regulator: rpi-panel-attiny: use new GPIO line value

Merge series from Bartosz Golaszewski <brgl@bgdev.pl>:

struct gpio_chip now has callbacks for setting line values that return
an integer, allowing to indicate failures. We're in the process of
converting all GPIO drivers to using the new API. This series converts
the only GPIO controller under drivers/regulator/ and - while at it -
refactors the code a bit.

Author: broonie

drivers/regulator/rpi-panel-attiny-regulator.c

@@ -6,12 +6,14 @@
  */
 
 #include <linux/backlight.h>
+#include <linux/cleanup.h>
 #include <linux/err.h>
 #include <linux/gpio/driver.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/regmap.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
@@ -93,7 +95,7 @@ static int attiny_lcd_power_enable(struct regulator_dev *rdev)
 {
 	struct attiny_lcd *state = rdev_get_drvdata(rdev);
 
-	mutex_lock(&state->lock);
+	guard(mutex)(&state->lock);
 
 	/* Ensure bridge, and tp stay in reset */
 	attiny_set_port_state(state, REG_PORTC, 0);
@@ -114,16 +116,14 @@ static int attiny_lcd_power_enable(struct regulator_dev *rdev)
 
 	msleep(80);
 
-	mutex_unlock(&state->lock);
-
 	return 0;
 }
 
 static int attiny_lcd_power_disable(struct regulator_dev *rdev)
 {
 	struct attiny_lcd *state = rdev_get_drvdata(rdev);
 
-	mutex_lock(&state->lock);
+	guard(mutex)(&state->lock);
 
 	regmap_write(rdev->regmap, REG_PWM, 0);
 	usleep_range(5000, 10000);
@@ -135,28 +135,24 @@ static int attiny_lcd_power_disable(struct regulator_dev *rdev)
 	attiny_set_port_state(state, REG_PORTC, 0);
 	msleep(30);
 
-	mutex_unlock(&state->lock);
-
 	return 0;
 }
 
 static int attiny_lcd_power_is_enabled(struct regulator_dev *rdev)
 {
 	struct attiny_lcd *state = rdev_get_drvdata(rdev);
 	unsigned int data;
-	int ret, i;
-
-	mutex_lock(&state->lock);
-
-	for (i = 0; i < 10; i++) {
-		ret = regmap_read(rdev->regmap, REG_PORTC, &data);
-		if (!ret)
-			break;
-		usleep_range(10000, 12000);
+	int ret = 0, i;
+
+	scoped_guard(mutex, &state->lock) {
+		for (i = 0; i < 10; i++) {
+			ret = regmap_read(rdev->regmap, REG_PORTC, &data);
+			if (!ret)
+				break;
+			usleep_range(10000, 12000);
+		}
 	}
 
-	mutex_unlock(&state->lock);
-
 	if (ret < 0)
 		return ret;
 
@@ -189,16 +185,14 @@ static int attiny_update_status(struct backlight_device *bl)
 	int brightness = backlight_get_brightness(bl);
 	int ret, i;
 
-	mutex_lock(&state->lock);
+	guard(mutex)(&state->lock);
 
 	for (i = 0; i < 10; i++) {
 		ret = regmap_write(regmap, REG_PWM, brightness);
 		if (!ret)
 			break;
 	}
 
-	mutex_unlock(&state->lock);
-
 	return ret;
 }
 
@@ -211,15 +205,12 @@ static int attiny_gpio_get_direction(struct gpio_chip *gc, unsigned int off)
 	return GPIO_LINE_DIRECTION_OUT;
 }
 
-static void attiny_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
+static int attiny_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
 {
 	struct attiny_lcd *state = gpiochip_get_data(gc);
 	u8 last_val;
 
-	if (off >= NUM_GPIO)
-		return;
-
-	mutex_lock(&state->lock);
+	guard(mutex)(&state->lock);
 
 	last_val = attiny_get_port_state(state, mappings[off].reg);
 	if (val)
@@ -242,7 +233,7 @@ static void attiny_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
 		msleep(100);
 	}
 
-	mutex_unlock(&state->lock);
+	return 0;
 }
 
 static int attiny_i2c_read(struct i2c_client *client, u8 reg, unsigned int *buf)
@@ -296,21 +287,24 @@ static int attiny_i2c_probe(struct i2c_client *i2c)
 	if (!state)
 		return -ENOMEM;
 
-	mutex_init(&state->lock);
+	ret = devm_mutex_init(&i2c->dev, &state->lock);
+	if (ret)
+		return ret;
+
 	i2c_set_clientdata(i2c, state);
 
 	regmap = devm_regmap_init_i2c(i2c, &attiny_regmap_config);
 	if (IS_ERR(regmap)) {
 		ret = PTR_ERR(regmap);
 		dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
 			ret);
-		goto error;
+		return ret;
 	}
 
 	ret = attiny_i2c_read(i2c, REG_ID, &data);
 	if (ret < 0) {
 		dev_err(&i2c->dev, "Failed to read REG_ID reg: %d\n", ret);
-		goto error;
+		return ret;
 	}
 
 	switch (data) {
@@ -319,8 +313,7 @@ static int attiny_i2c_probe(struct i2c_client *i2c)
 		break;
 	default:
 		dev_err(&i2c->dev, "Unknown Atmel firmware revision: 0x%02x\n", data);
-		ret = -ENODEV;
-		goto error;
+		return -ENODEV;
 	}
 
 	regmap_write(regmap, REG_POWERON, 0);
@@ -336,8 +329,7 @@ static int attiny_i2c_probe(struct i2c_client *i2c)
 	rdev = devm_regulator_register(&i2c->dev, &attiny_regulator, &config);
 	if (IS_ERR(rdev)) {
 		dev_err(&i2c->dev, "Failed to register ATTINY regulator\n");
-		ret = PTR_ERR(rdev);
-		goto error;
+		return PTR_ERR(rdev);
 	}
 
 	props.type = BACKLIGHT_RAW;
@@ -348,10 +340,8 @@ static int attiny_i2c_probe(struct i2c_client *i2c)
 	bl = devm_backlight_device_register(&i2c->dev, dev_name(&i2c->dev),
 					    &i2c->dev, state, &attiny_bl,
 					    &props);
-	if (IS_ERR(bl)) {
-		ret = PTR_ERR(bl);
-		goto error;
-	}
+	if (IS_ERR(bl))
+		return PTR_ERR(bl);
 
 	bl->props.brightness = 0xff;
 
@@ -361,31 +351,17 @@ static int attiny_i2c_probe(struct i2c_client *i2c)
 	state->gc.base = -1;
 	state->gc.ngpio = NUM_GPIO;
 
-	state->gc.set = attiny_gpio_set;
+	state->gc.set_rv = attiny_gpio_set;
 	state->gc.get_direction = attiny_gpio_get_direction;
 	state->gc.can_sleep = true;
 
 	ret = devm_gpiochip_add_data(&i2c->dev, &state->gc, state);
-	if (ret) {
+	if (ret)
 		dev_err(&i2c->dev, "Failed to create gpiochip: %d\n", ret);
-		goto error;
-	}
-
-	return 0;
-
-error:
-	mutex_destroy(&state->lock);
 
 	return ret;
 }
 
-static void attiny_i2c_remove(struct i2c_client *client)
-{
-	struct attiny_lcd *state = i2c_get_clientdata(client);
-
-	mutex_destroy(&state->lock);
-}
-
 static const struct of_device_id attiny_dt_ids[] = {
 	{ .compatible = "raspberrypi,7inch-touchscreen-panel-regulator" },
 	{},
@@ -399,7 +375,6 @@ static struct i2c_driver attiny_regulator_driver = {
 		.of_match_table = attiny_dt_ids,
 	},
 	.probe = attiny_i2c_probe,
-	.remove	= attiny_i2c_remove,
 };
 
 module_i2c_driver(attiny_regulator_driver);