[PATCH] iio: light: al3010: fix incorrect scale for the highest gain range

Vidhu Sarwal <[email protected]> Thu, 2 Jul 2026 10:59:13 +0530
Newsgroups dev.linux.lists.linux-kernel-mentees,org.kernel.vger.linux-iio,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
al3010_scales[] encodes the highest gain range as {0, 1187200}.
For IIO_VAL_INT_PLUS_MICRO, the fractional part must be less than
1000000, so the scale 1.1872 should instead be represented as
{1, 187200}.

Since write_raw() compares the value from userspace against this
table, writing  1.1872 scale never matches the malformed
entry and returns -EINVAL. As a result, the highest gain range cannot
be selected. Reading the scale in that state also reports the malformed
value.   

Fixes: c36b5195ab70 ("iio: light: add Dyna-Image AL3010 driver")
Signed-off-by: Vidhu Sarwal <[email protected]>
---
 drivers/iio/light/al3010.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/light/al3010.c b/drivers/iio/light/al3010.c
index d603b4a6b8e8..cc39f8af4ea3 100644
--- a/drivers/iio/light/al3010.c
+++ b/drivers/iio/light/al3010.c
@@ -42,7 +42,7 @@ enum al3xxxx_range {
 };
 
 static const int al3010_scales[][2] = {
-	{0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600}
+	{1, 187200}, {0, 296800}, {0, 74200}, {0, 18600}
 };
 
 static const struct regmap_config al3010_regmap_config = {
-- 
2.53.0