[1/2] video: exynos_dp: Add parsing of gpios pins to exynos-dp driver

Commit Message

Vikas C Sajjan May 14, 2013, 12:55 p.m. UTC

Adds GPIO parsing functionality for "LCD backlight" and "LCD enable"
 GPIO pins of exynos dp controller.

Signed-off-by: Vikas Sajjan <[e-mail]>
---
 drivers/video/exynos/exynos_dp_core.c |   45 +++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

Comments

Tomasz Figa May 14, 2013, 2:16 p.m. UTC | #1

Hi Vikas,

On Tuesday 14 of May 2013 18:25:51 Vikas Sajjan wrote:
>  Adds GPIO parsing functionality for "LCD backlight" and "LCD enable"
>  GPIO pins of exynos dp controller.
> 
> Signed-off-by: Vikas Sajjan <[e-mail]>
> ---
>  drivers/video/exynos/exynos_dp_core.c |   45
> +++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+)
> 

I don't think that Exynos DP driver is right place for such code. Backlight 
and LCD drivers are responsible for backlight and LCD power control using 
backlight and LCD subsystems.

IMHO the correct solution would be to either extend existing backlight/lcd 
drivers found in drivers/video/backlight to support direct GPIO control and 
parse GPIO pins from device tree or create new gpio_bl and gpio_lcd drivers.

CCing Richard, Florian and linux-fbdev.

Best regards,
Tomasz

--
To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/drivers/video/exynos/exynos_dp_core.c b/drivers/video/exynos/exynos_dp_core.c
index de9d4da..242a708 100644
--- a/drivers/video/exynos/exynos_dp_core.c
+++ b/drivers/video/exynos/exynos_dp_core.c
@@ -19,6 +19,7 @@ 
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/of.h>
+#include <linux/of_gpio.h>
 
 #include <video/exynos_dp.h>
 
@@ -895,11 +896,51 @@  static void exynos_dp_hotplug(struct work_struct *work)
 }
 
 #ifdef CONFIG_OF
+
+static int exynos_parse_gpio(struct device *dev)
+{
+	int gpio = -1;
+	struct device_node *np = dev->of_node;
+	enum of_gpio_flags flags;
+	u32 value;
+	int ret = -1;
+
+	if (!of_find_property(np, "lcd_bl_gpio", &value)) {
+                dev_err(dev, "no bl gpio property found\n");
+		return -1;
+        }
+
+	gpio = of_get_named_gpio_flags(np, "lcd_bl_gpio", 0, &flags);
+        if (gpio_is_valid(gpio)) {
+                ret = gpio_request_one(gpio, GPIOF_OUT_INIT_HIGH, "exynos4-fb");
+                if (ret < 0) {
+                        return ret;
+		}
+        }
+	gpio_set_value(gpio, 1);
+
+	if (!of_find_property(np, "lcd_en_gpio", &value)) {
+                dev_err(dev, "no bl gpio property found\n");
+		return -1;
+        }
+        gpio = of_get_named_gpio_flags(np, "lcd_en_gpio", 0, &flags);
+        if (gpio_is_valid(gpio)) {
+                ret = gpio_request_one(gpio, GPIOF_OUT_INIT_HIGH, "exynos4-fb");
+                if (ret < 0) {
+                        return ret;
+		}
+        }
+	gpio_set_value(gpio, 1);
+
+	return 0;
+}
+
 static struct exynos_dp_platdata *exynos_dp_dt_parse_pdata(struct device *dev)
 {
 	struct device_node *dp_node = dev->of_node;
 	struct exynos_dp_platdata *pd;
 	struct video_info *dp_video_config;
+	int ret = -1;
 
 	pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
 	if (!pd) {
@@ -960,6 +1001,10 @@  static struct exynos_dp_platdata *exynos_dp_dt_parse_pdata(struct device *dev)
 		return ERR_PTR(-EINVAL);
 	}
 
+	ret = exynos_parse_gpio(dev);
+	if (ret != 0)
+		return NULL;
+
 	return pd;
 }