1*7132b9fdSSimon GlassU-Boot I2C 2*7132b9fdSSimon Glass---------- 3*7132b9fdSSimon Glass 4*7132b9fdSSimon GlassU-Boot's I2C model has the concept of an offset within a chip (I2C target 5*7132b9fdSSimon Glassdevice). The offset can be up to 4 bytes long, but is normally 1 byte, 6*7132b9fdSSimon Glassmeaning that offsets from 0 to 255 are supported by the chip. This often 7*7132b9fdSSimon Glasscorresponds to register numbers. 8*7132b9fdSSimon Glass 9*7132b9fdSSimon GlassApart from the controller-specific I2C bindings, U-Boot supports a special 10*7132b9fdSSimon Glassproperty which allows the chip offset length to be selected. 11*7132b9fdSSimon Glass 12*7132b9fdSSimon GlassOptional properties: 13*7132b9fdSSimon Glass- u-boot,i2c-offset-len - length of chip offset in bytes. If omitted the 14*7132b9fdSSimon Glass default value of 1 is used. 15*7132b9fdSSimon Glass 16*7132b9fdSSimon Glass 17*7132b9fdSSimon GlassExample 18*7132b9fdSSimon Glass------- 19*7132b9fdSSimon Glass 20*7132b9fdSSimon Glassi2c4: i2c@12ca0000 { 21*7132b9fdSSimon Glass cros-ec@1e { 22*7132b9fdSSimon Glass reg = <0x1e>; 23*7132b9fdSSimon Glass compatible = "google,cros-ec"; 24*7132b9fdSSimon Glass i2c-max-frequency = <100000>; 25*7132b9fdSSimon Glass u-boot,i2c-offset-len = <0>; 26*7132b9fdSSimon Glass ec-interrupt = <&gpx1 6 GPIO_ACTIVE_LOW>; 27*7132b9fdSSimon Glass }; 28*7132b9fdSSimon Glass}; 29