Re: [PATCH v2 01/13] dt-bindings: gpio: add common schema for GPIO controllers
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2020-09-17 20:10:15
Also in:
alsa-devel, linux-arm-msm, linux-gpio, linux-media, linux-mediatek, linux-renesas-soc, linux-riscv, lkml
Hi Krzysztof, Thank you for the patch. On Thu, Sep 17, 2020 at 06:52:49PM +0200, Krzysztof Kozlowski wrote:
Convert parts of gpio.txt bindings into common dtschema file for GPIO controllers.
How about deleting the part that has been converted from gpio.txt ?
The schema enforces proper naming of GPIO controller nodes and GPIO hogs. The schema should be included by specific GPIO controllers bindings.
Instead of including it manually, could we use a conditional select: to apply the schema automatically when a gpio-controller property is present ?
quoted hunk ↗ jump to hunk
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> --- Changes since v1: 1. Do not require compatible (some child nodes are gpio-controllers without the compatible). --- .../devicetree/bindings/gpio/gpio-common.yaml | 125 ++++++++++++++++++ 1 file changed, 125 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/gpio-common.yamldiff --git a/Documentation/devicetree/bindings/gpio/gpio-common.yaml b/Documentation/devicetree/bindings/gpio/gpio-common.yaml new file mode 100644 index 000000000000..af9f6c7feeec --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-common.yaml@@ -0,0 +1,125 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gpio/gpio-common.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Common GPIO controller properties + +maintainers: + - Krzysztof Kozlowski <krzk@kernel.org> + - Linus Walleij <linus.walleij@linaro.org> + +properties: + nodename: + pattern: "^(gpio-controller|gpio)(@[0-9a-f]+|-[0-9a-f]+)?$" + + '#gpio-cells': true + gpio-controller: true + gpio-ranges: true + + gpio-line-names: + description: | + Optionally, a GPIO controller may have a "gpio-line-names" property. This + is an array of strings defining the names of the GPIO lines going out of + the GPIO controller. This name should be the most meaningful producer + name for the system, such as a rail name indicating the usage. Package + names such as pin name are discouraged: such lines have opaque names + (since they are by definition generic purpose) and such names are usually + not very helpful. + + For example "MMC-CD", "Red LED Vdd" and "ethernet reset" are reasonable + line names as they describe what the line is used for. "GPIO0" is not a + good name to give to a GPIO line. + + Placeholders are discouraged: rather use the "" (blank string) if the use + of the GPIO line is undefined in your design. The names are assigned + starting from line offset 0 from left to right from the passed array. An + incomplete array (where the number of passed named are less than ngpios) + will still be used up until the last provided valid line index. + + gpio-reserved-ranges: + description: + Indicates the start and size of the GPIOs that can't be used. + + ngpios: + description: | + Optionally, a GPIO controller may have a "ngpios" property. This property + indicates the number of in-use slots of available slots for GPIOs. The + typical example is something like this: the hardware register is 32 bits + wide, but only 18 of the bits have a physical counterpart. The driver is + generally written so that all 32 bits can be used, but the IP block is + reused in a lot of designs, some using all 32 bits, some using 18 and + some using 12. In this case, setting "ngpios = <18>;" informs the driver + that only the first 18 GPIOs, at local offset 0 .. 17, are in use. + + If these GPIOs do not happen to be the first N GPIOs at offset 0...N-1, + an additional set of tuples is needed to specify which GPIOs are + unusable, with the gpio-reserved-ranges binding. + +patternProperties: + "^(hog-[0-9]+|.+-hog(-[0-9]+)?)$": + type: object + description: + The GPIO chip may contain GPIO hog definitions. GPIO hogging is a mechanism + providing automatic GPIO request and configuration as part of the + gpio-controller's driver probe function. + Each GPIO hog definition is represented as a child node of the GPIO controller. + + properties: + gpio-hog: true + gpios: true + input: true + output-high: true + output-low: true + line-name: + description: + The GPIO label name. If not present the node name is used. + + required: + - gpio-hog + - gpios + + oneOf: + - required: + - input + - required: + - output-high + - required: + - output-low + + additionalProperties: false + +required: + - "#gpio-cells" + - gpio-controller + +examples: + - | + gpio-controller@15000000 { + compatible = "foo"; + reg = <0x15000000 0x1000>; + gpio-controller; + #gpio-cells = <2>; + ngpios = <18>; + gpio-reserved-ranges = <0 4>, <12 2>; + gpio-line-names = "MMC-CD", "MMC-WP", "VDD eth", "RST eth", "LED R", + "LED G", "LED B", "Col A", "Col B", "Col C", "Col D", + "Row A", "Row B", "Row C", "Row D", "NMI button", + "poweroff", "reset"; + }; + + - | + gpio-controller@1400 { + compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank"; + reg = <0x1400 0x18>; + gpio-controller; + #gpio-cells = <2>; + + line-b-hog { + gpio-hog; + gpios = <6 0>; + input; + line-name = "foo-bar-gpio"; + }; + };
-- Regards, Laurent Pinchart