diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio-altera.txt | 43 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio.txt | 30 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/mrvl-gpio.txt | 2 | ||||
| -rw-r--r-- | Documentation/gpio/consumer.txt | 65 |
4 files changed, 135 insertions, 5 deletions
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 <dt-bindings/interrupt-controller/irq.h> + 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 = <IRQ_TYPE_EDGE_RISING>; + #gpio-cells = <2>; + gpio-controller; + #interrupt-cells = <1>; + interrupt-controller; +}; 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 { 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. diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index d85fbae451ea..c21c1313f09e 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, @@ -82,20 +102,37 @@ 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) -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 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 =========== @@ -222,6 +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. |