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Diffstat (limited to 'Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt')
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diff --git a/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt new file mode 100644 index 000000000000..d907a74f8dc0 --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt @@ -0,0 +1,184 @@ +* STM32 GPIO and Pin Mux/Config controller + +STMicroelectronics's STM32 MCUs intregrate a GPIO and Pin mux/config hardware +controller. It controls the input/output settings on the available pins and +also provides ability to multiplex and configure the output of various on-chip +controllers onto these pads. + +Pin controller node: +Required properies: + - compatible: value should be one of the following: + "st,stm32f429-pinctrl" + "st,stm32f469-pinctrl" + "st,stm32f746-pinctrl" + "st,stm32h743-pinctrl" + - #address-cells: The value of this property must be 1 + - #size-cells : The value of this property must be 1 + - ranges : defines mapping between pin controller node (parent) to + gpio-bank node (children). + - pins-are-numbered: Specify the subnodes are using numbered pinmux to + specify pins. + +GPIO controller/bank node: +Required properties: + - gpio-controller : Indicates this device is a GPIO controller + - #gpio-cells : Should be two. + The first cell is the pin number + The second one is the polarity: + - 0 for active high + - 1 for active low + - reg : The gpio address range, relative to the pinctrl range + - clocks : clock that drives this bank + - st,bank-name : Should be a name string for this bank as specified in + the datasheet + +Optional properties: + - reset: : Reference to the reset controller + - interrupt-parent: phandle of the interrupt parent to which the external + GPIO interrupts are forwarded to. + - st,syscfg: Should be phandle/offset pair. The phandle to the syscon node + which includes IRQ mux selection register, and the offset of the IRQ mux + selection register. + - gpio-ranges: Define a dedicated mapping between a pin-controller and + a gpio controller. Format is <&phandle a b c> with: + -(phandle): phandle of pin-controller. + -(a): gpio base offset in range. + -(b): pin base offset in range. + -(c): gpio count in range + This entry has to be used either if there are holes inside a bank: + GPIOB0/B1/B2/B14/B15 (see example 2) + or if banks are not contiguous: + GPIOA/B/C/E... + NOTE: If "gpio-ranges" is used for a gpio controller, all gpio-controller + have to use a "gpio-ranges" entry. + More details in Documentation/devicetree/bindings/gpio/gpio.txt. + +Example 1: +#include <dt-bindings/pinctrl/stm32f429-pinfunc.h> +... + + pin-controller { + #address-cells = <1>; + #size-cells = <1>; + compatible = "st,stm32f429-pinctrl"; + ranges = <0 0x40020000 0x3000>; + pins-are-numbered; + + gpioa: gpio@40020000 { + gpio-controller; + #gpio-cells = <2>; + reg = <0x0 0x400>; + resets = <&reset_ahb1 0>; + st,bank-name = "GPIOA"; + }; + ... + pin-functions nodes follow... + }; + +Example 2: +#include <dt-bindings/pinctrl/stm32f429-pinfunc.h> +... + + pinctrl: pin-controller { + #address-cells = <1>; + #size-cells = <1>; + compatible = "st,stm32f429-pinctrl"; + ranges = <0 0x40020000 0x3000>; + pins-are-numbered; + + gpioa: gpio@40020000 { + gpio-controller; + #gpio-cells = <2>; + reg = <0x0 0x400>; + resets = <&reset_ahb1 0>; + st,bank-name = "GPIOA"; + gpio-ranges = <&pinctrl 0 0 16>; + }; + + gpiob: gpio@40020400 { + gpio-controller; + #gpio-cells = <2>; + reg = <0x0 0x400>; + resets = <&reset_ahb1 0>; + st,bank-name = "GPIOB"; + ngpios = 4; + gpio-ranges = <&pinctrl 0 16 3>, + <&pinctrl 14 30 2>; + }; + + + ... + pin-functions nodes follow... + }; + + +Contents of function subnode node: +---------------------------------- +Subnode format +A pinctrl node should contain at least one subnode representing the +pinctrl group 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, output high/low and output speed. + + 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 in + dt-bindings/pinctrl/<soc>-pinfunc.h directly. + These defines are calculated as: + ((port * 16 + line) << 8) | function + With: + - port: The gpio port index (PA = 0, PB = 1, ..., PK = 11) + - line: The line offset within the port (PA0 = 0, PA1 = 1, ..., PA15 = 15) + - function: The function number, can be: + * 0 : GPIO + * 1 : Alternate Function 0 + * 2 : Alternate Function 1 + * 3 : Alternate Function 2 + * ... + * 16 : Alternate Function 15 + * 17 : Analog + +Optional properties: +- GENERIC_PINCONFIG: is the generic pinconfig options to use. + Available options are: + - bias-disable, + - bias-pull-down, + - bias-pull-up, + - drive-push-pull, + - drive-open-drain, + - output-low + - output-high + - slew-rate = <x>, with x being: + < 0 > : Low speed + < 1 > : Medium speed + < 2 > : Fast speed + < 3 > : High speed + +Example: + +pin-controller { +... + usart1_pins_a: usart1@0 { + pins1 { + pinmux = <STM32F429_PA9_FUNC_USART1_TX>; + bias-disable; + drive-push-pull; + slew-rate = <0>; + }; + pins2 { + pinmux = <STM32F429_PA10_FUNC_USART1_RX>; + bias-disable; + }; + }; +}; + +&usart1 { + pinctrl-0 = <&usart1_pins_a>; + pinctrl-names = "default"; + status = "okay"; +}; |