| U-Boot I2C |
| ---------- |
| |
| U-Boot's I2C model has the concept of an offset within a chip (I2C target |
| device). The offset can be up to 4 bytes long, but is normally 1 byte, |
| meaning that offsets from 0 to 255 are supported by the chip. This often |
| corresponds to register numbers. |
| |
| Apart from the controller-specific I2C bindings, U-Boot supports a special |
| property which allows the chip offset length to be selected. |
| |
| Optional properties: |
| - u-boot,i2c-offset-len - length of chip offset in bytes. If omitted the |
| default value of 1 is used. |
| - gpios = <sda ...>, <scl ...>; |
| pinctrl-names = "default", "gpio"; |
| pinctrl-0 = <&i2c_xfer>; |
| pinctrl-1 = <&i2c_gpio>; |
| Pin description for I2C bus software deblocking. |
| |
| |
| Example |
| ------- |
| |
| i2c4: i2c@12ca0000 { |
| cros-ec@1e { |
| reg = <0x1e>; |
| compatible = "google,cros-ec"; |
| i2c-max-frequency = <100000>; |
| u-boot,i2c-offset-len = <0>; |
| ec-interrupt = <&gpx1 6 GPIO_ACTIVE_LOW>; |
| }; |
| }; |
| |
| &i2c1 { |
| pinctrl-names = "default", "gpio"; |
| pinctrl-0 = <&i2c1_xfer>; |
| pinctrl-1 = <&i2c1_gpio>; |
| gpios = <&gpio1 26 GPIO_ACTIVE_LOW>, /* SDA */ |
| <&gpio1 27 GPIO_ACTIVE_LOW>; /* SCL */ |
| }; |
