[PATCH v3 05/19] iio: adc: at91-sama5d2_adc: exit from write_raw() when buffers are enabled
From: Claudiu Beznea <hidden>
Date: 2022-08-03 10:27:14
Also in:
linux-devicetree, linux-iio, lkml
Subsystem:
iio subsystem and drivers, microchip sama5d2-compatible adc driver, the rest · Maintainers:
Jonathan Cameron, Eugen Hristev, Linus Torvalds
When buffers are enabled conversion may start asynchronously thus allowing changes on actual hardware could lead to bad behavior. Thus do not allow changing oversampling ratio and sample frequency when if iio_device_claim_direct_mode() returns with error. Signed-off-by: Claudiu Beznea <redacted> --- drivers/iio/adc/at91-sama5d2_adc.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index e2c82c5a2fac..64943d8ea869 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c@@ -1641,6 +1641,7 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, int val, int val2, long mask) { struct at91_adc_state *st = iio_priv(indio_dev); + int ret; switch (mask) { case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
@@ -1650,20 +1651,29 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev, /* if no change, optimize out */ if (val == st->oversampling_ratio) return 0; + + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; mutex_lock(&st->lock); st->oversampling_ratio = val; /* update ratio */ at91_adc_config_emr(st); mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); return 0; case IIO_CHAN_INFO_SAMP_FREQ: if (val < st->soc_info.min_sample_rate || val > st->soc_info.max_sample_rate) return -EINVAL; + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; mutex_lock(&st->lock); at91_adc_setup_samp_freq(indio_dev, val); mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); return 0; default: return -EINVAL;
--
2.34.1
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