iio: adc: ad9467: add mutex to struct ad9467_state

[ Upstream commit 737720197be445bb9eec2986101e4a386e019337 ]

When calling ad9467_set_scale(), multiple calls to ad9467_spi_write()
are done which means we need to properly protect the whole operation so
we are sure we will be in a sane state if two concurrent calls occur.

Fixes: ad67971202 ("iio: adc: ad9467: add support AD9467 ADC")
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20231207-iio-backend-prep-v2-3-a4a33bc4d70e@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Nuno Sa 2023-12-07 13:39:26 +01:00 committed by Greg Kroah-Hartman
parent 0c7b8f8831
commit a98f6c657c
1 changed files with 6 additions and 1 deletions

View File

@ -4,8 +4,9 @@
*
* Copyright 2012-2020 Analog Devices Inc.
*/
#include <linux/cleanup.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
@ -121,6 +122,8 @@ struct ad9467_state {
unsigned int output_mode;
struct gpio_desc *pwrdown_gpio;
/* ensure consistent state obtained on multiple related accesses */
struct mutex lock;
};
static int ad9467_spi_read(struct spi_device *spi, unsigned int reg)
@ -161,6 +164,7 @@ static int ad9467_reg_access(struct adi_axi_adc_conv *conv, unsigned int reg,
int ret;
if (readval == NULL) {
guard(mutex)(&st->lock);
ret = ad9467_spi_write(spi, reg, writeval);
if (ret)
return ret;
@ -310,6 +314,7 @@ static int ad9467_set_scale(struct adi_axi_adc_conv *conv, int val, int val2)
if (scale_val[0] != val || scale_val[1] != val2)
continue;
guard(mutex)(&st->lock);
ret = ad9467_spi_write(st->spi, AN877_ADC_REG_VREF,
info->scale_table[i][1]);
if (ret < 0)