iio: inkern: add iio_read_channel_offset helper

Allow access to underlying channel IIO_CHAN_INFO_OFFSET from a consumer.

Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index c4757e6..29df115 100644 (file)
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -658,6 +658,31 @@ err_unlock:
 }
 EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
 
+static int iio_read_channel_attribute(struct iio_channel *chan,
+                                     int *val, int *val2,
+                                     enum iio_chan_info_enum attribute)
+{
+       int ret;
+
+       mutex_lock(&chan->indio_dev->info_exist_lock);
+       if (chan->indio_dev->info == NULL) {
+               ret = -ENODEV;
+               goto err_unlock;
+       }
+
+       ret = iio_channel_read(chan, val, val2, attribute);
+err_unlock:
+       mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+       return ret;
+}
+
+int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2)
+{
+       return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_OFFSET);
+}
+EXPORT_SYMBOL_GPL(iio_read_channel_offset);
+
 int iio_read_channel_processed(struct iio_channel *chan, int *val)
 {
        int ret;
@@ -687,19 +712,7 @@ EXPORT_SYMBOL_GPL(iio_read_channel_processed);
 
 int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
 {
-       int ret;
-
-       mutex_lock(&chan->indio_dev->info_exist_lock);
-       if (chan->indio_dev->info == NULL) {
-               ret = -ENODEV;
-               goto err_unlock;
-       }
-
-       ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_SCALE);
-err_unlock:
-       mutex_unlock(&chan->indio_dev->info_exist_lock);
-
-       return ret;
+       return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_SCALE);
 }
 EXPORT_SYMBOL_GPL(iio_read_channel_scale);
 

diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index 9edccfb..6381572 100644 (file)
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -236,6 +236,19 @@ int iio_get_channel_type(struct iio_channel *channel,
                         enum iio_chan_type *type);
 
 /**
+ * iio_read_channel_offset() - read the offset value for a channel
+ * @chan:              The channel being queried.
+ * @val:               First part of value read back.
+ * @val2:              Second part of value read back.
+ *
+ * Note returns a description of what is in val and val2, such
+ * as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val
+ * + val2/1e6
+ */
+int iio_read_channel_offset(struct iio_channel *chan, int *val,
+                          int *val2);
+
+/**
  * iio_read_channel_scale() - read the scale value for a channel
  * @chan:              The channel being queried.
  * @val:               First part of value read back.