iio:adc:ad799x: Allow writing of event config

Allows explicity enabling of events

Previously, events were always reported as enabled, but actually only
implicitly enabled when updating the buffer scan mode

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c
index 08bcada39487..e37412da15f5 100644
--- a/drivers/iio/adc/ad799x.c
+++ b/drivers/iio/adc/ad799x.c
@@ -375,6 +375,39 @@ static int ad799x_read_event_config(struct iio_dev *indio_dev,
         return 0;
 }
 
+static int ad799x_write_event_config(struct iio_dev *indio_dev,
+                                     const struct iio_chan_spec *chan,
+                                     enum iio_event_type type,
+                                     enum iio_event_direction dir,
+                                     int state)
+{
+        struct ad799x_state *st = iio_priv(indio_dev);
+        int ret;
+
+        mutex_lock(&indio_dev->mlock);
+        if (iio_buffer_enabled(indio_dev)) {
+                ret = -EBUSY;
+                goto done;
+        }
+
+        if (state)
+                st->config |= BIT(chan->scan_index) << AD799X_CHANNEL_SHIFT;
+        else
+                st->config &= ~(BIT(chan->scan_index) << AD799X_CHANNEL_SHIFT);
+
+        if (st->config >> AD799X_CHANNEL_SHIFT)
+                st->config |= AD7998_ALERT_EN;
+        else
+                st->config &= ~AD7998_ALERT_EN;
+
+        ret = ad799x_write_config(st, st->config);
+
+done:
+        mutex_unlock(&indio_dev->mlock);
+
+        return ret;
+}
+
 static unsigned int ad799x_threshold_reg(const struct iio_chan_spec *chan,
                                          enum iio_event_direction dir,
                                          enum iio_event_info info)
@@ -502,6 +535,7 @@ static const struct iio_info ad7993_4_7_8_irq_info = {
         .read_raw = &ad799x_read_raw,
         .event_attrs = &ad799x_event_attrs_group,
         .read_event_config = &ad799x_read_event_config,
+        .write_event_config = &ad799x_write_event_config,
         .read_event_value = &ad799x_read_event_value,
         .write_event_value = &ad799x_write_event_value,
         .driver_module = THIS_MODULE,