Commit a7ac3718 authored by Eddie James's avatar Eddie James Committed by Guenter Roeck
Browse files

hwmon: (pmbus/core) Add lock and unlock functions 



Debugfs operations may set the page number, which must be done
atomically with the subsequent i2c operation. Lock the update_lock
in the debugfs functions and provide a function for pmbus drivers
to lock and unlock the update_lock.

Signed-off-by: default avatarEddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20230412161526.252294-2-eajames@linux.ibm.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent ab3e0041

drivers/hwmon/pmbus/pmbus.h

+2 −0
Original line number Diff line number Diff line
@@ -505,6 +505,8 @@ int pmbus_get_fan_rate_device(struct i2c_client *client, int page, int id, 
			      enum pmbus_fan_mode mode);

int pmbus_get_fan_rate_cached(struct i2c_client *client, int page, int id,

			      enum pmbus_fan_mode mode);

int pmbus_lock_interruptible(struct i2c_client *client);

void pmbus_unlock(struct i2c_client *client);

int pmbus_update_fan(struct i2c_client *client, int page, int id,

		     u8 config, u8 mask, u16 command);

struct dentry *pmbus_get_debugfs_dir(struct i2c_client *client);

drivers/hwmon/pmbus/pmbus_core.c

+30 −0
Original line number Diff line number Diff line
@@ -3263,8 +3263,13 @@ static int pmbus_debugfs_get(void *data, u64 *val) 
{

	int rc;

	struct pmbus_debugfs_entry *entry = data;

	struct pmbus_data *pdata = i2c_get_clientdata(entry->client);



	rc = mutex_lock_interruptible(&pdata->update_lock);

	if (rc)

		return rc;

	rc = _pmbus_read_byte_data(entry->client, entry->page, entry->reg);

	mutex_unlock(&pdata->update_lock);

	if (rc < 0)

		return rc;
@@ -3281,7 +3286,11 @@ static int pmbus_debugfs_get_status(void *data, u64 *val) 
	struct pmbus_debugfs_entry *entry = data;

	struct pmbus_data *pdata = i2c_get_clientdata(entry->client);



	rc = mutex_lock_interruptible(&pdata->update_lock);

	if (rc)

		return rc;

	rc = pdata->read_status(entry->client, entry->page);

	mutex_unlock(&pdata->update_lock);

	if (rc < 0)

		return rc;
@@ -3297,10 +3306,15 @@ static ssize_t pmbus_debugfs_mfr_read(struct file *file, char __user *buf, 
{

	int rc;

	struct pmbus_debugfs_entry *entry = file->private_data;

	struct pmbus_data *pdata = i2c_get_clientdata(entry->client);

	char data[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };



	rc = mutex_lock_interruptible(&pdata->update_lock);

	if (rc)

		return rc;

	rc = pmbus_read_block_data(entry->client, entry->page, entry->reg,

				   data);

	mutex_unlock(&pdata->update_lock);

	if (rc < 0)

		return rc;
@@ -3638,6 +3652,22 @@ struct dentry *pmbus_get_debugfs_dir(struct i2c_client *client) 
}

EXPORT_SYMBOL_NS_GPL(pmbus_get_debugfs_dir, PMBUS);



int pmbus_lock_interruptible(struct i2c_client *client)

{

	struct pmbus_data *data = i2c_get_clientdata(client);



	return mutex_lock_interruptible(&data->update_lock);

}

EXPORT_SYMBOL_NS_GPL(pmbus_lock_interruptible, PMBUS);



void pmbus_unlock(struct i2c_client *client)

{

	struct pmbus_data *data = i2c_get_clientdata(client);



	mutex_unlock(&data->update_lock);

}

EXPORT_SYMBOL_NS_GPL(pmbus_unlock, PMBUS);



static int __init pmbus_core_init(void)

{

	pmbus_debugfs_dir = debugfs_create_dir("pmbus", NULL);