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iio: frequency: adf4350: Replace indio_dev->mlock with own device lock 

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@mail.gmail.com/

Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20200916092731.77220-1-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Sergiu Cuciurean 2020-09-16 12:27:31 +03:00 committed by Jonathan Cameron
parent 20be66c193
commit f0e64305cf
1 changed files with 15 additions and 6 deletions
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21
drivers/iio/frequency/adf4350.c
View File

@ -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;