| Dustin Byford | 8eb5c87 | 2015-10-23 12:27:07 -0700 | [diff] [blame] | 1 | ACPI I2C Muxes |
| 2 | -------------- |
| 3 | |
| 4 | Describing an I2C device hierarchy that includes I2C muxes requires an ACPI |
| 5 | Device () scope per mux channel. |
| 6 | |
| 7 | Consider this topology: |
| 8 | |
| 9 | +------+ +------+ |
| 10 | | SMB1 |-->| MUX0 |--CH00--> i2c client A (0x50) |
| 11 | | | | 0x70 |--CH01--> i2c client B (0x50) |
| 12 | +------+ +------+ |
| 13 | |
| 14 | which corresponds to the following ASL: |
| 15 | |
| 16 | Device (SMB1) |
| 17 | { |
| 18 | Name (_HID, ...) |
| 19 | Device (MUX0) |
| 20 | { |
| 21 | Name (_HID, ...) |
| 22 | Name (_CRS, ResourceTemplate () { |
| 23 | I2cSerialBus (0x70, ControllerInitiated, I2C_SPEED, |
| 24 | AddressingMode7Bit, "^SMB1", 0x00, |
| 25 | ResourceConsumer,,) |
| 26 | } |
| 27 | |
| 28 | Device (CH00) |
| 29 | { |
| 30 | Name (_ADR, 0) |
| 31 | |
| 32 | Device (CLIA) |
| 33 | { |
| 34 | Name (_HID, ...) |
| 35 | Name (_CRS, ResourceTemplate () { |
| 36 | I2cSerialBus (0x50, ControllerInitiated, I2C_SPEED, |
| 37 | AddressingMode7Bit, "^CH00", 0x00, |
| 38 | ResourceConsumer,,) |
| 39 | } |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | Device (CH01) |
| 44 | { |
| 45 | Name (_ADR, 1) |
| 46 | |
| 47 | Device (CLIB) |
| 48 | { |
| 49 | Name (_HID, ...) |
| 50 | Name (_CRS, ResourceTemplate () { |
| 51 | I2cSerialBus (0x50, ControllerInitiated, I2C_SPEED, |
| 52 | AddressingMode7Bit, "^CH01", 0x00, |
| 53 | ResourceConsumer,,) |
| 54 | } |
| 55 | } |
| 56 | } |
| 57 | } |
| 58 | } |