[PATCH v2 0/6] iio: adc: ti-ads1015: modernize resource management

[PATCH v2 0/6] iio: adc: ti-ads1015: modernize resource management

[Archit Anant]

This series modernizes the ti-ads1015 by transitioning it
to a fully devm_ architecture.

By moving resource allocation, device registration, and runtime power
management to the devm_ infrastructure, the teardown sequence is now
guaranteed to execute safely in the reverse order of initialization.
This allows for the complete removal of the ads1015_remove() function,
eliminating boilerplate code and reducing the risk of future resource
leaks.

Additionally, housekeeping patches are included to ensure header
includes remain alphabetically sorted, dev_err_probe() is used
consistently, and PM macros are updated to modern standards.

Changes in v2:
- Split the monolithic v1 patch into a 6-patch series to isolate
  housekeeping, bug fixes, and API modernizations for easier review
  and backporting.
- Patch 1: Added to modernize PM ops and remove #ifdef CONFIG_PM.
- Patch 2: Added to fix a pre-existing PM leak on probe failure
  identified by Jonathan Cameron.
- Patch 3: Extracted header sorting into a prerequisite patch.
- Patch 4 & 5: Extracted the introduction of the local 'dev' pointer
  and dev_err_probe() conversions, suggested by Jonathan Cameron.
- Patch 6: Now contains only the devm_ conversions and the removal
  of ads1015_remove().

Archit Anant (6):
  iio: adc: ti-ads1015: use DEFINE_RUNTIME_DEV_PM_OPS()
  iio: adc: ti-ads1015: fix PM leak on probe failure
  iio: adc: ti-ads1015: sort headers alphabetically
  iio: adc: ti-ads1015: use local device pointer in probe
  iio: adc: ti-ads1015: use dev_err_probe() for error handling
  iio: adc: ti-ads1015: convert to fully managed resources

 drivers/iio/adc/ti-ads1015.c | 114 +++++++++++++++--------------------
 1 file changed, 50 insertions(+), 64 deletions(-)

-- 
2.39.5

[PATCH v2 1/6] iio: adc: ti-ads1015: use DEFINE_RUNTIME_DEV_PM_OPS()

[Archit Anant]

Replace the deprecated SET_RUNTIME_PM_OPS() with the modern
DEFINE_RUNTIME_DEV_PM_OPS() macro. This allows for the removal of the
macro automatically handles dropping unused functions when PM is
disabled.

Update the driver struct to use pm_ptr() to avoid unused variable
warnings.

Signed-off-by: Archit Anant <architanant5@gmail.com>
---
 drivers/iio/adc/ti-ads1015.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index 8a272af69f7d..9cd620b71429 100644
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -1066,7 +1066,6 @@ static void ads1015_remove(struct i2c_client *client)
 			 ERR_PTR(ret));
 }
 
-#ifdef CONFIG_PM
 static int ads1015_runtime_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
@@ -1087,12 +1086,11 @@ static int ads1015_runtime_resume(struct device *dev)
 
 	return ret;
 }
-#endif
 
-static const struct dev_pm_ops ads1015_pm_ops = {
-	SET_RUNTIME_PM_OPS(ads1015_runtime_suspend,
-			   ads1015_runtime_resume, NULL)
-};
+static DEFINE_RUNTIME_DEV_PM_OPS(ads1015_pm_ops,
+				 ads1015_runtime_suspend,
+				 ads1015_runtime_resume,
+				 NULL);
 
 static const struct ads1015_chip_data ads1015_data = {
 	.channels	= ads1015_channels,
@@ -1147,7 +1145,7 @@ static struct i2c_driver ads1015_driver = {
 	.driver = {
 		.name = ADS1015_DRV_NAME,
 		.of_match_table = ads1015_of_match,
-		.pm = &ads1015_pm_ops,
+		.pm = pm_ptr(&ads1015_pm_ops),
 	},
 	.probe		= ads1015_probe,
 	.remove		= ads1015_remove,
-- 
2.39.5

[PATCH v2 2/6] iio: adc: ti-ads1015: fix PM leak on probe failure

[Archit Anant]

If iio_device_register() fails during probe(), the runtime PM
subsystem is left enabled. This leads to a resource leak upon failure.

Add the missing pm_runtime_disable() and pm_runtime_set_suspended()
calls to the probe() error path to ensure proper cleanup.

Reported-by: Jonathan Cameron <jic23@kernel.org>
Link: https://lore.kernel.org/linux-iio/20260718225515.7e49a458@jic23-huawei/
Signed-off-by: Archit Anant <architanant5@gmail.com>
---
 drivers/iio/adc/ti-ads1015.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index 9cd620b71429..3a14fdab56d8 100644
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -1042,6 +1042,8 @@ static int ads1015_probe(struct i2c_client *client)
 	ret = iio_device_register(indio_dev);
 	if (ret < 0) {
 		dev_err(&client->dev, "Failed to register IIO device\n");
+		pm_runtime_disable(&client->dev);
+		pm_runtime_set_suspended(&client->dev);
 		return ret;
 	}
 
-- 
2.39.5

[PATCH v2 3/6] iio: adc: ti-ads1015: sort headers alphabetically

[Archit Anant]

Reorder include headers alphabetically to comply with the preferred
coding style and improve maintainability.

No functional changes.

Signed-off-by: Archit Anant <architanant5@gmail.com>
---
 drivers/iio/adc/ti-ads1015.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index 3a14fdab56d8..293fdd49381f 100644
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -11,24 +11,24 @@
  *	* 0x4B - ADDR connected to SCL
  */
 
-#include <linux/module.h>
 #include <linux/cleanup.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/irq.h>
-#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
-#include <linux/pm_runtime.h>
-#include <linux/mutex.h>
-#include <linux/delay.h>
 
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
 #include <linux/iio/iio.h>
-#include <linux/iio/types.h>
 #include <linux/iio/sysfs.h>
-#include <linux/iio/events.h>
-#include <linux/iio/buffer.h>
-#include <linux/iio/triggered_buffer.h>
 #include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/types.h>
 
 #define ADS1015_DRV_NAME "ads1015"
 
-- 
2.39.5

[PATCH v2 4/6] iio: adc: ti-ads1015: use local device pointer in probe

[Archit Anant]

Introduce a local device pointer 'dev' in ads1015_probe to
avoid accessing &client->dev repeatedly.

Signed-off-by: Archit Anant <architanant5@gmail.com>
---
 drivers/iio/adc/ti-ads1015.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index 293fdd49381f..59ce2f89daeb 100644
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -933,6 +933,7 @@ static int ads1015_set_conv_mode(struct ads1015_data *data, int mode)
 static int ads1015_probe(struct i2c_client *client)
 {
 	const struct ads1015_chip_data *chip;
+	struct device *dev = &client->dev;
 	struct iio_dev *indio_dev;
 	struct ads1015_data *data;
 	int ret;
@@ -940,9 +941,9 @@ static int ads1015_probe(struct i2c_client *client)
 
 	chip = i2c_get_match_data(client);
 	if (!chip)
-		return dev_err_probe(&client->dev, -EINVAL, "Unknown chip\n");
+		return dev_err_probe(dev, -EINVAL, "Unknown chip\n");
 
-	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 	if (!indio_dev)
 		return -ENOMEM;
 
@@ -978,15 +979,15 @@ static int ads1015_probe(struct i2c_client *client)
 					    &ads1015_regmap_config :
 					    &tla2024_regmap_config);
 	if (IS_ERR(data->regmap)) {
-		dev_err(&client->dev, "Failed to allocate register map\n");
+		dev_err(dev, "Failed to allocate register map\n");
 		return PTR_ERR(data->regmap);
 	}
 
-	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
 					      ads1015_trigger_handler,
 					      &ads1015_buffer_setup_ops);
 	if (ret < 0) {
-		dev_err(&client->dev, "iio triggered buffer setup failed\n");
+		dev_err(dev, "iio triggered buffer setup failed\n");
 		return ret;
 	}
 
@@ -1018,7 +1019,7 @@ static int ads1015_probe(struct i2c_client *client)
 		if (ret)
 			return ret;
 
-		ret = devm_request_threaded_irq(&client->dev, client->irq,
+		ret = devm_request_threaded_irq(dev, client->irq,
 						NULL, ads1015_event_handler,
 						irq_trig | IRQF_ONESHOT,
 						client->name, indio_dev);
@@ -1032,18 +1033,18 @@ static int ads1015_probe(struct i2c_client *client)
 
 	data->conv_invalid = true;
 
-	ret = pm_runtime_set_active(&client->dev);
+	ret = pm_runtime_set_active(dev);
 	if (ret)
 		return ret;
-	pm_runtime_set_autosuspend_delay(&client->dev, ADS1015_SLEEP_DELAY_MS);
-	pm_runtime_use_autosuspend(&client->dev);
-	pm_runtime_enable(&client->dev);
+	pm_runtime_set_autosuspend_delay(dev, ADS1015_SLEEP_DELAY_MS);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_enable(dev);
 
 	ret = iio_device_register(indio_dev);
 	if (ret < 0) {
-		dev_err(&client->dev, "Failed to register IIO device\n");
-		pm_runtime_disable(&client->dev);
-		pm_runtime_set_suspended(&client->dev);
+		dev_err(dev, "Failed to register IIO device\n");
+		pm_runtime_disable(dev);
+		pm_runtime_set_suspended(dev);
 		return ret;
 	}
 
-- 
2.39.5

[PATCH v2 5/6] iio: adc: ti-ads1015: use dev_err_probe() for error handling

[Archit Anant]

Simplify the error handling paths in ads1015_probe() and
ads1015_client_get_channels_config()  by converting dev_err()
calls that are immediately followed by a return statement
over to the modern dev_err_probe() helper.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Archit Anant <architanant5@gmail.com>
---
 drivers/iio/adc/ti-ads1015.c | 28 ++++++++++++----------------
 1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index 59ce2f89daeb..a8dba4e5aed3 100644
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -883,18 +883,16 @@ static int ads1015_client_get_channels_config(struct i2c_client *client)
 
 		if (!fwnode_property_read_u32(node, "ti,gain", &pval)) {
 			pga = pval;
-			if (pga > 5) {
-				dev_err(dev, "invalid gain on %pfw\n", node);
-				return -EINVAL;
-			}
+			if (pga > 5)
+				return dev_err_probe(dev, -EINVAL,
+						     "invalid gain on %pfw\n", node);
 		}
 
 		if (!fwnode_property_read_u32(node, "ti,datarate", &pval)) {
 			data_rate = pval;
-			if (data_rate > 7) {
-				dev_err(dev, "invalid data_rate on %pfw\n", node);
-				return -EINVAL;
-			}
+			if (data_rate > 7)
+				return dev_err_probe(dev, -EINVAL,
+						     "invalid data_rate on %pfw\n", node);
 		}
 
 		data->channel_data[channel].pga = pga;
@@ -978,18 +976,16 @@ static int ads1015_probe(struct i2c_client *client)
 	data->regmap = devm_regmap_init_i2c(client, chip->has_comparator ?
 					    &ads1015_regmap_config :
 					    &tla2024_regmap_config);
-	if (IS_ERR(data->regmap)) {
-		dev_err(dev, "Failed to allocate register map\n");
-		return PTR_ERR(data->regmap);
-	}
+	if (IS_ERR(data->regmap))
+		return dev_err_probe(dev, PTR_ERR(data->regmap),
+				     "Failed to allocate register map\n");
 
 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
 					      ads1015_trigger_handler,
 					      &ads1015_buffer_setup_ops);
-	if (ret < 0) {
-		dev_err(dev, "iio triggered buffer setup failed\n");
-		return ret;
-	}
+	if (ret < 0)
+		return dev_err_probe(dev, ret,
+				     "iio triggered buffer setup failed\n");
 
 	if (client->irq && chip->has_comparator) {
 		unsigned long irq_trig = irq_get_trigger_type(client->irq);
-- 
2.39.5

[PATCH v2 6/6] iio: adc: ti-ads1015: convert to fully managed resources

[Archit Anant]

Refactor the driver to use devm_ allocations and power
management, allowing for the complete removal of the
ads1015_remove()

Key changes:
- Use devm_add_action_or_reset() to ensure the ADC is safely powered
down upon driver removal.
- Move to devm_pm_runtime_set_active_enabled() to manage the runtime
PM lifecycle.
- Convert iio_device_register() and mutex_init() to their devm_
variants.
- Remove the thus obsolete ads1015_remove() function.

Signed-off-by: Archit Anant <architanant5@gmail.com>
---
 drivers/iio/adc/ti-ads1015.c | 45 ++++++++++++++----------------------
 1 file changed, 17 insertions(+), 28 deletions(-)

diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index a8dba4e5aed3..f92ec5941c47 100644
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -928,6 +928,11 @@ static int ads1015_set_conv_mode(struct ads1015_data *data, int mode)
 				  mode << ADS1015_CFG_MOD_SHIFT);
 }
 
+static void ads1015_power_off(void *st)
+{
+	ads1015_set_conv_mode(st, ADS1015_SINGLESHOT);
+}
+
 static int ads1015_probe(struct i2c_client *client)
 {
 	const struct ads1015_chip_data *chip;
@@ -948,7 +953,9 @@ static int ads1015_probe(struct i2c_client *client)
 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 
-	mutex_init(&data->lock);
+	ret = devm_mutex_init(dev, &data->lock);
+	if (ret)
+		return ret;
 
 	indio_dev->name = ADS1015_DRV_NAME;
 	indio_dev->modes = INDIO_DIRECT_MODE;
@@ -1029,40 +1036,23 @@ static int ads1015_probe(struct i2c_client *client)
 
 	data->conv_invalid = true;
 
-	ret = pm_runtime_set_active(dev);
+	ret = devm_add_action_or_reset(dev, ads1015_power_off, data);
 	if (ret)
 		return ret;
+
 	pm_runtime_set_autosuspend_delay(dev, ADS1015_SLEEP_DELAY_MS);
 	pm_runtime_use_autosuspend(dev);
-	pm_runtime_enable(dev);
 
-	ret = iio_device_register(indio_dev);
-	if (ret < 0) {
-		dev_err(dev, "Failed to register IIO device\n");
-		pm_runtime_disable(dev);
-		pm_runtime_set_suspended(dev);
+	ret = devm_pm_runtime_set_active_enabled(dev);
+	if (ret)
 		return ret;
-	}
-
-	return 0;
-}
-
-static void ads1015_remove(struct i2c_client *client)
-{
-	struct iio_dev *indio_dev = i2c_get_clientdata(client);
-	struct ads1015_data *data = iio_priv(indio_dev);
-	int ret;
 
-	iio_device_unregister(indio_dev);
-
-	pm_runtime_disable(&client->dev);
-	pm_runtime_set_suspended(&client->dev);
-
-	/* power down single shot mode */
-	ret = ads1015_set_conv_mode(data, ADS1015_SINGLESHOT);
+	ret = devm_iio_device_register(dev, indio_dev);
 	if (ret)
-		dev_warn(&client->dev, "Failed to power down (%pe)\n",
-			 ERR_PTR(ret));
+		return dev_err_probe(dev, ret,
+				     "Failed to register IIO device\n");
+
+	return 0;
 }
 
 static int ads1015_runtime_suspend(struct device *dev)
@@ -1147,7 +1137,6 @@ static struct i2c_driver ads1015_driver = {
 		.pm = pm_ptr(&ads1015_pm_ops),
 	},
 	.probe		= ads1015_probe,
-	.remove		= ads1015_remove,
 	.id_table	= ads1015_id,
 };
 
-- 
2.39.5