path: root/Documentation
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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-14 14:05:05 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-14 14:05:05 -0800
commit980f3c344ff1cb4a8be9a169c6bde2dc74ca6288 (patch)
treef7b22006dec2cebed697b0a2c6701ca16c58c7a2 /Documentation
parentMerge git://git.kvack.org/~bcrl/aio-next (diff)
parentgpio: mcp23s08: fix up compilation error (diff)
Merge tag 'gpio-v3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull take two of the GPIO updates: "Same stuff as last time, now with a fixup patch for the previous compile error plus I ran a few extra rounds of compile-testing. This is the bulk of GPIO changes for the v3.19 series: - A new API that allows setting more than one GPIO at the time. This is implemented for the new descriptor-based API only and makes it possible to e.g. toggle a clock and data line at the same time, if the hardware can do this with a single register write. Both consumers and drivers need new calls, and the core will fall back to driving individual lines where needed. Implemented for the MPC8xxx driver initially - Patched the mdio-mux-gpio and the serial mctrl driver that drives modems to use the new multiple-setting API to set several signals simultaneously - Get rid of the global GPIO descriptor array, and instead allocate descriptors dynamically for each GPIO on a certain GPIO chip. This moves us closer to getting rid of the limitation of using the global, static GPIO numberspace - New driver and device tree bindings for 74xx ICs - New driver and device tree bindings for the VF610 Vybrid - Support the RCAR r8a7793 and r8a7794 - Guidelines for GPIO device tree bindings trying to get things a bit more strict with the advent of combined device properties - Suspend/resume support for the MVEBU driver - A slew of minor fixes and improvements" * tag 'gpio-v3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (33 commits) gpio: mcp23s08: fix up compilation error gpio: pl061: document gpio-ranges property for bindings file gpio: pl061: hook request if gpio-ranges avaiable gpio: mcp23s08: Add option to configure IRQ output polarity as active high gpio: fix deferred probe detection for legacy API serial: mctrl_gpio: use gpiod_set_array function mdio-mux-gpio: Use GPIO descriptor interface and new gpiod_set_array function gpio: remove const modifier from gpiod_get_direction() gpio: remove gpio_descs global array gpio: mxs: implement get_direction callback gpio: em: Use dynamic allocation of GPIOs gpio: Check if base is positive before calling gpio_is_valid() gpio: mcp23s08: Add simple IRQ support for SPI devices gpio: mcp23s08: request a shared interrupt gpio: mcp23s08: Do not free unrequested interrupt gpio: rcar: Add r8a7793 and r8a7794 support gpio-mpc8xxx: add mpc8xxx_gpio_set_multiple function gpiolib: allow simultaneous setting of multiple GPIO outputs gpio: mvebu: add suspend/resume support gpio: gpio-davinci: remove duplicate check on resource ..
Diffstat (limited to 'Documentation')
8 files changed, 146 insertions, 18 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-74xx-mmio.txt b/Documentation/devicetree/bindings/gpio/gpio-74xx-mmio.txt
new file mode 100644
index 000000000000..7bb1a9d60133
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-74xx-mmio.txt
@@ -0,0 +1,30 @@
+* 74XX MMIO GPIO driver
+Required properties:
+- compatible: Should contain one of the following:
+ "ti,741g125": for 741G125 (1-bit Input),
+ "ti,741g174": for 741G74 (1-bit Output),
+ "ti,742g125": for 742G125 (2-bit Input),
+ "ti,7474" : for 7474 (2-bit Output),
+ "ti,74125" : for 74125 (4-bit Input),
+ "ti,74175" : for 74175 (4-bit Output),
+ "ti,74365" : for 74365 (6-bit Input),
+ "ti,74174" : for 74174 (6-bit Output),
+ "ti,74244" : for 74244 (8-bit Input),
+ "ti,74273" : for 74273 (8-bit Output),
+ "ti,741624" : for 741624 (16-bit Input),
+ "ti,7416374": for 7416374 (16-bit Output).
+- reg: Physical base address and length where IC resides.
+- gpio-controller: Marks the device node as a gpio controller.
+- #gpio-cells: Should be two. The first cell is the pin number and
+ the second cell is used to specify the GPIO polarity:
+ 0 = Active High,
+ 1 = Active Low.
+ ctrl: gpio@30008004 {
+ compatible = "ti,74174";
+ reg = <0x30008004 0x1>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
diff --git a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
index c306a2d0f2b1..f3332b9a8ed4 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
@@ -57,6 +57,8 @@ Optional device specific properties:
occurred 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.
+- microchip,irq-active-high: Sets the INTPOL flag in the IOCON register. This
+ configures the IRQ output polarity as active high.
Example I2C (with interrupt):
gpiom1: gpio@20 {
diff --git a/Documentation/devicetree/bindings/gpio/gpio-vf610.txt b/Documentation/devicetree/bindings/gpio/gpio-vf610.txt
new file mode 100644
index 000000000000..436cc99c6598
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-vf610.txt
@@ -0,0 +1,55 @@
+* Freescale VF610 PORT/GPIO module
+The Freescale PORT/GPIO modules are two adjacent modules providing GPIO
+functionality. Each pair serves 32 GPIOs. The VF610 has 5 instances of
+each, and each PORT module has its own interrupt.
+Required properties for GPIO node:
+- compatible : Should be "fsl,<soc>-gpio", currently "fsl,vf610-gpio"
+- reg : The first reg tuple represents the PORT module, the second tuple
+ the GPIO module.
+- interrupts : Should be the port interrupt shared by all 32 pins.
+- gpio-controller : Marks the device node as a gpio controller.
+- #gpio-cells : Should be two. The first cell is the pin number and
+ the second cell is used to specify the gpio polarity:
+ 0 = active high
+ 1 = active low
+- interrupt-controller: Marks the device node as an interrupt controller.
+- #interrupt-cells : Should be 2. The first cell is the GPIO number.
+ The second cell bits[3:0] is used to specify trigger type and level flags:
+ 1 = low-to-high edge triggered.
+ 2 = high-to-low edge triggered.
+ 4 = active high level-sensitive.
+ 8 = active low level-sensitive.
+Note: Each GPIO port should have an alias correctly numbered in "aliases"
+aliases {
+ gpio0 = &gpio1;
+ gpio1 = &gpio2;
+gpio1: gpio@40049000 {
+ compatible = "fsl,vf610-gpio";
+ reg = <0x40049000 0x1000 0x400ff000 0x40>;
+ interrupts = <0 107 IRQ_TYPE_LEVEL_HIGH>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ gpio-ranges = <&iomuxc 0 0 32>;
+gpio2: gpio@4004a000 {
+ compatible = "fsl,vf610-gpio";
+ reg = <0x4004a000 0x1000 0x400ff040 0x40>;
+ interrupts = <0 108 IRQ_TYPE_LEVEL_HIGH>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ gpio-ranges = <&iomuxc 0 32 32>;
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index 3fb8f53071b8..b9bd1d64cfa6 100644
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -13,13 +13,22 @@ properties, each containing a 'gpio-list':
gpio-specifier : Array of #gpio-cells specifying specific gpio
(controller specific)
-GPIO properties should be named "[<name>-]gpios". The exact
-meaning of each gpios property must be documented in the device tree
-binding for each device.
+GPIO properties should be named "[<name>-]gpios", with <name> being the purpose
+of this GPIO for the device. While a non-existent <name> is considered valid
+for compatibility reasons (resolving to the "gpios" property), it is not allowed
+for new bindings.
-For example, the following could be used to describe GPIO pins used
-as chip select lines; with chip selects 0, 1 and 3 populated, and chip
-select 2 left empty:
+GPIO properties can contain one or more GPIO phandles, but only in exceptional
+cases should they contain more than one. If your device uses several GPIOs with
+distinct functions, reference each of them under its own property, giving it a
+meaningful name. The only case where an array of GPIOs is accepted is when
+several GPIOs serve the same function (e.g. a parallel data line).
+The exact purpose of each gpios property must be documented in the device tree
+binding of the device.
+The following example could be used to describe GPIO pins used as device enable
+and bit-banged data signals:
gpio1: gpio1 {
@@ -30,10 +39,12 @@ select 2 left empty:
#gpio-cells = <1>;
- chipsel-gpios = <&gpio1 12 0>,
- <&gpio1 13 0>,
- <0>, /* holes are permitted, means no GPIO 2 */
- <&gpio2 2>;
+ enable-gpios = <&gpio2 2>;
+ data-gpios = <&gpio1 12 0>,
+ <&gpio1 13 0>,
+ <&gpio1 14 0>,
+ <&gpio1 15 0>;
Note that gpio-specifier length is controller dependent. In the
above example, &gpio1 uses 2 cells to specify a gpio, while &gpio2
@@ -42,16 +53,17 @@ only uses one.
gpio-specifier may encode: bank, pin position inside the bank,
whether pin is open-drain and whether pin is logically inverted.
Exact meaning of each specifier cell is controller specific, and must
-be documented in the device tree binding for the device.
+be documented in the device tree binding for the device. Use the macros
+defined in include/dt-bindings/gpio/gpio.h whenever possible:
Example of a node using GPIOs:
node {
- gpios = <&qe_pio_e 18 0>;
+ enable-gpios = <&qe_pio_e 18 GPIO_ACTIVE_HIGH>;
-In this example gpio-specifier is "18 0" and encodes GPIO pin number,
-and GPIO flags as accepted by the "qe_pio_e" gpio-controller.
+GPIO_ACTIVE_HIGH is 0, so in this example gpio-specifier is "18 0" and encodes
+GPIO pin number, and GPIO flags as accepted by the "qe_pio_e" gpio-controller.
1.1) GPIO specifier best practices
diff --git a/Documentation/devicetree/bindings/gpio/pl061-gpio.txt b/Documentation/devicetree/bindings/gpio/pl061-gpio.txt
index a2c416bcbccc..89058d375b7c 100644
--- a/Documentation/devicetree/bindings/gpio/pl061-gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/pl061-gpio.txt
@@ -7,4 +7,4 @@ Required properties:
- bit 0 specifies polarity (0 for normal, 1 for inverted)
- gpio-controller : Marks the device node as a GPIO controller.
- interrupts : Interrupt mapping for GPIO IRQ.
+- gpio-ranges : Interaction with the PINCTRL subsystem.
diff --git a/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt b/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt
index 941a26aa4322..38fb86f28ba2 100644
--- a/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt
+++ b/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt
@@ -6,7 +6,9 @@ Required Properties:
- "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-r8a7791": for R8A7791 (R-Car M2-W) compatible GPIO controller.
+ - "renesas,gpio-r8a7793": for R8A7793 (R-Car M2-N) compatible GPIO controller.
+ - "renesas,gpio-r8a7794": for R8A7794 (R-Car E2) 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/consumer.txt b/Documentation/gpio/consumer.txt
index 859918db36b8..d85fbae451ea 100644
--- a/Documentation/gpio/consumer.txt
+++ b/Documentation/gpio/consumer.txt
@@ -199,6 +199,33 @@ The active-low state of a GPIO can also be queried using the following call:
Note that these functions should only be used with great moderation ; a driver
should not have to care about the physical line level.
+Set multiple GPIO outputs with a single function call
+The following functions set the output values of an array of GPIOs:
+ void gpiod_set_array(unsigned int array_size,
+ struct gpio_desc **desc_array,
+ int *value_array)
+ void gpiod_set_raw_array(unsigned int array_size,
+ struct gpio_desc **desc_array,
+ int *value_array)
+ void gpiod_set_array_cansleep(unsigned int array_size,
+ struct gpio_desc **desc_array,
+ int *value_array)
+ void gpiod_set_raw_array_cansleep(unsigned int array_size,
+ struct gpio_desc **desc_array,
+ int *value_array)
+The array can be an arbitrary set of GPIOs. The functions will try to set
+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
+Note that for optimal performance GPIOs belonging to the same chip should be
+contiguous within the array of descriptors.
GPIOs mapped to IRQs
GPIO lines can quite often be used as IRQs. You can get the IRQ number
diff --git a/Documentation/gpio/driver.txt b/Documentation/gpio/driver.txt
index 31e0b5db55d8..90d0f6aba7a6 100644
--- a/Documentation/gpio/driver.txt
+++ b/Documentation/gpio/driver.txt
@@ -158,12 +158,12 @@ Locking IRQ usage
Input GPIOs can be used as IRQ signals. When this happens, a driver is requested
to mark the GPIO as being used as an IRQ:
- int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
+ int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
This will prevent the use of non-irq related GPIO APIs until the GPIO IRQ lock
is released:
- void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
+ void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
When implementing an irqchip inside a GPIO driver, these two functions should
typically be called in the .startup() and .shutdown() callbacks from the