diff mbox

[PATCHv12] video: backlight: gpio-backlight: Add DT support.

Message ID 1393511313-18756-1-git-send-email-denis@eukrea.com
State Accepted, archived
Commit 9a6adb339e5d1827da5e8b2459b12863d72ed3e7
Headers show

Commit Message

Denis Carikli Feb. 27, 2014, 2:28 p.m. UTC 
Signed-off-by: Denis Carikli <denis@eukrea.com>
---
ChangeLog v11-resend->v12:
- Moved the Cc from the commit message to the "email patch".
- The documentation is now more clear.
- The unnecessary default_on variable was removed.
- gbl->fbdev was already NULL and didn't need to be re-assigned,
  so the re-assignement was removed.
- The of_device_id struct and .of_match_table are now guarded
  against the driver beeing compiled without CONFIG_OF.

ChangeLog v11->v11-resend:
- Removed the Cc list because it's only one patch.

ChangeLog v10->v11:
- Shrinked the Cc list.
- Fixed the of_match_table warning.

ChangeLog v9->v10:
- Only the respective maintainers, or people who responded to the patch
  were kept in the Cc.
- The unnecessary of_match_ptr in of_match_table was removed.

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    |   16 ++++++
 drivers/video/backlight/gpio_backlight.c           |   58 +++++++++++++++++---
 2 files changed, 67 insertions(+), 7 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt

Comments

Lee Jones Feb. 27, 2014, 3:22 p.m. UTC | #1 
On Thu, 27 Feb 2014, Denis Carikli wrote:

> Signed-off-by: Denis Carikli <denis@eukrea.com>
> ---
> ChangeLog v11-resend->v12:
> - Moved the Cc from the commit message to the "email patch".
> - The documentation is now more clear.
> - The unnecessary default_on variable was removed.
> - gbl->fbdev was already NULL and didn't need to be re-assigned,
>   so the re-assignement was removed.
> - The of_device_id struct and .of_match_table are now guarded
>   against the driver beeing compiled without CONFIG_OF.
> 
> ChangeLog v11->v11-resend:
> - Removed the Cc list because it's only one patch.
> 
> ChangeLog v10->v11:
> - Shrinked the Cc list.
> - Fixed the of_match_table warning.
> 
> ChangeLog v9->v10:
> - Only the respective maintainers, or people who responded to the patch
>   were kept in the Cc.
> - The unnecessary of_match_ptr in of_match_table was removed.
> 
> 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    |   16 ++++++
>  drivers/video/backlight/gpio_backlight.c           |   58 +++++++++++++++++---
>  2 files changed, 67 insertions(+), 7 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt

Patch looks good to me now, I just want to see if Jingoo and/or Bryan
with to add anything. If they don't respond within the next couple of
days I'll apply the patch.

Acked-by: Lee Jones <lee.jones@linaro.org>
Jingoo Han March 4, 2014, 9:55 a.m. UTC | #2 
On Friday, February 28, 2014 12:22 AM, Lee Jones wrote:
> On Thu, 27 Feb 2014, Denis Carikli wrote:
> 
> > Signed-off-by: Denis Carikli <denis@eukrea.com>
> > ---
> > ChangeLog v11-resend->v12:
> > - Moved the Cc from the commit message to the "email patch".
> > - The documentation is now more clear.
> > - The unnecessary default_on variable was removed.
> > - gbl->fbdev was already NULL and didn't need to be re-assigned,
> >   so the re-assignement was removed.
> > - The of_device_id struct and .of_match_table are now guarded
> >   against the driver beeing compiled without CONFIG_OF.
> >
> > ChangeLog v11->v11-resend:
> > - Removed the Cc list because it's only one patch.
> >
> > ChangeLog v10->v11:
> > - Shrinked the Cc list.
> > - Fixed the of_match_table warning.
> >
> > ChangeLog v9->v10:
> > - Only the respective maintainers, or people who responded to the patch
> >   were kept in the Cc.
> > - The unnecessary of_match_ptr in of_match_table was removed.
> >
> > 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    |   16 ++++++
> >  drivers/video/backlight/gpio_backlight.c           |   58 +++++++++++++++++---
> >  2 files changed, 67 insertions(+), 7 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt
> 
> Patch looks good to me now, I just want to see if Jingoo and/or Bryan
> with to add anything. If they don't respond within the next couple of
> days I'll apply the patch.
> 
> Acked-by: Lee Jones <lee.jones@linaro.org>

Acked-by: Jingoo Han <jg1.han@samsung.com>

Best regards,
Jingoo Han

> 
> --
> Lee Jones
> Linaro STMicroelectronics Landing Team Lead
> Linaro.org │ Open source software for ARM SoCs
> Follow Linaro: Facebook | Twitter | Blog

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Lee Jones March 5, 2014, 2 a.m. UTC | #3 
On Thu, 27 Feb 2014, Denis Carikli wrote:

> Signed-off-by: Denis Carikli <denis@eukrea.com>
> ---
> ChangeLog v11-resend->v12:
> - Moved the Cc from the commit message to the "email patch".
> - The documentation is now more clear.
> - The unnecessary default_on variable was removed.
> - gbl->fbdev was already NULL and didn't need to be re-assigned,
>   so the re-assignement was removed.
> - The of_device_id struct and .of_match_table are now guarded
>   against the driver beeing compiled without CONFIG_OF.
> 
> ChangeLog v11->v11-resend:
> - Removed the Cc list because it's only one patch.
> 
> ChangeLog v10->v11:
> - Shrinked the Cc list.
> - Fixed the of_match_table warning.
> 
> ChangeLog v9->v10:
> - Only the respective maintainers, or people who responded to the patch
>   were kept in the Cc.
> - The unnecessary of_match_ptr in of_match_table was removed.
> 
> 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    |   16 ++++++
>  drivers/video/backlight/gpio_backlight.c           |   58 +++++++++++++++++---
>  2 files changed, 67 insertions(+), 7 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt

Applied with Jingoo's Ack.
diff mbox

Patch

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..321be66
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt
@@ -0,0 +1,16 @@ 
+gpio-backlight bindings
+
+Required properties:
+  - compatible: "gpio-backlight"
+  - gpios: describes the gpio that is used for enabling/disabling the backlight.
+    refer to bindings/gpio/gpio.txt for more details.
+
+Optional properties:
+  - default-on: enable the backlight at boot.
+
+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..a2eba12 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 +63,29 @@  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;
+
+	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;
+
+	gbl->def_value = of_property_read_bool(np, "default-on");
+
+	return 0;
+}
+
 static int gpio_backlight_probe(struct platform_device *pdev)
 {
 	struct gpio_backlight_platform_data *pdata =
@@ -67,10 +93,12 @@  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 +107,22 @@  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 +139,25 @@  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;
 }
 
+#ifdef CONFIG_OF
+static struct of_device_id gpio_backlight_of_match[] = {
+	{ .compatible = "gpio-backlight" },
+	{ /* sentinel */ }
+};
+#endif
+
 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,
 };