Hung-ying Tyan | 8836438 | 2013-05-15 18:27:28 +0800 | [diff] [blame] | 1 | Chrome OS CROS_EC Binding |
| 2 | ====================== |
| 3 | |
| 4 | The device tree node which describes the operation of the CROS_EC interface |
| 5 | is as follows: |
| 6 | |
| 7 | Required properties : |
| 8 | - compatible = "google,cros-ec" |
| 9 | |
| 10 | Optional properties : |
| 11 | - spi-max-frequency : Sets the maximum frequency (in Hz) for SPI bus |
| 12 | operation |
| 13 | - i2c-max-frequency : Sets the maximum frequency (in Hz) for I2C bus |
| 14 | operation |
| 15 | - ec-interrupt : Selects the EC interrupt, defined as a GPIO according |
| 16 | to the platform |
| 17 | - optimise-flash-write : Boolean property - if present then flash blocks |
| 18 | containing all 0xff will not be written, since we assume that the EC |
| 19 | uses that pattern for erased blocks |
| 20 | |
| 21 | The CROS_EC node should appear as a subnode of the interrupt that connects it |
| 22 | to the EC (e.g. i2c, spi, lpc). The reg property (as usual) will indicate |
| 23 | the unit address on that bus. |
| 24 | |
| 25 | |
| 26 | Example |
| 27 | ======= |
| 28 | |
| 29 | spi@131b0000 { |
| 30 | cros-ec@0 { |
| 31 | reg = <0>; |
| 32 | compatible = "google,cros-ec"; |
| 33 | spi-max-frequency = <5000000>; |
| 34 | ec-interrupt = <&gpio 174 1>; |
| 35 | optimise-flash-write; |
| 36 | status = "disabled"; |
| 37 | }; |
| 38 | }; |