Commit 87625b24 authored by Nicolin Chen's avatar Nicolin Chen Committed by Guenter Roeck
Browse files

hwmon: (ina3221) Serialize sysfs ABI accesses 



This change adds a mutex to serialize accesses of sysfs attributes.

This is required when polling CVRF bit of the MASK/ENABLE register
because this bit is cleared on a read of this MASK/ENABLE register
or a write to CONFIG register, which means that this bit might be
accidentally cleared by reading other fields like alert flags.

So this patch adds a mutex lock to protect the write() and read()
callbacks. The read_string() callback won't need the lock since it
just returns the label without touching any hardware register.

Signed-off-by: default avatarNicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent efb0489e

drivers/hwmon/ina3221.c

+45 −6
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/hwmon-sysfs.h>

#include <linux/i2c.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/of.h>

#include <linux/regmap.h>
@@ -94,12 +95,14 @@ struct ina3221_input { 
 * @regmap: Register map of the device

 * @fields: Register fields of the device

 * @inputs: Array of channel input source specific structures

 * @lock: mutex lock to serialize sysfs attribute accesses

 * @reg_config: Register value of INA3221_CONFIG

 */

struct ina3221_data {

	struct regmap *regmap;

	struct regmap_field *fields[F_MAX_FIELDS];

	struct ina3221_input inputs[INA3221_NUM_CHANNELS];

	struct mutex lock;

	u32 reg_config;

};
@@ -265,29 +268,53 @@ static int ina3221_write_enable(struct device *dev, int channel, bool enable) 
static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,

			u32 attr, int channel, long *val)

{

	struct ina3221_data *ina = dev_get_drvdata(dev);

	int ret;



	mutex_lock(&ina->lock);



	switch (type) {

	case hwmon_in:

		/* 0-align channel ID */

		return ina3221_read_in(dev, attr, channel - 1, val);

		ret = ina3221_read_in(dev, attr, channel - 1, val);

		break;

	case hwmon_curr:

		return ina3221_read_curr(dev, attr, channel, val);

		ret = ina3221_read_curr(dev, attr, channel, val);

		break;

	default:

		return -EOPNOTSUPP;

		ret = -EOPNOTSUPP;

		break;

	}



	mutex_unlock(&ina->lock);



	return ret;

}



static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,

			 u32 attr, int channel, long val)

{

	struct ina3221_data *ina = dev_get_drvdata(dev);

	int ret;



	mutex_lock(&ina->lock);



	switch (type) {

	case hwmon_in:

		/* 0-align channel ID */

		return ina3221_write_enable(dev, channel - 1, val);

		ret = ina3221_write_enable(dev, channel - 1, val);

		break;

	case hwmon_curr:

		return ina3221_write_curr(dev, attr, channel, val);

		ret = ina3221_write_curr(dev, attr, channel, val);

		break;

	default:

		return -EOPNOTSUPP;

		ret = -EOPNOTSUPP;

		break;

	}



	mutex_unlock(&ina->lock);



	return ret;

}



static int ina3221_read_string(struct device *dev, enum hwmon_sensor_types type,
@@ -582,6 +609,7 @@ static int ina3221_probe(struct i2c_client *client, 
	if (ret)

		return ret;



	mutex_init(&ina->lock);

	dev_set_drvdata(dev, ina);



	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, ina,
@@ -589,12 +617,22 @@ static int ina3221_probe(struct i2c_client *client, 
							 ina3221_groups);

	if (IS_ERR(hwmon_dev)) {

		dev_err(dev, "Unable to register hwmon device\n");

		mutex_destroy(&ina->lock);

		return PTR_ERR(hwmon_dev);

	}



	return 0;

}



static int ina3221_remove(struct i2c_client *client)

{

	struct ina3221_data *ina = dev_get_drvdata(&client->dev);



	mutex_destroy(&ina->lock);



	return 0;

}



static int __maybe_unused ina3221_suspend(struct device *dev)

{

	struct ina3221_data *ina = dev_get_drvdata(dev);
@@ -663,6 +701,7 @@ MODULE_DEVICE_TABLE(i2c, ina3221_ids); 


static struct i2c_driver ina3221_i2c_driver = {

	.probe = ina3221_probe,

	.remove = ina3221_remove,

	.driver = {

		.name = INA3221_DRIVER_NAME,

		.of_match_table = ina3221_of_match_table,

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