iio: inkern: add iio_write_channel_raw

Introduce API for easy in-kernel setting of DAC values.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

2 files changed, 35 insertions, 0 deletions

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 866fe904cba2..21655fd1465c 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -631,3 +631,28 @@ err_unlock:
         return ret;
 }
 EXPORT_SYMBOL_GPL(iio_get_channel_type);
+
+static int iio_channel_write(struct iio_channel *chan, int val, int val2,
+                             enum iio_chan_info_enum info)
+{
+        return chan->indio_dev->info->write_raw(chan->indio_dev,
+                                                chan->channel, val, val2, info);
+}
+
+int iio_write_channel_raw(struct iio_channel *chan, int val)
+{
+        int ret;
+
+        mutex_lock(&chan->indio_dev->info_exist_lock);
+        if (chan->indio_dev->info == NULL) {
+                ret = -ENODEV;
+                goto err_unlock;
+        }
+
+        ret = iio_channel_write(chan, val, 0, IIO_CHAN_INFO_RAW);
+err_unlock:
+        mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(iio_write_channel_raw);
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index 651f9a0e2765..6f64624f329b 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -151,6 +151,16 @@ int iio_read_channel_average_raw(struct iio_channel *chan, int *val);
 int iio_read_channel_processed(struct iio_channel *chan, int *val);
 
 /**
+ * iio_write_channel_raw() - write to a given channel
+ * @chan:               The channel being queried.
+ * @val:                Value being written.
+ *
+ * Note raw writes to iio channels are in dac counts and hence
+ * scale will need to be applied if standard units required.
+ */
+int iio_write_channel_raw(struct iio_channel *chan, int val);
+
+/**
  * iio_get_channel_type() - get the type of a channel
  * @channel:            The channel being queried.
  * @type:               The type of the channel.