From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [RFC][PATCH v3 1/3] runtime interpreted power sequences Date: Thu, 2 Aug 2012 10:21:57 +0200 Message-ID: <20120802082157.GA14866@avionic-0098.adnet.avionic-design.de> References: <1343390750-3642-1-git-send-email-acourbot@nvidia.com> <1343390750-3642-2-git-send-email-acourbot@nvidia.com> <50170EA0.1010408@wwwdotorg.org> <501A338D.7080105@nvidia.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="OgqxwSJOaUobr8KG" Return-path: Content-Disposition: inline In-Reply-To: <501A338D.7080105-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alex Courbot Cc: Stephen Warren , Stephen Warren , Simon Glass , Grant Likely , Rob Herring , Greg Kroah-Hartman , Mark Brown , Arnd Bergmann , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" List-Id: devicetree@vger.kernel.org --OgqxwSJOaUobr8KG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 02, 2012 at 05:00:13PM +0900, Alex Courbot wrote: > On 07/31/2012 07:45 AM, Stephen Warren wrote: > >Oh I see. That's a little confusing. Why not just reference the relevant > >resources directly in each step; something more like: > > > > gpio@1 { > > action =3D "enable-gpio"; > > gpio =3D <&gpio 1 0>; > > }; > > > >I guess that might make parsing/building a little harder, since you'd > >have to detect when you'd already done gpio_request() on a given GPIO > >and not repeat it or something like that, but to me this makes the DT a > >lot easier to comprehend. >=20 > I tried to move towards having the phandles directly in the > sequences themselves - that reminded me why I did not do that in the > first place. Let's say we have a sequence like this (reg property > omitted on purpose): >=20 > power-on-sequence { > step@0 { > regulator =3D <&backlight_reg>; > enable; > }; > step@1 { > delay =3D <10000>; > }; > step@2 { > pwm =3D <&pwm 2 5000000>; > enable; > }; > step@3 { > gpio =3D <&gpio 28 0>; > enable; > }; > }; >=20 > The problem is, how do we turn these phandles into the resource of > interest. The type of the resource can be infered by the name of the > property. The hard part is resolving the resource from the phandle - > it seems like the API just does not allow to do this. GPIO has > of_get_named_gpio, but AFAIK there are no equivalent for regulator > consumer and PWM: the only way to use the DT with them is through > get_regulator and get_pwm which work at the device level. >=20 > Or is there a way that I overlooked? No, you are right. Perhaps we should add exported functions that do the equivalent of of_pwm_request() or the regulator_dev_lookup() and of_get_regulator() pair. Thierry --OgqxwSJOaUobr8KG Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQIcBAEBAgAGBQJQGjilAAoJEN0jrNd/PrOhWQIP/ia8nbamFqB7B7+uXDeV7vqy GRrn/b9KIIWdIIij79MoJKaoljC2Cwf+i5gviN5IrbN/wvLlZtPXLbO6du3u+YF6 4+b48S8oEysitxKCw3/9t1GGRZVbcLuC2ulHr+GOAsH42J5tD/X8NsSOPBMiL6Zm jqNP56WcuDAyAG1maCu3cBX66rp8K3ErfOb6QveFmzAWZKGajvQY+/bkdp+bQRPX gAe7SOqVp1n9u4Tj8gqJC6UQyp+hDulDEZ4yQx/fyRJbxuy1i0gu+33FWhFSVolQ +aHDIhSZdClv9AnCp2HM8FrXh4BWTh2h31wu+P3h+IV2D0OzQ45SJ/uptMPkwhoT CjeGIsDxfOI7yriCUxZ65zHnhdlPRJP9FSF+5qknRthgxP4LCidEcdMidPU5lLQa ditQPl8iiuMq3gDr/GTkOQpiSThAP6GOqhdRVWz8wJgnxKibKMMNvV8mgz+kfMSW N+N38Lj/njak7rIqkdrDilxrtpqFJq3kqOY97O0wVGdelpx8lT8Qu7NoOIsanDdh IL1UO5pXgCX1QzS/M++hNnx6riRjIUood1cYyzyd8J/qOY9Sl9MT+9gOMcwfRevh oaR18VD5uPrSxtYufrvO/tXFB90hucHfosEnDuKP3uB45tUhddgRsUi1iKIjr7MO yEb1u6FLcbdCIbqD49rQ =HfNb -----END PGP SIGNATURE----- --OgqxwSJOaUobr8KG--