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Subject[PATCH v1 2/5] dt-bindings: clock: renesas,r9a06g032-pinctrl: documentation
Date
The Renesas R9A06G032 PINCTRL node description.

Signed-off-by: Michel Pollet <michel.pollet@bp.renesas.com>
---
.../bindings/pinctrl/renesas,r9a06g032-pinctrl.txt | 124 +++++++++++++++++++++
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create mode 100644 Documentation/devicetree/bindings/pinctrl/renesas,r9a06g032-pinctrl.txt

diff --git a/Documentation/devicetree/bindings/pinctrl/renesas,r9a06g032-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/renesas,r9a06g032-pinctrl.txt
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@@ -0,0 +1,124 @@
+Renesas RZ/A1 combined Pin and GPIO controller
+
+The Renesas SoCs of the RZ/A1 family feature a combined Pin and GPIO controller,
+named "Ports" in the hardware reference manual.
+Pin multiplexing and GPIO configuration is performed on a per-pin basis
+writing configuration values to per-port register sets.
+Each "port" features up to 16 pins, each of them configurable for GPIO
+function (port mode) or in alternate function mode.
+Up to 8 different alternate function modes exist for each single pin.
+
+Pin controller node
+-------------------
+
+Required properties:
+ - compatible: should be:
+ - "renesas,r9a05g032-pinctrl"
+ - reg
+ address base and length of the memory area where the pin controller
+ hardware is mapped to.
+
+Example:
+ pinctrl: pinctrl@40067000 {
+ compatible = "renesas,r9a06g032-pinctrl";
+ reg = <0x40067000 0x1000>, <0x51000000 0x800>;
+ clocks = <&sysctrl R9A06G032_HCLK_PINCONFIG>;
+ clock-names = "bus";
+ status = "okay";
+ };
+
+
+Sub-nodes
+---------
+ The child nodes of the pin controller node describe a pin multiplexing
+ group that can be used by driver nodes.
+
+ A pin multiplexing sub-node describes how to configure a set of
+ (or a single) pin in some desired alternate function mode.
+ A single sub-node may define several pin configurations.
+
+ The allowed generic formats for a pin multiplexing sub-node are the
+ following ones:
+
+ Client sub-nodes shall refer to pin multiplexing sub-nodes using the phandle
+ of the most external one.
+
+ Eg.
+
+ client-1 {
+ ...
+ pinctrl-0 = <&node-1>;
+ ...
+ };
+
+ client-2 {
+ ...
+ pinctrl-0 = <&node-2>;
+ ...
+ };
+
+ Required properties:
+ - renesas,rzn1-pinctrl:
+ Array of integers representing each 'pin' and it's configuration.
+
+ A 'pin number' does not correspond 1:1 to the hardware manual notion of
+ PL_GPIO directly. Numbers 0...169 are PL_GPIOs, however there is also two
+ extra 170 and 171 that corresponds to the MDIO0 and MDIO1 bus config.
+
+ A 'function' also does not correspond 1:1 to the hardware manual. There
+ are 2 levels of pin muxing, Level 1, level 2 -- to this are added the
+ MDIO configurations.
+
+ Helper macros to ease assembling the pin index and function identifier
+ are provided by the pin controller header file at:
+ <include/dt-bindings/pinctrl/r9a06g032-pinctrl.h>
+
+Example #1:
+ A simple case configuring only the function for a given 'pin' works as follow:
+ #include <include/dt-bindings/pinctrl/r9a06g032-pinctrl.h>
+ &pinctrl {
+ pinsuart0: pinsuart0 {
+ renesas,rzn1-pinmux-ids = <
+ RZN1_MUX(103, UART0_I) /* UART0_TXD */
+ RZN1_MUX(104, UART0_I) /* UART0_RXD */
+ >;
+ };
+ };
+
+ &uart0 {
+ status = "okay";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinsuart0>;
+ };
+ Note that in this case the other functions of the pins are not changed.
+
+Example #2:
+ Here we also set the pullups on the RXD pin:
+ &pinctrl {
+ pinsuart0: pinsuart0 {
+ renesas,rzn1-pinmux-ids = <
+ RZN1_MUX(103, UART0_I) /* UART0_TXD */
+ RZN1_MUX_PUP(104, UART0_I) /* UART0_RXD */
+ >;
+ };
+ };
+ There are many alternative macros to set the pullup/down/none and the drive
+ strenght in the r9a06g032-pinctrl.h header file.
+
+Example #3:
+ The Soc has two configurable MDIO muxes, these can also be configured
+ with this interface using the 'special' MDIO constants:
+
+ &pinctrl {
+ mdio_mux: mdiomux {
+ renesas,rzn1-pinmux-ids = <
+ RZN1_MUX(RZN1_MDIO_BUS0, RZN1_FUNC_MDIO_MUX_MAC0)
+ RZN1_MUX(RZN1_MDIO_BUS1, RZN1_FUNC_MDIO_MUX_SWITCH)
+ >;
+ };
+ };
+ Clearly the pull/up/none and drive constants will be ignored, even if
+ specified.
+
+Note that Renesas provides an extensive webapp that can generates a device tree
+file for your board. See their website for this part number for details.
--
2.7.4
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