From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753448Ab2KPU4s (ORCPT ); Fri, 16 Nov 2012 15:56:48 -0500 Received: from moutng.kundenserver.de ([212.227.17.10]:61099 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751549Ab2KPU4q (ORCPT ); Fri, 16 Nov 2012 15:56:46 -0500 Date: Fri, 16 Nov 2012 21:56:37 +0100 From: Thierry Reding To: Andrew Morton Cc: Jingoo Han , "'Richard Purdie'" , "'Florian Tobias Schandinat'" , linux-fbdev@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] backlight: Add of_find_backlight_by_node() function Message-ID: <20121116205636.GA27469@avionic-0098.mockup.avionic-design.de> References: <1352469878-4532-1-git-send-email-thierry.reding@avionic-design.de> <004201cdc2d0$c1920210$44b60630$%han@samsung.com> <20121115065140.GA21208@avionic-0098.mockup.avionic-design.de> <001201cdc30f$65a17be0$30e473a0$%han@samsung.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="r5Pyd7+fXNt84Ff3" Content-Disposition: inline In-Reply-To: <001201cdc30f$65a17be0$30e473a0$%han@samsung.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Provags-ID: V02:K0:+Qp/cK9s2WafPZLIoWg4UP5eG5LdfYskmLaCtJ4w/4t kFqdhd5EGg4hXjuFaUmymWrBQzoW12ovO2lz/5WVRJw4H6mrOW ClnU+VxRlpCGzSf3qzUbCeqxsyN7yANmn9bKKleFjhXhCnV7ae XgRq4pnonF7YPYfG99FMlgWXAizZCQOeS1U7jdYkQ1f7FtLUMi xDc6qbhM77lONJ8FHC2/UZrVkhGlXu5hXapOyCSTP+1+CSK3hX Ls/QJmXTa9HdRGPpM7PAwmoEciTO+5vWTm0VtzR5agZ7xShzgO rg0tpJZ9A1EDzUWKUCRbro2kDGb7Ls3AqaYFNtbdh+VtiIcxof iVBIAqmdfAXVVp6r/JzHsF1hjreT7/Pp03FNqScq4eJqnT64k9 PU7rSm7FRxYN52sn2Og5Bi+n362nvLB6ViJ+ZGEeCzBg1s7/Dr ByUAP Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --r5Pyd7+fXNt84Ff3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Nov 15, 2012 at 05:58:35PM +0900, Jingoo Han wrote: > On Thursday, November 15, 2012 3:52 PM Thierry Reding wrote > > On Thu, Nov 15, 2012 at 10:30:11AM +0900, Jingoo Han wrote: > > > On Friday, November 09, 2012 11:05 PM Thierry Reding wrote > > > > > > > > This function finds the struct backlight_device for a given device = tree > > > > node. A dummy function is provided so that it safely compiles out i= f OF > > > > support is disabled. > > > > > > > > Signed-off-by: Thierry Reding > > > > > > CC'ed Andrew Morton > >=20 > > Yes, the backlight subsystem isn't very well maintained, so I should > > have added Andrew in the first place. Thanks. > >=20 > > > > > > Hi Thierry Reding, > > > > > > The patch itself looks good. > > > Could you explain when this API is used? > > > Thank you. > >=20 > > I use this for the upcoming Tegra DRM driver in order to hook up the > > backlight with the DRM driver via DT to allow switching off the > > backlight when the corresponding DRM output is switched of using DPMS. > > Basically what you have is something like this in the device tree: > >=20 > > display { > > ... > >=20 > > backlight =3D <&backlight>; > >=20 > > ... > > } > >=20 > > Then you call something along these lines: > >=20 > > np =3D of_parse_phandle(display, "backlight", 0); > > if (np) { > > backlight =3D of_find_backlight_by_node(np); > > of_node_put(np); > > } > >=20 > > And then use the standard backlight API on the returned pointer. >=20 > OK, I see how this API can be called. > AS you mentioned, it will allow Tegra DRM driver to use > the backlight driver. >=20 > Acked-by: Jingoo Han Andrew, any chance we could still get this in for the 3.8 merge window? Thierry --r5Pyd7+fXNt84Ff3 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQIcBAEBAgAGBQJQpqiEAAoJEN0jrNd/PrOhK7cP/RYi+y4AaxgU2MYHIsU1ymiE ssNsEp4yZZD3uydDrpMUJEwyznnBJeGhd21SEg7drz2+dABafgGt3G/7PqA/xu43 Xv07AaSbOyqVGubIon9ssrzj27s2jTwjXUeu2fzFlPbIFZjMorP7HoeuLRYy5yce ZcsRy40juP7htTT1LlYwxpwh6RWK26kqzCQNMXVz+T7TQRmzGiM4MCOf/gQ89D2T SX134RTtKM63YXqrSdpC81XUpDicWKr4nOwGQ1c9e/bDg3kc45xBOYvGUD3zfPrR i38R3NIEIlvuAJRzXCFL0b3MK/E8BFWg4jON0qQgn9Kk9TqS0sNtYNSKga1c1K6N 1u+VWNLY13lIYT2sEUgqKMcZIVU+YZaprfiLuKn2epMxm5ecINJANm4ZvwYHBhV4 PqrxNhY7CKRPxRPYP2U+6ETOq6Q7KP5u9amrtP9nsKgBno1crC8BUuMG/0+Bwojp SaqXdNorPE0Knn3TiGppH2JMx5n2E45EZb+WhtGr4//OAGTgvwrTxApVx5mRya/I mEAx3Aec0o/c4kVJk0b9CeV01Plh9hLqjGdG7x17v5NWt/u+RqI/XbqNoOhC2Hbb fPYhiAo+3p3qX9hDvXW5u+W/tbG6xLZbCN5DJXVUvJGFR+XbP6ea2JQWujP3bPDk PIWJ8zlY5pYD+dSfA2py =Z5Mn -----END PGP SIGNATURE----- --r5Pyd7+fXNt84Ff3--