17132b9fdSSimon GlassU-Boot I2C 27132b9fdSSimon Glass---------- 37132b9fdSSimon Glass 47132b9fdSSimon GlassU-Boot's I2C model has the concept of an offset within a chip (I2C target 57132b9fdSSimon Glassdevice). The offset can be up to 4 bytes long, but is normally 1 byte, 67132b9fdSSimon Glassmeaning that offsets from 0 to 255 are supported by the chip. This often 77132b9fdSSimon Glasscorresponds to register numbers. 87132b9fdSSimon Glass 97132b9fdSSimon GlassApart from the controller-specific I2C bindings, U-Boot supports a special 107132b9fdSSimon Glassproperty which allows the chip offset length to be selected. 117132b9fdSSimon Glass 127132b9fdSSimon GlassOptional properties: 137132b9fdSSimon Glass- u-boot,i2c-offset-len - length of chip offset in bytes. If omitted the 147132b9fdSSimon Glass default value of 1 is used. 15*df8dcac8SAlexander Kochetkov- gpios = <sda ...>, <scl ...>; 16*df8dcac8SAlexander Kochetkov pinctrl-names = "default", "gpio"; 17*df8dcac8SAlexander Kochetkov pinctrl-0 = <&i2c_xfer>; 18*df8dcac8SAlexander Kochetkov pinctrl-1 = <&i2c_gpio>; 19*df8dcac8SAlexander Kochetkov Pin description for I2C bus software deblocking. 207132b9fdSSimon Glass 217132b9fdSSimon Glass 227132b9fdSSimon GlassExample 237132b9fdSSimon Glass------- 247132b9fdSSimon Glass 257132b9fdSSimon Glassi2c4: i2c@12ca0000 { 267132b9fdSSimon Glass cros-ec@1e { 277132b9fdSSimon Glass reg = <0x1e>; 287132b9fdSSimon Glass compatible = "google,cros-ec"; 297132b9fdSSimon Glass i2c-max-frequency = <100000>; 307132b9fdSSimon Glass u-boot,i2c-offset-len = <0>; 317132b9fdSSimon Glass ec-interrupt = <&gpx1 6 GPIO_ACTIVE_LOW>; 327132b9fdSSimon Glass }; 337132b9fdSSimon Glass}; 34*df8dcac8SAlexander Kochetkov 35*df8dcac8SAlexander Kochetkov&i2c1 { 36*df8dcac8SAlexander Kochetkov pinctrl-names = "default", "gpio"; 37*df8dcac8SAlexander Kochetkov pinctrl-0 = <&i2c1_xfer>; 38*df8dcac8SAlexander Kochetkov pinctrl-1 = <&i2c1_gpio>; 39*df8dcac8SAlexander Kochetkov gpios = <&gpio1 26 GPIO_ACTIVE_LOW>, /* SDA */ 40*df8dcac8SAlexander Kochetkov <&gpio1 27 GPIO_ACTIVE_LOW>; /* SCL */ 41*df8dcac8SAlexander Kochetkov}; 42