diff options
Diffstat (limited to 'Documentation/acpi')
| -rw-r--r-- | Documentation/acpi/i2c-muxes.txt | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/Documentation/acpi/i2c-muxes.txt b/Documentation/acpi/i2c-muxes.txt new file mode 100644 index 000000000000..9fcc4f0b885e --- /dev/null +++ b/Documentation/acpi/i2c-muxes.txt @@ -0,0 +1,58 @@ +ACPI I2C Muxes +-------------- + +Describing an I2C device hierarchy that includes I2C muxes requires an ACPI +Device () scope per mux channel. + +Consider this topology: + ++------+ +------+ +| SMB1 |-->| MUX0 |--CH00--> i2c client A (0x50) +| | | 0x70 |--CH01--> i2c client B (0x50) ++------+ +------+ + +which corresponds to the following ASL: + +Device (SMB1) +{ + Name (_HID, ...) + Device (MUX0) + { + Name (_HID, ...) + Name (_CRS, ResourceTemplate () { + I2cSerialBus (0x70, ControllerInitiated, I2C_SPEED, + AddressingMode7Bit, "^SMB1", 0x00, + ResourceConsumer,,) + } + + Device (CH00) + { + Name (_ADR, 0) + + Device (CLIA) + { + Name (_HID, ...) + Name (_CRS, ResourceTemplate () { + I2cSerialBus (0x50, ControllerInitiated, I2C_SPEED, + AddressingMode7Bit, "^CH00", 0x00, + ResourceConsumer,,) + } + } + } + + Device (CH01) + { + Name (_ADR, 1) + + Device (CLIB) + { + Name (_HID, ...) + Name (_CRS, ResourceTemplate () { + I2cSerialBus (0x50, ControllerInitiated, I2C_SPEED, + AddressingMode7Bit, "^CH01", 0x00, + ResourceConsumer,,) + } + } + } + } +} |