From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denis Carikli 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> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jingoo Han Cc: linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Alexander Shiyan , Grant Likely , Mark Rutland , Denis Carikli , Richard Purdie , Laurent Pinchart , Rob Herring , Pawel Moll , Stephen Warren , Ian Campbell , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Sascha Hauer , Shawn Guo , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= , Jean-Christophe Plagniol-Villard , Thierry Reding , =?UTF-8?q?Eric=20B=C3=A9nard?= List-Id: linux-gpio@vger.kernel.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-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Sascha Hauer Cc: Shawn Guo Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: Lothar Wa=C3=9Fmann Cc: Jean-Christophe Plagniol-Villard Cc: Thierry Reding Cc: Eric B=C3=A9nard 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= =2E - 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 ar= e able to read the gpio value. - switched the default-brightness-level to boolean values (0 or 1) inst= ead 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 dec= laration. 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 i= s 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/g= pio-backlight.txt diff --git a/Documentation/devicetree/bindings/video/backlight/gpio-bac= klight.txt b/Documentation/devicetree/bindings/video/backlight/gpio-bac= klight.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 =3D "gpio-backlight"; + gpios =3D <&gpio3 4 GPIO_ACTIVE_HIGH>; + default-on; + }; diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/b= acklight/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 { =20 int gpio; int active; + int def_value; }; =20 static int gpio_backlight_update_status(struct backlight_device *bl) @@ -60,6 +63,33 @@ static const struct backlight_ops gpio_backlight_ops= =3D { .check_fb =3D gpio_backlight_check_fb, }; =20 +static int gpio_backlight_probe_dt(struct platform_device *pdev, + struct gpio_backlight *gbl) +{ + struct device_node *np =3D pdev->dev.of_node; + enum of_gpio_flags gpio_flags; + bool default_on =3D false; + + gbl->fbdev =3D NULL; + gbl->gpio =3D of_get_gpio_flags(np, 0, &gpio_flags); + + if (!gpio_is_valid(gbl->gpio)) { + if (gbl->gpio !=3D -EPROBE_DEFER) { + dev_err(&pdev->dev, + "Error: The gpios parameter is missing or invalid.\n"); + } + return gbl->gpio; + } + + gbl->active =3D (gpio_flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1; + + default_on =3D of_property_read_bool(np, "default-on"); + + gbl->def_value =3D default_on; + + return 0; +} + static int gpio_backlight_probe(struct platform_device *pdev) { struct gpio_backlight_platform_data *pdata =3D @@ -67,10 +97,12 @@ static int gpio_backlight_probe(struct platform_dev= ice *pdev) struct backlight_properties props; struct backlight_device *bl; struct gpio_backlight *gbl; + struct device_node *np =3D pdev->dev.of_node; int ret; =20 - 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; } =20 @@ -79,14 +111,22 @@ static int gpio_backlight_probe(struct platform_de= vice *pdev) return -ENOMEM; =20 gbl->dev =3D &pdev->dev; - gbl->fbdev =3D pdata->fbdev; - gbl->gpio =3D pdata->gpio; - gbl->active =3D pdata->active_low ? 0 : 1; + + if (np) { + ret =3D gpio_backlight_probe_dt(pdev, gbl); + if (ret) + return ret; + } else { + gbl->fbdev =3D pdata->fbdev; + gbl->gpio =3D pdata->gpio; + gbl->active =3D pdata->active_low ? 0 : 1; + gbl->def_value =3D pdata->def_value; + } =20 ret =3D 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_d= evice *pdev) return PTR_ERR(bl); } =20 - bl->props.brightness =3D pdata->def_value; + bl->props.brightness =3D gbl->def_value; backlight_update_status(bl); =20 platform_set_drvdata(pdev, bl); return 0; } =20 +static struct of_device_id gpio_backlight_of_match[] =3D { + { .compatible =3D "gpio-backlight" }, + { /* sentinel */ } +}; + static struct platform_driver gpio_backlight_driver =3D { .driver =3D { .name =3D "gpio-backlight", .owner =3D THIS_MODULE, + .of_match_table =3D of_match_ptr(gpio_backlight_of_match), }, .probe =3D gpio_backlight_probe, }; --=20 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html