mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-26 14:40:41 +00:00
7132b9fd68
Since U-Boot can support different offset lengths (0-4 bytes), add a device tree property to specify this. This avoids hard-coding it in the driver. Signed-off-by: Simon Glass <sjg@chromium.org>
28 lines
755 B
Text
28 lines
755 B
Text
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.
|
|
|
|
|
|
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>;
|
|
};
|
|
};
|