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>
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>
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>
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>
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>
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>
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
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>
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>
Alexandre Courbot