staging: iio: cdc: ad7152: Replace mlock with a local mutex lock

mlock is intended to protect only switches between modes.
Given this driver doesn't support more than one mode (sysfs polled reads
only), replace mlock with a local mutex lock.

Signed-off-by: sayli karnik <karniksayli1995@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/staging/iio/cdc/ad7152.c b/drivers/staging/iio/cdc/ad7152.c
index 0203c810375017401c52a989e95d98f287659059..b91b50f345bd9110d6d6552981d27062583f45d4 100644 (file)
--- a/drivers/staging/iio/cdc/ad7152.c
+++ b/drivers/staging/iio/cdc/ad7152.c
@@ -89,6 +89,7 @@ struct ad7152_chip_info {
         */
        u8      filter_rate_setup;
        u8      setup[2];
+       struct mutex state_lock;        /* protect hardware state */
 };
 
 static inline ssize_t ad7152_start_calib(struct device *dev,
@@ -115,10 +116,10 @@ static inline ssize_t ad7152_start_calib(struct device *dev,
        else
                regval |= AD7152_CONF_CH2EN;
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&chip->state_lock);
        ret = i2c_smbus_write_byte_data(chip->client, AD7152_REG_CFG, regval);
        if (ret < 0) {
-               mutex_unlock(&indio_dev->mlock);
+               mutex_unlock(&chip->state_lock);
                return ret;
        }
 
@@ -126,12 +127,12 @@ static inline ssize_t ad7152_start_calib(struct device *dev,
                mdelay(20);
                ret = i2c_smbus_read_byte_data(chip->client, AD7152_REG_CFG);
                if (ret < 0) {
-                       mutex_unlock(&indio_dev->mlock);
+                       mutex_unlock(&chip->state_lock);
                        return ret;
                }
        } while ((ret == regval) && timeout--);
 
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&chip->state_lock);
        return len;
 }
 
@@ -230,16 +231,16 @@ static int ad7152_write_raw_samp_freq(struct device *dev, int val)
        if (i >= ARRAY_SIZE(ad7152_filter_rate_table))
                i = ARRAY_SIZE(ad7152_filter_rate_table) - 1;
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&chip->state_lock);
        ret = i2c_smbus_write_byte_data(chip->client,
                                        AD7152_REG_CFG2, AD7152_CFG2_OSR(i));
        if (ret < 0) {
-               mutex_unlock(&indio_dev->mlock);
+               mutex_unlock(&chip->state_lock);
                return ret;
        }
 
        chip->filter_rate_setup = i;
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&chip->state_lock);
 
        return ret;
 }
@@ -252,7 +253,7 @@ static int ad7152_write_raw(struct iio_dev *indio_dev,
        struct ad7152_chip_info *chip = iio_priv(indio_dev);
        int ret, i;
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&chip->state_lock);
 
        switch (mask) {
        case IIO_CHAN_INFO_CALIBSCALE:
@@ -321,7 +322,7 @@ static int ad7152_write_raw(struct iio_dev *indio_dev,
        }
 
 out:
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&chip->state_lock);
        return ret;
 }
 
@@ -334,7 +335,7 @@ static int ad7152_read_raw(struct iio_dev *indio_dev,
        int ret;
        u8 regval = 0;
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&chip->state_lock);
 
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
@@ -422,7 +423,7 @@ static int ad7152_read_raw(struct iio_dev *indio_dev,
                ret = -EINVAL;
        }
 out:
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&chip->state_lock);
        return ret;
 }
 
@@ -509,6 +510,7 @@ static int ad7152_probe(struct i2c_client *client,
        i2c_set_clientdata(client, indio_dev);
 
        chip->client = client;
+       mutex_init(&chip->state_lock);
 
        /* Establish that the iio_dev is a child of the i2c device */
        indio_dev->name = id->name;