[PATCH] iio: light: vcnl4035: Fix reversed ALS mode bit

[PATCH] iio: light: vcnl4035: Fix reversed ALS mode bit

[Alexander Sarmanow]

According to the datasheet (table 2) the ALS_SD bit behaves the opposite
way the current ALS mode defines are set, writing 0 powers the sensor
and writing 1 shuts it down.

The current driver thinks the ALS is up while it's actually shut down
and it's down when the systems powers it up.

Fixes: 55707294c4eb ("iio: light: Add support for vishay vcnl4035")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Sarmanow <as@discnull.de>
---
Tested on a Raspberry Pi 3B+ with a VCNL4035 on I2C, running Raspberry
Pi OS downstream kernel 6.18.50. Checked with i2cget that bit 0 of the
config register 0x00 is 0 while PM runtime resume and 1 once it's
runtime suspended. Also builds cleanly against iio/testing.

 drivers/iio/light/vcnl4035.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/light/vcnl4035.c b/drivers/iio/light/vcnl4035.c
index ce1bd42b0c7c..f1cc75245001 100644
--- a/drivers/iio/light/vcnl4035.c
+++ b/drivers/iio/light/vcnl4035.c
@@ -44,8 +44,8 @@
 #define VCNL4035_DEV_ID_MASK		GENMASK(7, 0)
 
 /* Default values */
-#define VCNL4035_MODE_ALS_ENABLE	BIT(0)
-#define VCNL4035_MODE_ALS_DISABLE	0x00
+#define VCNL4035_MODE_ALS_ENABLE	0x00
+#define VCNL4035_MODE_ALS_DISABLE	BIT(0)
 #define VCNL4035_MODE_ALS_INT_ENABLE	BIT(1)
 #define VCNL4035_MODE_ALS_INT_DISABLE	0
 #define VCNL4035_DEV_ID_VAL		0x80

base-commit: a22dc7ebb21a6bd4c8b63bc2c1dd46a24945aae7

Best regards,
Alexander
-- 
2.47.3

Re: [PATCH] iio: light: vcnl4035: Fix reversed ALS mode bit

[Nuno Sá]

On Mon, Oct 12, 2026 at 04:43:15PM +0200, Alexander Sarmanow wrote:
> According to the datasheet (table 2) the ALS_SD bit behaves the opposite
> way the current ALS mode defines are set, writing 0 powers the sensor
> and writing 1 shuts it down.
> 
> The current driver thinks the ALS is up while it's actually shut down
> and it's down when the systems powers it up.
> 
> Fixes: 55707294c4eb ("iio: light: Add support for vishay vcnl4035")
> Cc: stable@vger.kernel.org
> Signed-off-by: Alexander Sarmanow <as@discnull.de>
> ---

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

> Tested on a Raspberry Pi 3B+ with a VCNL4035 on I2C, running Raspberry
> Pi OS downstream kernel 6.18.50. Checked with i2cget that bit 0 of the
> config register 0x00 is 0 while PM runtime resume and 1 once it's
> runtime suspended. Also builds cleanly against iio/testing.
> 
>  drivers/iio/light/vcnl4035.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/light/vcnl4035.c b/drivers/iio/light/vcnl4035.c
> index ce1bd42b0c7c..f1cc75245001 100644
> --- a/drivers/iio/light/vcnl4035.c
> +++ b/drivers/iio/light/vcnl4035.c
> @@ -44,8 +44,8 @@
>  #define VCNL4035_DEV_ID_MASK		GENMASK(7, 0)
>  
>  /* Default values */
> -#define VCNL4035_MODE_ALS_ENABLE	BIT(0)
> -#define VCNL4035_MODE_ALS_DISABLE	0x00
> +#define VCNL4035_MODE_ALS_ENABLE	0x00
> +#define VCNL4035_MODE_ALS_DISABLE	BIT(0)
>  #define VCNL4035_MODE_ALS_INT_ENABLE	BIT(1)
>  #define VCNL4035_MODE_ALS_INT_DISABLE	0
>  #define VCNL4035_DEV_ID_VAL		0x80
> 
> base-commit: a22dc7ebb21a6bd4c8b63bc2c1dd46a24945aae7
> 
> Best regards,
> Alexander
> -- 
> 2.47.3
>