ...

So far this particular aspect of various DT-bindings has been handled
on a per-driver basis. With this change, hopefully, we'll have a
single place to handle necessary logic inversions and eventually
would be able to migrate existing users as well as avoiding adding
redundant code to new drivers.

Cc: cphealy@gmail.com
Cc: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gpio: Drop asm-generic/gpio.h ...

Since we no longer have custom gpio function prototypes we can
drop the prototypes from asm-generic/gpio.h can add them to
include/gpio.h instead. While at it add static inline dummy wrappers
for !CONFIG_GENERIC_GPIO so that code using gpios can compile without
gpio support.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gpio: move gpio_is_valid to include/gpio.h ...

No architectue implements its own gpio_is_valid() function, so move
the only existing implementation to include/gpio.h where it's available
for all users.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gpiolib: import gpio_request_array() from linux 3.7 ...

Also import related functions gpio_request_one() and
gpio_free_array().

This commit imports code from linux 3.7 as
the more recent linux kernel versions use gpiolib descriptors,
see this commit for details:

  commit 372e722
  Author: Alexandre Courbot <acourbot@nvidia.com>
  Date:   Sun Feb 3 01:29:29 2013 +0900

      gpiolib: use descriptors internally

      Make sure gpiolib works internally with descriptors and (chip, offset)
      pairs instead of using the global integer namespace. This prepares the
      ground for the removal of the global gpio_desc[] array and the
      introduction of the descriptor-based GPIO API.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gpio: unify gpio direction macros names with Linux kernel ...

See linux.git/include/linux/gpio.h and
linux.git/Documentation/gpio.txt for details.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gpiolib: add get_direction callback ...

At least for debugging purposes it is helpful to determine the current
direction for a given GPIO. Add a callback to gpiochip, to allow to
get it.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gpio: fix typos ...

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add Generic GPIO driver ...

This patch adds generic memory-mapped GPIO controller support.
Code taken from Linux Kernel and adopted for barebox.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gpiolib: add gpio_request and gpio_free support ...

as today if no request or free provided do not complain

if the gpio is not request auto requested at first use

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

add gpiolib support ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>

gpio: add static inlines for gpio_request/gpio_free ...

Some drivers use gpio_request/gpio_free. Currently no architecture
has code behind these functions. Provide static inline functions
for these and remvoe the at91 specific inline functions.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

GPIO support ...

adopted Linux gpio code. Implemented for at91sam9. No gpiolib support
yet.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>