[PATCH v3 1/2] iio: adc: adi-axi-adc: don't allow concurrent enable/disable calls

[Nuno Sa via B4 Relay <devnull+nuno.sa.analog.com@xxxxxxxxxx>]

From: Nuno Sa <nuno.sa@xxxxxxxxxx>

Add proper mutex guards as we should not be able to disable
the core in the middle of enabling it.

Note there's no need to rush in backporting this as the only user of the
backend does not do anything crazy..

Fixes: 794ef0e57854 ("iio: adc: adi-axi-adc: move to backend framework")
Signed-off-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
---
 drivers/iio/adc/adi-axi-adc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index 0cf0d81358fd..bf51d619ebbc 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -85,6 +85,7 @@ static int axi_adc_enable(struct iio_backend *back)
 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
 	int ret;
 
+	guard(mutex)(&st->lock);
 	ret = regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
 			      ADI_AXI_REG_RSTN_MMCM_RSTN);
 	if (ret)
@@ -99,6 +100,7 @@ static void axi_adc_disable(struct iio_backend *back)
 {
 	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
 
+	guard(mutex)(&st->lock);
 	regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
 }
 

-- 
2.45.1