From patchwork Fri Jan 10 15:07:23 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Denis Carikli X-Patchwork-Id: 309309 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)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id A6F262C008F for ; Sat, 11 Jan 2014 02:08:22 +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 1W1dgy-0007co-FU; Fri, 10 Jan 2014 15:08:12 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1W1dgv-0003Uc-Pk; Fri, 10 Jan 2014 15:08:09 +0000 Received: from smtp5-g21.free.fr ([2a01:e0c:1:1599::14]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1W1dgr-0003T5-Im for linux-arm-kernel@lists.infradead.org; Fri, 10 Jan 2014 15:08:07 +0000 Received: from denis-N73SV.local.eukrea.com (unknown [88.170.243.169]) by smtp5-g21.free.fr (Postfix) with ESMTP id 9D5CCD4812B; Fri, 10 Jan 2014 16:07:30 +0100 (CET) From: Denis Carikli To: Jingoo Han Subject: [PATCHv9 1/2] video: backlight: gpio-backlight: Add DT support. Date: Fri, 10 Jan 2014 16:07:23 +0100 Message-Id: <1389366444-29449-1-git-send-email-denis@eukrea.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140110_100806_491203_F15F35B3 X-CRM114-Status: GOOD ( 23.56 ) 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, Ian Campbell , Pawel Moll , Alexander Shiyan , Denis Carikli , Stephen Warren , Rob Herring , Grant Likely , linux-gpio@vger.kernel.org, Thierry Reding , Richard Purdie , Laurent Pinchart , Sascha Hauer , =?UTF-8?q?Eric=20B=C3=A9nard?= , Shawn Guo , 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: Shawn Guo 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 v8->v9: - Added Shawn Guo in the Cc list. - The default-brightness-level is now a boolean default-on property, the gpio is only touched if the gpio-backlight driver instance probes. - The code and documentation was updated accordingly. ChangeLog v7->v8: - The default-state was renamed to default-brightness-level. - default-brightness-level is now mandatory, like for backlight-pwm, That way we avoid having to handle the case where it's not set, which means that we would need not to set the gpio, but still report a brightness value for sysfs, when not all gpio controllers are able to read the gpio value. - switched the default-brightness-level to boolean values (0 or 1) instead of using strings ("on", "off", "keep"). - The documentation was updated accordingly. - The example in the documentation now uses the dts gpio defines. - The "backlight: gpio_backlight: Use a default state enum." patch was then dropped, becuase it is not necessary anymore. 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 | 19 +++++++ drivers/video/backlight/gpio_backlight.c | 60 +++++++++++++++++--- 2 files changed, 72 insertions(+), 7 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..a923193 --- /dev/null +++ b/Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt @@ -0,0 +1,19 @@ +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-on: enable the backlight at boot. + +[0]: Documentation/devicetree/bindings/gpio/gpio.txt + +Example: + + backlight { + compatible = "gpio-backlight"; + gpios = <&gpio3 4 GPIO_ACTIVE_HIGH>; + default-on; + }; diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c index 81fb127..05f84f1 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 @@ -23,6 +25,7 @@ struct gpio_backlight { int gpio; int active; + int def_value; }; static int gpio_backlight_update_status(struct backlight_device *bl) @@ -60,6 +63,33 @@ 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; + bool default_on = false; + + 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; + + default_on = of_property_read_bool(np, "default-on"); + + gbl->def_value = default_on; + + return 0; +} + static int gpio_backlight_probe(struct platform_device *pdev) { struct gpio_backlight_platform_data *pdata = @@ -67,10 +97,12 @@ 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; } @@ -79,14 +111,22 @@ 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; + 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; @@ -103,17 +143,23 @@ static int gpio_backlight_probe(struct platform_device *pdev) return PTR_ERR(bl); } - bl->props.brightness = pdata->def_value; + bl->props.brightness = gbl->def_value; backlight_update_status(bl); platform_set_drvdata(pdev, bl); 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, };