From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Christophe PLAGNIOL-VILLARD Subject: Re: [PATCHv4] video: backlight: gpio-backlight: Add DT support. Date: Tue, 22 Oct 2013 06:58:33 +0200 Message-ID: <20131022045833.GB17512@ns203013.ovh.net> References: <20131019104555.GI18477@ns203013.ovh.net> <1382346813-8449-1-git-send-email-denis@eukrea.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <1382346813-8449-1-git-send-email-denis@eukrea.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Denis Carikli Cc: Mark Rutland , devicetree@vger.kernel.org, Ian Campbell , Eric B??nard , Pawel Moll , Stephen Warren , Jingoo Han , Rob Herring , Richard Purdie , Laurent Pinchart , Sascha Hauer , linux-arm-kernel@lists.infradead.org, Lothar Wa??mann List-Id: devicetree@vger.kernel.org On 11:13 Mon 21 Oct , Denis Carikli wrote: > 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 Wa=DFmann > Cc: Jean-Christophe Plagniol-Villard > Cc: Eric B=E9nard > Signed-off-by: Denis Carikli > --- > ChangeLog v3->v4: > - The default-brightness property is now optional, it defaults to 1 if no= t set. by default we set OFF not ON do not actiate driver or properti by default you can not known to consequen= ce on the hw Best Regards, J. > - def_value int becomes an u32. > - gbl->def_value was set to pdata->def_value in pdata mode to avoid an ex= tra > check. > --- > .../bindings/video/backlight/gpio-backlight.txt | 20 ++++++ > drivers/video/backlight/gpio_backlight.c | 69 ++++++++++++++= ++++-- > 2 files changed, 82 insertions(+), 7 deletions(-) > create mode 100644 Documentation/devicetree/bindings/video/backlight/gpi= o-backlight.txt > = > diff --git a/Documentation/devicetree/bindings/video/backlight/gpio-backl= ight.txt b/Documentation/devicetree/bindings/video/backlight/gpio-backlight= .txt > new file mode 100644 > index 0000000..3474d4a > --- /dev/null > +++ b/Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt > @@ -0,0 +1,20 @@ > +gpio-backlight bindings > + > +Required properties: > + - compatible: "gpio-backlight" > + - gpios: describes the gpio that is used for enabling/disabling the ba= cklight > + (see GPIO binding[0] for more details). > + > +Optional properties: > + - default-brightness-level: the default brightness level (can be 0(off= ) or > + 1(on) since GPIOs only support theses levels). > + > +[0]: Documentation/devicetree/bindings/gpio/gpio.txt > + > +Example: > + > + backlight { > + compatible =3D "gpio-backlight"; > + gpios =3D <&gpio3 4 0>; > + default-brightness-level =3D <0>; > + }; > diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/bac= klight/gpio_backlight.c > index 81fb127..248124d 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; > + u32 def_value; > }; > = > static int gpio_backlight_update_status(struct backlight_device *bl) > @@ -60,6 +63,41 @@ static const struct backlight_ops gpio_backlight_ops = =3D { > .check_fb =3D gpio_backlight_check_fb, > }; > = > +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; > + int ret; > + > + gbl->fbdev =3D NULL; > + gbl->gpio =3D of_get_gpio_flags(np, 0, &gpio_flags); > + > + gbl->active =3D (gpio_flags & OF_GPIO_ACTIVE_LOW) ? 0 : 1; > + > + if (gbl->gpio =3D=3D -EPROBE_DEFER) { > + return ERR_PTR(-EPROBE_DEFER); > + } else if (gbl->gpio < 0) { > + dev_err(&pdev->dev, "Error: gpios is a required parameter.\n"); > + return gbl->gpio; > + } > + > + ret =3D of_property_read_u32(np, "default-brightness-level", > + &gbl->def_value); > + if (ret < 0) { > + /* The property is optional. */ > + gbl->def_value =3D 1; > + } > + > + if (gbl->def_value > 1) { > + dev_warn(&pdev->dev, > + "Warning: Invalid default-brightness-level value. Its value can be ei= ther 0(off) or 1(on).\n"); > + gbl->def_value =3D 1; > + } > + > + return 0; > +} > + > static int gpio_backlight_probe(struct platform_device *pdev) > { > struct gpio_backlight_platform_data *pdata =3D > @@ -67,10 +105,12 @@ static int gpio_backlight_probe(struct platform_devi= ce *pdev) > struct backlight_properties props; > struct backlight_device *bl; > struct gpio_backlight *gbl; > + struct device_node *np =3D 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 +119,22 @@ static int gpio_backlight_probe(struct platform_devi= ce *pdev) > return -ENOMEM; > = > 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; > + } > = > 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 +151,24 @@ static int gpio_backlight_probe(struct platform_dev= ice *pdev) > return PTR_ERR(bl); > } > = > - bl->props.brightness =3D pdata->def_value; > + bl->props.brightness =3D gbl->def_value; > + > backlight_update_status(bl); > = > platform_set_drvdata(pdev, bl); > return 0; > } > = > +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, > }; > -- = > 1.7.9.5 > =