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8d393b2c22
Changes in relation to FriendlyARM's U-Boot nanopi2-v2016.01: - livetree API (dev_read_...) is used instead of fdt one (fdt...). - doc/device-tree-bindings/pinctrl/nexell,s5pxx18-pinctrl.txt added. Signed-off-by: Stefan Bosch <stefan_b@posteo.net>
79 lines
2.4 KiB
Plaintext
79 lines
2.4 KiB
Plaintext
Binding for Nexell s5pxx18 pin cotroller
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========================================
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Nexell's ARM bases SoC's integrates a GPIO and Pin mux/config hardware
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controller. It controls the input/output settings on the available pads/pins
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and also provides ability to multiplex and configure the output of various
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on-chip controllers onto these pads.
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Please refer to pinctrl-bindings.txt in this directory for details of the
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common pinctrl bindings used by client devices, including the meaning of the
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phrase "pin configuration node".
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Required properties:
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- compatible: "nexell,s5pxx18-pinctrl"
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- reg: should be register base and length as documented in the datasheet
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- interrupts: interrupt specifier for the controller over gpio and alive pins
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Example:
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pinctrl_0: pinctrl@c0010000 {
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compatible = "nexell,s5pxx18-pinctrl";
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reg = <0xc0010000 0xf000>;
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u-boot,dm-pre-reloc;
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};
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Nexell's pin configuration nodes act as a container for an arbitrary number of
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subnodes. Each of these subnodes represents some desired configuration for a
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pin, a group, or a list of pins or groups. This configuration can include the
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mux function to select on those pin(s)/group(s), and various pin configuration
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parameters.
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Child nodes must be set at least one of the following settings:
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- pins = Select pins for using this function.
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- pin-function = Select the function for use in a selected pin.
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- pin-pull = Pull up/down configuration.
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- pin-strength = Drive strength configuration.
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Valid values for nexell,pins are:
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"gpioX-N" : X in {A,B,C,D,E}, N in {0-31}
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Valid values for nexell,pin-function are:
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"N" : N in {0-3}.
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This setting means that the value is different for each pin.
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Please refer to datasheet.
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Valid values for nexell,pin-pull are:
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"N" : 0 - Down, 1 - Up, 2 - Off
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Valid values for nexell,pin-strength are:
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"N" : 0,1,2,3
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Example:
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- pin settings
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mmc0_clk: mmc0-clk {
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pins = "gpioa-29";
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pin-function = <1>;
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pin-pull = <2>;
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pin-strength = <2>;
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};
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mmc0_cmd: mmc0-cmd {
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pins = "gpioa-31";
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pin-function = <1>;
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pin-pull = <2>;
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pin-strength = <1>;
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};
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mmc0_bus4: mmc0-bus-width4 {
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pins = "gpiob-1, gpiob-3, gpiob-5, gpiob-7";
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pin-function = <1>;
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pin-pull = <2>;
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pin-strength = <1>;
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};
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- used by client devices
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mmc0:mmc@... {
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pinctrl-names = "default";
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pinctrl-0 = <&mmc0_clk>, <&mmc0_cmd>, <&mmc0_bus4>;
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...
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};
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