iio: inkern: API for reading available iio channel attribute values

Extend the inkern API with a function for reading available
attribute values of iio channels.

Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 06ca3f7..f19dbde 100644 (file)
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -733,6 +733,26 @@ static int iio_channel_read_avail(struct iio_channel *chan,
                                                 vals, type, length, info);
 }
 
+int iio_read_avail_channel_attribute(struct iio_channel *chan,
+                                    const int **vals, int *type, int *length,
+                                    enum iio_chan_info_enum attribute)
+{
+       int ret;
+
+       mutex_lock(&chan->indio_dev->info_exist_lock);
+       if (!chan->indio_dev->info) {
+               ret = -ENODEV;
+               goto err_unlock;
+       }
+
+       ret = iio_channel_read_avail(chan, vals, type, length, attribute);
+err_unlock:
+       mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(iio_read_avail_channel_attribute);
+
 int iio_read_avail_channel_raw(struct iio_channel *chan,
                               const int **vals, int *length)
 {

diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index 9887f4f..b2d3483 100644 (file)
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -291,6 +291,20 @@ int iio_read_avail_channel_raw(struct iio_channel *chan,
                               const int **vals, int *length);
 
 /**
+ * iio_read_avail_channel_attribute() - read available channel attribute values
+ * @chan:              The channel being queried.
+ * @vals:              Available values read back.
+ * @type:              Type of values read back.
+ * @length:            Number of entries in vals.
+ * @attribute:         info attribute to be read back.
+ *
+ * Returns an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST.
+ */
+int iio_read_avail_channel_attribute(struct iio_channel *chan,
+                                    const int **vals, int *type, int *length,
+                                    enum iio_chan_info_enum attribute);
+
+/**
  * iio_get_channel_type() - get the type of a channel
  * @channel:           The channel being queried.
  * @type:              The type of the channel.