This adds documentation of device tree bindings for the
STM32 pin controller.
Signed-off-by: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
---
.../devicetree/bindings/pinctrl/pinctrl-stm32.txt | 99 ++++++++++++++++++++++
1 file changed, 99 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt
diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-stm32.txt
new file mode 100644
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+* 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 : "st,stm32-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).
+
+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
+- 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 <dt-bindings/pinctrl/pinctrl-stm32.h>
+...
+
+ pin-controller {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "st,stm32-pinctrl";
+ ranges = <0 0x40020000 0x3000>;
+
+ 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:
+----------------------------------
+
+Required properties for pin configuration node:
+- st,pins : Child node with list of pins with configuration.
+
+Below is the format of how each pin conf should look like.
+
+<bank offset altmode pull type speed>
+
+Every PIO is represented with 4 to 6 parameters.
+Each parameter is explained as below.
+
+- bank : Should be bank phandle to which this PIO belongs.
+- offset : Offset in the PIO bank.
+- altmode : Should be mode or alternate function number associated this pin, as
+described in the datasheet (IN, OUT, ALT0...ALT15, ANALOG)
+- pull : Should be either NO_PULL, PULL_UP or PULL_DOWN
+- type : Should be either PUSH_PULL or OPEN_DRAIN.
+ Setting it is not needed for IN and ANALOG modes, or alternate
+ functions acting as inputs.
+- speed : Value taken from the datasheet, depending on the function
+(LOW_SPEED, MEDIUM_SPEED, FAST_SPEED, HIGH_SPEED)
+ Setting it is not needed for IN and ANALOG modes, or alternate
+ functions acting as inputs.
+
+usart1 {
+ pinctrl_usart1: usart1-0 {
+ st,pins {
+ tx = <&gpioa 9 ALT7 NO_PULL PUSH_PULL LOW_SPEED>;
+ rx = <&gpioa 10 ALT7 NO_PULL PUSH_PULL LOW_SPEED>;
+ };
+ };
+};
+
+adc2 {
+ pinctrl_adc2: adc2-0 {
+ st,pins {
+ adc0 = <&gpioe 4 ANALOG NO_PULL>;
+ };
+ };
+};
+
+usart1: usart@40011000 {
+ ...
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_usart1>;
+};
--
1.9.1
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