Re: [PATCH] Documentation: acpi: Add an example for PRP0001

Andy Shevchenko
2019-03-25T11:51:23Z

On Mon, Mar 25, 2019 at 10:31:13AM +0100, Rafael J. Wysocki wrote:
> On Fri, Mar 22, 2019 at 2:47 PM Thomas Preston
> <thomas.preston@codethink.co.uk> wrote:
> >
> > Add an example for the magic PRP0001 device ID which allows matching
> > ACPI devices against drivers using OF Device Tree compatible property.
> > It wasn't clear to me that PRP0001 could be used in _CID.
>
> Mika, Andy, can you have a look at this, please?

Good to me,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Though one thing I would like to add (not directly related to the patch
per se), i.e. it would be nice to keep such examples under meta-acpi [1]
umbrella as a database for such excerpts.

Thomas, can you do that?

[1]: https://github.com/westeri/meta-acpi

> > Signed-off-by: Thomas Preston <thomas.preston@codethink.co.uk>
> > ---
> > Documentation/acpi/enumeration.txt | 27 +++++++++++++++++++++++++++
> > 1 file changed, 27 insertions(+)
> >
> > diff --git a/Documentation/acpi/enumeration.txt b/Documentation/acpi/enumeration.txt
> > index 7bcf9c3d9fbe..391db643065a 100644
> > --- a/Documentation/acpi/enumeration.txt
> > +++ b/Documentation/acpi/enumeration.txt
> > @@ -410,6 +410,33 @@ Specifically, the device IDs returned by _HID and preceding PRP0001 in the _CID
> > return package will be checked first. Also in that case the bus type the device
> > will be enumerated to depends on the device ID returned by _HID.
> >
> > +For example, the following ACPI sample might be used to enumerate an lm75-type
> > +I2C temperature sensor and match it to the driver using the Device Tree
> > +namespace link:
> > +
> > + Device (TMP0)
> > + {
> > + Name (_HID, "TITMP75") /* _HID will appear in sysfs */
> > + Name (_CID, "PRP0001")
> > + Name (_DSD, Package() {
> > + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> > + Package () {
> > + Package (2) { "compatible", "ti,tmp75" },
> > + }
> > + })
> > + Method (_CRS, 0, Serialized)
> > + {
> > + Name (SBUF, ResourceTemplate ()
> > + {
> > + I2cSerialBusV2 (0x48, ControllerInitiated,
> > + 400000, AddressingMode7Bit,
> > + "\\_SB.PCI0.I2C1", 0x00,
> > + ResourceConsumer, , Exclusive,)
> > + })
> > + Return (SBUF)
> > + }
> > + }
> > +
> > It is valid to define device objects with a _HID returning PRP0001 and without
> > the "compatible" property in the _DSD or a _CID as long as one of their
> > ancestors provides a _DSD with a valid "compatible" property. Such device
> > --
> > 2.11.0
> >

--
With Best Regards,
Andy Shevchenko