2017-09-24 22:00:48

by Stefan Brüns

Subject: [PATCH v3 4/4] iio: light: vl6180: Correct ALS scale for non-default gain/integration time

The reported scale was only correct for the default settings of 100 ms
integration time and gain 1.

This aligns the reported scale with the behaviour of any other IIO driver
and the documented ABI, but may require userspace changes if someone uses
non-default settings.

Signed-off-by: Stefan Brüns <[email protected]>

---

Changes in v3: None
Changes in v2: None

drivers/iio/light/vl6180.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/light/vl6180.c b/drivers/iio/light/vl6180.c
index 49e9f92cd116..67f8beb84fc3 100644
--- a/drivers/iio/light/vl6180.c
+++ b/drivers/iio/light/vl6180.c
@@ -315,9 +315,12 @@ static int vl6180_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_LIGHT:
- *val = 0; /* one ALS count is 0.32 Lux */
- *val2 = 320000;
- break;
+ /* one ALS count is 0.32 Lux @ gain 1, IT 100 ms */
+ *val = 32000; /* 0.32 * 1000 * 100 */
+ *val2 = data->als_gain_milli * data->als_it_ms;
+
+ return IIO_VAL_FRACTIONAL;
+
case IIO_DISTANCE:
*val = 0; /* sensor reports mm, scale to meter */
*val2 = 1000;
--
2.14.1

2017-09-30 20:31:45

by Jonathan Cameron

Subject: Re: [PATCH v3 4/4] iio: light: vl6180: Correct ALS scale for non-default gain/integration time

On Sun, 24 Sep 2017 23:59:20 +0200
Stefan Brüns <[email protected]> wrote:

> The reported scale was only correct for the default settings of 100 ms
> integration time and gain 1.
>
> This aligns the reported scale with the behaviour of any other IIO driver
> and the documented ABI, but may require userspace changes if someone uses
> non-default settings.
>
> Signed-off-by: Stefan Brüns <[email protected]>

Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

Whilst this is clearly a fix, it isn't a regression. As such the extent
of the changes mean I've queued this up for the next merge window rather
than going in quicker as a fix.

Thanks,

Jonathan

>
> ---
>
> Changes in v3: None
> Changes in v2: None
>
> drivers/iio/light/vl6180.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/light/vl6180.c b/drivers/iio/light/vl6180.c
> index 49e9f92cd116..67f8beb84fc3 100644
> --- a/drivers/iio/light/vl6180.c
> +++ b/drivers/iio/light/vl6180.c
> @@ -315,9 +315,12 @@ static int vl6180_read_raw(struct iio_dev *indio_dev,
> case IIO_CHAN_INFO_SCALE:
> switch (chan->type) {
> case IIO_LIGHT:
> - *val = 0; /* one ALS count is 0.32 Lux */
> - *val2 = 320000;
> - break;
> + /* one ALS count is 0.32 Lux @ gain 1, IT 100 ms */
> + *val = 32000; /* 0.32 * 1000 * 100 */
> + *val2 = data->als_gain_milli * data->als_it_ms;
> +
> + return IIO_VAL_FRACTIONAL;
> +
> case IIO_DISTANCE:
> *val = 0; /* sensor reports mm, scale to meter */
> *val2 = 1000;