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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-23 08:45:05 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-23 08:45:05 +0100
commit114b5f8f7efc036dd7dd16efb0f218a88e6c6c02 (patch)
treeac02a222661b8b0bfb87f15773dc1d23220edfd9 /Documentation/devicetree
parentb0b6a28bc4b265aa56cbf4fa8fd27c0a4fa3a49c (diff)
parent40f5ff4f9f23a849ad135cb736d4d448d810ac17 (diff)
Merge tag 'gpio-v4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Linus Walleij: "This is the bulk of GPIO changes for the v4.20 series: Core changes: - A patch series from Hans Verkuil to make it possible to enable/disable IRQs on a GPIO line at runtime and drive GPIO lines as output without having to put/get them from scratch. The irqchip callbacks have been improved so that they can use only the fastpatch callbacks to enable/disable irqs like any normal irqchip, especially the gpiod_lock_as_irq() has been improved to be callable in fastpath context. A bunch of rework had to be done to achieve this but it is a big win since I never liked to restrict this to slowpath. The only call requireing slowpath was try_module_get() and this is kept at the .request_resources() slowpath callback. In the GPIO CEC driver this is a big win sine a single line is used for both outgoing and incoming traffic, and this needs to use IRQs for incoming traffic while actively driving the line for outgoing traffic. - Janusz Krzysztofik improved the GPIO array API to pass a "cookie" (struct gpio_array) and a bitmap for setting or getting multiple GPIO lines at once. This improvement orginated in a specific need to speed up an OMAP1 driver and has led to a much better API and real performance gains when the state of the array can be used to bypass a lot of checks and code when we want things to go really fast. The previous code would minimize the number of calls down to the driver callbacks assuming the CPU speed was orders of magnitude faster than the I/O latency, but this assumption was wrong on several platforms: what we needed to do was to profile and improve the speed on the hot path of the array functions and this change is now completed. - Clean out the painful and hard to grasp BNF experiments from the device tree bindings. Future approaches are looking into using JSON schema for this purpose. (Rob Herring is floating a patch series.) New drivers: - The RCAR driver now supports r8a774a1 (RZ/G2M). - Synopsys GPIO via CREGs driver. Major improvements: - Modernization of the EP93xx driver to use irqdomain and other contemporary concepts. - The ingenic driver has been merged into the Ingenic pin control driver and removed from the GPIO subsystem. - Debounce support in the ftgpio010 driver" * tag 'gpio-v4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (116 commits) gpio: Clarify kerneldoc on gpiochip_set_chained_irqchip() gpio: Remove unused 'irqchip' argument to gpiochip_set_cascaded_irqchip() gpio: Drop parent irq assignment during cascade setup mmc: pwrseq_simple: Fix incorrect handling of GPIO bitmap gpio: fix SNPS_CREG kconfig dependency warning gpiolib: Initialize gdev field before is used gpio: fix kernel-doc after devres.c file rename gpio: fix doc string for devm_gpiochip_add_data() to not talk about irq_chip gpio: syscon: Fix possible NULL ptr usage gpiolib: Show correct direction from the beginning pinctrl: msm: Use init_valid_mask exported function gpiolib: Add init_valid_mask exported function GPIO: add single-register GPIO via CREG driver dt-bindings: Document the Synopsys GPIO via CREG bindings gpio: mockup: use device properties instead of platform_data gpio: Slightly more helpful debugfs gpio: omap: Remove set but not used variable 'dev' gpio: omap: drop omap_gpio_list Accept partial 'gpio-line-names' property. gpio: omap: get rid of the conditional PM runtime calls ...
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio.txt142
-rw-r--r--Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt65
-rw-r--r--Documentation/devicetree/bindings/gpio/snps,creg-gpio.txt21
3 files changed, 134 insertions, 94 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index a7c31de29362..f0ba154b5723 100644
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -1,18 +1,9 @@
Specifying GPIO information for devices
-============================================
+=======================================
1) gpios property
-----------------
-Nodes that makes use of GPIOs should specify them using one or more
-properties, each containing a 'gpio-list':
-
- gpio-list ::= <single-gpio> [gpio-list]
- single-gpio ::= <gpio-phandle> <gpio-specifier>
- gpio-phandle : phandle to gpio controller node
- gpio-specifier : Array of #gpio-cells specifying specific gpio
- (controller specific)
-
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
@@ -33,33 +24,27 @@ The following example could be used to describe GPIO pins used as device enable
and bit-banged data signals:
gpio1: gpio1 {
- gpio-controller
- #gpio-cells = <2>;
- };
- gpio2: gpio2 {
- gpio-controller
- #gpio-cells = <1>;
+ gpio-controller;
+ #gpio-cells = <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
-only uses one.
+In the above example, &gpio1 uses 2 cells to specify a gpio. The first cell is
+a local offset to the GPIO line and the second cell represent consumer flags,
+such as if the consumer desire the line to be active low (inverted) or open
+drain. This is the recommended practice.
-gpio-specifier may encode: bank, pin position inside the bank,
-whether pin is open-drain and whether pin is logically inverted.
+The exact meaning of each specifier cell is controller specific, and must be
+documented in the device tree binding for the device, but it is strongly
+recommended to use the two-cell approach.
-Exact meaning of each specifier cell is controller specific, and must
-be documented in the device tree binding for the device.
-
-Most controllers are however specifying a generic flag bitfield
-in the last cell, so for these, use the macros defined in
+Most controllers are specifying a generic flag bitfield in the last cell, so
+for these, use the macros defined in
include/dt-bindings/gpio/gpio.h whenever possible:
Example of a node using GPIOs:
@@ -236,46 +221,40 @@ Example of two SOC GPIO banks defined as gpio-controller nodes:
Some or all of the GPIOs provided by a GPIO controller may be routed to pins
on the package via a pin controller. This allows muxing those pins between
-GPIO and other functions.
+GPIO and other functions. It is a fairly common practice among silicon
+engineers.
+
+2.2) Ordinary (numerical) GPIO ranges
+-------------------------------------
It is useful to represent which GPIOs correspond to which pins on which pin
-controllers. The gpio-ranges property described below represents this, and
-contains information structures as follows:
-
- gpio-range-list ::= <single-gpio-range> [gpio-range-list]
- single-gpio-range ::= <numeric-gpio-range> | <named-gpio-range>
- numeric-gpio-range ::=
- <pinctrl-phandle> <gpio-base> <pinctrl-base> <count>
- named-gpio-range ::= <pinctrl-phandle> <gpio-base> '<0 0>'
- pinctrl-phandle : phandle to pin controller node
- gpio-base : Base GPIO ID in the GPIO controller
- pinctrl-base : Base pinctrl pin ID in the pin controller
- count : The number of GPIOs/pins in this range
-
-The "pin controller node" mentioned above must conform to the bindings
-described in ../pinctrl/pinctrl-bindings.txt.
-
-In case named gpio ranges are used (ranges with both <pinctrl-base> and
-<count> set to 0), the property gpio-ranges-group-names contains one string
-for every single-gpio-range in gpio-ranges:
- gpiorange-names-list ::= <gpiorange-name> [gpiorange-names-list]
- gpiorange-name : Name of the pingroup associated to the GPIO range in
- the respective pin controller.
-
-Elements of gpiorange-names-list corresponding to numeric ranges contain
-the empty string. Elements of gpiorange-names-list corresponding to named
-ranges contain the name of a pin group defined in the respective pin
-controller. The number of pins/GPIOs in the range is the number of pins in
-that pin group.
+controllers. The gpio-ranges property described below represents this with
+a discrete set of ranges mapping pins from the pin controller local number space
+to pins in the GPIO controller local number space.
-Previous versions of this binding required all pin controller nodes that
-were referenced by any gpio-ranges property to contain a property named
-#gpio-range-cells with value <3>. This requirement is now deprecated.
-However, that property may still exist in older device trees for
-compatibility reasons, and would still be required even in new device
-trees that need to be compatible with older software.
+The format is: <[pin controller phandle], [GPIO controller offset],
+ [pin controller offset], [number of pins]>;
+
+The GPIO controller offset pertains to the GPIO controller node containing the
+range definition.
+
+The pin controller node referenced by the phandle must conform to the bindings
+described in pinctrl/pinctrl-bindings.txt.
+
+Each offset runs from 0 to N. It is perfectly fine to pile any number of
+ranges with just one pin-to-GPIO line mapping if the ranges are concocted, but
+in practice these ranges are often lumped in discrete sets.
+
+Example:
+
+ gpio-ranges = <&foo 0 20 10>, <&bar 10 50 20>;
-Example 1:
+This means:
+- pins 20..29 on pin controller "foo" is mapped to GPIO line 0..9 and
+- pins 50..69 on pin controller "bar" is mapped to GPIO line 10..29
+
+
+Verbose example:
qe_pio_e: gpio-controller@1460 {
#gpio-cells = <2>;
@@ -289,7 +268,28 @@ Here, a single GPIO controller has GPIOs 0..9 routed to pin controller
pinctrl1's pins 20..29, and GPIOs 10..29 routed to pin controller pinctrl2's
pins 50..69.
-Example 2:
+
+2.3) GPIO ranges from named pin groups
+--------------------------------------
+
+It is also possible to use pin groups for gpio ranges when pin groups are the
+easiest and most convenient mapping.
+
+Both both <pinctrl-base> and <count> must set to 0 when using named pin groups
+names.
+
+The property gpio-ranges-group-names must contain exactly one string for each
+range.
+
+Elements of gpio-ranges-group-names must contain the name of a pin group
+defined in the respective pin controller. The number of pins/GPIO lines in the
+range is the number of pins in that pin group. The number of pins of that
+group is defined int the implementation and not in the device tree.
+
+If numerical and named pin groups are mixed, the string corresponding to a
+numerical pin range in gpio-ranges-group-names must be empty.
+
+Example:
gpio_pio_i: gpio-controller@14b0 {
#gpio-cells = <2>;
@@ -306,6 +306,14 @@ Example 2:
"bar";
};
-Here, three GPIO ranges are defined wrt. two pin controllers. pinctrl1 GPIO
-ranges are defined using pin numbers whereas the GPIO ranges wrt. pinctrl2
-are named "foo" and "bar".
+Here, three GPIO ranges are defined referring to two pin controllers.
+
+pinctrl1 GPIO ranges are defined using pin numbers whereas the GPIO ranges
+in pinctrl2 are defined using the pin groups named "foo" and "bar".
+
+Previous versions of this binding required all pin controller nodes that
+were referenced by any gpio-ranges property to contain a property named
+#gpio-range-cells with value <3>. This requirement is now deprecated.
+However, that property may still exist in older device trees for
+compatibility reasons, and would still be required even in new device
+trees that need to be compatible with older software.
diff --git a/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt b/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt
index 4018ee57a6af..2889bbcd7416 100644
--- a/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt
+++ b/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt
@@ -4,8 +4,10 @@ Required Properties:
- compatible: should contain one or more of the following:
- "renesas,gpio-r8a7743": for R8A7743 (RZ/G1M) compatible GPIO controller.
+ - "renesas,gpio-r8a7744": for R8A7744 (RZ/G1N) compatible GPIO controller.
- "renesas,gpio-r8a7745": for R8A7745 (RZ/G1E) compatible GPIO controller.
- "renesas,gpio-r8a77470": for R8A77470 (RZ/G1C) compatible GPIO controller.
+ - "renesas,gpio-r8a774a1": for R8A774A1 (RZ/G2M) compatible GPIO controller.
- "renesas,gpio-r8a7778": for R8A7778 (R-Car 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.
@@ -22,7 +24,7 @@ Required Properties:
- "renesas,gpio-r8a77995": for R8A77995 (R-Car D3) compatible GPIO controller.
- "renesas,rcar-gen1-gpio": for a generic R-Car Gen1 GPIO controller.
- "renesas,rcar-gen2-gpio": for a generic R-Car Gen2 or RZ/G1 GPIO controller.
- - "renesas,rcar-gen3-gpio": for a generic R-Car Gen3 GPIO controller.
+ - "renesas,rcar-gen3-gpio": for a generic R-Car Gen3 or RZ/G2 GPIO controller.
- "renesas,gpio-rcar": deprecated.
When compatible with the generic version nodes must list the
@@ -38,7 +40,7 @@ Required Properties:
- #gpio-cells: Should be 2. The first cell is the GPIO number and the second
cell specifies GPIO flags, as defined in <dt-bindings/gpio/gpio.h>. Only the
GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported.
- - gpio-ranges: Range of pins managed by the GPIO controller.
+ - gpio-ranges: See gpio.txt.
Optional properties:
@@ -46,35 +48,44 @@ Optional properties:
mandatory if the hardware implements a controllable functional clock for
the GPIO instance.
-Please refer to gpio.txt in this directory for details of gpio-ranges property
-and the common GPIO bindings used by client devices.
+ - gpio-reserved-ranges: See gpio.txt.
+
+Please refer to gpio.txt in this directory for the common GPIO bindings used by
+client devices.
The GPIO controller also acts as an interrupt controller. It uses the default
two cells specifier as described in Documentation/devicetree/bindings/
interrupt-controller/interrupts.txt.
-Example: R8A7779 (R-Car H1) GPIO controller nodes
+Example: R8A77470 (RZ/G1C) GPIO controller nodes
- gpio0: gpio@ffc40000 {
- compatible = "renesas,gpio-r8a7779", "renesas,rcar-gen1-gpio";
- reg = <0xffc40000 0x2c>;
- interrupt-parent = <&gic>;
- interrupts = <0 141 0x4>;
- #gpio-cells = <2>;
- gpio-controller;
- gpio-ranges = <&pfc 0 0 32>;
- interrupt-controller;
- #interrupt-cells = <2>;
- };
+ gpio0: gpio@e6050000 {
+ compatible = "renesas,gpio-r8a77470",
+ "renesas,rcar-gen2-gpio";
+ reg = <0 0xe6050000 0 0x50>;
+ interrupts = <GIC_SPI 4 IRQ_TYPE_LEVEL_HIGH>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ gpio-ranges = <&pfc 0 0 23>;
+ #interrupt-cells = <2>;
+ interrupt-controller;
+ clocks = <&cpg CPG_MOD 912>;
+ power-domains = <&sysc R8A77470_PD_ALWAYS_ON>;
+ resets = <&cpg 912>;
+ };
...
- gpio6: gpio@ffc46000 {
- compatible = "renesas,gpio-r8a7779", "renesas,rcar-gen1-gpio";
- reg = <0xffc46000 0x2c>;
- interrupt-parent = <&gic>;
- interrupts = <0 147 0x4>;
- #gpio-cells = <2>;
- gpio-controller;
- gpio-ranges = <&pfc 0 192 9>;
- interrupt-controller;
- #interrupt-cells = <2>;
- };
+ gpio3: gpio@e6053000 {
+ compatible = "renesas,gpio-r8a77470",
+ "renesas,rcar-gen2-gpio";
+ reg = <0 0xe6053000 0 0x50>;
+ interrupts = <GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>;
+ #gpio-cells = <2>;
+ gpio-controller;
+ gpio-ranges = <&pfc 0 96 30>;
+ gpio-reserved-ranges = <17 10>;
+ #interrupt-cells = <2>;
+ interrupt-controller;
+ clocks = <&cpg CPG_MOD 909>;
+ power-domains = <&sysc R8A77470_PD_ALWAYS_ON>;
+ resets = <&cpg 909>;
+ };
diff --git a/Documentation/devicetree/bindings/gpio/snps,creg-gpio.txt b/Documentation/devicetree/bindings/gpio/snps,creg-gpio.txt
new file mode 100644
index 000000000000..1b30812b015b
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/snps,creg-gpio.txt
@@ -0,0 +1,21 @@
+Synopsys GPIO via CREG (Control REGisters) driver
+
+Required properties:
+- compatible : "snps,creg-gpio-hsdk" or "snps,creg-gpio-axs10x".
+- reg : Exactly one register range with length 0x4.
+- #gpio-cells : Since the generic GPIO binding is used, the
+ amount of cells must be specified as 2. The first cell is the
+ pin number, the second cell is used to specify optional parameters:
+ See "gpio-specifier" in .../devicetree/bindings/gpio/gpio.txt.
+- gpio-controller : Marks the device node as a GPIO controller.
+- ngpios: Number of GPIO pins.
+
+Example:
+
+gpio: gpio@f00014b0 {
+ compatible = "snps,creg-gpio-hsdk";
+ reg = <0xf00014b0 0x4>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ ngpios = <2>;
+};