xref: /OK3568_Linux_fs/u-boot/doc/device-tree-bindings/i2c/i2c.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunU-Boot I2C
2*4882a593Smuzhiyun----------
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunU-Boot's I2C model has the concept of an offset within a chip (I2C target
5*4882a593Smuzhiyundevice). The offset can be up to 4 bytes long, but is normally 1 byte,
6*4882a593Smuzhiyunmeaning that offsets from 0 to 255 are supported by the chip. This often
7*4882a593Smuzhiyuncorresponds to register numbers.
8*4882a593Smuzhiyun
9*4882a593SmuzhiyunApart from the controller-specific I2C bindings, U-Boot supports a special
10*4882a593Smuzhiyunproperty which allows the chip offset length to be selected.
11*4882a593Smuzhiyun
12*4882a593SmuzhiyunOptional properties:
13*4882a593Smuzhiyun- u-boot,i2c-offset-len - length of chip offset in bytes. If omitted the
14*4882a593Smuzhiyun    default value of 1 is used.
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun
17*4882a593SmuzhiyunExample
18*4882a593Smuzhiyun-------
19*4882a593Smuzhiyun
20*4882a593Smuzhiyuni2c4: i2c@12ca0000 {
21*4882a593Smuzhiyun	cros-ec@1e {
22*4882a593Smuzhiyun		reg = <0x1e>;
23*4882a593Smuzhiyun		compatible = "google,cros-ec";
24*4882a593Smuzhiyun		i2c-max-frequency = <100000>;
25*4882a593Smuzhiyun		u-boot,i2c-offset-len = <0>;
26*4882a593Smuzhiyun		ec-interrupt = <&gpx1 6 GPIO_ACTIVE_LOW>;
27*4882a593Smuzhiyun	};
28*4882a593Smuzhiyun};
29