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staging: iio: adc: ad7192: use driver private lock to protect hardware state changes

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The IIO subsystem is redefining iio_dev->mlock to be used by
the IIO core only for protecting device operating mode changes.
ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes.

In this driver, mlock was being used to protect hardware state
changes.  Replace it with a driver private lock.

Also, as there are state changes in the ad7192_ write_raw function, a lock
is added to prevent the concurrent state changes.

Signed-off-by: Aastha Gupta <aastha.gupta4104@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Aastha Gupta 2017-09-27 12:01:59 +05:30 committed by Jonathan Cameron
parent 103f3afe91
commit 2db82e320d
1 changed files with 7 additions and 2 deletions
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9
drivers/staging/iio/adc/ad7192.c
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@ -162,6 +162,7 @@ struct ad7192_state {
u32 scale_avail[8][2];
u8 gpocon;
u8 devid;
struct mutex lock; /* protect sensor state */
struct ad_sigma_delta sd;
};
@ -461,10 +462,10 @@ static int ad7192_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_VOLTAGE:
mutex_lock(&indio_dev->mlock);
mutex_lock(&st->lock);
*val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
*val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
mutex_unlock(&indio_dev->mlock);
mutex_unlock(&st->lock);
return IIO_VAL_INT_PLUS_NANO;
case IIO_TEMP:
*val = 0;
@ -508,6 +509,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_SCALE:
ret = -EINVAL;
mutex_lock(&st->lock);
for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
if (val2 == st->scale_avail[i][1]) {
ret = 0;
@ -521,6 +523,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
ad7192_calibrate_all(st);
break;
}
mutex_unlock(&st->lock);
break;
case IIO_CHAN_INFO_SAMP_FREQ:
if (!val) {
@ -630,6 +633,8 @@ static int ad7192_probe(struct spi_device *spi)
st = iio_priv(indio_dev);
mutex_init(&st->lock);
st->avdd = devm_regulator_get(&spi->dev, "avdd");
if (IS_ERR(st->avdd))
return PTR_ERR(st->avdd);