[PATCH v3 0/3] backlight: mp3309c: Allow to use on non-OF platforms

[PATCH v3 0/3] backlight: mp3309c: Allow to use on non-OF platforms

[Andy Shevchenko]

Allow to use driver on non-OF platforms and other cleanups.

Changelog v3:
- rebased on top of the last changes against this driver (Lee)
- added tags to patch 2 (Daniel, Flavio)

Changelog v2:
- rename pm3309c_parse_dt_node() --> mp3309c_parse_fwnode() (Daniel)                                             - add tags (Daniel, Flavio)
- new patch 2

Andy Shevchenko (3):
  backlight: mp3309c: Make use of device properties
  backlight: mp3309c: use dev_err_probe() instead of dev_err()
  backlight: mp3309c: Utilise temporary variable for struct device

 drivers/video/backlight/mp3309c.c | 88 ++++++++++++-------------------
 1 file changed, 35 insertions(+), 53 deletions(-)

-- 
2.43.0.rc1.1.gbec44491f096

[PATCH v3 1/3] backlight: mp3309c: Make use of device properties

[Andy Shevchenko]

Convert the module to be property provider agnostic and allow
it to be used on non-OF platforms.

Add mod_devicetable.h include.

Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/video/backlight/mp3309c.c | 44 +++++++++++++------------------
 1 file changed, 18 insertions(+), 26 deletions(-)

diff --git a/drivers/video/backlight/mp3309c.c b/drivers/video/backlight/mp3309c.c
index b0d9aef6942b..397f35dafc5e 100644
--- a/drivers/video/backlight/mp3309c.c
+++ b/drivers/video/backlight/mp3309c.c
@@ -15,6 +15,8 @@
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
 #include <linux/pwm.h>
 #include <linux/regmap.h>
 
@@ -199,18 +201,15 @@ static const struct backlight_ops mp3309c_bl_ops = {
 	.update_status = mp3309c_bl_update_status,
 };
 
-static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
-				 struct mp3309c_platform_data *pdata)
+static int mp3309c_parse_fwnode(struct mp3309c_chip *chip,
+				struct mp3309c_platform_data *pdata)
 {
-	struct device_node *node = chip->dev->of_node;
-	struct property *prop_pwms;
-	struct property *prop_levels = NULL;
-	int length = 0;
 	int ret, i;
 	unsigned int num_levels, tmp_value;
+	struct device *dev = chip->dev;
 
-	if (!node) {
-		dev_err(chip->dev, "failed to get DT node\n");
+	if (!dev_fwnode(dev)) {
+		dev_err(dev, "failed to get firmware node\n");
 		return -ENODEV;
 	}
 
@@ -224,8 +223,7 @@ static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
 	 * found in the backlight node, the mode switches to PWM mode.
 	 */
 	pdata->dimming_mode = DIMMING_ANALOG_I2C;
-	prop_pwms = of_find_property(node, "pwms", &length);
-	if (prop_pwms) {
+	if (device_property_present(dev, "pwms")) {
 		chip->pwmd = devm_pwm_get(chip->dev, NULL);
 		if (IS_ERR(chip->pwmd))
 			return dev_err_probe(chip->dev, PTR_ERR(chip->pwmd),
@@ -257,11 +255,9 @@ static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
 		/*
 		 * PWM control mode: check for brightness level in DT
 		 */
-		prop_levels = of_find_property(node, "brightness-levels",
-					       &length);
-		if (prop_levels) {
+		if (device_property_present(dev, "brightness-levels")) {
 			/* Read brightness levels from DT */
-			num_levels = length / sizeof(u32);
+			num_levels = device_property_count_u32(dev, "brightness-levels");
 			if (num_levels < 2)
 				return -EINVAL;
 		} else {
@@ -275,10 +271,9 @@ static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
 				     sizeof(*pdata->levels), GFP_KERNEL);
 	if (!pdata->levels)
 		return -ENOMEM;
-	if (prop_levels) {
-		ret = of_property_read_u32_array(node, "brightness-levels",
-						 pdata->levels,
-						 num_levels);
+	if (device_property_present(dev, "brightness-levels")) {
+		ret = device_property_read_u32_array(dev, "brightness-levels",
+						     pdata->levels, num_levels);
 		if (ret < 0)
 			return ret;
 	} else {
@@ -288,8 +283,7 @@ static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
 
 	pdata->max_brightness = num_levels - 1;
 
-	ret = of_property_read_u32(node, "default-brightness",
-				   &pdata->default_brightness);
+	ret = device_property_read_u32(dev, "default-brightness", &pdata->default_brightness);
 	if (ret)
 		pdata->default_brightness = pdata->max_brightness;
 	if (pdata->default_brightness > pdata->max_brightness) {
@@ -310,8 +304,8 @@ static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
 	 * If missing, the default value for OVP is 35.5V
 	 */
 	pdata->over_voltage_protection = REG_I2C_1_OVP1;
-	if (!of_property_read_u32(node, "mps,overvoltage-protection-microvolt",
-				  &tmp_value)) {
+	ret = device_property_read_u32(dev, "mps,overvoltage-protection-microvolt", &tmp_value);
+	if (!ret) {
 		switch (tmp_value) {
 		case 13500000:
 			pdata->over_voltage_protection = 0x00;
@@ -328,9 +322,7 @@ static int pm3309c_parse_dt_node(struct mp3309c_chip *chip,
 	}
 
 	/* Synchronous (default) and non-synchronous mode */
-	pdata->sync_mode = true;
-	if (of_property_read_bool(node, "mps,no-sync-mode"))
-		pdata->sync_mode = false;
+	pdata->sync_mode = !device_property_read_bool(dev, "mps,no-sync-mode");
 
 	return 0;
 }
@@ -366,7 +358,7 @@ static int mp3309c_probe(struct i2c_client *client)
 		if (!pdata)
 			return -ENOMEM;
 
-		ret = pm3309c_parse_dt_node(chip, pdata);
+		ret = mp3309c_parse_fwnode(chip, pdata);
 		if (ret)
 			return ret;
 	}
-- 
2.43.0.rc1.1.gbec44491f096

[PATCH v3 2/3] backlight: mp3309c: use dev_err_probe() instead of dev_err()

[Andy Shevchenko]

Replace dev_err() with dev_err_probe().

This helps in simplifing code and standardizing the error output.

Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/video/backlight/mp3309c.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/video/backlight/mp3309c.c b/drivers/video/backlight/mp3309c.c
index 397f35dafc5e..426e9f2356ad 100644
--- a/drivers/video/backlight/mp3309c.c
+++ b/drivers/video/backlight/mp3309c.c
@@ -208,10 +208,8 @@ static int mp3309c_parse_fwnode(struct mp3309c_chip *chip,
 	unsigned int num_levels, tmp_value;
 	struct device *dev = chip->dev;
 
-	if (!dev_fwnode(dev)) {
-		dev_err(dev, "failed to get firmware node\n");
-		return -ENODEV;
-	}
+	if (!dev_fwnode(dev))
+		return dev_err_probe(dev, -ENODEV, "failed to get firmware node\n");
 
 	/*
 	 * Dimming mode: the MP3309C provides two dimming control mode:
@@ -287,8 +285,7 @@ static int mp3309c_parse_fwnode(struct mp3309c_chip *chip,
 	if (ret)
 		pdata->default_brightness = pdata->max_brightness;
 	if (pdata->default_brightness > pdata->max_brightness) {
-		dev_err(chip->dev,
-			"default brightness exceeds max brightness\n");
+		dev_err_probe(dev, -ERANGE, "default brightness exceeds max brightness\n");
 		pdata->default_brightness = pdata->max_brightness;
 	}
 
@@ -329,16 +326,15 @@ static int mp3309c_parse_fwnode(struct mp3309c_chip *chip,
 
 static int mp3309c_probe(struct i2c_client *client)
 {
-	struct mp3309c_platform_data *pdata = dev_get_platdata(&client->dev);
+	struct device *dev = &client->dev;
+	struct mp3309c_platform_data *pdata = dev_get_platdata(dev);
 	struct mp3309c_chip *chip;
 	struct backlight_properties props;
 	struct pwm_state pwmstate;
 	int ret;
 
-	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
-		dev_err(&client->dev, "failed to check i2c functionality\n");
-		return -EOPNOTSUPP;
-	}
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return dev_err_probe(dev, -EOPNOTSUPP, "failed to check i2c functionality\n");
 
 	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
-- 
2.43.0.rc1.1.gbec44491f096

[PATCH v3 3/3] backlight: mp3309c: Utilise temporary variable for struct device

[Andy Shevchenko]

We have a temporary variable to keep pointer to struct device.
Utilise it where it makes sense.

Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/video/backlight/mp3309c.c | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/drivers/video/backlight/mp3309c.c b/drivers/video/backlight/mp3309c.c
index 426e9f2356ad..708c053d492c 100644
--- a/drivers/video/backlight/mp3309c.c
+++ b/drivers/video/backlight/mp3309c.c
@@ -222,10 +222,9 @@ static int mp3309c_parse_fwnode(struct mp3309c_chip *chip,
 	 */
 	pdata->dimming_mode = DIMMING_ANALOG_I2C;
 	if (device_property_present(dev, "pwms")) {
-		chip->pwmd = devm_pwm_get(chip->dev, NULL);
+		chip->pwmd = devm_pwm_get(dev, NULL);
 		if (IS_ERR(chip->pwmd))
-			return dev_err_probe(chip->dev, PTR_ERR(chip->pwmd),
-					     "error getting pwm data\n");
+			return dev_err_probe(dev, PTR_ERR(chip->pwmd), "error getting pwm data\n");
 		pdata->dimming_mode = DIMMING_PWM;
 		pwm_apply_args(chip->pwmd);
 	}
@@ -243,11 +242,9 @@ static int mp3309c_parse_fwnode(struct mp3309c_chip *chip,
 		num_levels = ANALOG_I2C_NUM_LEVELS;
 
 		/* Enable GPIO used in I2C dimming mode only */
-		chip->enable_gpio = devm_gpiod_get(chip->dev, "enable",
-						   GPIOD_OUT_HIGH);
+		chip->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
 		if (IS_ERR(chip->enable_gpio))
-			return dev_err_probe(chip->dev,
-					     PTR_ERR(chip->enable_gpio),
+			return dev_err_probe(dev, PTR_ERR(chip->enable_gpio),
 					     "error getting enable gpio\n");
 	} else {
 		/*
@@ -265,8 +262,7 @@ static int mp3309c_parse_fwnode(struct mp3309c_chip *chip,
 	}
 
 	/* Fill brightness levels array */
-	pdata->levels = devm_kcalloc(chip->dev, num_levels,
-				     sizeof(*pdata->levels), GFP_KERNEL);
+	pdata->levels = devm_kcalloc(dev, num_levels, sizeof(*pdata->levels), GFP_KERNEL);
 	if (!pdata->levels)
 		return -ENOMEM;
 	if (device_property_present(dev, "brightness-levels")) {
@@ -336,21 +332,21 @@ static int mp3309c_probe(struct i2c_client *client)
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 		return dev_err_probe(dev, -EOPNOTSUPP, "failed to check i2c functionality\n");
 
-	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
 		return -ENOMEM;
 
-	chip->dev = &client->dev;
+	chip->dev = dev;
 
 	chip->regmap = devm_regmap_init_i2c(client, &mp3309c_regmap);
 	if (IS_ERR(chip->regmap))
-		return dev_err_probe(&client->dev, PTR_ERR(chip->regmap),
+		return dev_err_probe(dev, PTR_ERR(chip->regmap),
 				     "failed to allocate register map\n");
 
 	i2c_set_clientdata(client, chip);
 
 	if (!pdata) {
-		pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL);
+		pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 		if (!pdata)
 			return -ENOMEM;
 
@@ -367,11 +363,10 @@ static int mp3309c_probe(struct i2c_client *client)
 	props.type = BACKLIGHT_RAW;
 	props.power = FB_BLANK_UNBLANK;
 	props.fb_blank = FB_BLANK_UNBLANK;
-	chip->bl = devm_backlight_device_register(chip->dev, "mp3309c",
-						  chip->dev, chip,
+	chip->bl = devm_backlight_device_register(dev, "mp3309c", dev, chip,
 						  &mp3309c_bl_ops, &props);
 	if (IS_ERR(chip->bl))
-		return dev_err_probe(chip->dev, PTR_ERR(chip->bl),
+		return dev_err_probe(dev, PTR_ERR(chip->bl),
 				     "error registering backlight device\n");
 
 	/* In PWM dimming mode, enable pwm device */
@@ -383,8 +378,7 @@ static int mp3309c_probe(struct i2c_client *client)
 		pwmstate.enabled = true;
 		ret = pwm_apply_might_sleep(chip->pwmd, &pwmstate);
 		if (ret)
-			return dev_err_probe(chip->dev, ret,
-					     "error setting pwm device\n");
+			return dev_err_probe(dev, ret, "error setting pwm device\n");
 	}
 
 	chip->pdata->status = FIRST_POWER_ON;
-- 
2.43.0.rc1.1.gbec44491f096

Re: [PATCH v3 1/3] backlight: mp3309c: Make use of device properties

[Andy Shevchenko]

On Thu, Feb 08, 2024 at 08:24:46PM +0200, Andy Shevchenko wrote:
> Convert the module to be property provider agnostic and allow
> it to be used on non-OF platforms.
> 
> Add mod_devicetable.h include.

It seems some emails are missing, I just sent a 'resend v3' hopefully without
missing parts.

-- 
With Best Regards,
Andy Shevchenko

[PATCH v3 2/3] backlight: mp3309c: use dev_err_probe() instead of dev_err()

[Andy Shevchenko]

Replace dev_err() with dev_err_probe().

This helps in simplifing code and standardizing the error output.

Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/video/backlight/mp3309c.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/video/backlight/mp3309c.c b/drivers/video/backlight/mp3309c.c
index 397f35dafc5e..426e9f2356ad 100644
--- a/drivers/video/backlight/mp3309c.c
+++ b/drivers/video/backlight/mp3309c.c
@@ -208,10 +208,8 @@ static int mp3309c_parse_fwnode(struct mp3309c_chip *chip,
 	unsigned int num_levels, tmp_value;
 	struct device *dev = chip->dev;
 
-	if (!dev_fwnode(dev)) {
-		dev_err(dev, "failed to get firmware node\n");
-		return -ENODEV;
-	}
+	if (!dev_fwnode(dev))
+		return dev_err_probe(dev, -ENODEV, "failed to get firmware node\n");
 
 	/*
 	 * Dimming mode: the MP3309C provides two dimming control mode:
@@ -287,8 +285,7 @@ static int mp3309c_parse_fwnode(struct mp3309c_chip *chip,
 	if (ret)
 		pdata->default_brightness = pdata->max_brightness;
 	if (pdata->default_brightness > pdata->max_brightness) {
-		dev_err(chip->dev,
-			"default brightness exceeds max brightness\n");
+		dev_err_probe(dev, -ERANGE, "default brightness exceeds max brightness\n");
 		pdata->default_brightness = pdata->max_brightness;
 	}
 
@@ -329,16 +326,15 @@ static int mp3309c_parse_fwnode(struct mp3309c_chip *chip,
 
 static int mp3309c_probe(struct i2c_client *client)
 {
-	struct mp3309c_platform_data *pdata = dev_get_platdata(&client->dev);
+	struct device *dev = &client->dev;
+	struct mp3309c_platform_data *pdata = dev_get_platdata(dev);
 	struct mp3309c_chip *chip;
 	struct backlight_properties props;
 	struct pwm_state pwmstate;
 	int ret;
 
-	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
-		dev_err(&client->dev, "failed to check i2c functionality\n");
-		return -EOPNOTSUPP;
-	}
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+		return dev_err_probe(dev, -EOPNOTSUPP, "failed to check i2c functionality\n");
 
 	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip)
-- 
2.43.0.rc1.1.gbec44491f096