The raw values notes mention 'ADC counts' and are not fully accurate.
Reword the notes in order to remove the 'ADC counts' and describe the
conversion needed between a raw value and a value in the standard units.
Signed-off-by: Herve Codina <[email protected]>
---
include/linux/iio/consumer.h | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index 6802596b017c..f536820b9cf2 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -201,8 +201,9 @@ struct iio_dev
* @chan: The channel being queried.
* @val: Value read back.
*
- * Note raw reads from iio channels are in adc counts and hence
- * scale will need to be applied if standard units required.
+ * Note, if standard units are required, raw reads from iio channels
+ * need the offset (default 0) and scale (default 1) to be applied
+ * as (raw + offset) * scale.
*/
int iio_read_channel_raw(struct iio_channel *chan,
int *val);
@@ -212,8 +213,9 @@ int iio_read_channel_raw(struct iio_channel *chan,
* @chan: The channel being queried.
* @val: Value read back.
*
- * Note raw reads from iio channels are in adc counts and hence
- * scale will need to be applied if standard units required.
+ * Note, if standard units are required, raw reads from iio channels
+ * need the offset (default 0) and scale (default 1) to be applied
+ * as (raw + offset) * scale.
*
* In opposit to the normal iio_read_channel_raw this function
* returns the average of multiple reads.
@@ -281,8 +283,9 @@ int iio_read_channel_attribute(struct iio_channel *chan, int *val,
* @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.
+ * Note that for raw writes to iio channels, if the value provided is
+ * in standard units, the affect of the scale and offset must be removed
+ * as (value / scale) - offset.
*/
int iio_write_channel_raw(struct iio_channel *chan, int val);
@@ -292,8 +295,9 @@ int iio_write_channel_raw(struct iio_channel *chan, int val);
* @chan: The channel being queried.
* @val: Value read back.
*
- * Note raw reads from iio channels are in adc counts and hence
- * scale will need to be applied if standard units are required.
+ * Note, if standard units are required, raw reads from iio channels
+ * need the offset (default 0) and scale (default 1) to be applied
+ * as (raw + offset) * scale.
*/
int iio_read_max_channel_raw(struct iio_channel *chan, int *val);
@@ -308,8 +312,9 @@ int iio_read_max_channel_raw(struct iio_channel *chan, int *val);
* For ranges, three vals are always returned; min, step and max.
* For lists, all the possible values are enumerated.
*
- * Note raw available values from iio channels are in adc counts and
- * hence scale will need to be applied if standard units are required.
+ * Note, if standard units are required, raw available values from iio
+ * channels need the offset (default 0) and scale (default 1) to be applied
+ * as (raw + offset) * scale.
*/
int iio_read_avail_channel_raw(struct iio_channel *chan,
const int **vals, int *length);
--
2.40.1
On Tue, 23 May 2023 17:12:18 +0200
Herve Codina <[email protected]> wrote:
> The raw values notes mention 'ADC counts' and are not fully accurate.
>
> Reword the notes in order to remove the 'ADC counts' and describe the
> conversion needed between a raw value and a value in the standard units.
>
> Signed-off-by: Herve Codina <[email protected]>
I'm not 100% sure what path this will take - though hopefully and immutable
branch I can pick up will be involved. On that basis I won't pick this up
now and instead give
Acked-by: Jonathan Cameron <[email protected]>
> ---
> include/linux/iio/consumer.h | 25 +++++++++++++++----------
> 1 file changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
> index 6802596b017c..f536820b9cf2 100644
> --- a/include/linux/iio/consumer.h
> +++ b/include/linux/iio/consumer.h
> @@ -201,8 +201,9 @@ struct iio_dev
> * @chan: The channel being queried.
> * @val: Value read back.
> *
> - * Note raw reads from iio channels are in adc counts and hence
> - * scale will need to be applied if standard units required.
> + * Note, if standard units are required, raw reads from iio channels
> + * need the offset (default 0) and scale (default 1) to be applied
> + * as (raw + offset) * scale.
> */
> int iio_read_channel_raw(struct iio_channel *chan,
> int *val);
> @@ -212,8 +213,9 @@ int iio_read_channel_raw(struct iio_channel *chan,
> * @chan: The channel being queried.
> * @val: Value read back.
> *
> - * Note raw reads from iio channels are in adc counts and hence
> - * scale will need to be applied if standard units required.
> + * Note, if standard units are required, raw reads from iio channels
> + * need the offset (default 0) and scale (default 1) to be applied
> + * as (raw + offset) * scale.
> *
> * In opposit to the normal iio_read_channel_raw this function
> * returns the average of multiple reads.
> @@ -281,8 +283,9 @@ int iio_read_channel_attribute(struct iio_channel *chan, int *val,
> * @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.
> + * Note that for raw writes to iio channels, if the value provided is
> + * in standard units, the affect of the scale and offset must be removed
> + * as (value / scale) - offset.
> */
> int iio_write_channel_raw(struct iio_channel *chan, int val);
>
> @@ -292,8 +295,9 @@ int iio_write_channel_raw(struct iio_channel *chan, int val);
> * @chan: The channel being queried.
> * @val: Value read back.
> *
> - * Note raw reads from iio channels are in adc counts and hence
> - * scale will need to be applied if standard units are required.
> + * Note, if standard units are required, raw reads from iio channels
> + * need the offset (default 0) and scale (default 1) to be applied
> + * as (raw + offset) * scale.
> */
> int iio_read_max_channel_raw(struct iio_channel *chan, int *val);
>
> @@ -308,8 +312,9 @@ int iio_read_max_channel_raw(struct iio_channel *chan, int *val);
> * For ranges, three vals are always returned; min, step and max.
> * For lists, all the possible values are enumerated.
> *
> - * Note raw available values from iio channels are in adc counts and
> - * hence scale will need to be applied if standard units are required.
> + * Note, if standard units are required, raw available values from iio
> + * channels need the offset (default 0) and scale (default 1) to be applied
> + * as (raw + offset) * scale.
> */
> int iio_read_avail_channel_raw(struct iio_channel *chan,
> const int **vals, int *length);