Antwort: [PATCH 013/108] acpi: Add a binding for ACPI settings in the device tree

[Wolfgang Wallner]

Hi Simon,

> +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

Nit: "_HID" in ACPI stands for "Hardware ID"

> + - 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

Would it make sense to automatically infer ACPI properties from existing
device tree properties?

E.g. if the compatible string contains "hid-over-i2c", then _CID could be set
to "PNP0C50".
And a "hid-over-i2c" device would also have a "hid-descr-addr" device tree
property for the offset of the HID descriptor register which could be passed
on in ACPI as part of the _DSM method.

> +
> +
> +Example
> +-------
> +
> +synaptics_touchpad: synaptics-touchpad at 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>;

regards, Wolfgang