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| author | Alison Schofield <amsfield22@gmail.com> | 2016-05-31 21:35:49 -0700 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2016-06-03 13:12:50 +0100 |
| commit | d7203ad864db0b34f0e106ec0659890c4e58c143 (patch) | |
| tree | f1e4612e277b371c44c13099c8342ca2066259a3 /drivers/iio/adc | |
| parent | afa814841c812cd1a36dbbb124542a487c2df5ee (diff) | |
| download | linux-stable-d7203ad864db0b34f0e106ec0659890c4e58c143.tar.gz linux-stable-d7203ad864db0b34f0e106ec0659890c4e58c143.tar.bz2 linux-stable-d7203ad864db0b34f0e106ec0659890c4e58c143.zip | |
iio: adc: ad7791: claim direct mode when writing frequency
Driver was checking for direct mode and trying to lock it, but
left a gap where mode could change before the desired operation.
Use iio_device_claim_direct_mode() to guarantee device stays in
direct mode.
Refactor function to clarify look-up followed by lock sequence.
Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Cc: Daniel Baluta <daniel.baluta@gmail.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/adc')
| -rw-r--r-- | drivers/iio/adc/ad7791.c | 36 |
1 files changed, 14 insertions, 22 deletions
diff --git a/drivers/iio/adc/ad7791.c b/drivers/iio/adc/ad7791.c index cf172d58cd44..1dfe6410c64c 100644 --- a/drivers/iio/adc/ad7791.c +++ b/drivers/iio/adc/ad7791.c @@ -272,30 +272,22 @@ static ssize_t ad7791_write_frequency(struct device *dev, struct ad7791_state *st = iio_priv(indio_dev); int i, ret; - mutex_lock(&indio_dev->mlock); - if (iio_buffer_enabled(indio_dev)) { - mutex_unlock(&indio_dev->mlock); - return -EBUSY; - } - mutex_unlock(&indio_dev->mlock); - - ret = -EINVAL; - - for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) { - if (sysfs_streq(ad7791_sample_freq_avail[i], buf)) { - - mutex_lock(&indio_dev->mlock); - st->filter &= ~AD7791_FILTER_RATE_MASK; - st->filter |= i; - ad_sd_write_reg(&st->sd, AD7791_REG_FILTER, - sizeof(st->filter), st->filter); - mutex_unlock(&indio_dev->mlock); - ret = 0; + for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) + if (sysfs_streq(ad7791_sample_freq_avail[i], buf)) break; - } - } + if (i == ARRAY_SIZE(ad7791_sample_freq_avail)) + return -EINVAL; + + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + st->filter &= ~AD7791_FILTER_RATE_MASK; + st->filter |= i; + ad_sd_write_reg(&st->sd, AD7791_REG_FILTER, sizeof(st->filter), + st->filter); + iio_device_release_direct_mode(indio_dev); - return ret ? ret : len; + return len; } static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, |