From patchwork Thu Dec 5 17:55:09 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Denis Carikli X-Patchwork-Id: 297338 Return-Path: X-Original-To: incoming-imx@patchwork.ozlabs.org Delivered-To: patchwork-incoming-imx@bilbo.ozlabs.org Received: from casper.infradead.org (unknown [IPv6:2001:770:15f::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id BB3712C00A4 for ; Fri, 6 Dec 2013 04:57:02 +1100 (EST) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vod9p-0007Rd-Sd; Thu, 05 Dec 2013 17:56:14 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vod9d-0000IP-J3; Thu, 05 Dec 2013 17:56:01 +0000 Received: from smtp1-g21.free.fr ([2a01:e0c:1:1599::10]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Vod9Z-0000Ga-2l for linux-arm-kernel@lists.infradead.org; Thu, 05 Dec 2013 17:55:58 +0000 Received: from denis-N73SV.local.eukrea.com (unknown [88.170.243.169]) by smtp1-g21.free.fr (Postfix) with ESMTP id A2D3294020F; Thu, 5 Dec 2013 18:55:24 +0100 (CET) From: Denis Carikli To: Richard Purdie , Jingoo Han Subject: [PATCHv7][ 2/2] video: backlight: gpio-backlight: Add DT support. Date: Thu, 5 Dec 2013 18:55:09 +0100 Message-Id: <1386266109-16071-2-git-send-email-denis@eukrea.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1386266109-16071-1-git-send-email-denis@eukrea.com> References: <1386266109-16071-1-git-send-email-denis@eukrea.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131205_125558_039856_7AB3683A X-CRM114-Status: GOOD ( 23.35 ) X-Spam-Score: -1.2 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- 0.7 SPF_SOFTFAIL SPF: sender does not match SPF record (softfail) -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Mark Rutland , devicetree@vger.kernel.org, =?UTF-8?q?Eric=20B=C3=A9nard?= , Pawel Moll , Stephen Warren , Ian Campbell , Rob Herring , Denis Carikli , Thierry Reding , Laurent Pinchart , Sascha Hauer , Jean-Christophe Plagniol-Villard , linux-arm-kernel@lists.infradead.org, =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org List-Id: linux-imx-kernel.lists.patchwork.ozlabs.org Cc: Richard Purdie Cc: Jingoo Han Cc: Laurent Pinchart Cc: Rob Herring Cc: Pawel Moll Cc: Mark Rutland Cc: Stephen Warren Cc: Ian Campbell Cc: devicetree@vger.kernel.org Cc: Sascha Hauer Cc: linux-arm-kernel@lists.infradead.org Cc: Lothar Waßmann Cc: Jean-Christophe Plagniol-Villard Cc: Thierry Reding Cc: Eric Bénard Signed-off-by: Denis Carikli --- ChangeLog v6->v7: - removed a compilation warning with the removal of the useless ret declaration. ChangeLog v5->v6: - The default state handling was reworked: - it's now called default-state, and looks like the gpio-leds default-state. - it now has a "keep" option, like for the gpio-leds. - that "keep" option is the default when the default-state property is not set. - The documentation was updated accordingly. ChangeLog v4->v5: - The default-brightness property now defaults to 0 in the driver. - def_value int becomes a bool. - The check for the gpio validity has been reworked. --- .../bindings/video/backlight/gpio-backlight.txt | 23 +++++++ drivers/video/backlight/gpio_backlight.c | 71 +++++++++++++++++--- 2 files changed, 86 insertions(+), 8 deletions(-) create mode 100644 Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt diff --git a/Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt b/Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt new file mode 100644 index 0000000..f36f6e3 --- /dev/null +++ b/Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt @@ -0,0 +1,23 @@ +gpio-backlight bindings + +Required properties: + - compatible: "gpio-backlight" + - gpios: describes the gpio that is used for enabling/disabling the backlight + (see GPIO binding[0] for more details). + +Optional properties: + - default-state: The initial state of the backlight. + Valid values are "on", "off", and "keep". + The "keep" setting will keep the backlight at whatever its current + state is, without producing a glitch. The default is keep if this + property is not present. + +[0]: Documentation/devicetree/bindings/gpio/gpio.txt + +Example: + + backlight { + compatible = "gpio-backlight"; + gpios = <&gpio3 4 0>; + default-state = "on"; + }; diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c index 6ddeba9..2e20e32 100644 --- a/drivers/video/backlight/gpio_backlight.c +++ b/drivers/video/backlight/gpio_backlight.c @@ -13,6 +13,8 @@ #include #include #include +#include +#include #include #include #include @@ -61,6 +63,42 @@ static const struct backlight_ops gpio_backlight_ops = { .check_fb = gpio_backlight_check_fb, }; +static int gpio_backlight_probe_dt(struct platform_device *pdev, + struct gpio_backlight *gbl) +{ + struct device_node *np = pdev->dev.of_node; + enum of_gpio_flags gpio_flags; + const char *state; + + gbl->fbdev = NULL; + gbl->gpio = of_get_gpio_flags(np, 0, &gpio_flags); + + if (!gpio_is_valid(gbl->gpio)) { + if (gbl->gpio != -EPROBE_DEFER) { + dev_err(&pdev->dev, + "Error: The gpios parameter is missing or invalid.\n"); + } + return gbl->gpio; + } + + gbl->active = (gpio_flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1; + + state = of_get_property(np, "default-state", NULL); + if (state) { + if (!strcmp(state, "keep")) + gbl->def_value = BACKLIGHT_GPIO_DEFSTATE_KEEP; + else if (!strcmp(state, "on")) + gbl->def_value = BACKLIGHT_GPIO_DEFSTATE_ON; + else + gbl->def_value = BACKLIGHT_GPIO_DEFSTATE_OFF; + } else { + /* we don't want to touch the hardware if we're not told to */ + gbl->def_value = BACKLIGHT_GPIO_DEFSTATE_KEEP; + } + + return 0; +} + static int gpio_backlight_probe(struct platform_device *pdev) { struct gpio_backlight_platform_data *pdata = @@ -68,10 +106,12 @@ static int gpio_backlight_probe(struct platform_device *pdev) struct backlight_properties props; struct backlight_device *bl; struct gpio_backlight *gbl; + struct device_node *np = pdev->dev.of_node; int ret; - if (!pdata) { - dev_err(&pdev->dev, "failed to find platform data\n"); + if (!pdata && !np) { + dev_err(&pdev->dev, + "failed to find platform data or device tree node.\n"); return -ENODEV; } @@ -80,14 +120,23 @@ static int gpio_backlight_probe(struct platform_device *pdev) return -ENOMEM; gbl->dev = &pdev->dev; - gbl->fbdev = pdata->fbdev; - gbl->gpio = pdata->gpio; - gbl->active = pdata->active_low ? 0 : 1; + + if (np) { + ret = gpio_backlight_probe_dt(pdev, gbl); + if (ret) + return ret; + } else { + gbl->fbdev = pdata->fbdev; + gbl->gpio = pdata->gpio; + gbl->active = pdata->active_low ? 0 : 1; + if (pdata->def_value != BACKLIGHT_GPIO_DEFSTATE_KEEP) + gbl->def_value = pdata->def_value; + } ret = devm_gpio_request_one(gbl->dev, gbl->gpio, GPIOF_DIR_OUT | (gbl->active ? GPIOF_INIT_LOW : GPIOF_INIT_HIGH), - pdata->name); + pdata ? pdata->name : "backlight"); if (ret < 0) { dev_err(&pdev->dev, "unable to request GPIO\n"); return ret; @@ -104,8 +153,8 @@ static int gpio_backlight_probe(struct platform_device *pdev) return PTR_ERR(bl); } - if (pdata->def_value != BACKLIGHT_GPIO_DEFSTATE_KEEP) { - bl->props.brightness = pdata->def_value; + if (gbl->def_value != BACKLIGHT_GPIO_DEFSTATE_KEEP) { + bl->props.brightness = gbl->def_value; backlight_update_status(bl); } @@ -113,10 +162,16 @@ static int gpio_backlight_probe(struct platform_device *pdev) return 0; } +static struct of_device_id gpio_backlight_of_match[] = { + { .compatible = "gpio-backlight" }, + { /* sentinel */ } +}; + static struct platform_driver gpio_backlight_driver = { .driver = { .name = "gpio-backlight", .owner = THIS_MODULE, + .of_match_table = of_match_ptr(gpio_backlight_of_match), }, .probe = gpio_backlight_probe, };