path: root/Documentation
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authorLinus Torvalds <torvalds@linux-foundation.org>2013-05-06 15:40:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-06 15:40:55 -0700
commit30c67e93c526639aaac90fa873800104b7c16d16 (patch)
tree6d8d0fd248d4e60bdc175dacbd196fc44f23ce11 /Documentation
parentf87bb9ee62700fa11713c630ac5671f253233b94 (diff)
parent08ffb2229fafc2c3a696b325a74bf4198d6b91d7 (diff)
Merge tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux
Pull GPIO changes from Grant Likely: "The usual selection of bug fixes and driver updates for GPIO. Nothing really stands out except the addition of the GRGPIO driver and some enhacements to ACPI support" I'm pulling this despite the earlier mess. Let's hope it compiles these days. * tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux: (46 commits) gpio: grgpio: Add irq support gpio: grgpio: Add device driver for GRGPIO cores gpiolib-acpi: introduce acpi_get_gpio_by_index() helper GPIO: gpio-generic: remove kfree() from bgpio_remove call gpio / ACPI: Handle ACPI events in accordance with the spec gpio: lpc32xx: Fix off-by-one valid range checking for bank gpio: mcp23s08: convert driver to DT gpio/omap: force restore if context loss is not detectable gpio/omap: optimise interrupt service routine gpio/omap: remove extra context restores in *_runtime_resume() gpio/omap: free irq domain in probe() failure paths gpio: gpio-generic: Add 16 and 32 bit big endian byte order support gpio: samsung: Add terminating entry for exynos_pinctrl_ids gpio: mvebu: add dbg_show function MAX7301 GPIO: Do not force SPI speed when using OF Platform gpio: gpio-tps65910.c: fix checkpatch error gpio: gpio-timberdale.c: fix checkpatch error gpio: gpio-tc3589x.c: fix checkpatch errors gpio: gpio-stp-xway.c: fix checkpatch error gpio: gpio-sch.c: fix checkpatch error ...
Diffstat (limited to 'Documentation')
4 files changed, 109 insertions, 3 deletions
diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt
index 94a65613188..b0d541042ac 100644
--- a/Documentation/acpi/enumeration.txt
+++ b/Documentation/acpi/enumeration.txt
@@ -199,6 +199,8 @@ the device to the driver. For example:
Name (SBUF, ResourceTemplate()
+ ...
+ // Used to power on/off the device
GpioIo (Exclusive, PullDefault, 0x0000, 0x0000,
IoRestrictionOutputOnly, "\\_SB.PCI0.GPI0",
0x00, ResourceConsumer,,)
@@ -206,10 +208,20 @@ the device to the driver. For example:
// Pin List
+ // Interrupt for the device
+ GpioInt (Edge, ActiveHigh, ExclusiveAndWake, PullNone,
+ 0x0000, "\\_SB.PCI0.GPI0", 0x00, ResourceConsumer,,)
+ {
+ // Pin list
+ 0x0058
+ }
- Return (SBUF)
+ Return (SBUF)
These GPIO numbers are controller relative and path "\\_SB.PCI0.GPI0"
@@ -220,6 +232,24 @@ The driver can do this by including <linux/acpi_gpio.h> and then calling
acpi_get_gpio(path, gpio). This will return the Linux GPIO number or
negative errno if there was no translation found.
+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:
+ 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.
diff --git a/Documentation/devicetree/bindings/gpio/gpio-grgpio.txt b/Documentation/devicetree/bindings/gpio/gpio-grgpio.txt
new file mode 100644
index 00000000000..e466598105f
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-grgpio.txt
@@ -0,0 +1,26 @@
+Aeroflex Gaisler GRGPIO General Purpose I/O cores.
+The GRGPIO GPIO core is available in the GRLIB VHDL IP core library.
+Note: In the ordinary environment for the GRGPIO core, a Leon SPARC system,
+these properties are built from information in the AMBA plug&play.
+Required properties:
+- name : Should be "GAISLER_GPIO" or "01_01a"
+- reg : Address and length of the register set for the device
+- interrupts : Interrupt numbers for this device
+Optional properties:
+- nbits : The number of gpio lines. If not present driver assumes 32 lines.
+- irqmap : An array with an index for each gpio line. An index is either a valid
+ index into the interrupts property array, or 0xffffffff that indicates
+ no irq for that line. Driver provides no interrupt support if not
+ present.
+For further information look in the documentation for the GLIB IP core library:
diff --git a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
new file mode 100644
index 00000000000..629d0ef1730
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt
@@ -0,0 +1,47 @@
+Microchip MCP2308/MCP23S08/MCP23017/MCP23S17 driver for
+8-/16-bit I/O expander with serial interface (I2C/SPI)
+Required properties:
+- compatible : Should be
+ - "mcp,mcp23s08" for 8 GPIO SPI version
+ - "mcp,mcp23s17" for 16 GPIO SPI version
+ - "mcp,mcp23008" for 8 GPIO I2C version or
+ - "mcp,mcp23017" for 16 GPIO I2C version of the chip
+- #gpio-cells : Should be two.
+ - first cell is the pin number
+ - second cell is used to specify flags. Flags are currently unused.
+- gpio-controller : Marks the device node as a GPIO controller.
+- reg : For an address on its bus. I2C uses this a the I2C address of the chip.
+ SPI uses this to specify the chipselect line which the chip is
+ connected to. The driver and the SPI variant of the chip support
+ multiple chips on the same chipselect. Have a look at
+ mcp,spi-present-mask below.
+Required device specific properties (only for SPI chips):
+- mcp,spi-present-mask : This is a present flag, that makes only sense for SPI
+ chips - as the name suggests. Multiple SPI chips can share the same
+ SPI chipselect. Set a bit in bit0-7 in this mask to 1 if there is a
+ chip connected with the corresponding spi address set. For example if
+ you have a chip with address 3 connected, you have to set bit3 to 1,
+ which is 0x08. mcp23s08 chip variant only supports bits 0-3. It is not
+ possible to mix mcp23s08 and mcp23s17 on the same chipselect. Set at
+ least one bit to 1 for SPI chips.
+- spi-max-frequency = The maximum frequency this chip is able to handle
+Example I2C:
+gpiom1: gpio@20 {
+ compatible = "mcp,mcp23017";
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <0x20>;
+Example SPI:
+gpiom1: gpio@0 {
+ compatible = "mcp,mcp23s17";
+ gpio-controller;
+ #gpio-cells = <2>;
+ spi-present-mask = <0x01>;
+ reg = <0>;
+ spi-max-frequency = <1000000>;
diff --git a/Documentation/devicetree/bindings/gpio/gpio-omap.txt b/Documentation/devicetree/bindings/gpio/gpio-omap.txt
index bff51a2fee1..1b524c0c79f 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-omap.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-omap.txt
@@ -20,8 +20,11 @@ Required properties:
8 = active low level-sensitive.
OMAP specific properties:
-- ti,hwmods: Name of the hwmod associated to the GPIO:
- "gpio<X>", <X> being the 1-based instance number from the HW spec
+- ti,hwmods: Name of the hwmod associated to the GPIO:
+ "gpio<X>", <X> being the 1-based instance number
+ from the HW spec.
+- ti,gpio-always-on: Indicates if a GPIO bank is always powered and
+ so will never lose its logic state.