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authorMika Westerberg <mika.westerberg@linux.intel.com>2017-01-23 15:34:34 +0300
committerLinus Walleij <linus.walleij@linaro.org>2017-01-26 15:27:37 +0100
commit2956b5d94a76b596fa5057c2b3ca915cb27d7652 (patch)
tree3a1dbce1201ef4923a4124f63eb209026e8fba7e /Documentation/gpio
parentpinctrl: Allow configuration of pins from gpiolib based drivers (diff)
downloadlinux-dev-2956b5d94a76b596fa5057c2b3ca915cb27d7652.tar.xz
linux-dev-2956b5d94a76b596fa5057c2b3ca915cb27d7652.zip
pinctrl / gpio: Introduce .set_config() callback for GPIO chips
Currently we already have two pin configuration related callbacks available for GPIO chips .set_single_ended() and .set_debounce(). In future we expect to have even more, which does not scale well if we need to add yet another callback to the GPIO chip structure for each possible configuration parameter. Better solution is to reuse what we already have available in the generic pinconf. To support this, we introduce a new .set_config() callback for GPIO chips. The callback takes a single packed pin configuration value as parameter. This can then be extended easily beyond what is currently supported by just adding new types to the generic pinconf enum. If the GPIO driver is backed up by a pinctrl driver the GPIO driver can just assign gpiochip_generic_config() (introduced in this patch) to .set_config and that will take care configuration requests are directed to the pinctrl driver. We then convert the existing drivers over .set_config() and finally remove the .set_single_ended() and .set_debounce() callbacks. Suggested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/gpio')
-rw-r--r--Documentation/gpio/driver.txt9
1 files changed, 5 insertions, 4 deletions
diff --git a/Documentation/gpio/driver.txt b/Documentation/gpio/driver.txt
index 747c721776ed..ad8f0c0cd13f 100644
--- a/Documentation/gpio/driver.txt
+++ b/Documentation/gpio/driver.txt
@@ -146,10 +146,11 @@ a pull-up resistor is needed on the outgoing rail to complete the circuit, and
in the second case, a pull-down resistor is needed on the rail.
Hardware that supports open drain or open source or both, can implement a
-special callback in the gpio_chip: .set_single_ended() that takes an enum flag
-telling whether to configure the line as open drain, open source or push-pull.
-This will happen in response to the GPIO_OPEN_DRAIN or GPIO_OPEN_SOURCE flag
-set in the machine file, or coming from other hardware descriptions.
+special callback in the gpio_chip: .set_config() that takes a generic
+pinconf packed value telling whether to configure the line as open drain,
+open source or push-pull. This will happen in response to the
+GPIO_OPEN_DRAIN or GPIO_OPEN_SOURCE flag set in the machine file, or coming
+from other hardware descriptions.
If this state can not be configured in hardware, i.e. if the GPIO hardware does
not support open drain/open source in hardware, the GPIO library will instead