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Diffstat (limited to 'Documentation/devicetree/bindings/pinctrl')
| -rw-r--r-- | Documentation/devicetree/bindings/pinctrl/img,tz1090-pdc-pinctrl.txt | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pinctrl/img,tz1090-pdc-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/img,tz1090-pdc-pinctrl.txt new file mode 100644 index 000000000000..9f7a85bb8fca --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/img,tz1090-pdc-pinctrl.txt @@ -0,0 +1,130 @@ +ImgTec TZ1090 PDC pin controller + +Required properties: +- compatible: "img,tz1090-pdc-pinctrl" +- reg: Should contain the register physical address and length of the + SOC_GPIO_CONTROL registers in the PDC register region. + +Please refer to pinctrl-bindings.txt in this directory for details of the +common pinctrl bindings used by client devices, including the meaning of the +phrase "pin configuration node". + +TZ1090-PDC's pin configuration nodes act as a container for an abitrary number +of subnodes. Each of these subnodes represents some desired configuration for a +pin, a group, or a list of pins or groups. This configuration can include the +mux function to select on those pin(s)/group(s), and various pin configuration +parameters, such as pull-up, drive strength, etc. + +The name of each subnode is not important; all subnodes should be enumerated +and processed purely based on their content. + +Each subnode only affects those parameters that are explicitly listed. In +other words, a subnode that lists a mux function but no pin configuration +parameters implies no information about any pin configuration parameters. +Similarly, a pin subnode that describes a pullup parameter implies no +information about e.g. the mux function. For this reason, even seemingly boolean +values are actually tristates in this binding: unspecified, off, or on. +Unspecified is represented as an absent property, and off/on are represented as +integer values 0 and 1. + +Required subnode-properties: +- tz1090,pins : An array of strings. Each string contains the name of a pin or + group. Valid values for these names are listed below. + +Optional subnode-properties: +- tz1090,function: A string containing the name of the function to mux to the + pin or group. Valid values for function names are listed below, including + which pingroups can be muxed to them. +- supported generic pinconfig properties (for further details see + Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt): + - bias-disable + - bias-high-impedance + - bias-bus-hold + - bias-pull-up + - bias-pull-down + - input-schmitt-enable + - input-schmitt-disable + - slew-rate: Integer, control slew rate of pins. + 0: slow (half frequency) + 1: fast + - drive-strength: Integer, control drive strength of pins in mA. + 2: 2mA + 4: 4mA + 8: 8mA + 12: 12mA + - low-power-enable: Flag, power-on-start weak pull-down for invalid power. + - low-power-disable: Flag, power-on-start weak pull-down disabled. + +Note that many of these properties are only valid for certain specific pins +or groups. See the TZ1090 TRM for complete details regarding which groups +support which functionality. The Linux pinctrl driver may also be a useful +reference. + +Valid values for pin and group names are: + + pins: + + These all support bias-high-impediance, bias-pull-up, bias-pull-down, and + bias-bus-hold (which can also be provided to any of the groups below to set + it for all gpio pins in that group). + + gpio0, gpio1, sys_wake0, sys_wake1, sys_wake2, ir_data, ext_power. + + mux groups: + + These all support function. + + gpio0 + pins: gpio0. + function: ir_mod_stable_out. + gpio1 + pins: gpio1. + function: ir_mod_power_out. + + drive groups: + + These support input-schmitt-enable, input-schmitt-disable, slew-rate, + drive-strength, low-power-enable, and low-power-disable. + + pdc + pins: gpio0, gpio1, sys_wake0, sys_wake1, sys_wake2, ir_data, + ext_power. + +Example: + + pinctrl_pdc: pinctrl@02006500 { + #gpio-range-cells = <3>; + compatible = "img,tz1090-pdc-pinctrl"; + reg = <0x02006500 0x100>; + }; + +Example board file extracts: + + &pinctrl_pdc { + pinctrl-names = "default"; + pinctrl-0 = <&syswake_default>; + + syswake_default: syswakes { + syswake_cfg { + tz1090,pins = "sys_wake0", + "sys_wake1", + "sys_wake2"; + pull-up; + }; + }; + irmod_default: irmod { + gpio0_cfg { + tz1090,pins = "gpio0"; + tz1090,function = "ir_mod_stable_out"; + }; + gpio1_cfg { + tz1090,pins = "gpio1"; + tz1090,function = "ir_mod_power_out"; + }; + }; + }; + + ir: ir@02006200 { + pinctrl-names = "default"; + pinctrl-0 = <&irmod_default>; + }; |