drivers/leds/leds-lm3530.c: add regulator

Add add regulator support to lm3530 driver. The lm3530 driver needs to
get proper regulator during device probe and enable it before accessing
the device. Also it disables the regulator in case of brightness ==
LED_OFF, and puts it back during driver removal.

[[e-mail]: coding-style fixes]
Signed-off-by: Shreshtha Kumar Sahu <[e-mail]>
Cc: Lee Jones <[e-mail]>
Cc: Shreshtha Kumar Sahu <[e-mail]>
Cc: Richard Purdie <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/leds/leds-lm3530.c

···
 #include <linux/input.h>
 #include <linux/led-lm3530.h>
 #include <linux/types.h>
+#include <linux/regulator/consumer.h>
 
 #define LM3530_LED_DEV "lcd-backlight"
 #define LM3530_NAME "lm3530-led"
···
  * @client: i2c client
  * @pdata: LM3530 platform data
  * @mode: mode of operation - manual, ALS, PWM
+ * @regulator: regulator
+ * @brighness: previous brightness value
+ * @enable: regulator is enabled
  */
 struct lm3530_data {
 	struct led_classdev led_dev;
 	struct i2c_client *client;
 	struct lm3530_platform_data *pdata;
 	enum lm3530_mode mode;
+	struct regulator *regulator;
+	enum led_brightness brightness;
+	bool enable;
 };
 
 static const u8 lm3530_reg[LM3530_REG_MAX] = {
···
 	brt_ramp = (pltfm->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
 			(pltfm->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);
 
-	brightness = pltfm->brt_val;
+	if (drvdata->brightness)
+		brightness = drvdata->brightness;
+	else
+		brightness = drvdata->brightness = pltfm->brt_val;
 
 	reg_val[0] = gen_config;	/* LM3530_GEN_CONFIG */
 	reg_val[1] = als_config;	/* LM3530_ALS_CONFIG */
···
 	reg_val[12] = LM3530_DEF_ZT_2;	/* LM3530_ALS_Z2T_REG */
 	reg_val[13] = LM3530_DEF_ZT_3;	/* LM3530_ALS_Z3T_REG */
 	reg_val[14] = LM3530_DEF_ZT_4;	/* LM3530_ALS_Z4T_REG */
+
+	if (!drvdata->enable) {
+		ret = regulator_enable(drvdata->regulator);
+		if (ret) {
+			dev_err(&drvdata->client->dev,
+					"Enable regulator failed\n");
+			return ret;
+		}
+		drvdata->enable = true;
+	}
 
 	for (i = 0; i < LM3530_REG_MAX; i++) {
 		ret = i2c_smbus_write_byte_data(client,
···
 	switch (drvdata->mode) {
 	case LM3530_BL_MODE_MANUAL:
 
+		if (!drvdata->enable) {
+			err = lm3530_init_registers(drvdata);
+			if (err) {
+				dev_err(&drvdata->client->dev,
+					"Register Init failed: %d\n", err);
+				break;
+			}
+		}
+
 		/* set the brightness in brightness control register*/
 		err = i2c_smbus_write_byte_data(drvdata->client,
 				LM3530_BRT_CTRL_REG, brt_val / 2);
 		if (err)
 			dev_err(&drvdata->client->dev,
 				"Unable to set brightness: %d\n", err);
+		else
+			drvdata->brightness = brt_val / 2;
+
+		if (brt_val == 0) {
+			err = regulator_disable(drvdata->regulator);
+			if (err)
+				dev_err(&drvdata->client->dev,
+					"Disable regulator failed\n");
+			drvdata->enable = false;
+		}
 		break;
 	case LM3530_BL_MODE_ALS:
 		break;
···
 	drvdata->mode = pdata->mode;
 	drvdata->client = client;
 	drvdata->pdata = pdata;
+	drvdata->brightness = LED_OFF;
+	drvdata->enable = false;
 	drvdata->led_dev.name = LM3530_LED_DEV;
 	drvdata->led_dev.brightness_set = lm3530_brightness_set;
 
 	i2c_set_clientdata(client, drvdata);
 
-	err = lm3530_init_registers(drvdata);
-	if (err < 0) {
-		dev_err(&client->dev, "Register Init failed: %d\n", err);
-		err = -ENODEV;
-		goto err_reg_init;
+	drvdata->regulator = regulator_get(&client->dev, "vin");
+	if (IS_ERR(drvdata->regulator)) {
+		dev_err(&client->dev, "regulator get failed\n");
+		err = PTR_ERR(drvdata->regulator);
+		drvdata->regulator = NULL;
+		goto err_regulator_get;
 	}
 
-	err = led_classdev_register((struct device *)
-				      &client->dev, &drvdata->led_dev);
+	if (drvdata->pdata->brt_val) {
+		err = lm3530_init_registers(drvdata);
+		if (err < 0) {
+			dev_err(&client->dev,
+				"Register Init failed: %d\n", err);
+			err = -ENODEV;
+			goto err_reg_init;
+		}
+	}
+	err = led_classdev_register(&client->dev, &drvdata->led_dev);
 	if (err < 0) {
 		dev_err(&client->dev, "Register led class failed: %d\n", err);
 		err = -ENODEV;
···
 	led_classdev_unregister(&drvdata->led_dev);
 err_class_register:
 err_reg_init:
+	regulator_put(drvdata->regulator);
+err_regulator_get:
+	i2c_set_clientdata(client, NULL);
 	kfree(drvdata);
 err_out:
 	return err;
···
 	struct lm3530_data *drvdata = i2c_get_clientdata(client);
 
 	device_remove_file(drvdata->led_dev.dev, &dev_attr_mode);
+
+	if (drvdata->enable)
+		regulator_disable(drvdata->regulator);
+	regulator_put(drvdata->regulator);
 	led_classdev_unregister(&drvdata->led_dev);
 	kfree(drvdata);
 	return 0;