OMAP: LCD LS037V7DW01: Add Backlight driver support

Tested on OMAP3EVM for OMAP3530 and AM/DM 3730.
Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
[tomi.valkeinen@nokia.com: added slab.h include]
[tomi.valkeinen@nokia.com: added dependency to BACKLIGHT_CLASS_DEVICE]
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>

drivers/video/omap2/displays/Kconfig

@@ -10,6 +10,7 @@ config PANEL_GENERIC
 config PANEL_SHARP_LS037V7DW01
         tristate "Sharp LS037V7DW01 LCD Panel"
         depends on OMAP2_DSS
+        select BACKLIGHT_CLASS_DEVICE
         help
           LCD Panel used in TI's SDP3430 and EVM boards
 

drivers/video/omap2/displays/panel-sharp-ls037v7dw01.c

@@ -20,10 +20,17 @@
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/backlight.h>
+#include <linux/fb.h>
 #include <linux/err.h>
+#include <linux/slab.h>
 
 #include <plat/display.h>
 
+struct sharp_data {
+	struct backlight_device *bl;
+};
+
 static struct omap_video_timings sharp_ls_timings = {
 	.x_res = 480,
 	.y_res = 640,
@@ -39,18 +46,89 @@ static struct omap_video_timings sharp_ls_timings = {
 	.vbp		= 1,
 };
 
+static int sharp_ls_bl_update_status(struct backlight_device *bl)
+{
+	struct omap_dss_device *dssdev = dev_get_drvdata(&bl->dev);
+	int level;
+
+	if (!dssdev->set_backlight)
+		return -EINVAL;
+
+	if (bl->props.fb_blank == FB_BLANK_UNBLANK &&
+			bl->props.power == FB_BLANK_UNBLANK)
+		level = bl->props.brightness;
+	else
+		level = 0;
+
+	return dssdev->set_backlight(dssdev, level);
+}
+
+static int sharp_ls_bl_get_brightness(struct backlight_device *bl)
+{
+	if (bl->props.fb_blank == FB_BLANK_UNBLANK &&
+			bl->props.power == FB_BLANK_UNBLANK)
+		return bl->props.brightness;
+
+	return 0;
+}
+
+static const struct backlight_ops sharp_ls_bl_ops = {
+	.get_brightness = sharp_ls_bl_get_brightness,
+	.update_status  = sharp_ls_bl_update_status,
+};
+
+
+
 static int sharp_ls_panel_probe(struct omap_dss_device *dssdev)
 {
+	struct backlight_properties props;
+	struct backlight_device *bl;
+	struct sharp_data *sd;
+	int r;
+
 	dssdev->panel.config = OMAP_DSS_LCD_TFT | OMAP_DSS_LCD_IVS |
 		OMAP_DSS_LCD_IHS;
 	dssdev->panel.acb = 0x28;
 	dssdev->panel.timings = sharp_ls_timings;
 
+	sd = kzalloc(sizeof(*sd), GFP_KERNEL);
+	if (!sd)
+		return -ENOMEM;
+
+	dev_set_drvdata(&dssdev->dev, sd);
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.max_brightness = dssdev->max_backlight_level;
+
+	bl = backlight_device_register("sharp-ls", &dssdev->dev, dssdev,
+			&sharp_ls_bl_ops, &props);
+	if (IS_ERR(bl)) {
+		r = PTR_ERR(bl);
+		kfree(sd);
+		return r;
+	}
+	sd->bl = bl;
+
+	bl->props.fb_blank = FB_BLANK_UNBLANK;
+	bl->props.power = FB_BLANK_UNBLANK;
+	bl->props.brightness = dssdev->max_backlight_level;
+	r = sharp_ls_bl_update_status(bl);
+	if (r < 0)
+		dev_err(&dssdev->dev, "failed to set lcd brightness\n");
+
 	return 0;
 }
 
 static void sharp_ls_panel_remove(struct omap_dss_device *dssdev)
 {
+	struct sharp_data *sd = dev_get_drvdata(&dssdev->dev);
+	struct backlight_device *bl = sd->bl;
+
+	bl->props.power = FB_BLANK_POWERDOWN;
+	sharp_ls_bl_update_status(bl);
+	backlight_device_unregister(bl);
+
+	kfree(sd);
 }
 
 static int sharp_ls_power_on(struct omap_dss_device *dssdev)