From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH 04/10] dt/bindings: Add binding for BCM2835 mailbox power channel driver Date: Tue, 03 Mar 2015 20:07:55 -0700 Message-ID: <54F6770B.9080808@wwwdotorg.org> References: <1425329684-23968-1-git-send-email-eric@anholt.net> <1425329684-23968-5-git-send-email-eric@anholt.net> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1425329684-23968-5-git-send-email-eric-WhKQ6XTQaPysTnJN9+BGXg@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Eric Anholt , linux-arm-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Lee Jones , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jassi Brar , Craig McGeachie , Lubomir Rintel List-Id: devicetree@vger.kernel.org On 03/02/2015 01:54 PM, Eric Anholt wrote: > I was tempted to have the mailbox power channel support just be in the > 2835 mailbox driver itself, but mbox_request_channel() wants its > device to have the "mboxes" node, and that appears to be only intended > for mailbox clients, not controllers. > diff --git a/Documentation/devicetree/bindings/mailbox/brcm,bcm2835-mbox-power.txt b/Documentation/devicetree/bindings/mailbox/brcm,bcm2835-mbox-power.txt > +Broadcom BCM2835 VideoCore mailbox power channel IPC > + > +Required properties: > + > +- compatible : Should be "brcm,bcm2835-mbox-power" > +- mboxes: Single-entry list which specifies which mailbox controller > + and channel is the power channel. > + > +Example: > + > +mailbox-power { > + compatible = "brcm,bcm2835-mbox-power"; > + mboxes = <&mailbox 0> > +}; I think the driver for this device should provide its services to other drivers using some standard in-kernel API (power domains, regulators?), which in turn would presumably have some subsystem-level DT binding. So, I would expect this DT node to implement the server-side of that binding, and probably have a property like "#power-domain-cells = <1>", and the client nodes to "consume" this service via a property like "power-domain = <&mbox_power N>" where N is the ID of the client's power domain within the firmware protocol. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html