4.18-stable review patch. If anyone has any objections, please let me know.
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From: Alexandru Ardelean alexandru.ardelean@analog.com
[ Upstream commit 4ee033301c898dd0835d035d0e0eb768a3d35da1 ]
Fixes commit 17be2a2905a6ec9aa27cd59521495e2f490d2af0 ("staging: iio: ad7606: replace range/range_available with corresponding scale").
The AD7606 devices don't have a 2.5V voltage range, they have 5V & 10V voltage range, which is selectable via the `gpio_range` descriptor.
The scales also seem to have been miscomputed, because when they were applied to the raw values, the results differ from the expected values. After checking the ADC transfer function in the datasheet, these were re-computed.
Signed-off-by: Alexandru Ardelean alexandru.ardelean@analog.com Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/iio/adc/ad7606.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/staging/iio/adc/ad7606.c +++ b/drivers/staging/iio/adc/ad7606.c @@ -26,9 +26,12 @@
#include "ad7606.h"
-/* Scales are computed as 2.5/2**16 and 5/2**16 respectively */ +/* + * Scales are computed as 5000/32768 and 10000/32768 respectively, + * so that when applied to the raw values they provide mV values + */ static const unsigned int scale_avail[2][2] = { - {0, 38147}, {0, 76294} + {0, 152588}, {0, 305176} };
static int ad7606_reset(struct ad7606_state *st)