Re: [PATCH] mailbox: add ACPI support for mailbox framework

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Wed, Apr 01, 2015 at 10:01:45AM -0700, Feng Kan wrote:
> On Wed, Apr 1, 2015 at 12:45 AM, Mika Westerberg
> <mika.westerberg@linux.intel.com> wrote:
> > On Tue, Mar 31, 2015 at 02:18:00PM -0700, Feng Kan wrote:
> >> This will add support for ACPI parsing of the mboxes attribute
> >> when booting with ACPI table. The client will have a attribute
> >> mimic the dts call "mboxes". In the ACPI case, the client will
> >> mark "mboxes" with the ACPI HID of the mbox it wishes to use.
> >>
> >>       Name (_DSD, Package () {
> >>               ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> >>               Package () {
> >>                       Package (2) {"mboxes", "ACPIHID"},
> >>               }
> >>       })
> >
> > Instead of this, why not match against the DT compatible property?
> >
> >         Name (_HID, "PRP0001")
> >
> >         Name (_DSD, Package () {
> >                 ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
> >                 Package () {
> >                         Package (2) {"compatible", "your-dt-compatible-string"},
> >                 }
> >         })
> I think my description was not clear enough. The _DSD section is not
> meant to identify the mailbox driver, but used by the acpi node that will
> request the mailbox channel. The dts version would be as below.
> 
>    mailbox: {
>    }
> 
>    user-mbox: {
>       mboxes: <&mailbox 0>
>    }
> 
> The mboxes attribute in the user of the mbox has to specify the HID of the
> mbox in order to retrieve channel pointer.

Okay, then I think you can use reference instead of _HID, like

	// The mailbox device
	Device (MLBX) {
	}

	// User-mbox device
	Device (USBX) {
		Name (_DSD, Package () {
			ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
			Package () {
				Package () {"mboxes", Package () {^^MLBX, 0}}),
			}
		})
	}