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hwmon: (max31827) Rely on subsystem locking 

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Guenter Roeck 2025-06-09 11:14:16 -07:00
parent a07eb5f6f9
commit e1c4d5db9a
1 changed files with 14 additions and 46 deletions
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48
drivers/hwmon/max31827.c
View File

@ -10,7 +10,6 @@
#include <linux/delay.h>
#include <linux/hwmon.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
@ -99,7 +98,6 @@ struct max31827_state {
/*
* Prevent simultaneous access to the i2c client.
*/
struct mutex lock;
struct regmap *regmap;
bool enable;
unsigned int resolution;
@ -123,30 +121,23 @@ static int shutdown_write(struct max31827_state *st, unsigned int reg,
* Before the Temperature Threshold Alarm, Alarm Hysteresis Threshold
* and Resolution bits from Configuration register are changed over I2C,
* the part must be in shutdown mode.
*
* Mutex is used to ensure, that some other process doesn't change the
* configuration register.
*/
mutex_lock(&st->lock);
if (!st->enable) {
if (!mask)
ret = regmap_write(st->regmap, reg, val);
else
ret = regmap_update_bits(st->regmap, reg, mask, val);
goto unlock;
return regmap_write(st->regmap, reg, val);
return regmap_update_bits(st->regmap, reg, mask, val);
}
ret = regmap_read(st->regmap, MAX31827_CONFIGURATION_REG, &cfg);
if (ret)
goto unlock;
return ret;
cnv_rate = MAX31827_CONFIGURATION_CNV_RATE_MASK & cfg;
cfg = cfg & ~(MAX31827_CONFIGURATION_1SHOT_MASK |
MAX31827_CONFIGURATION_CNV_RATE_MASK);
ret = regmap_write(st->regmap, MAX31827_CONFIGURATION_REG, cfg);
if (ret)
goto unlock;
return ret;
if (!mask)
ret = regmap_write(st->regmap, reg, val);
@ -154,15 +145,11 @@ static int shutdown_write(struct max31827_state *st, unsigned int reg,
ret = regmap_update_bits(st->regmap, reg, mask, val);
if (ret)
goto unlock;
return ret;
ret = regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
return regmap_update_bits(st->regmap, MAX31827_CONFIGURATION_REG,
MAX31827_CONFIGURATION_CNV_RATE_MASK,
cnv_rate);
unlock:
mutex_unlock(&st->lock);
return ret;
}
static int write_alarm_val(struct max31827_state *st, unsigned int reg,
@ -223,23 +210,13 @@ static int max31827_read(struct device *dev, enum hwmon_sensor_types type,
break;
case hwmon_temp_input:
mutex_lock(&st->lock);
if (!st->enable) {
/*
* This operation requires mutex protection,
* because the chip configuration should not
* be changed during the conversion process.
*/
ret = regmap_update_bits(st->regmap,
MAX31827_CONFIGURATION_REG,
MAX31827_CONFIGURATION_1SHOT_MASK,
1);
if (ret) {
mutex_unlock(&st->lock);
if (ret)
return ret;
}
msleep(max31827_conv_times[st->resolution]);
}
@ -254,8 +231,6 @@ static int max31827_read(struct device *dev, enum hwmon_sensor_types type,
ret = regmap_read(st->regmap, MAX31827_T_REG, &uval);
mutex_unlock(&st->lock);
if (ret)
break;
@ -352,7 +327,6 @@ static int max31827_write(struct device *dev, enum hwmon_sensor_types type,
if (val >> 1)
return -EINVAL;
mutex_lock(&st->lock);
/**
* The chip should not be enabled while a conversion is
* performed. Neither should the chip be enabled when
@ -361,16 +335,12 @@ static int max31827_write(struct device *dev, enum hwmon_sensor_types type,
st->enable = val;
ret = regmap_update_bits(st->regmap,
return regmap_update_bits(st->regmap,
MAX31827_CONFIGURATION_REG,
MAX31827_CONFIGURATION_1SHOT_MASK |
MAX31827_CONFIGURATION_CNV_RATE_MASK,
MAX31827_DEVICE_ENABLE(val));
mutex_unlock(&st->lock);
return ret;
case hwmon_temp_max:
return write_alarm_val(st, MAX31827_TH_REG, val);
@ -623,8 +593,6 @@ static int max31827_probe(struct i2c_client *client)
if (!st)
return -ENOMEM;
mutex_init(&st->lock);
st->regmap = devm_regmap_init_i2c(client, &max31827_regmap);
if (IS_ERR(st->regmap))
return dev_err_probe(dev, PTR_ERR(st->regmap),