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-rw-r--r--Documentation/devicetree/bindings/gpio/cirrus,clps711x-mctrl-gpio.txt17
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio-davinci.txt25
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio-zevio.txt16
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio.txt60
-rw-r--r--Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt60
-rw-r--r--Documentation/gpio/consumer.txt1
-rw-r--r--Documentation/gpio/driver.txt35
7 files changed, 204 insertions, 10 deletions
diff --git a/Documentation/devicetree/bindings/gpio/cirrus,clps711x-mctrl-gpio.txt b/Documentation/devicetree/bindings/gpio/cirrus,clps711x-mctrl-gpio.txt
new file mode 100644
index 000000000000..94ae9f82dcf8
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/cirrus,clps711x-mctrl-gpio.txt
@@ -0,0 +1,17 @@
+* ARM Cirrus Logic CLPS711X SYSFLG1 MCTRL GPIOs
+
+Required properties:
+- compatible: Should contain "cirrus,clps711x-mctrl-gpio".
+- 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.
+
+Example:
+ sysgpio: sysgpio {
+ compatible = "cirrus,ep7312-mctrl-gpio",
+ "cirrus,clps711x-mctrl-gpio";
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
diff --git a/Documentation/devicetree/bindings/gpio/gpio-davinci.txt b/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
index a2e839d6e338..5079ba7d6568 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-davinci.txt
@@ -1,13 +1,17 @@
-Davinci GPIO controller bindings
+Davinci/Keystone GPIO controller bindings
Required Properties:
-- compatible: should be "ti,dm6441-gpio"
+- compatible: should be "ti,dm6441-gpio", "ti,keystone-gpio"
- reg: Physical base address of the controller and the size of memory mapped
registers.
- gpio-controller : Marks the device node as a gpio controller.
+- #gpio-cells : Should be two.
+ - first cell is the pin number
+ - second cell is used to specify optional parameters (unused)
+
- interrupt-parent: phandle of the parent interrupt controller.
- interrupts: Array of GPIO interrupt number. Only banked or unbanked IRQs are
@@ -27,6 +31,7 @@ Example:
gpio: gpio@1e26000 {
compatible = "ti,dm6441-gpio";
gpio-controller;
+ #gpio-cells = <2>;
reg = <0x226000 0x1000>;
interrupt-parent = <&intc>;
interrupts = <42 IRQ_TYPE_EDGE_BOTH 43 IRQ_TYPE_EDGE_BOTH
@@ -39,3 +44,19 @@ gpio: gpio@1e26000 {
interrupt-controller;
#interrupt-cells = <2>;
};
+
+leds {
+ compatible = "gpio-leds";
+
+ led1 {
+ label = "davinci:green:usr1";
+ gpios = <&gpio 10 GPIO_ACTIVE_HIGH>;
+ ...
+ };
+
+ led2 {
+ label = "davinci:red:debug1";
+ gpios = <&gpio 11 GPIO_ACTIVE_HIGH>;
+ ...
+ };
+};
diff --git a/Documentation/devicetree/bindings/gpio/gpio-zevio.txt b/Documentation/devicetree/bindings/gpio/gpio-zevio.txt
new file mode 100644
index 000000000000..a37bd9ae2730
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-zevio.txt
@@ -0,0 +1,16 @@
+Zevio GPIO controller
+
+Required properties:
+- compatible: Should be "lsi,zevio-gpio"
+- reg: Address and length of the register set for the device
+- #gpio-cells: Should be two. The first cell is the pin number and the
+ second cell is used to specify optional parameters (currently unused).
+- gpio-controller: Marks the device node as a GPIO controller.
+
+Example:
+ gpio: gpio@90000000 {
+ compatible = "lsi,zevio-gpio";
+ reg = <0x90000000 0x1000>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index 0c85bb6e3a80..3fb8f53071b8 100644
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -13,11 +13,11 @@ properties, each containing a 'gpio-list':
gpio-specifier : Array of #gpio-cells specifying specific gpio
(controller specific)
-GPIO properties should be named "[<name>-]gpios". Exact
+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.
-For example, the following could be used to describe gpios pins to use
+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:
@@ -44,35 +44,79 @@ 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.
-Example of the node using GPIOs:
+Example of a node using GPIOs:
node {
gpios = <&qe_pio_e 18 0>;
};
In this example gpio-specifier is "18 0" and encodes GPIO pin number,
-and empty GPIO flags as accepted by the "qe_pio_e" gpio-controller.
+and GPIO flags as accepted by the "qe_pio_e" gpio-controller.
+
+1.1) GPIO specifier best practices
+----------------------------------
+
+A gpio-specifier should contain a flag indicating the GPIO polarity; active-
+high or active-low. If it does, the follow best practices should be followed:
+
+The gpio-specifier's polarity flag should represent the physical level at the
+GPIO controller that achieves (or represents, for inputs) a logically asserted
+value at the device. The exact definition of logically asserted should be
+defined by the binding for the device. If the board inverts the signal between
+the GPIO controller and the device, then the gpio-specifier will represent the
+opposite physical level than the signal at the device's pin.
+
+When the device's signal polarity is configurable, the binding for the
+device must either:
+
+a) Define a single static polarity for the signal, with the expectation that
+any software using that binding would statically program the device to use
+that signal polarity.
+
+The static choice of polarity may be either:
+
+a1) (Preferred) Dictated by a binding-specific DT property.
+
+or:
+
+a2) Defined statically by the DT binding itself.
+
+In particular, the polarity cannot be derived from the gpio-specifier, since
+that would prevent the DT from separately representing the two orthogonal
+concepts of configurable signal polarity in the device, and possible board-
+level signal inversion.
+
+or:
+
+b) Pick a single option for device signal polarity, and document this choice
+in the binding. The gpio-specifier should represent the polarity of the signal
+(at the GPIO controller) assuming that the device is configured for this
+particular signal polarity choice. If software chooses to program the device
+to generate or receive a signal of the opposite polarity, software will be
+responsible for correctly interpreting (inverting) the GPIO signal at the GPIO
+controller.
2) gpio-controller nodes
------------------------
-Every GPIO controller node must both an empty "gpio-controller"
-property, and have #gpio-cells contain the size of the gpio-specifier.
+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.
Example of two SOC GPIO banks defined as gpio-controller nodes:
qe_pio_a: gpio-controller@1400 {
- #gpio-cells = <2>;
compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
reg = <0x1400 0x18>;
gpio-controller;
+ #gpio-cells = <2>;
};
qe_pio_e: gpio-controller@1460 {
- #gpio-cells = <2>;
compatible = "fsl,qe-pario-bank-e", "fsl,qe-pario-bank";
reg = <0x1460 0x18>;
gpio-controller;
+ #gpio-cells = <2>;
};
2.1) gpio- and pin-controller interaction
diff --git a/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt b/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt
new file mode 100644
index 000000000000..dd5d2c0394b1
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt
@@ -0,0 +1,60 @@
+* Synopsys DesignWare APB GPIO controller
+
+Required properties:
+- compatible : Should contain "snps,dw-apb-gpio"
+- reg : Address and length of the register set for the device.
+- #address-cells : should be 1 (for addressing port subnodes).
+- #size-cells : should be 0 (port subnodes).
+
+The GPIO controller has a configurable number of ports, each of which are
+represented as child nodes with the following properties:
+
+Required properties:
+- compatible : "snps,dw-apb-gpio-port"
+- 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
+- reg : The integer port index of the port, a single cell.
+
+Optional properties:
+- interrupt-controller : The first port may be configured to be an interrupt
+controller.
+- #interrupt-cells : Specifies the number of cells needed to encode an
+ interrupt. Shall be set to 2. The first cell defines the interrupt number,
+ the second encodes the triger flags encoded as described in
+ Documentation/devicetree/bindings/interrupts.txt
+- interrupt-parent : The parent interrupt controller.
+- interrupts : The interrupt to the parent controller raised when GPIOs
+ generate the interrupts.
+- snps,nr-gpios : The number of pins in the port, a single cell.
+
+Example:
+
+gpio: gpio@20000 {
+ compatible = "snps,dw-apb-gpio";
+ reg = <0x20000 0x1000>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ porta: gpio-controller@0 {
+ compatible = "snps,dw-apb-gpio-port";
+ gpio-controller;
+ #gpio-cells = <2>;
+ snps,nr-gpios = <8>;
+ reg = <0>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ interrupt-parent = <&vic1>;
+ interrupts = <0>;
+ };
+
+ portb: gpio-controller@1 {
+ compatible = "snps,dw-apb-gpio-port";
+ gpio-controller;
+ #gpio-cells = <2>;
+ snps,nr-gpios = <8>;
+ reg = <1>;
+ };
+};
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt
index e42f77d8d4ca..09854fe59307 100644
--- a/Documentation/gpio/consumer.txt
+++ b/Documentation/gpio/consumer.txt
@@ -154,6 +154,7 @@ raw line value:
void gpiod_set_raw_value(struct gpio_desc *desc, int value)
int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
+ int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
The active-low state of a GPIO can also be queried using the following call:
diff --git a/Documentation/gpio/driver.txt b/Documentation/gpio/driver.txt
index 9da0bfa74781..f73cc7b5dc85 100644
--- a/Documentation/gpio/driver.txt
+++ b/Documentation/gpio/driver.txt
@@ -62,6 +62,37 @@ Any debugfs dump method should normally ignore signals which haven't been
requested as GPIOs. They can use gpiochip_is_requested(), which returns either
NULL or the label associated with that GPIO when it was requested.
+
+GPIO drivers providing IRQs
+---------------------------
+It is custom that GPIO drivers (GPIO chips) are also providing interrupts,
+most often cascaded off a parent interrupt controller, and in some special
+cases the GPIO logic is melded with a SoC's primary interrupt controller.
+
+The IRQ portions of the GPIO block are implemented using an irqchip, using
+the header <linux/irq.h>. So basically such a driver is utilizing two sub-
+systems simultaneously: gpio and irq.
+
+It is legal for any IRQ consumer to request an IRQ from any irqchip no matter
+if that is a combined GPIO+IRQ driver. The basic premise is that gpio_chip and
+irq_chip are orthogonal, and offering their services independent of each
+other.
+
+gpiod_to_irq() is just a convenience function to figure out the IRQ for a
+certain GPIO line and should not be relied upon to have been called before
+the IRQ is used.
+
+So always prepare the hardware and make it ready for action in respective
+callbacks from the GPIO and irqchip APIs. Do not rely on gpiod_to_irq() having
+been called first.
+
+This orthogonality leads to ambiguities that we need to solve: if there is
+competition inside the subsystem which side is using the resource (a certain
+GPIO line and register for example) it needs to deny certain operations and
+keep track of usage inside of the gpiolib subsystem. This is why the API
+below exists.
+
+
Locking IRQ usage
-----------------
Input GPIOs can be used as IRQ signals. When this happens, a driver is requested
@@ -73,3 +104,7 @@ This will prevent the use of non-irq related GPIO APIs until the GPIO IRQ lock
is released:
void gpiod_unlock_as_irq(struct gpio_desc *desc)
+
+When implementing an irqchip inside a GPIO driver, these two functions should
+typically be called in the .startup() and .shutdown() callbacks from the
+irqchip.