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Diffstat (limited to 'Documentation/devicetree/bindings')
| -rw-r--r-- | Documentation/devicetree/bindings/pinctrl/renesas,rza1-pinctrl.txt | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pinctrl/renesas,rza1-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/renesas,rza1-pinctrl.txt new file mode 100644 index 000000000000..43e21474528a --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/renesas,rza1-pinctrl.txt @@ -0,0 +1,221 @@ +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 + this shall be "renesas,r7s72100-ports". + + - reg + address base and length of the memory area where the pin controller + hardware is mapped to. + +Example: +Pin controller node for RZ/A1H SoC (r7s72100) + +pinctrl: pin-controller@fcfe3000 { + compatible = "renesas,r7s72100-ports"; + + reg = <0xfcfe3000 0x4230>; +}; + +Sub-nodes +--------- + +The child nodes of the pin controller node describe a pin multiplexing +function or a GPIO controller alternatively. + +- Pin multiplexing sub-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. + A few alternate function require special pin configuration flags to be + supplied along with the alternate function configuration number. + The hardware reference manual specifies when a pin function requires + "software IO driven" mode to be specified. To do so use the generic + properties from the <include/linux/pinctrl/pinconf_generic.h> header file + to instruct the pin controller to perform the desired pin configuration + operation. + Please refer to pinctrl-bindings.txt to get to know more on generic + pin properties usage. + + The allowed generic formats for a pin multiplexing sub-node are the + following ones: + + node-1 { + pinmux = <PIN_ID_AND_MUX>, <PIN_ID_AND_MUX>, ... ; + GENERIC_PINCONFIG; + }; + + node-2 { + sub-node-1 { + pinmux = <PIN_ID_AND_MUX>, <PIN_ID_AND_MUX>, ... ; + GENERIC_PINCONFIG; + }; + + sub-node-2 { + pinmux = <PIN_ID_AND_MUX>, <PIN_ID_AND_MUX>, ... ; + GENERIC_PINCONFIG; + }; + + ... + + sub-node-n { + pinmux = <PIN_ID_AND_MUX>, <PIN_ID_AND_MUX>, ... ; + GENERIC_PINCONFIG; + }; + }; + + Use the second format when pins part of the same logical group need to have + different generic pin configuration flags applied. + + 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: + - pinmux: + integer array representing pin number and pin multiplexing configuration. + When a pin has to be configured in alternate function mode, use this + property to identify the pin by its global index, and provide its + alternate function configuration number along with it. + When multiple pins are required to be configured as part of the same + alternate function they shall be specified as members of the same + argument list of a single "pinmux" property. + Helper macros to ease assembling the pin index from its position + (port where it sits on and pin number) and alternate function identifier + are provided by the pin controller header file at: + <include/dt-bindings/pinctrl/r7s72100-pinctrl.h> + Integers values in "pinmux" argument list are assembled as: + ((PORT * 16 + PIN) | MUX_FUNC << 16) + + Optional generic properties: + - input-enable: + enable input bufer for pins requiring software driven IO input + operations. + - output-high: + enable output buffer for pins requiring software driven IO output + operations. output-low can be used alternatively, as line value is + ignored by the driver. + + The hardware reference manual specifies when a pin has to be configured to + work in bi-directional mode and when the IO direction has to be specified + by software. Bi-directional pins are managed by the pin controller driver + internally, while software driven IO direction has to be explicitly + selected when multiple options are available. + + Example: + A serial communication interface with a TX output pin and an RX input pin. + + &pinctrl { + scif2_pins: serial2 { + pinmux = <RZA1_PINMUX(3, 0, 6)>, <RZA1_PINMUX(3, 2, 4)>; + }; + }; + + Pin #0 on port #3 is configured as alternate function #6. + Pin #2 on port #3 is configured as alternate function #4. + + Example 2: + I2c master: both SDA and SCL pins need bi-directional operations + + &pinctrl { + i2c2_pins: i2c2 { + pinmux = <RZA1_PINMUX(1, 4, 1)>, <RZA1_PINMUX(1, 5, 1)>; + }; + }; + + Pin #4 on port #1 is configured as alternate function #1. + Pin #5 on port #1 is configured as alternate function #1. + Both need to work in bi-directional mode, the driver manages this internally. + + Example 3: + Multi-function timer input and output compare pins. + Configure TIOC0A as software driven input and TIOC0B as software driven + output. + + &pinctrl { + tioc0_pins: tioc0 { + tioc0_input_pins { + pinumx = <RZA1_PINMUX(4, 0, 2)>; + input-enable; + }; + + tioc0_output_pins { + pinmux = <RZA1_PINMUX(4, 1, 1)>; + output-enable; + }; + }; + }; + + &tioc0 { + ... + pinctrl-0 = <&tioc0_pins>; + ... + }; + + Pin #0 on port #4 is configured as alternate function #2 with IO direction + specified by software as input. + Pin #1 on port #4 is configured as alternate function #1 with IO direction + specified by software as output. + +- GPIO controller sub-nodes: + Each port of the r7s72100 pin controller hardware is itself a GPIO controller. + Different SoCs have different numbers of available pins per port, but + generally speaking, each of them can be configured in GPIO ("port") mode + on this hardware. + Describe GPIO controllers using sub-nodes with the following properties. + + Required properties: + - gpio-controller + empty property as defined by the GPIO bindings documentation. + - #gpio-cells + number of cells required to identify and configure a GPIO. + Shall be 2. + - gpio-ranges + Describes a GPIO controller specifying its specific pin base, the pin + base in the global pin numbering space, and the number of controlled + pins, as defined by the GPIO bindings documentation. Refer to + Documentation/devicetree/bindings/gpio/gpio.txt file for a more detailed + description. + + Example: + A GPIO controller node, controlling 16 pins indexed from 0. + The GPIO controller base in the global pin indexing space is pin 48, thus + pins [0 - 15] on this controller map to pins [48 - 63] in the global pin + indexing space. + + port3: gpio-3 { + gpio-controller; + #gpio-cells = <2>; + gpio-ranges = <&pinctrl 0 48 16>; + }; + + A device node willing to use pins controlled by this GPIO controller, shall + refer to it as follows: + + led1 { + gpios = <&port3 10 GPIO_ACTIVE_LOW>; + }; |