hwmon: (ltc4282) 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>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>

diff --git a/drivers/hwmon/ltc4282.c b/drivers/hwmon/ltc4282.c
index 44102879694a1a7ff1a5dfb2e7e433b4ecbbf058..b9cad89f2cd9a813ac5af2e8870367e7b867562c 100644 (file)
--- a/drivers/hwmon/ltc4282.c
+++ b/drivers/hwmon/ltc4282.c
@@ -17,7 +17,6 @@
 #include <linux/minmax.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
-#include <linux/mutex.h>
 #include <linux/regmap.h>
 #include <linux/property.h>
 #include <linux/string.h>
@@ -131,8 +130,6 @@ struct ltc4282_cache {
 
 struct ltc4282_state {
        struct regmap *map;
-       /* Protect against multiple accesses to the device registers */
-       struct mutex lock;
        struct clk_hw clk_hw;
        /*
         * Used to cache values for VDD/VSOURCE depending which will be used
@@ -281,14 +278,12 @@ static int __ltc4282_read_alarm(struct ltc4282_state *st, u32 reg, u32 mask,
 static int ltc4282_read_alarm(struct ltc4282_state *st, u32 reg, u32 mask,
                              long *val)
 {
-       guard(mutex)(&st->lock);
        return __ltc4282_read_alarm(st, reg, mask, val);
 }
 
 static int ltc4282_vdd_source_read_in(struct ltc4282_state *st, u32 channel,
                                      long *val)
 {
-       guard(mutex)(&st->lock);
        if (!st->in0_1_cache[channel].en)
                return -ENODATA;
 
@@ -300,7 +295,6 @@ static int ltc4282_vdd_source_read_hist(struct ltc4282_state *st, u32 reg,
 {
        int ret;
 
-       guard(mutex)(&st->lock);
        if (!st->in0_1_cache[channel].en) {
                *val = *cached;
                return 0;
@@ -317,7 +311,6 @@ static int ltc4282_vdd_source_read_hist(struct ltc4282_state *st, u32 reg,
 static int ltc4282_vdd_source_read_lim(struct ltc4282_state *st, u32 reg,
                                       u32 channel, u32 *cached, long *val)
 {
-       guard(mutex)(&st->lock);
        if (!st->in0_1_cache[channel].en)
                return ltc4282_read_voltage_byte_cached(st, reg, st->vfs_out,
                                                        val, cached);
@@ -328,7 +321,6 @@ static int ltc4282_vdd_source_read_lim(struct ltc4282_state *st, u32 reg,
 static int ltc4282_vdd_source_read_alm(struct ltc4282_state *st, u32 mask,
                                       u32 channel, long *val)
 {
-       guard(mutex)(&st->lock);
        if (!st->in0_1_cache[channel].en) {
                /*
                 * Do this otherwise alarms can get confused because we clear
@@ -412,9 +404,7 @@ static int ltc4282_read_in(struct ltc4282_state *st, u32 attr, long *val,
                                                   channel,
                                                   &st->in0_1_cache[channel].in_min_raw, val);
        case hwmon_in_enable:
-               scoped_guard(mutex, &st->lock) {
-                       *val = st->in0_1_cache[channel].en;
-               }
+               *val = st->in0_1_cache[channel].en;
                return 0;
        case hwmon_in_fault:
                /*
@@ -612,15 +602,11 @@ static int ltc4282_read(struct device *dev, enum hwmon_sensor_types type,
        case hwmon_power:
                return ltc4282_read_power(st, attr, val);
        case hwmon_energy:
-               scoped_guard(mutex, &st->lock) {
-                       *val = st->energy_en;
-               }
+               *val = st->energy_en;
                return 0;
        case hwmon_energy64:
-               scoped_guard(mutex, &st->lock) {
-                       if (st->energy_en)
-                               return ltc4282_read_energy(st, (s64 *)val);
-               }
+               if (st->energy_en)
+                       return ltc4282_read_energy(st, (s64 *)val);
                return -ENODATA;
        default:
                return -EOPNOTSUPP;
@@ -688,7 +674,6 @@ static int __ltc4282_in_write_history(const struct ltc4282_state *st, u32 reg,
 static int ltc4282_in_write_history(struct ltc4282_state *st, u32 reg,
                                    long lowest, long highest, u32 fs)
 {
-       guard(mutex)(&st->lock);
        return __ltc4282_in_write_history(st, reg, lowest, highest, fs);
 }
 
@@ -696,8 +681,6 @@ static int ltc4282_power_reset_hist(struct ltc4282_state *st)
 {
        int ret;
 
-       guard(mutex)(&st->lock);
-
        ret = ltc4282_write_power_word(st, LTC4282_POWER_LOWEST,
                                       st->power_max);
        if (ret)
@@ -803,7 +786,6 @@ static int ltc4282_vdd_source_write_lim(struct ltc4282_state *st, u32 reg,
 {
        int ret;
 
-       guard(mutex)(&st->lock);
        if (st->in0_1_cache[channel].en)
                ret = ltc4282_write_voltage_byte(st, reg, st->vfs_out, val);
        else
@@ -821,7 +803,6 @@ static int ltc4282_vdd_source_reset_hist(struct ltc4282_state *st, int channel)
        if (channel == LTC4282_CHAN_VDD)
                lowest = st->vdd;
 
-       guard(mutex)(&st->lock);
        if (st->in0_1_cache[channel].en) {
                ret = __ltc4282_in_write_history(st, LTC4282_VSOURCE_LOWEST,
                                                 lowest, 0, st->vfs_out);
@@ -861,7 +842,6 @@ static int ltc4282_vdd_source_enable(struct ltc4282_state *st, int channel,
        int ret, other_chan = ~channel & 0x1;
        u8 __val = val;
 
-       guard(mutex)(&st->lock);
        if (st->in0_1_cache[channel].en == !!val)
                return 0;
 
@@ -938,8 +918,6 @@ static int ltc4282_curr_reset_hist(struct ltc4282_state *st)
 {
        int ret;
 
-       guard(mutex)(&st->lock);
-
        ret = __ltc4282_in_write_history(st, LTC4282_VSENSE_LOWEST,
                                         st->vsense_max, 0, 40 * MILLI);
        if (ret)
@@ -974,7 +952,6 @@ static int ltc4282_energy_enable_set(struct ltc4282_state *st, long val)
 {
        int ret;
 
-       guard(mutex)(&st->lock);
        /* setting the bit halts the meter */
        ret = regmap_update_bits(st->map, LTC4282_ADC_CTRL,
                                 LTC4282_METER_HALT_MASK,
@@ -1699,7 +1676,6 @@ static int ltc4282_probe(struct i2c_client *i2c)
        if (ret)
                return ret;
 
-       mutex_init(&st->lock);
        hwmon = devm_hwmon_device_register_with_info(dev, "ltc4282", st,
                                                     &ltc4282_chip_info, NULL);
        if (IS_ERR(hwmon))