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| author | Gargi Sharma <gs051095@gmail.com> | 2017-03-30 15:03:46 +0530 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2017-03-30 19:20:38 +0100 |
| commit | b71244b62be470327a59fe940587ccb0811cf8d7 (patch) | |
| tree | f20f84ab971ae91c70005174d18da7a90a66a31e /drivers/staging/iio/meter | |
| parent | 5e13b6f0e7cc7e53466d1b62a6d0ccbd7632f71f (diff) | |
| download | linux-b71244b62be470327a59fe940587ccb0811cf8d7.tar.gz linux-b71244b62be470327a59fe940587ccb0811cf8d7.tar.bz2 linux-b71244b62be470327a59fe940587ccb0811cf8d7.zip | |
staging: iio: update locking method during frequency writes
The driver needs to insure atomicity during frequency
changes of bus and device. The iiodev->mlock as used
was not doing that. Replace it with the drivers existing
buffer lock and introduce an auxiliary spi_write() that does
not hold the lock.
Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/staging/iio/meter')
| -rw-r--r-- | drivers/staging/iio/meter/ade7754.c | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/drivers/staging/iio/meter/ade7754.c b/drivers/staging/iio/meter/ade7754.c index 6d8eb13f143d..32dc50341746 100644 --- a/drivers/staging/iio/meter/ade7754.c +++ b/drivers/staging/iio/meter/ade7754.c @@ -96,7 +96,7 @@ /** * struct ade7754_state - device instance specific data * @us: actual spi_device - * @buf_lock: mutex to protect tx and rx + * @buf_lock: mutex to protect tx, rx and write frequency * @tx: transmit buffer * @rx: receive buffer **/ @@ -107,17 +107,25 @@ struct ade7754_state { u8 rx[ADE7754_MAX_RX]; }; -static int ade7754_spi_write_reg_8(struct device *dev, u8 reg_address, u8 val) +/* Unlocked version of ade7754_spi_write_reg_8 function */ +static int __ade7754_spi_write_reg_8(struct device *dev, u8 reg_address, u8 val) { - int ret; struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct ade7754_state *st = iio_priv(indio_dev); - mutex_lock(&st->buf_lock); st->tx[0] = ADE7754_WRITE_REG(reg_address); st->tx[1] = val; + return spi_write(st->us, st->tx, 2); +} - ret = spi_write(st->us, st->tx, 2); +static int ade7754_spi_write_reg_8(struct device *dev, u8 reg_address, u8 val) +{ + int ret; + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct ade7754_state *st = iio_priv(indio_dev); + + mutex_lock(&st->buf_lock); + ret = __ade7754_spi_write_reg_8(dev, reg_address, val); mutex_unlock(&st->buf_lock); return ret; @@ -512,7 +520,7 @@ static ssize_t ade7754_write_frequency(struct device *dev, if (!val) return -EINVAL; - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->buf_lock); t = 26000 / val; if (t > 0) @@ -530,10 +538,10 @@ static ssize_t ade7754_write_frequency(struct device *dev, reg &= ~(3 << 3); reg |= t << 3; - ret = ade7754_spi_write_reg_8(dev, ADE7754_WAVMODE, reg); + ret = __ade7754_spi_write_reg_8(dev, ADE7754_WAVMODE, reg); out: - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->buf_lock); return ret ? ret : len; } |