[PATCH v2 10/10] iio: adc: ad7606: Disable PWM usage for non backend version

Guillaume Stols
2024-09-20T17:33:38Z

Since the pwm was introduced before backend, there was an example use
whit triggered buffers. However, using it may be dangerous, because if
the PWM goes too fast, a new conversion can be triggered before the
transmission is over, whit the associated mess in the buffers.
Until a solution is found to mitigate this risk, for instante CRC
support, the PWM will be disabled.

Signed-off-by: Guillaume Stols <gstols@baylibre.com>
---
drivers/iio/adc/ad7606.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index f710445bdc22..0c12ca237ee9 100644
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -599,7 +599,6 @@ static int ad7606_buffer_postenable(struct iio_dev *indio_dev)
struct ad7606_state *st = iio_priv(indio_dev);

gpiod_set_value(st->gpio_convst, 1);
- ad7606_pwm_set_swing(st);

return 0;
}
@@ -609,7 +608,6 @@ static int ad7606_buffer_predisable(struct iio_dev *indio_dev)
struct ad7606_state *st = iio_priv(indio_dev);

gpiod_set_value(st->gpio_convst, 0);
- ad7606_pwm_set_low(st);

return 0;
}
@@ -838,6 +836,12 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
indio_dev->setup_ops = &ad7606_pwm_buffer_ops;
} else {
init_completion(&st->completion);
+
+ /* Reserve the PWM use only for backend (force gpio_convst definition) */
+ if (!st->gpio_convst)
+ return dev_err_probe(dev, -EINVAL,
+ "No backend, connect convst to a GPIO");
+
ret = devm_request_threaded_irq(dev, irq,
NULL,
&ad7606_interrupt,

--
2.34.1