1 U-Boot I2C 2 ---------- 3 4 U-Boot's I2C model has the concept of an offset within a chip (I2C target 5 device). The offset can be up to 4 bytes long, but is normally 1 byte, 6 meaning that offsets from 0 to 255 are supported by the chip. This often 7 corresponds to register numbers. 8 9 Apart from the controller-specific I2C bindings, U-Boot supports a special 10 property which allows the chip offset length to be selected. 11 12 Optional properties: 13 - u-boot,i2c-offset-len - length of chip offset in bytes. If omitted the 14 default value of 1 is used. 15 - gpios = <sda ...>, <scl ...>; 16 pinctrl-names = "default", "gpio"; 17 pinctrl-0 = <&i2c_xfer>; 18 pinctrl-1 = <&i2c_gpio>; 19 Pin description for I2C bus software deblocking. 20 21 22 Example 23 ------- 24 25 i2c4: i2c@12ca0000 { 26 cros-ec@1e { 27 reg = <0x1e>; 28 compatible = "google,cros-ec"; 29 i2c-max-frequency = <100000>; 30 u-boot,i2c-offset-len = <0>; 31 ec-interrupt = <&gpx1 6 GPIO_ACTIVE_LOW>; 32 }; 33 }; 34 35 &i2c1 { 36 pinctrl-names = "default", "gpio"; 37 pinctrl-0 = <&i2c1_xfer>; 38 pinctrl-1 = <&i2c1_gpio>; 39 gpios = <&gpio1 26 GPIO_ACTIVE_LOW>, /* SDA */ 40 <&gpio1 27 GPIO_ACTIVE_LOW>; /* SCL */ 41 }; 42
