diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/acpi/enumeration.txt | 36 | ||||
| -rw-r--r-- | Documentation/arm/Samsung-S3C24XX/GPIO.txt | 13 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt | 28 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/moxa,moxart-gpio.txt | 19 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt | 3 | ||||
| -rw-r--r-- | Documentation/gpio/board.txt | 28 | ||||
| -rw-r--r-- | Documentation/gpio/consumer.txt | 6 |
7 files changed, 78 insertions, 55 deletions
diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt index b994bcb32b9..2a1519b8717 100644 --- a/Documentation/acpi/enumeration.txt +++ b/Documentation/acpi/enumeration.txt @@ -293,36 +293,13 @@ the device to the driver. For example: These GPIO numbers are controller relative and path "\\_SB.PCI0.GPI0" specifies the path to the controller. In order to use these GPIOs in Linux -we need to translate them to the Linux GPIO numbers. +we need to translate them to the corresponding Linux GPIO descriptors. -In a simple case of just getting the Linux GPIO number from device -resources one can use acpi_get_gpio_by_index() helper function. It takes -pointer to the device and index of the GpioIo/GpioInt descriptor in the -device resources list. For example: +There is a standard GPIO API for that and is documented in +Documentation/gpio.txt. - int gpio_irq, gpio_power; - int ret; - - gpio_irq = acpi_get_gpio_by_index(dev, 1, NULL); - if (gpio_irq < 0) - /* handle error */ - - gpio_power = acpi_get_gpio_by_index(dev, 0, NULL); - if (gpio_power < 0) - /* handle error */ - - /* Now we can use the GPIO numbers */ - -Other GpioIo parameters must be converted first by the driver to be -suitable to the gpiolib before passing them. - -In case of GpioInt resource an additional call to gpio_to_irq() must be -done before calling request_irq(). - -Note that the above API is ACPI specific and not recommended for drivers -that need to support non-ACPI systems. The recommended way is to use -the descriptor based GPIO interfaces. The above example looks like this -when converted to the GPIO desc: +In the above example we can get the corresponding two GPIO descriptors with +a code like this: #include <linux/gpio/consumer.h> ... @@ -339,4 +316,5 @@ when converted to the GPIO desc: /* Now we can use the GPIO descriptors */ -See also Documentation/gpio.txt. +There are also devm_* versions of these functions which release the +descriptors once the device is released. diff --git a/Documentation/arm/Samsung-S3C24XX/GPIO.txt b/Documentation/arm/Samsung-S3C24XX/GPIO.txt index 8b46c79679c..0ebd7e2244d 100644 --- a/Documentation/arm/Samsung-S3C24XX/GPIO.txt +++ b/Documentation/arm/Samsung-S3C24XX/GPIO.txt @@ -85,21 +85,10 @@ between the calls. Headers ------- - See arch/arm/mach-s3c2410/include/mach/regs-gpio.h for the list + See arch/arm/mach-s3c24xx/include/mach/regs-gpio.h for the list of GPIO pins, and the configuration values for them. This is included by using #include <mach/regs-gpio.h> - The GPIO management functions are defined in the hardware - header arch/arm/mach-s3c2410/include/mach/hardware.h which can be - included by #include <mach/hardware.h> - - A useful amount of documentation can be found in the hardware - header on how the GPIO functions (and others) work. - - Whilst a number of these functions do make some checks on what - is passed to them, for speed of use, they may not always ensure - that the user supplied data to them is correct. - PIN Numbers ----------- diff --git a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt index daa30174bcc..3ddc7ccfe5f 100644 --- a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt +++ b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt @@ -38,12 +38,38 @@ Required device specific properties (only for SPI chips): removed. - spi-max-frequency = The maximum frequency this chip is able to handle -Example I2C: +Optional properties: +- #interrupt-cells : Should be two. + - first cell is the pin number + - second cell is used to specify flags. +- interrupt-controller: Marks the device node as a interrupt controller. +NOTE: The interrupt functionality is only supported for i2c versions of the +chips. The spi chips can also do the interrupts, but this is not supported by +the linux driver yet. + +Optional device specific properties: +- microchip,irq-mirror: Sets the mirror flag in the IOCON register. Devices + with two interrupt outputs (these are the devices ending with 17 and + those that have 16 IOs) have two IO banks: IO 0-7 form bank 1 and + IO 8-15 are bank 2. These chips have two different interrupt outputs: + One for bank 1 and another for bank 2. If irq-mirror is set, both + interrupts are generated regardless of the bank that an input change + occured on. If it is not set, the interrupt are only generated for the + bank they belong to. + On devices with only one interrupt output this property is useless. + +Example I2C (with interrupt): gpiom1: gpio@20 { compatible = "microchip,mcp23017"; gpio-controller; #gpio-cells = <2>; reg = <0x20>; + + interrupt-parent = <&gpio1>; + interrupts = <17 IRQ_TYPE_LEVEL_LOW>; + interrupt-controller; + #interrupt-cells=<2>; + microchip,irq-mirror; }; Example SPI: diff --git a/Documentation/devicetree/bindings/gpio/moxa,moxart-gpio.txt b/Documentation/devicetree/bindings/gpio/moxa,moxart-gpio.txt new file mode 100644 index 00000000000..f8e8f185a3d --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/moxa,moxart-gpio.txt @@ -0,0 +1,19 @@ +MOXA ART GPIO Controller + +Required properties: + +- #gpio-cells : Should be 2, The first cell is the pin number, + the second cell is used to specify polarity: + 0 = active high + 1 = active low +- compatible : Must be "moxa,moxart-gpio" +- reg : Should contain registers location and length + +Example: + + gpio: gpio@98700000 { + gpio-controller; + #gpio-cells = <2>; + compatible = "moxa,moxart-gpio"; + reg = <0x98700000 0xC>; + }; diff --git a/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt b/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt index 8655df9440d..f61cef74a21 100644 --- a/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt +++ b/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt @@ -2,10 +2,11 @@ Required Properties: - - compatible: should be one of the following. + - compatible: should contain one of the following. - "renesas,gpio-r8a7778": for R8A7778 (R-Mobile M1) compatible GPIO controller. - "renesas,gpio-r8a7779": for R8A7779 (R-Car H1) compatible GPIO controller. - "renesas,gpio-r8a7790": for R8A7790 (R-Car H2) compatible GPIO controller. + - "renesas,gpio-r8a7791": for R8A7791 (R-Car M2) compatible GPIO controller. - "renesas,gpio-rcar": for generic R-Car GPIO controller. - reg: Base address and length of each memory resource used by the GPIO diff --git a/Documentation/gpio/board.txt b/Documentation/gpio/board.txt index 0d03506f2cc..ba169faad5c 100644 --- a/Documentation/gpio/board.txt +++ b/Documentation/gpio/board.txt @@ -72,10 +72,11 @@ where - chip_label is the label of the gpiod_chip instance providing the GPIO - chip_hwnum is the hardware number of the GPIO within the chip - - dev_id is the identifier of the device that will make use of this GPIO. If - NULL, the GPIO will be available to all devices. + - dev_id is the identifier of the device that will make use of this GPIO. It + can be NULL, in which case it will be matched for calls to gpiod_get() + with a NULL device. - con_id is the name of the GPIO function from the device point of view. It - can be NULL. + can be NULL, in which case it will match any function. - idx is the index of the GPIO within the function. - flags is defined to specify the following properties: * GPIOF_ACTIVE_LOW - to configure the GPIO as active-low @@ -86,18 +87,23 @@ In the future, these flags might be extended to support more properties. Note that GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0. -A lookup table can then be defined as follows: +A lookup table can then be defined as follows, with an empty entry defining its +end: - struct gpiod_lookup gpios_table[] = { - GPIO_LOOKUP_IDX("gpio.0", 15, "foo.0", "led", 0, GPIO_ACTIVE_HIGH), - GPIO_LOOKUP_IDX("gpio.0", 16, "foo.0", "led", 1, GPIO_ACTIVE_HIGH), - GPIO_LOOKUP_IDX("gpio.0", 17, "foo.0", "led", 2, GPIO_ACTIVE_HIGH), - GPIO_LOOKUP("gpio.0", 1, "foo.0", "power", GPIO_ACTIVE_LOW), - }; +struct gpiod_lookup_table gpios_table = { + .dev_id = "foo.0", + .table = { + GPIO_LOOKUP_IDX("gpio.0", 15, "led", 0, GPIO_ACTIVE_HIGH), + GPIO_LOOKUP_IDX("gpio.0", 16, "led", 1, GPIO_ACTIVE_HIGH), + GPIO_LOOKUP_IDX("gpio.0", 17, "led", 2, GPIO_ACTIVE_HIGH), + GPIO_LOOKUP("gpio.0", 1, "power", GPIO_ACTIVE_LOW), + { }, + }, +}; And the table can be added by the board code as follows: - gpiod_add_table(gpios_table, ARRAY_SIZE(gpios_table)); + gpiod_add_lookup_table(&gpios_table); The driver controlling "foo.0" will then be able to obtain its GPIOs as follows: diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt index 07c74a3765a..e42f77d8d4c 100644 --- a/Documentation/gpio/consumer.txt +++ b/Documentation/gpio/consumer.txt @@ -38,7 +38,11 @@ device that displays digits), an additional index argument can be specified: const char *con_id, unsigned int idx) Both functions return either a valid GPIO descriptor, or an error code checkable -with IS_ERR(). They will never return a NULL pointer. +with IS_ERR() (they will never return a NULL pointer). -ENOENT will be returned +if and only if no GPIO has been assigned to the device/function/index triplet, +other error codes are used for cases where a GPIO has been assigned but an error +occured while trying to acquire it. This is useful to discriminate between mere +errors and an absence of GPIO for optional GPIO parameters. Device-managed variants of these functions are also defined: |