From: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx> As part of the general cleanup of indio_dev->mlock, this change replaces it with a local lock. The lock protect the state of the device from potential concurrent writes. The device is configured via a sequence of SPI writes, and this lock is meant to prevent the start of another sequence before another one has finished. This is part of a bigger cleanup. Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@xxxxxxxxxxxxxx/ Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> --- drivers/iio/frequency/adf4350.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/iio/frequency/adf4350.c b/drivers/iio/frequency/adf4350.c index 409c9c47161e..82c050a3899d 100644 --- a/drivers/iio/frequency/adf4350.c +++ b/drivers/iio/frequency/adf4350.c @@ -47,6 +47,13 @@ struct adf4350_state { unsigned long regs[6]; unsigned long regs_hw[6]; unsigned long long freq_req; + /* + * Lock to protect the state of the device from potential concurrent + * writes. The device is configured via a sequence of SPI writes, + * and this lock is meant to prevent the start of another sequence + * before another one has finished. + */ + struct mutex lock; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. @@ -99,7 +106,7 @@ static int adf4350_reg_access(struct iio_dev *indio_dev, if (reg > ADF4350_REG5) return -EINVAL; - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); if (readval == NULL) { st->regs[reg] = writeval & ~(BIT(0) | BIT(1) | BIT(2)); ret = adf4350_sync_config(st); @@ -107,7 +114,7 @@ static int adf4350_reg_access(struct iio_dev *indio_dev, *readval = st->regs_hw[reg]; ret = 0; } - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return ret; } @@ -254,7 +261,7 @@ static ssize_t adf4350_write(struct iio_dev *indio_dev, if (ret) return ret; - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); switch ((u32)private) { case ADF4350_FREQ: ret = adf4350_set_freq(st, readin); @@ -295,7 +302,7 @@ static ssize_t adf4350_write(struct iio_dev *indio_dev, default: ret = -EINVAL; } - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return ret ? ret : len; } @@ -309,7 +316,7 @@ static ssize_t adf4350_read(struct iio_dev *indio_dev, unsigned long long val; int ret = 0; - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); switch ((u32)private) { case ADF4350_FREQ: val = (u64)((st->r0_int * st->r1_mod) + st->r0_fract) * @@ -338,7 +345,7 @@ static ssize_t adf4350_read(struct iio_dev *indio_dev, ret = -EINVAL; val = 0; } - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return ret < 0 ? ret : sprintf(buf, "%llu\n", val); } @@ -539,6 +546,8 @@ static int adf4350_probe(struct spi_device *spi) indio_dev->channels = &adf4350_chan; indio_dev->num_channels = 1; + mutex_init(&st->lock); + st->chspc = pdata->channel_spacing; if (clk) { st->clk = clk; -- 2.17.1
