backlight: lp855x: Use private data for regulator control

LP855x backlight device can be enabled by external VDD input. The
'supply' data is used for this purpose. It's kind of private data
which runs internally, so there is no reason to expose to the
platform data.

And devm_regulator_get() is moved from _parse_dt() to _probe().
Regulator consumer(lp855x) can control regulator not only from DT
but also from platform data configuration in a source file such
like board-*.c.

Signed-off-by: Milo Kim <[e-mail]>
Acked-by: Sean Paul <[e-mail]>
Acked-by: Jingoo Han <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/video/backlight/lp855x_bl.c

···
 	struct device *dev;
 	struct lp855x_platform_data *pdata;
 	struct pwm_device *pwm;
+	struct regulator *supply;	/* regulator for VDD input */
 };
 
 static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data)
···
 		pdata->rom_data = &rom[0];
 	}
 
-	pdata->supply = devm_regulator_get(dev, "power");
-	if (IS_ERR(pdata->supply)) {
-		if (PTR_ERR(pdata->supply) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
-		pdata->supply = NULL;
-	}
-
 	lp->pdata = pdata;
 
 	return 0;
···
 	else
 		lp->mode = REGISTER_BASED;
 
-	if (lp->pdata->supply) {
-		ret = regulator_enable(lp->pdata->supply);
+	lp->supply = devm_regulator_get(lp->dev, "power");
+	if (IS_ERR(lp->supply)) {
+		if (PTR_ERR(lp->supply) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		lp->supply = NULL;
+	}
+
+	if (lp->supply) {
+		ret = regulator_enable(lp->supply);
 		if (ret < 0) {
 			dev_err(&cl->dev, "failed to enable supply: %d\n", ret);
 			return ret;
···
 
 	lp->bl->props.brightness = 0;
 	backlight_update_status(lp->bl);
-	if (lp->pdata->supply)
-		regulator_disable(lp->pdata->supply);
+	if (lp->supply)
+		regulator_disable(lp->supply);
 	sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group);
 
 	return 0;

include/linux/platform_data/lp855x.h

···
 		Only valid when mode is PWM_BASED.
  * @size_program : total size of lp855x_rom_data
  * @rom_data : list of new eeprom/eprom registers
- * @supply : regulator that supplies 3V input
  */
 struct lp855x_platform_data {
 	const char *name;
···
 	unsigned int period_ns;
 	int size_program;
 	struct lp855x_rom_data *rom_data;
-	struct regulator *supply;
 };
 
 #endif