Commit Graph

13 Commits

Author SHA1 Message Date
Mika Westerberg 40b7318319 gpio: Support for unified device properties interface
Some drivers need to deal with only firmware representation of its
GPIOs. An example would be a GPIO button array driver where each button
is described as a separate firmware node in device tree. Typically these
child nodes do not have physical representation in the Linux device
model.

In order to help device drivers to handle such firmware child nodes we
add dev[m]_get_named_gpiod_from_child() that takes a child firmware
node pointer as its second argument (the first one is the parent device
itself), finds the GPIO using whatever is the underlying firmware
method, and requests the GPIO properly.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-04 21:58:23 +01:00
Julia Lawall 0f05a3ae45 gpiolib: devres: use correct structure type name in sizeof
Correct typo in the name of the type given to sizeof.  Because it is the
size of a pointer that is wanted, the typo has no impact on compilation or
execution.

This problem was found using Coccinelle (http://coccinelle.lip6.fr/).  The
semantic patch used can be found in message 0 of this patch series.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-08-17 09:12:35 -05:00
Alexandre Courbot 39b2bbe3d7 gpio: add flags argument to gpiod_get*() functions
The huge majority of GPIOs have their direction and initial value set
right after being obtained by one of the gpiod_get() functions. The
integer GPIO API had gpio_request_one() that took a convenience flags
parameter allowing to specify an direction and value applied to the
returned GPIO. This feature greatly simplifies client code and ensures
errors are always handled properly.

A similar feature has been requested for the gpiod API. Since setting
the direction of a GPIO is so often the very next action done after
obtaining its descriptor, we prefer to extend the existing functions
instead of introducing new functions that would raise the
number of gpiod getters to 16 (!).

The drawback of this approach is that all gpiod clients need to be
updated. To limit the pain, temporary macros are introduced that allow
gpiod_get*() to be called with or without the extra flags argument. They
will be removed once all consumer code has been updated.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-28 12:28:05 +02:00
Thierry Reding 29a1f2333e gpio: Add helpers for optional GPIOs
Introduce gpiod_get_optional() and gpiod_get_index_optional() helpers
that make it easier for drivers to handle optional GPIOs.

Currently in order to handle optional GPIOs, a driver needs to special
case error handling for -ENOENT, such as this:

	gpio = gpiod_get(dev, "foo");
	if (IS_ERR(gpio)) {
		if (PTR_ERR(gpio) != -ENOENT)
			return PTR_ERR(gpio);

		gpio = NULL;
	}

	if (gpio) {
		/* set up GPIO */
	}

With these new helpers the above is reduced to:

	gpio = gpiod_get_optional(dev, "foo");
	if (IS_ERR(gpio))
		return PTR_ERR(gpio);

	if (gpio) {
		/* set up GPIO */
	}

While at it, device-managed variants of these functions are also
provided.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-05-09 13:48:30 +02:00
Alexandre Courbot 3c2c628f82 gpiolib: devres: add missing headers
Add missing headers for drivers/gpiolib/devres.c.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-29 18:26:14 -07:00
Alexandre Courbot 5fcdb9dc98 gpiolib: devres: fix devm_gpiod_get_index()
Fix the return value if devm_gpiod_get_index(). It was returning 0 while
it should return the obtained GPIO descriptor.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-23 10:09:22 +02:00
Alexandre Courbot bae48da237 gpiolib: add gpiod_get() and gpiod_put() functions
Add gpiod_get(), gpiod_get_index() and gpiod_put() functions that
provide safer management of GPIOs.

These functions put the GPIO framework in line with the conventions of
other frameworks in the kernel, and help ensure every GPIO is declared
properly and valid while it is used.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-19 23:24:56 +02:00
Wolfram Sang 713b7ef835 gpio: devres: make comments proper
The free-function mentioned "interrupt" instead of "GPIO". While we are
here, use "GPIO" (capital letters) consistently.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-06-17 07:53:00 +02:00
Stephen Warren 3996bfc787 gpio: export devm_gpio_request_one
Without this, modules can't use this API, leading to build failures.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-07-05 14:49:13 +02:00
Linus Torvalds b1bf7d4d1b GPIO driver changes for v3.5 merge window
Lots of gpio changes, both to core code and drivers.  Changes do touch
 architecture code to remove the need for separate arm/gpio.h includes
 in most architectures.  Some new drivers are added, and a number of
 gpio drivers are converted to use irq_domains for gpio inputs used as
 interrupts.  Device tree support has been amended to allow multiple
 gpio_chips to use the same device tree node.  Remaining changes are
 primarily bug fixes.
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Merge tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6

Pull GPIO driver changes from Grant Likely:
 "Lots of gpio changes, both to core code and drivers.

  Changes do touch architecture code to remove the need for separate
  arm/gpio.h includes in most architectures.

  Some new drivers are added, and a number of gpio drivers are converted
  to use irq_domains for gpio inputs used as interrupts.  Device tree
  support has been amended to allow multiple gpio_chips to use the same
  device tree node.

  Remaining changes are primarily bug fixes."

* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6: (33 commits)
  gpio/generic: initialize basic_mmio_gpio shadow variables properly
  gpiolib: Remove 'const' from data argument of gpiochip_find()
  gpio/rc5t583: add gpio driver for RICOH PMIC RC5T583
  gpiolib: quiet gpiochip_add boot message noise
  gpio: mpc8xxx: Prevent NULL pointer deref in demux handler
  gpio/lpc32xx: Add device tree support
  gpio: Adjust of_xlate API to support multiple GPIO chips
  gpiolib: Implement devm_gpio_request_one()
  gpio-mcp23s08: dbg_show: fix pullup configuration display
  Add support for TCA6424A
  gpio/omap: (re)fix wakeups on level-triggered GPIOs
  gpio/omap: fix broken context restore for non-OFF mode transitions
  gpio/omap: fix missing check in *_runtime_suspend()
  gpio/omap: remove cpu_is_omapxxxx() checks from *_runtime_resume()
  gpio/omap: remove suspend/resume callbacks
  gpio/omap: remove retrigger variable in gpio_irq_handler
  gpio/omap: remove saved_wakeup field from struct gpio_bank
  gpio/omap: remove suspend_wakeup field from struct gpio_bank
  gpio/omap: remove saved_fallingdetect, saved_risingdetect
  gpio/omap: remove virtual_irq_start variable
  ...

Conflicts:
	drivers/gpio/gpio-samsung.c
2012-05-24 14:01:46 -07:00
Mark Brown 09d71ff194 gpiolib: Implement devm_gpio_request_one()
Allow drivers to use the modern request and configure idiom together
with devres.

As with plain gpio_request() and gpio_request_one() we can't implement
the old school version in terms of _one() as this would force the
explicit selection of a direction in gpio_request() which could break
systems if we pick the wrong one.  Implementing devm_gpio_request_one()
in terms of devm_gpio_request() would needlessly complicate things or
lead to duplication from the unmanaged version depending on how it's
done.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-18 16:48:35 -06:00
Mark Brown a85990b3b1 gpiolib: Convert to devres_release()
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-04 16:33:17 -07:00
John Crispin 1a0703ede4 GPIO: add bindings for managed devices
This patch adds 2 functions that allow managed devices to request GPIOs.
These GPIOs will then be managed by drivers/base/devres.c.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-01-04 11:37:42 -07:00