[PATCH 2/3] dt-bindings: pinctrl: mt8192: add binding document
Rob Herring
robh at kernel.org
Fri Jul 10 12:39:05 EDT 2020
On Fri, Jul 10, 2020 at 03:27:16PM +0800, Zhiyong Tao wrote:
> The commit adds mt8192 compatible node in binding document.
>
> Signed-off-by: Zhiyong Tao <zhiyong.tao at mediatek.com>
> ---
> .../bindings/pinctrl/pinctrl-mt8192.yaml | 170 ++++++++++++++++++
> 1 file changed, 170 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pinctrl/pinctrl-mt8192.yaml
>
> diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8192.yaml b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8192.yaml
> new file mode 100644
> index 000000000000..c698b7f65950
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8192.yaml
> @@ -0,0 +1,170 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pinctrl/pinctrl-mt8192.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Mediatek MT8192 Pin Controller
> +
> +maintainers:
> + - Linus Walleij <linus.walleij at linaro.org>
Should be someone who knows the h/w (Mediatek).
> +
> +description: |
> + The Mediatek's Pin controller is used to control SoC pins.
> +
> +properties:
> + compatible:
> + const: mediatek,mt8192-pinctrl
> +
> + gpio-controller: true
> +
> + '#gpio-cells':
> + description:
> + Number of cells in GPIO specifier. Since the generic GPIO binding is used,
> + the amount of cells must be specified as 2. See the below
> + mentioned gpio binding representation for description of particular cells.
> + const: 2
> +
> + gpio-ranges:
> + description: gpio valid number range.
> + maxItems: 1
> +
> + reg:
> + description:
> + Physical address base for gpio base registers. There are 11 GPIO
> + physical address base in mt8192.
> + maxItems: 11
> +
> + reg-names:
> + description:
> + Gpio base register names. There are 11 gpio base register names in mt8192.
> + They are "iocfg0", "iocfg_rm", "iocfg_bm", "iocfg_bl", "iocfg_br",
> + "iocfg_lm", "iocfg_lb", "iocfg_rt", "iocfg_lt", "iocfg_tl", "eint".
Should be a schema.
> + maxItems: 11
> +
> + interrupt-controller: true
> +
> + '#interrupt-cells':
> + const: 2
> +
> + interrupts:
> + description: The interrupt outputs to sysirq.
> + maxItems: 1
> +
> +#PIN CONFIGURATION NODES
> +patternProperties:
> + subnode format:
The child node name is 'subnode format'?
> + description:
> + A pinctrl node should contain at least one subnodes representing the
> + pinctrl groups available on the machine. Each subnode will list the
> + pins it needs, and how they should be configured, with regard to muxer
> + configuration, pullups, drive strength, input enable/disable and
> + input schmitt.
> +
> + node {
> + pinmux = <PIN_NUMBER_PINMUX>;
> + GENERIC_PINCONFIG;
> + };
If you want to preserve formatting, description needs a literal block
notation on the end ('|').
> + '-pinmux$':
> + description:
> + Integer array, represents gpio pin number and mux setting.
> + Supported pin number and mux varies for different SoCs, and are defined
> + as macros in dt-bindings/pinctrl/<soc>-pinfunc.h directly.
> + $ref: "/schemas/pinctrl/pincfg-node.yaml"
> +
> + GENERIC_PINCONFIG:
You just defined a property called 'GENERIC_PINCONFIG'...
> + description:
> + It is the generic pinconfig options to use, bias-disable,
> + bias-pull-down, bias-pull-up, input-enable, input-disable, output-low,
> + output-high, input-schmitt-enable, input-schmitt-disable
> + and drive-strength are valid.
> +
> + Some special pins have extra pull up strength, there are R0 and R1 pull-up
> + resistors available, but for user, it's only need to set R1R0 as 00, 01,
> + 10 or 11. So It needs config "mediatek,pull-up-adv" or
> + "mediatek,pull-down-adv" to support arguments for those special pins.
> + Valid arguments are from 0 to 3.
> +
> + We can use "mediatek,tdsel" which is an integer describing the steps for
> + output level shifter duty cycle when asserted (high pulse width adjustment).
> + Valid arguments are from 0 to 15.
> + We can use "mediatek,rdsel" which is an integer describing the steps for
> + input level shifter duty cycle when asserted (high pulse width adjustment).
> + Valid arguments are from 0 to 63.
> +
> + When config drive-strength, it can support some arguments, such as
> + MTK_DRIVE_4mA, MTK_DRIVE_6mA, etc. See dt-bindings/pinctrl/mt65xx.h.
> + It can only support 2/4/6/8/10/12/14/16mA in mt8192.
> + For I2C pins, there are existing generic driving setup and the specific
> + driving setup. I2C pins can only support 2/4/6/8/10/12/14/16mA driving
> + adjustment in generic driving setup. But in specific driving setup,
> + they can support 0.125/0.25/0.5/1mA adjustment. If we enable specific
> + driving setup for I2C pins, the existing generic driving setup will be
> + disabled. For some special features, we need the I2C pins specific
> + driving setup. The specific driving setup is controlled by E1E0EN.
> + So we need add extra vendor driving preperty instead of
> + the generic driving property.
> + We can add "mediatek,drive-strength-adv = <XXX>;" to describe the specific
> + driving setup property. "XXX" means the value of E1E0EN. EN is 0 or 1.
> + It is used to enable or disable the specific driving setup.
> + E1E0 is used to describe the detail strength specification of the I2C pin.
> + When E1=0/E0=0, the strength is 0.125mA.
> + When E1=0/E0=1, the strength is 0.25mA.
> + When E1=1/E0=0, the strength is 0.5mA.
> + When E1=1/E0=1, the strength is 1mA.
> + So the valid arguments of "mediatek,drive-strength-adv" are from 0 to 7.
> +
> +required:
> + - compatible
> + - reg
> + - interrupts
> + - interrupt-controller
> + - '#interrupt-cells'
> + - gpio-controller
> + - '#gpio-cells'
> + - gpio-ranges
> +
> +examples:
> + - |
> + #include <dt-bindings/pinctrl/mt8192-pinfunc.h>
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + pio: pinctrl at 10005000 {
Drop unused labels.
> + compatible = "mediatek,mt8192-pinctrl";
> + reg = <0 0x10005000 0 0x1000>,
> + <0 0x11c20000 0 0x1000>,
> + <0 0x11d10000 0 0x1000>,
> + <0 0x11d30000 0 0x1000>,
> + <0 0x11d40000 0 0x1000>,
> + <0 0x11e20000 0 0x1000>,
> + <0 0x11e70000 0 0x1000>,
> + <0 0x11ea0000 0 0x1000>,
> + <0 0x11f20000 0 0x1000>,
> + <0 0x11f30000 0 0x1000>,
> + <0 0x1000b000 0 0x1000>;
> + reg-names = "iocfg0", "iocfg_rm", "iocfg_bm",
> + "iocfg_bl", "iocfg_br", "iocfg_lm",
> + "iocfg_lb", "iocfg_rt", "iocfg_lt",
> + "iocfg_tl", "eint";
> + gpio-controller;
> + #gpio-cells = <2>;
> + gpio-ranges = <&pio 0 0 220>;
> + interrupt-controller;
> + interrupts = <GIC_SPI 212 IRQ_TYPE_LEVEL_HIGH 0>;
> + #interrupt-cells = <2>;
> + i2c0_pins_a: i2c0 {
Doesn't match the schema.
> + pins {
Doesn't match the schema. Why do you need 2 levels of nodes here?
> + pinmux = <PINMUX_GPIO118__FUNC_SCL1>,
> + <PINMUX_GPIO119__FUNC_SDA1>;
> + mediatek,pull-up-adv = <3>;
> + mediatek,drive-strength-adv = <7>;
> + };
> + };
> + i2c1_pins_a: i2c1 {
> + pins {
> + pinmux = <PINMUX_GPIO141__FUNC_SCL2>,
> + <PINMUX_GPIO142__FUNC_SDA2>;
> + mediatek,pull-down-adv = <2>;
> + mediatek,drive-strength-adv = <4>;
> + };
> + };
> + };
> --
> 2.18.0
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