This allows the iio consumer to get the offset of the channel.
The value of offset can be used when calculating the result such
as 'result = raw * scale + offset'.

Signed-off-by: Milo(Woogyom) Kim <milo....@ti.com>
---
 drivers/iio/inkern.c         |   21 +++++++++++++++++++++
 include/linux/iio/consumer.h |    9 +++++++++
 2 files changed, 30 insertions(+), 0 deletions(-)

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index b5afc2f..bd09245 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -269,6 +269,27 @@ err_unlock:
 }
 EXPORT_SYMBOL_GPL(iio_read_channel_scale);
 
+int iio_read_channel_offset(struct iio_channel *chan, int *val)
+{
+       int val2, ret;
+
+       mutex_lock(&chan->indio_dev->info_exist_lock);
+       if (chan->indio_dev->info == NULL) {
+               ret = -ENODEV;
+               goto err_unlock;
+       }
+
+       ret = chan->indio_dev->info->read_raw(chan->indio_dev,
+                                             chan->channel,
+                                             val, &val2,
+                                             IIO_CHAN_INFO_OFFSET);
+err_unlock:
+       mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(iio_read_channel_offset);
+
 int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type)
 {
        int ret = 0;
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index e2657e6..d9d69fa 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -93,4 +93,13 @@ int iio_get_channel_type(struct iio_channel *channel,
 int iio_read_channel_scale(struct iio_channel *chan, int *val,
                           int *val2);
 
+/**
+ * iio_read_channel_offset() - read offset from a given channel
+ * @channel:           The channel being queried.
+ * @val:               Offset Value read back.
+ *
+ * Note offset can be used in the consumer when calculating the result
+ * such as 'result = raw * scale + offset'.
+ */
+int iio_read_channel_offset(struct iio_channel *chan, int *val);
 #endif
-- 
1.7.2.5


Best Regards,
Milo


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