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authorJanusz Krzysztofik <jmkrzyszt@gmail.com>2018-09-05 23:50:07 +0200
committerLinus Walleij <linus.walleij@linaro.org>2018-09-13 11:16:54 +0200
commit77588c14ac868caece82fddbfae7de03b2cec941 (patch)
treea3a12bd5ee612c4ca5143f744cc6de1449221a03 /Documentation/driver-api/gpio
parentgpiolib: Identify arrays matching GPIO hardware (diff)
downloadlinux-dev-77588c14ac868caece82fddbfae7de03b2cec941.tar.xz
linux-dev-77588c14ac868caece82fddbfae7de03b2cec941.zip
gpiolib: Pass array info to get/set array functions
In order to make use of array info obtained from gpiod_get_array() and speed up processing of arrays matching single GPIO chip layout, that information must be passed to get/set array functions. Extend the functions' API with that additional parameter and update all users. Pass NULL if a user builds an array itself from single GPIOs. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com> Cc: Lukas Wunner <lukas@wunner.de> Cc: Peter Korsgaard <peter.korsgaard@barco.com> Cc: Peter Rosin <peda@axentia.se> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Rojhalat Ibrahim <imr@rtschenk.de> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Kishon Vijay Abraham I <kishon@ti.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Michael Hennerich <Michael.Hennerich@analog.com> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Yegor Yefremov <yegorslists@googlemail.com> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'Documentation/driver-api/gpio')
-rw-r--r--Documentation/driver-api/gpio/consumer.rst14
1 files changed, 12 insertions, 2 deletions
diff --git a/Documentation/driver-api/gpio/consumer.rst b/Documentation/driver-api/gpio/consumer.rst
index 7e0298b9a7b9..0afd95a12b10 100644
--- a/Documentation/driver-api/gpio/consumer.rst
+++ b/Documentation/driver-api/gpio/consumer.rst
@@ -325,28 +325,36 @@ The following functions get or set the values of an array of GPIOs::
int gpiod_get_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
unsigned long *value_bitmap);
int gpiod_get_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
unsigned long *value_bitmap);
int gpiod_get_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
unsigned long *value_bitmap);
int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
unsigned long *value_bitmap);
void gpiod_set_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
unsigned long *value_bitmap)
void gpiod_set_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
unsigned long *value_bitmap)
void gpiod_set_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
unsigned long *value_bitmap)
void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
+ struct gpio_array *array_info,
unsigned long *value_bitmap)
The array can be an arbitrary set of GPIOs. The functions will try to access
@@ -358,6 +366,7 @@ accessed sequentially.
The functions take three arguments:
* array_size - the number of array elements
* desc_array - an array of GPIO descriptors
+ * array_info - optional information obtained from gpiod_array_get()
* value_bitmap - a bitmap to store the GPIOs' values (get) or
a bitmap of values to assign to the GPIOs (set)
@@ -368,12 +377,13 @@ the struct gpio_descs returned by gpiod_get_array()::
struct gpio_descs *my_gpio_descs = gpiod_get_array(...);
gpiod_set_array_value(my_gpio_descs->ndescs, my_gpio_descs->desc,
- my_gpio_value_bitmap);
+ my_gpio_descs->info, my_gpio_value_bitmap);
It is also possible to access a completely arbitrary array of descriptors. The
descriptors may be obtained using any combination of gpiod_get() and
gpiod_get_array(). Afterwards the array of descriptors has to be setup
-manually before it can be passed to one of the above functions.
+manually before it can be passed to one of the above functions. In that case,
+array_info should be set to NULL.
Note that for optimal performance GPIOs belonging to the same chip should be
contiguous within the array of descriptors.