Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt

   1 * STM32 GPIO and Pin Mux/Config controller
   2
   3 STMicroelectronics's STM32 MCUs intregrate a GPIO and Pin mux/config hardware
   4 controller. It controls the input/output settings on the available pins and
   5 also provides ability to multiplex and configure the output of various on-chip
   6 controllers onto these pads.
   7
   8 Pin controller node:
   9 Required properies:
  10  - compatible: value should be one of the following:
  11    (a) "st,stm32f429-pinctrl"
  12  - #address-cells: The value of this property must be 1
  13  - #size-cells  : The value of this property must be 1
  14  - ranges       : defines mapping between pin controller node (parent) to
  15    gpio-bank node (children).
  16  - pins-are-numbered: Specify the subnodes are using numbered pinmux to
  17    specify pins.
  18
  19 GPIO controller/bank node:
  20 Required properties:
  21  - gpio-controller : Indicates this device is a GPIO controller
  22  - #gpio-cells    : Should be two.
  23                         The first cell is the pin number
  24                         The second one is the polarity:
  25                                 - 0 for active high
  26                                 - 1 for active low
  27  - reg            : The gpio address range, relative to the pinctrl range
  28  - clocks         : clock that drives this bank
  29  - st,bank-name   : Should be a name string for this bank as specified in
  30    the datasheet
  31
  32 Optional properties:
  33  - reset:         : Reference to the reset controller
  34
  35 Example:
  36 #include <dt-bindings/pinctrl/stm32f429-pinfunc.h>
  37 ...
  38
  39         pin-controller {
  40                 #address-cells = <1>;
  41                 #size-cells = <1>;
  42                 compatible = "st,stm32f429-pinctrl";
  43                 ranges = <0 0x40020000 0x3000>;
  44                 pins-are-numbered;
  45
  46                 gpioa: gpio@40020000 {
  47                         gpio-controller;
  48                         #gpio-cells = <2>;
  49                         reg = <0x0 0x400>;
  50                         resets = <&reset_ahb1 0>;
  51                         st,bank-name = "GPIOA";
  52                 };
  53                 ...
  54                 pin-functions nodes follow...
  55         };
  56
  57 Contents of function subnode node:
  58 ----------------------------------
  59 Subnode format
  60 A pinctrl node should contain at least one subnode representing the
  61 pinctrl group available on the machine. Each subnode will list the
  62 pins it needs, and how they should be configured, with regard to muxer
  63 configuration, pullups, drive, output high/low and output speed.
  64
  65     node {
  66         pinmux = <PIN_NUMBER_PINMUX>;
  67         GENERIC_PINCONFIG;
  68     };
  69
  70 Required properties:
  71 - pinmux: integer array, represents gpio pin number and mux setting.
  72   Supported pin number and mux varies for different SoCs, and are defined in
  73   dt-bindings/pinctrl/<soc>-pinfunc.h directly.
  74   These defines are calculated as:
  75     ((port * 16 + line) << 8) | function
  76   With:
  77     - port: The gpio port index (PA = 0, PB = 1, ..., PK = 11)
  78     - line: The line offset within the port (PA0 = 0, PA1 = 1, ..., PA15 = 15)
  79     - function: The function number, can be:
  80       * 0 : GPIO
  81       * 1 : Alternate Function 0
  82       * 2 : Alternate Function 1
  83       * 3 : Alternate Function 2
  84       * ...
  85       * 16 : Alternate Function 15
  86       * 17 : Analog
  87
  88 Optional properties:
  89 - GENERIC_PINCONFIG: is the generic pinconfig options to use.
  90   Available options are:
  91    - bias-disable,
  92    - bias-pull-down,
  93    - bias-pull-up,
  94    - drive-push-pull,
  95    - drive-open-drain,
  96    - output-low
  97    - output-high
  98    - slew-rate = <x>, with x being:
  99        < 0 > : Low speed
 100        < 1 > : Medium speed
 101        < 2 > : Fast speed
 102        < 3 > : High speed
 103
 104 Example:
 105
 106 pin-controller {
 107 ...
 108         usart1_pins_a: usart1@0 {
 109                 pins1 {
 110                         pinmux = <STM32F429_PA9_FUNC_USART1_TX>;
 111                         bias-disable;
 112                         drive-push-pull;
 113                         slew-rate = <0>;
 114                 };
 115                 pins2 {
 116                         pinmux = <STM32F429_PA10_FUNC_USART1_RX>;
 117                         bias-disable;
 118                 };
 119         };
 120 };
 121
 122 &usart1 {
 123         pinctrl-0 = <&usart1_pins_a>;
 124         pinctrl-names = "default";
 125         status = "okay";
 126 };