backlight: da903x_bl: control WLED output current in da9034

Update WLED output current source before changing brightness.
Signed-off-by: NHaojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: NEric Miao <eric.y.miao@gmail.com>

drivers/video/backlight/da903x_bl.c

@@ -25,6 +25,7 @@
 
 #define DA9034_WLED_CONTROL1	0x3C
 #define DA9034_WLED_CONTROL2	0x3D
+#define DA9034_WLED_ISET(x)	((x) & 0x1f)
 
 #define DA9034_WLED_BOOST_EN	(1 << 5)
 
@@ -101,6 +102,7 @@ static struct backlight_ops da903x_backlight_ops = {
 
 static int da903x_backlight_probe(struct platform_device *pdev)
 {
+	struct da9034_backlight_pdata *pdata = pdev->dev.platform_data;
 	struct da903x_backlight_data *data;
 	struct backlight_device *bl;
 	int max_brightness;
@@ -127,6 +129,11 @@ static int da903x_backlight_probe(struct platform_device *pdev)
 	data->da903x_dev = pdev->dev.parent;
 	data->current_brightness = 0;
 
+	/* adjust the WLED output current */
+	if (pdata)
+		da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2,
+				DA9034_WLED_ISET(pdata->output_current));
+
 	bl = backlight_device_register(pdev->name, data->da903x_dev,
 			data, &da903x_backlight_ops);
 	if (IS_ERR(bl)) {

include/linux/mfd/da903x.h

@@ -96,6 +96,10 @@ struct da9034_touch_pdata {
 	int	y_inverted;
 };
 
+struct da9034_backlight_pdata {
+	int	output_current;	/* output current of WLED, from 0-31 (in mA) */
+};
+
 /* DA9030 battery charger data */
 struct power_supply_info;