drivers/video/backlight/tps65217_bl.c add default brightness value option

Signed-off-by: Matus Ujhelyi <matus.ujhelyi@streamunlimited.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/devicetree/bindings/video/backlight/tps65217-backlight.txt

@@ -9,6 +9,7 @@ Required properties:
 - backlight: node for specifying WLED1 and WLED2 lines in TPS65217
 - isel: selection bit, valid values: 1 for ISEL1 (low-level) and 2 for ISEL2 (high-level)
 - fdim: PWM dimming frequency, valid values: 100, 200, 500, 1000
+- default-brightness: valid values: 0-100
 
 Each regulator is defined using the standard binding for regulators.
 
@@ -20,5 +21,7 @@ Example:
 		backlight {
 			isel = <1>;  /* 1 - ISET1, 2 ISET2 */
 			fdim = <100>; /* TPS65217_BL_FDIM_100HZ */
+			default-brightness = <50>;
 		};
 	};
+

drivers/video/backlight/tps65217_bl.c

@@ -245,6 +245,18 @@ tps65217_bl_parse_dt(struct platform_device *pdev)
 		}
 	}
 
+	if (!of_property_read_u32(node, "default-brightness", &val)) {
+		if (val < 0 ||
+			val > 100) {
+			dev_err(&pdev->dev,
+				"invalid 'default-brightness' value in the device tree\n");
+			err = ERR_PTR(-EINVAL);
+			goto err;
+		}
+
+		pdata->dft_brightness = val;
+	}
+
 	of_node_put(node);
 
 	return pdata;
@@ -311,7 +323,8 @@ static int tps65217_bl_probe(struct platform_device *pdev)
 		return PTR_ERR(tps65217_bl->bl);
 	}
 
-	tps65217_bl->bl->props.brightness = 0;
+	tps65217_bl->bl->props.brightness = pdata->dft_brightness;
+	backlight_update_status(tps65217_bl->bl);
 	platform_set_drvdata(pdev, tps65217_bl);
 
 	return 0;

include/linux/mfd/tps65217.h

@@ -228,6 +228,7 @@ enum tps65217_bl_fdim {
 struct tps65217_bl_pdata {
 	enum tps65217_bl_isel isel;
 	enum tps65217_bl_fdim fdim;
+	int dft_brightness;
 };
 
 /**