From patchwork Tue Dec 20 10:32:18 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thierry Reding X-Patchwork-Id: 132386 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4DB2DB7035 for ; Tue, 20 Dec 2011 21:33:07 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753077Ab1LTKdG (ORCPT ); Tue, 20 Dec 2011 05:33:06 -0500 Received: from moutng.kundenserver.de ([212.227.17.8]:53022 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752516Ab1LTKdF (ORCPT ); Tue, 20 Dec 2011 05:33:05 -0500 Received: from benhur.adnet.avionic-design.de (p548E07FD.dip0.t-ipconnect.de [84.142.7.253]) by mrelayeu.kundenserver.de (node=mrbap4) with ESMTP (Nemesis) id 0LcP1q-1QwhkT17R8-00jnGq; Tue, 20 Dec 2011 11:32:27 +0100 Received: from mailbox.adnet.avionic-design.de (add-virt-zarafa.adnet.avionic-design.de [172.20.129.9]) by benhur.adnet.avionic-design.de (Postfix) with ESMTP id DFC9C2C4124; Tue, 20 Dec 2011 11:32:28 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by mailbox.adnet.avionic-design.de (Postfix) with ESMTP id A31E62A28243; Tue, 20 Dec 2011 11:32:26 +0100 (CET) X-Virus-Scanned: amavisd-new at avionic-design.de Received: from mailbox.adnet.avionic-design.de ([127.0.0.1]) by localhost (mailbox.avionic-design.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id uoz9GbScOwkF; Tue, 20 Dec 2011 11:32:25 +0100 (CET) Received: from localhost (avionic-0098.adnet.avionic-design.de [172.20.31.233]) (Authenticated sender: thierry.reding) by mailbox.adnet.avionic-design.de (Postfix) with ESMTPA id B64392A28247; Tue, 20 Dec 2011 11:32:23 +0100 (CET) From: Thierry Reding To: devicetree-discuss@lists.ozlabs.org Cc: linux-tegra@vger.kernel.org, Sascha Hauer , Arnd Bergmann , Matthias Kaehlcke , Kurt Van Dijck , Rob Herring , Grant Likely , Colin Cross , Olof Johansson , Richard Purdie Subject: [RFC 7/7] pwm-backlight: Add rudimentary device-tree support Date: Tue, 20 Dec 2011 11:32:18 +0100 Message-Id: <1324377138-32129-8-git-send-email-thierry.reding@avionic-design.de> X-Mailer: git-send-email 1.7.8 In-Reply-To: <1324377138-32129-1-git-send-email-thierry.reding@avionic-design.de> References: <1324377138-32129-1-git-send-email-thierry.reding@avionic-design.de> X-Provags-ID: V02:K0:M1duX03FNuznB13kPruhrfOdjm2gNNpw0dkfiUzdvI8 gZv/Q51nD06XUSMkmg2WeBWJ3XrbF2GJmbeGxM0vshusJ45zTD khWQ+MPkgiiE99V1RoWLby2wZ7W7SOAm79oopOuewUS7mgqeWC vS5lsmnvli0JxpHfzIHAmqh6ziEq+Om64/uFoCF07H9YU+/E2y lZR4fMSeUFKEqvz4m1TlX2y76TueAQkDEfwX2dTVsRrBn/QmRY v+3mObuqK/d61NhGbkl2XmsPCc14zsSG7kPyFO/2erFDae4YOJ p1ndnKUJdssHMVnNlW0MW2SHLcl+rofpN88xV/S9S15auOoqSb LHn1hFhKL0ns5GTauO2i4Ei3ENqfdCd3ht/JKqQ3GfQP2efD7F Hmd57ylFqcFbD2v3CRr4OkxCmgqfb6cPn5pzDek/vScys2IJU4 EVnCW Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org This commit adds very basic support for device-tree probing. Currently, only a PWM and maximum and default brightness values can be specified. Enabling or disabling backlight power via GPIOs is not yet supported. Signed-off-by: Thierry Reding --- .../bindings/video/backlight/pwm-backlight | 16 +++++ drivers/video/backlight/Kconfig | 2 +- drivers/video/backlight/pwm_bl.c | 70 ++++++++++++++++++- 3 files changed, 83 insertions(+), 5 deletions(-) create mode 100644 Documentation/devicetree/bindings/video/backlight/pwm-backlight diff --git a/Documentation/devicetree/bindings/video/backlight/pwm-backlight b/Documentation/devicetree/bindings/video/backlight/pwm-backlight new file mode 100644 index 0000000..ce65280 --- /dev/null +++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight @@ -0,0 +1,16 @@ +pwm-backlight bindings + +Required properties: + - compatible: "pwm-backlight" + - default-brightness: the default brightness setting + - max-brightness: the maximum brightness setting + - pwm: OF device-tree PWM specification + +Example: + + backlight { + compatible = "pwm-backlight"; + default-brightness = <224>; + max-brightness = <255>; + pwm = <&pwm 0 5000000>; + }; diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 278aeaa..51c3642 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -233,7 +233,7 @@ config BACKLIGHT_CARILLO_RANCH config BACKLIGHT_PWM tristate "Generic PWM based Backlight Driver" - depends on HAVE_PWM + depends on HAVE_PWM || PWM help If you have a LCD backlight adjustable by PWM, say Y to enable this driver. diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 8b5b2a4..742934c 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -83,17 +84,77 @@ static const struct backlight_ops pwm_backlight_ops = { .check_fb = pwm_backlight_check_fb, }; +#ifdef CONFIG_OF +static int pwm_backlight_parse_dt(struct device *dev, + struct platform_pwm_backlight_data *data) +{ + struct device_node *node = dev->of_node; + u32 value; + int ret; + + if (!node) + return -ENODEV; + + memset(data, 0, sizeof(*data)); + + ret = of_get_named_pwm(node, "pwm", 0, &data->pwm_period_ns); + if (ret < 0) + return ret; + + data->pwm_id = ret; + + ret = of_property_read_u32(node, "default-brightness", &value); + if (ret < 0) + return ret; + + data->dft_brightness = value; + + ret = of_property_read_u32(node, "max-brightness", &value); + if (ret < 0) + return ret; + + data->max_brightness = value; + + /* + * TODO: Most users of this driver use a number of GPIOs to control + * backlight power. Support for specifying these needs to be + * added. + */ + + return 0; +} + +static struct of_device_id pwm_backlight_of_match[] = { + { .compatible = "pwm-backlight" }, + { } +}; + +MODULE_DEVICE_TABLE(of, pwm_backlight_of_match); +#else +static int pwm_backlight_parse_dt(struct device *dev, + struct platform_pwm_backlight_data *data) +{ + return -ENODEV; +} +#endif + static int pwm_backlight_probe(struct platform_device *pdev) { struct backlight_properties props; struct platform_pwm_backlight_data *data = pdev->dev.platform_data; + struct platform_pwm_backlight_data defdata; struct backlight_device *bl; struct pwm_bl_data *pb; int ret; if (!data) { - dev_err(&pdev->dev, "failed to find platform data\n"); - return -EINVAL; + ret = pwm_backlight_parse_dt(&pdev->dev, &defdata); + if (ret < 0) { + dev_err(&pdev->dev, "failed to find platform data\n"); + return ret; + } + + data = &defdata; } if (data->init) { @@ -198,8 +259,9 @@ static int pwm_backlight_resume(struct platform_device *pdev) static struct platform_driver pwm_backlight_driver = { .driver = { - .name = "pwm-backlight", - .owner = THIS_MODULE, + .name = "pwm-backlight", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(pwm_backlight_of_match), }, .probe = pwm_backlight_probe, .remove = pwm_backlight_remove,