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Diffstat (limited to 'Documentation/devicetree/bindings/i2c/i2c-rk3x.txt')
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diff --git a/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt new file mode 100644 index 000000000..22f2eeb2c --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt @@ -0,0 +1,68 @@ +* Rockchip RK3xxx I2C controller + +This driver interfaces with the native I2C controller present in Rockchip +RK3xxx SoCs. + +Required properties : + + - reg : Offset and length of the register set for the device + - compatible: should be one of the following: + - "rockchip,rv1108-i2c": for rv1108 + - "rockchip,rk3066-i2c": for rk3066 + - "rockchip,rk3188-i2c": for rk3188 + - "rockchip,rk3228-i2c": for rk3228 + - "rockchip,rk3288-i2c": for rk3288 + - "rockchip,rk3328-i2c", "rockchip,rk3399-i2c": for rk3328 + - "rockchip,rk3399-i2c": for rk3399 + - interrupts : interrupt number + - clocks: See ../clock/clock-bindings.txt + - For older hardware (rk3066, rk3188, rk3228, rk3288): + - There is one clock that's used both to derive the functional clock + for the device and as the bus clock. + - For newer hardware (rk3399): specified by name + - "i2c": This is used to derive the functional clock. + - "pclk": This is the bus clock. + +Required on RK3066, RK3188 : + + - rockchip,grf : the phandle of the syscon node for the general register + file (GRF) + - on those SoCs an alias with the correct I2C bus ID (bit offset in the GRF) + is also required. + +Optional properties : + + - clock-frequency : SCL frequency to use (in Hz). If omitted, 100kHz is used. + - i2c-scl-rising-time-ns : Number of nanoseconds the SCL signal takes to rise + (t(r) in I2C specification). If not specified this is assumed to be + the maximum the specification allows(1000 ns for Standard-mode, + 300 ns for Fast-mode) which might cause slightly slower communication. + - i2c-scl-falling-time-ns : Number of nanoseconds the SCL signal takes to fall + (t(f) in the I2C specification). If not specified this is assumed to + be the maximum the specification allows (300 ns) which might cause + slightly slower communication. + - i2c-sda-falling-time-ns : Number of nanoseconds the SDA signal takes to fall + (t(f) in the I2C specification). If not specified we'll use the SCL + value since they are the same in nearly all cases. + +Example: + +aliases { + i2c0 = &i2c0; +} + +i2c0: i2c@2002d000 { + compatible = "rockchip,rk3188-i2c"; + reg = <0x2002d000 0x1000>; + interrupts = <GIC_SPI 40 IRQ_TYPE_LEVEL_HIGH>; + #address-cells = <1>; + #size-cells = <0>; + + rockchip,grf = <&grf>; + + clock-names = "i2c"; + clocks = <&cru PCLK_I2C0>; + + i2c-scl-rising-time-ns = <800>; + i2c-scl-falling-time-ns = <100>; +}; |