From 936516bfb3a111982295675055d1659274be70f0 Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Thu, 14 Jan 2016 13:16:28 +0100 Subject: Documentation: dt-bindings: Document STM32 pinctrl driver DT bindings Acked-by: Patrice Chotard Signed-off-by: Maxime Coquelin Acked-by: Rob Herring Signed-off-by: Linus Walleij --- .../bindings/pinctrl/st,stm32-pinctrl.txt | 126 +++++++++++++++++++++ 1 file changed, 126 insertions(+) create mode 100644 Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt (limited to 'Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt') 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 0000000..7b4800c --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt @@ -0,0 +1,126 @@ +* 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: + (a) "st,stm32f429-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 + +Example: +#include +... + + 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... + }; + +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 = ; + 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/-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 = , 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 = ; + bias-disable; + drive-push-pull; + slew-rate = <0>; + }; + pins2 { + pinmux = ; + bias-disable; + }; + }; +}; + +&usart1 { + pinctrl-0 = <&usart1_pins_a>; + pinctrl-names = "default"; + status = "okay"; +}; -- cgit v1.1