projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 9d230c9e DA |
1 | I2C bus that tunnels through the ChromeOS EC (cros-ec) |
| 2 | ====================================================== | |
| 3 | On some ChromeOS board designs we've got a connection to the EC (embedded | |
| 4 | controller) but no direct connection to some devices on the other side of | |
| 5 | the EC (like a battery and PMIC). To get access to those devices we need | |
| 6 | to tunnel our i2c commands through the EC. | |
| 7 | ||
| 8 | The node for this device should be under a cros-ec node like google,cros-ec-spi | |
| 9 | or google,cros-ec-i2c. | |
| 10 | ||
| 11 | ||
| 12 | Required properties: | |
| 13 | - compatible: google,cros-ec-i2c-tunnel | |
| 14 | - google,remote-bus: The EC bus we'd like to talk to. | |
| 15 | ||
| 16 | Optional child nodes: | |
| 17 | - One node per I2C device connected to the tunnelled I2C bus. | |
| 18 | ||
| 19 | ||
| 20 | Example: | |
| 21 | cros-ec@0 { | |
| 22 | compatible = "google,cros-ec-spi"; | |
| 23 | ||
| 24 | ... | |
| 25 | ||
| 26 | i2c-tunnel { | |
| 27 | compatible = "google,cros-ec-i2c-tunnel"; | |
| 28 | #address-cells = <1>; | |
| 29 | #size-cells = <0>; | |
| 30 | ||
| 31 | google,remote-bus = <0>; | |
| 32 | ||
| 33 | battery: sbs-battery@b { | |
| 34 | compatible = "sbs,sbs-battery"; | |
| 35 | reg = <0xb>; | |
| 36 | sbs,poll-retry-count = <1>; | |
| 37 | }; | |
| 38 | }; | |
| 39 | } |