From 6b516a1093006a39368dd11a5396be5bb00c99df Mon Sep 17 00:00:00 2001 From: Benoit Parrot Date: Mon, 2 Feb 2015 11:44:45 -0600 Subject: gpio: Document GPIO hogging mechanism Add GPIO hogging documentation to gpio.txt Signed-off-by: Benoit Parrot Reviewed-by: Alexandre Courbot Signed-off-by: Linus Walleij --- Documentation/devicetree/bindings/gpio/gpio.txt | 30 +++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt index f7a158d85862..5788d5cf1252 100644 --- a/Documentation/devicetree/bindings/gpio/gpio.txt +++ b/Documentation/devicetree/bindings/gpio/gpio.txt @@ -116,6 +116,29 @@ Every GPIO controller node must contain both an empty "gpio-controller" property, and a #gpio-cells integer property, which indicates the number of cells in a gpio-specifier. +The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism +providing automatic GPIO request and configuration as part of the +gpio-controller's driver probe function. + +Each GPIO hog definition is represented as a child node of the GPIO controller. +Required properties: +- gpio-hog: A property specifying that this child node represent a GPIO hog. +- gpios: Store the GPIO information (id, flags, ...). Shall contain the + number of cells specified in its parent node (GPIO controller + node). +Only one of the following properties scanned in the order shown below. +This means that when multiple properties are present they will be searched +in the order presented below and the first match is taken as the intended +configuration. +- input: A property specifying to set the GPIO direction as input. +- output-low A property specifying to set the GPIO direction as output with + the value low. +- output-high A property specifying to set the GPIO direction as output with + the value high. + +Optional properties: +- line-name: The GPIO label name. If not present the node name is used. + Example of two SOC GPIO banks defined as gpio-controller nodes: qe_pio_a: gpio-controller@1400 { @@ -123,6 +146,13 @@ Example of two SOC GPIO banks defined as gpio-controller nodes: reg = <0x1400 0x18>; gpio-controller; #gpio-cells = <2>; + + line_b { + gpio-hog; + gpios = <6 0>; + output-low; + line-name = "foo-bar-gpio"; + }; }; qe_pio_e: gpio-controller@1460 { -- cgit v1.2.3 From 668585273246f67b0cdafa30dd2da2047a2e1290 Mon Sep 17 00:00:00 2001 From: Rojhalat Ibrahim Date: Wed, 11 Feb 2015 17:27:58 +0100 Subject: gpiolib: add gpiod_get_array and gpiod_put_array functions Introduce new functions for conveniently obtaining and disposing of an entire array of GPIOs with one function call. ACPI parts tested by Mika Westerberg, DT parts tested by Rojhalat Ibrahim. Change log: v5: move the ACPI functions to gpiolib-acpi.c v4: - use shorter names for members of struct gpio_descs - rename lut_gpio_count to platform_gpio_count for clarity - add check for successful memory allocation - use ERR_CAST() v3: - rebase on current linux-gpio devel branch - fix ACPI GPIO counting - allow for zero-sized arrays - make the flags argument mandatory for the new functions - clarify documentation v2: change interface Suggested-by: Alexandre Courbot Signed-off-by: Rojhalat Ibrahim Reviewed-by: Alexandre Courbot Reviewed-by: Mika Westerberg Tested-by: Mika Westerberg Tested-by: Rojhalat Ibrahim Signed-off-by: Linus Walleij --- Documentation/gpio/consumer.txt | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index d85fbae451ea..2924f2ffcd91 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -58,7 +58,6 @@ pattern where a GPIO is optional, the gpiod_get_optional() and gpiod_get_index_optional() functions can be used. These functions return NULL instead of -ENOENT if no GPIO has been assigned to the requested function: - struct gpio_desc *gpiod_get_optional(struct device *dev, const char *con_id, enum gpiod_flags flags) @@ -68,6 +67,27 @@ instead of -ENOENT if no GPIO has been assigned to the requested function: unsigned int index, enum gpiod_flags flags) +For a function using multiple GPIOs all of those can be obtained with one call: + + struct gpio_descs *gpiod_get_array(struct device *dev, + const char *con_id, + enum gpiod_flags flags) + +This function returns a struct gpio_descs which contains an array of +descriptors: + + struct gpio_descs { + unsigned int ndescs; + struct gpio_desc *desc[]; + } + +The following function returns NULL instead of -ENOENT if no GPIOs have been +assigned to the requested function: + + struct gpio_descs *gpiod_get_array_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags) + Device-managed variants of these functions are also defined: struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id, @@ -91,8 +111,15 @@ A GPIO descriptor can be disposed of using the gpiod_put() function: void gpiod_put(struct gpio_desc *desc) -It is strictly forbidden to use a descriptor after calling this function. The -device-managed variant is, unsurprisingly: +For an array of GPIOs this function can be used: + + void gpiod_put_array(struct gpio_descs *descs) + +It is strictly forbidden to use a descriptor after calling these functions. +It is also not allowed to individually release descriptors (using gpiod_put()) +from an array acquired with gpiod_get_array(). + +The device-managed variant is, unsurprisingly: void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) -- cgit v1.2.3 From 331758eef83620eef3f21289f0f44aba094d0503 Mon Sep 17 00:00:00 2001 From: Rojhalat Ibrahim Date: Wed, 11 Feb 2015 17:28:02 +0100 Subject: gpiolib: add devm_gpiod_get_array and devm_gpiod_put_array functions Add device managed variants of gpiod_get_array() / gpiod_put_array() functions for conveniently obtaining and disposing of an entire array of GPIOs with one function call. Signed-off-by: Rojhalat Ibrahim Reviewed-by: Alexandre Courbot Signed-off-by: Linus Walleij --- Documentation/gpio/consumer.txt | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index 2924f2ffcd91..d29a9725c9e5 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -102,11 +102,19 @@ Device-managed variants of these functions are also defined: const char *con_id, enum gpiod_flags flags) - struct gpio_desc * devm_gpiod_get_index_optional(struct device *dev, + struct gpio_desc *devm_gpiod_get_index_optional(struct device *dev, const char *con_id, unsigned int index, enum gpiod_flags flags) + struct gpio_descs *devm_gpiod_get_array(struct device *dev, + const char *con_id, + enum gpiod_flags flags) + + struct gpio_descs *devm_gpiod_get_array_optional(struct device *dev, + const char *con_id, + enum gpiod_flags flags) + A GPIO descriptor can be disposed of using the gpiod_put() function: void gpiod_put(struct gpio_desc *desc) @@ -119,10 +127,12 @@ It is strictly forbidden to use a descriptor after calling these functions. It is also not allowed to individually release descriptors (using gpiod_put()) from an array acquired with gpiod_get_array(). -The device-managed variant is, unsurprisingly: +The device-managed variants are, unsurprisingly: void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) + void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs) + Using GPIOs =========== -- cgit v1.2.3 From 4fd9bbc6e0713a0106a7771b639a963f4b2411c6 Mon Sep 17 00:00:00 2001 From: Tien Hock Loh Date: Tue, 24 Feb 2015 01:53:02 -0800 Subject: drivers/gpio: Altera soft IP GPIO driver device tree binding Adds a new driver device tree binding for Altera soft GPIO IP Signed-off-by: Tien Hock Loh Signed-off-by: Linus Walleij --- .../devicetree/bindings/gpio/gpio-altera.txt | 43 ++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/gpio-altera.txt (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/gpio/gpio-altera.txt b/Documentation/devicetree/bindings/gpio/gpio-altera.txt new file mode 100644 index 000000000000..12f50149e1ed --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-altera.txt @@ -0,0 +1,43 @@ +Altera GPIO controller bindings + +Required properties: +- compatible: + - "altr,pio-1.0" +- reg: Physical base address and length of the controller's registers. +- #gpio-cells : Should be 2 + - The first cell is the gpio offset number. + - The second cell is reserved and is currently unused. +- gpio-controller : Marks the device node as a GPIO controller. +- interrupt-controller: Mark the device node as an interrupt controller +- #interrupt-cells : Should be 1. The interrupt type is fixed in the hardware. + - The first cell is the GPIO offset number within the GPIO controller. +- interrupts: Specify the interrupt. +- altr,interrupt-trigger: Specifies the interrupt trigger type the GPIO + hardware is synthesized. This field is required if the Altera GPIO controller + used has IRQ enabled as the interrupt type is not software controlled, + but hardware synthesized. Required if GPIO is used as an interrupt + controller. The value is defined in + Only the following flags are supported: + IRQ_TYPE_EDGE_RISING + IRQ_TYPE_EDGE_FALLING + IRQ_TYPE_EDGE_BOTH + IRQ_TYPE_LEVEL_HIGH + +Optional properties: +- altr,ngpio: Width of the GPIO bank. This defines how many pins the + GPIO device has. Ranges between 1-32. Optional and defaults to 32 if not + specified. + +Example: + +gpio_altr: gpio@0xff200000 { + compatible = "altr,pio-1.0"; + reg = <0xff200000 0x10>; + interrupts = <0 45 4>; + altr,ngpio = <32>; + altr,interrupt-trigger = ; + #gpio-cells = <2>; + gpio-controller; + #interrupt-cells = <1>; + interrupt-controller; +}; -- cgit v1.2.3 From 39521090e93671c01fbc50d47b6422c2b0aa63b1 Mon Sep 17 00:00:00 2001 From: Josh Wu Date: Wed, 4 Mar 2015 11:50:29 +0800 Subject: gpio: mrvl: documentation: trivial: fix typo fix typo in the document. Signed-off-by: Josh Wu Signed-off-by: Linus Walleij --- Documentation/devicetree/bindings/gpio/mrvl-gpio.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/gpio/mrvl-gpio.txt b/Documentation/devicetree/bindings/gpio/mrvl-gpio.txt index 67a2e4e414a5..98d198396956 100644 --- a/Documentation/devicetree/bindings/gpio/mrvl-gpio.txt +++ b/Documentation/devicetree/bindings/gpio/mrvl-gpio.txt @@ -12,7 +12,7 @@ Required properties: gpio_mux. - interrupt-names : Should be the names of irq resources. Each interrupt uses its own interrupt name, so there should be as many interrupt names - as referenced interrups. + as referenced interrupts. - interrupt-controller : Identifies the node as an interrupt controller. - #interrupt-cells: Specifies the number of cells needed to encode an interrupt source. -- cgit v1.2.3 From de3b696542d3e0fb897149680821dae480c314af Mon Sep 17 00:00:00 2001 From: Rojhalat Ibrahim Date: Thu, 5 Mar 2015 14:36:36 +0100 Subject: extend documentation for gpiod_set_array() functions Extend the documentation for the gpiod_set_array() functions and elaborate a bit on possible use cases. Signed-off-by: Rojhalat Ibrahim Signed-off-by: Linus Walleij --- Documentation/gpio/consumer.txt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'Documentation') diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index d29a9725c9e5..c21c1313f09e 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -259,6 +259,26 @@ GPIOs belonging to the same bank or chip simultaneously if supported by the corresponding chip driver. In that case a significantly improved performance can be expected. If simultaneous setting is not possible the GPIOs will be set sequentially. + +The gpiod_set_array() functions take three arguments: + * array_size - the number of array elements + * desc_array - an array of GPIO descriptors + * value_array - an array of values to assign to the GPIOs + +The descriptor array can be obtained using the gpiod_get_array() function +or one of its variants. If the group of descriptors returned by that function +matches the desired group of GPIOs, those GPIOs can be set by simply using +the struct gpio_descs returned by gpiod_get_array(): + + struct gpio_descs *my_gpio_descs = gpiod_get_array(...); + gpiod_set_array(my_gpio_descs->ndescs, my_gpio_descs->desc, + my_gpio_values); + +It is also possible to set 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 used with gpiod_set_array(). + Note that for optimal performance GPIOs belonging to the same chip should be contiguous within the array of descriptors. -- cgit v1.2.3