From mboxrd@z Thu Jan 1 00:00:00 1970 From: tomi.valkeinen@ti.com (Tomi Valkeinen) Date: Tue, 20 Nov 2012 16:48:18 +0200 Subject: [PATCHv9 1/3] Runtime Interpreted Power Sequences In-Reply-To: <1353149747-31871-2-git-send-email-acourbot@nvidia.com> References: <1353149747-31871-1-git-send-email-acourbot@nvidia.com> <1353149747-31871-2-git-send-email-acourbot@nvidia.com> Message-ID: <50AB9832.90709@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On 2012-11-17 12:55, Alexandre Courbot wrote: A few questions after looking at the documentation: > +Example > +------- > +Here are example sequences declared within a backlight device that use all the > +supported resources types: > + > + backlight { > + compatible = "pwm-backlight"; > + ... > + > + /* resources used by the power sequences */ > + pwms = <&pwm 2 5000000>; > + pwm-names = "backlight"; > + power-supply = <&backlight_reg>; > + > + power-sequences { > + power-on { > + step0 { > + type = "regulator"; > + id = "power"; > + enable; > + }; > + step1 { > + type = "delay"; > + delay = <10000>; > + }; > + step2 { > + type = "pwm"; > + id = "backlight"; > + enable; > + }; > + step3 { > + type = "gpio"; > + gpio = <&gpio 28 0>; > + value = <1>; > + }; > + }; I guess there's a reason, but the above looks a bit inconsistent. For gpio you define the gpio resource inside the step. For power and pwm the resource is defined before the steps. Why wouldn't "pwm = <&pwm 2 5000000>;" work in step2? > +When a power sequence is run, its steps is executed one after the other until > +one step fails or the end of the sequence is reached. The document doesn't give any hint of what the driver should do if running the power sequence fails. Run the "opposite" power sequence? Will that work for all resources? I'm mainly thinking of a case where each enable of the resource should be matched by a disable, i.e. you can't call disable if no enable was called. Tomi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 897 bytes Desc: OpenPGP digital signature URL: