Commit f0e64305 authored by Sergiu Cuciurean's avatar Sergiu Cuciurean Committed by Jonathan Cameron
Browse files

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: default avatarSergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: default avatarAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20200916092731.77220-1-alexandru.ardelean@analog.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 20be66c1

drivers/iio/frequency/adf4350.c

+15 −6
Original line number Diff line number Diff line
@@ -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;