hwmon: (ltc2947-core) 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/ltc2947-core.c b/drivers/hwmon/ltc2947-core.c
index 90f70f732b411a94e6b8900b1c5c3586ef522bfa..ad7120d1e4695c22ce27c3a34a487c166f587052 100644 (file)
--- a/drivers/hwmon/ltc2947-core.c
+++ b/drivers/hwmon/ltc2947-core.c
@@ -120,12 +120,6 @@
 struct ltc2947_data {
        struct regmap *map;
        struct device *dev;
-       /*
-        * The mutex is needed because the device has 2 memory pages. When
-        * reading/writing the correct page needs to be set so that, the
-        * complete sequence select_page->read/write needs to be protected.
-        */
-       struct mutex lock;
        u32 lsb_energy;
        bool gpio_out;
 };
@@ -181,13 +175,9 @@ static int ltc2947_val_read(struct ltc2947_data *st, const u8 reg,
        int ret;
        u64 __val = 0;
 
-       mutex_lock(&st->lock);
-
        ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, page);
-       if (ret) {
-               mutex_unlock(&st->lock);
+       if (ret)
                return ret;
-       }
 
        dev_dbg(st->dev, "Read val, reg:%02X, p:%d sz:%zu\n", reg, page,
                size);
@@ -207,8 +197,6 @@ static int ltc2947_val_read(struct ltc2947_data *st, const u8 reg,
                break;
        }
 
-       mutex_unlock(&st->lock);
-
        if (ret)
                return ret;
 
@@ -242,13 +230,10 @@ static int ltc2947_val_write(struct ltc2947_data *st, const u8 reg,
 {
        int ret;
 
-       mutex_lock(&st->lock);
        /* set device on correct page */
        ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, page);
-       if (ret) {
-               mutex_unlock(&st->lock);
+       if (ret)
                return ret;
-       }
 
        dev_dbg(st->dev, "Write val, r:%02X, p:%d, sz:%zu, val:%016llX\n",
                reg, page, size, val);
@@ -265,8 +250,6 @@ static int ltc2947_val_write(struct ltc2947_data *st, const u8 reg,
                break;
        }
 
-       mutex_unlock(&st->lock);
-
        return ret;
 }
 
@@ -295,11 +278,9 @@ static int ltc2947_alarm_read(struct ltc2947_data *st, const u8 reg,
 
        memset(alarms, 0, sizeof(alarms));
 
-       mutex_lock(&st->lock);
-
        ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, LTC2947_PAGE0);
        if (ret)
-               goto unlock;
+               return ret;
 
        dev_dbg(st->dev, "Read alarm, reg:%02X, mask:%02X\n", reg, mask);
        /*
@@ -310,13 +291,11 @@ static int ltc2947_alarm_read(struct ltc2947_data *st, const u8 reg,
        ret = regmap_bulk_read(st->map, LTC2947_REG_STATUS, alarms,
                               sizeof(alarms));
        if (ret)
-               goto unlock;
+               return ret;
 
        /* get the alarm */
        *val = !!(alarms[offset] & mask);
-unlock:
-       mutex_unlock(&st->lock);
-       return ret;
+       return 0;
 }
 
 static int ltc2947_read_temp(struct device *dev, const u32 attr, long *val,
@@ -1100,7 +1079,6 @@ int ltc2947_core_probe(struct regmap *map, const char *name)
        st->map = map;
        st->dev = dev;
        dev_set_drvdata(dev, st);
-       mutex_init(&st->lock);
 
        ret = ltc2947_setup(st);
        if (ret)