^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) Pinctrl-based I2C Bus Mux
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) This binding describes an I2C bus multiplexer that uses pin multiplexing to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) route the I2C signals, and represents the pin multiplexing configuration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) using the pinctrl device tree bindings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) +-----+ +-----+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) | dev | | dev |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) +------------------------+ +-----+ +-----+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) | SoC | | |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) | /----|------+--------+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) | +---+ +------+ | child bus A, on first set of pins
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) | |I2C|---|Pinmux| |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) | +---+ +------+ | child bus B, on second set of pins
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) | \----|------+--------+--------+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) | | | | |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) +------------------------+ +-----+ +-----+ +-----+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) | dev | | dev | | dev |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) +-----+ +-----+ +-----+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) Required properties:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) - compatible: i2c-mux-pinctrl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) - i2c-parent: The phandle of the I2C bus that this multiplexer's master-side
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) port is connected to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) Also required are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * Standard pinctrl properties that specify the pin mux state for each child
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) bus. See ../pinctrl/pinctrl-bindings.txt.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * Standard I2C mux properties. See i2c-mux.txt in this directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * I2C child bus nodes. See i2c-mux.txt in this directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) For each named state defined in the pinctrl-names property, an I2C child bus
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) will be created. I2C child bus numbers are assigned based on the index into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) the pinctrl-names property.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) The only exception is that no bus will be created for a state named "idle". If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) such a state is defined, it must be the last entry in pinctrl-names. For
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) pinctrl-names = "ddc", "pta", "idle" -> ddc = bus 0, pta = bus 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) pinctrl-names = "ddc", "idle", "pta" -> Invalid ("idle" not last)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) pinctrl-names = "idle", "ddc", "pta" -> Invalid ("idle" not last)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) Whenever an access is made to a device on a child bus, the relevant pinctrl
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) state will be programmed into hardware.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) If an idle state is defined, whenever an access is not being made to a device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) on a child bus, the idle pinctrl state will be programmed into hardware.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) If an idle state is not defined, the most recently used pinctrl state will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) left programmed into hardware whenever no access is being made of a device on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) a child bus.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) Example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) i2cmux {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) compatible = "i2c-mux-pinctrl";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) #address-cells = <1>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) #size-cells = <0>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) i2c-parent = <&i2c1>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) pinctrl-names = "ddc", "pta", "idle";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) pinctrl-0 = <&state_i2cmux_ddc>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) pinctrl-1 = <&state_i2cmux_pta>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) pinctrl-2 = <&state_i2cmux_idle>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) i2c@0 {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) reg = <0>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) #address-cells = <1>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) #size-cells = <0>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) eeprom {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) compatible = "eeprom";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) reg = <0x50>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) i2c@1 {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) reg = <1>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) #address-cells = <1>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) #size-cells = <0>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) eeprom {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) compatible = "eeprom";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) reg = <0x50>;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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