Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / devicetree / bindings / i2c / i2c-rk3x.txt

diff --git a/kernel/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt b/kernel/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt
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+* 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 "rockchip,rk3066-i2c", "rockchip,rk3188-i2c" or
+               "rockchip,rk3288-i2c".
+ - interrupts : interrupt number
+ - clocks : parent 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>;
+};