| Message ID | 1389366444-29449-1-git-send-email-denis@eukrea.com |
|---|---|
| State | New |
| Headers | show |
Hi, Denis Carikli wrote: > Cc: Richard Purdie <rpurdie@rpsys.net> > Cc: Jingoo Han <jg1.han@samsung.com> > Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > Cc: Rob Herring <rob.herring@calxeda.com> > Cc: Pawel Moll <pawel.moll@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Stephen Warren <swarren@wwwdotorg.org> > Cc: Ian Campbell <ijc+devicetree@hellion.org.uk> > Cc: devicetree@vger.kernel.org > Cc: Sascha Hauer <kernel@pengutronix.de> > Cc: Shawn Guo <shawn.guo@linaro.org> > Cc: linux-arm-kernel@lists.infradead.org > Cc: Lothar Waßmann <LW@KARO-electronics.de> > Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> > Cc: Thierry Reding <thierry.reding@gmail.com> > Cc: Eric Bénard <eric@eukrea.com> > Signed-off-by: Denis Carikli <denis@eukrea.com> > --- > 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 > [...] > +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), > useless use of of_match_ptr(). This would make sense, if the gpio_backlight_of_match struct was conditionally compiled in depending on CONFIG_OF. Since you unconditionally provide it you can use &gpio_backlight_of_match directly. Lothar Waßmann
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 <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/of.h> +#include <linux/of_gpio.h> #include <linux/platform_data/gpio_backlight.h> #include <linux/platform_device.h> #include <linux/slab.h> @@ -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, };
Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Jingoo Han <jg1.han@samsung.com> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Rob Herring <rob.herring@calxeda.com> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk> Cc: devicetree@vger.kernel.org Cc: Sascha Hauer <kernel@pengutronix.de> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: linux-arm-kernel@lists.infradead.org Cc: Lothar Waßmann <LW@KARO-electronics.de> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Eric Bénard <eric@eukrea.com> Signed-off-by: Denis Carikli <denis@eukrea.com> --- 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