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diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt new file mode 100644 index 000000000..eccbe3f55 --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8183.txt @@ -0,0 +1,132 @@ +* Mediatek MT8183 Pin Controller + +The Mediatek's Pin controller is used to control SoC pins. + +Required properties: +- compatible: value should be one of the following. + "mediatek,mt8183-pinctrl", compatible with mt8183 pinctrl. +- gpio-controller : Marks the device node as a gpio controller. +- #gpio-cells: 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. +- gpio-ranges : gpio valid number range. +- reg: physical address base for gpio base registers. There are 10 GPIO + physical address base in mt8183. + +Optional properties: +- reg-names: gpio base register names. There are 10 gpio base register + names in mt8183. They are "iocfg0", "iocfg1", "iocfg2", "iocfg3", "iocfg4", + "iocfg5", "iocfg6", "iocfg7", "iocfg8", "eint". +- interrupt-controller: Marks the device node as an interrupt controller +- #interrupt-cells: Should be two. +- interrupts : The interrupt outputs to sysirq. + +Please refer to pinctrl-bindings.txt in this directory for details of the +common pinctrl bindings used by client devices. + +Subnode format +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; + }; + +Required properties: +- pinmux: integer array, represents gpio pin number and mux setting. + Supported pin number and mux varies for different SoCs, and are defined + as macros in boot/dts/<soc>-pinfunc.h directly. + +Optional properties: +- GENERIC_PINCONFIG: 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. + + mediatek,tdsel: An integer describing the steps for output level shifter + duty cycle when asserted (high pulse width adjustment). Valid arguments + are from 0 to 15. + mediatek,rdsel: 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 mt8183. + 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. + +Examples: + +#include "mt8183-pinfunc.h" + +... +{ + pio: pinctrl@10005000 { + compatible = "mediatek,mt8183-pinctrl"; + reg = <0 0x10005000 0 0x1000>, + <0 0x11f20000 0 0x1000>, + <0 0x11e80000 0 0x1000>, + <0 0x11e70000 0 0x1000>, + <0 0x11e90000 0 0x1000>, + <0 0x11d30000 0 0x1000>, + <0 0x11d20000 0 0x1000>, + <0 0x11c50000 0 0x1000>, + <0 0x11f30000 0 0x1000>, + <0 0x1000b000 0 0x1000>; + reg-names = "iocfg0", "iocfg1", "iocfg2", + "iocfg3", "iocfg4", "iocfg5", + "iocfg6", "iocfg7", "iocfg8", + "eint"; + gpio-controller; + #gpio-cells = <2>; + gpio-ranges = <&pio 0 0 192>; + interrupt-controller; + interrupts = <GIC_SPI 177 IRQ_TYPE_LEVEL_HIGH>; + #interrupt-cells = <2>; + + i2c0_pins_a: i2c0 { + pins1 { + pinmux = <PINMUX_GPIO48__FUNC_SCL5>, + <PINMUX_GPIO49__FUNC_SDA5>; + mediatek,pull-up-adv = <3>; + mediatek,drive-strength-adv = <7>; + }; + }; + + i2c1_pins_a: i2c1 { + pins { + pinmux = <PINMUX_GPIO50__FUNC_SCL3>, + <PINMUX_GPIO51__FUNC_SDA3>; + mediatek,pull-down-adv = <2>; + mediatek,drive-strength-adv = <4>; + }; + }; + ... + }; +}; |