Devices need to report various identifiers in the ACPI tables. Rather than hard-coding these in drivers it is typically better to put them in the device tree.
Add a binding file to describe this. Signed-off-by: Simon Glass <s...@chromium.org> --- doc/device-tree-bindings/device.txt | 37 +++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 doc/device-tree-bindings/device.txt diff --git a/doc/device-tree-bindings/device.txt b/doc/device-tree-bindings/device.txt new file mode 100644 index 0000000000..e625e67f43 --- /dev/null +++ b/doc/device-tree-bindings/device.txt @@ -0,0 +1,37 @@ +Devices +======= + +Device bindings are described by their own individual binding files. + +U-Boot provides for some optional properties which are documented here. + + - acpi,has-power-resource : (boolean) true if this device has a power resource. + This causes a PRIC (ACPI PowerResource) to be written containing the + properties provided by this binding, to describe how to handle powering the + device up and down using GPIOs + - acpi,cid : Contains the string to use as the compatible ID (_CID) + - acpi,compatible : compatible string to report + - acpi,desc : Contains the string to use as the _DDN (DOS (Disk Operating + System) Device Name) + - acpi,hid : Contains the string to use as the HID (Human Interface Device) + identifier _HID + - acpi,hid-desc-reg-offset : HID register offset (for Human Interface Devices) + - acpi,probed : Tells U-Boot to add 'linux,probed' to the ACPI tables so that + Linux will not re-init the device + - acpi,uid : _UID value for device + + +Example +------- + +synaptics_touchpad: synaptics-touchpad@2c { + compatible = "i2c-chip"; + reg = <0x2c>; + acpi,hid = "PNP0C50"; + acpi,cid = "PNP0C50"; + acpi,desc = "Synaptics Touchpad"; + interrupts-extended = <&acpi_gpe GPIO_18_IRQ + IRQ_TYPE_EDGE_FALLING>; + acpi,probed; + acpi,hid-desc-reg-offset = <0x20>; +}; -- 2.25.0.341.g760bfbb309-goog