[PATCH 0/4] iio: light: stk3310: stk3337 support + vdd supply

[PATCH 0/4] iio: light: stk3310: stk3337 support + vdd supply

[Roman Vivchar via B4 Relay]

This patch series adds support for stk3337 light sensor, found in the
Xiaomi Redmi Note 9 phone. The sensor is compatible with stk3310
registers, while having Clear channel, similar to the stk36c61.

The series also adds vdd-supply property, since on this board the sensor
is wired to the shared power supply.

Signed-off-by: Roman Vivchar <rva333@protonmail.com>
---
Roman Vivchar (4):
      dt-bindings: iio: light: stk33xx: add power supply support
      dt-bindings: iio: light: stk33xx: add stk3337
      iio: light: stk3310: add vdd regulator support
      iio: light: stk3310: add stk3337 support

 .../devicetree/bindings/iio/light/stk33xx.yaml      |  3 +++
 drivers/iio/light/stk3310.c                         | 21 +++++++++++++++++++++
 2 files changed, 24 insertions(+)
---
base-commit: ddfe51b0a0f5dc9e415cc2c8ad8db17532dd426b
change-id: 20261107-6768-stk3337-34f7a2db3a24

Best regards,
--  
Roman Vivchar <rva333@protonmail.com>

[PATCH 1/4] dt-bindings: iio: light: stk33xx: add power supply support

[Roman Vivchar via B4 Relay]

From: Roman Vivchar <rva333@protonmail.com>

On some boards, the chip shares a power rail with other components. If
that rail is turned off, the chip can't function.

Add vdd-supply property to document the chip power supply.

Signed-off-by: Roman Vivchar <rva333@protonmail.com>
---
 Documentation/devicetree/bindings/iio/light/stk33xx.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/light/stk33xx.yaml b/Documentation/devicetree/bindings/iio/light/stk33xx.yaml
index f655a570aac7..114cf87eb54d 100644
--- a/Documentation/devicetree/bindings/iio/light/stk33xx.yaml
+++ b/Documentation/devicetree/bindings/iio/light/stk33xx.yaml
@@ -37,6 +37,8 @@ properties:
 
   proximity-near-level: true
 
+  vdd-supply: true
+
 required:
   - compatible
   - reg

-- 
2.56.0

Re: [PATCH 1/4] dt-bindings: iio: light: stk33xx: add power supply support

[Jonathan Cameron]

On Sun, 08 Nov 2026 00:15:03 +0200
Roman Vivchar via B4 Relay <devnull+rva333.protonmail.com@kernel.org> wrote:

> From: Roman Vivchar <rva333@protonmail.com>
> 
> On some boards, the chip shares a power rail with other components. If
> that rail is turned off, the chip can't function.
Not sure how the sharing is relevant.  Even if shared with nothing
else we need to turn it on.  So just mention that on some boards it
isn't always on.

The only reason this would be optional in the binding is if there
was internal routing in some packaging or similar that meant there
was no pin to connect.

Upshot, make this required in the binding. Note that doesn't mean
the driver must require it - we are simply documenting that the
device needs power. 

Thanks,

Jonathan

> 
> Add vdd-supply property to document the chip power supply.
> 
> Signed-off-by: Roman Vivchar <rva333@protonmail.com>
> ---
>  Documentation/devicetree/bindings/iio/light/stk33xx.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/light/stk33xx.yaml b/Documentation/devicetree/bindings/iio/light/stk33xx.yaml
> index f655a570aac7..114cf87eb54d 100644
> --- a/Documentation/devicetree/bindings/iio/light/stk33xx.yaml
> +++ b/Documentation/devicetree/bindings/iio/light/stk33xx.yaml
> @@ -37,6 +37,8 @@ properties:
>  
>    proximity-near-level: true
>  
> +  vdd-supply: true
> +
>  required:
>    - compatible
>    - reg
> 

Re: [PATCH 1/4] dt-bindings: iio: light: stk33xx: add power supply support

[Roman Vivchar]

Hi Jonathan,

On Sunday, November 8th, 2026 at 12:36 AM, Jonathan Cameron <jic23@kernel.org> wrote:

> On Sun, 08 Nov 2026 00:15:03 +0200
> Roman Vivchar via B4 Relay <devnull+rva333.protonmail.com@kernel.org> wrote:
> 
> > From: Roman Vivchar <rva333@protonmail.com>
> >
> > On some boards, the chip shares a power rail with other components. If
> > that rail is turned off, the chip can't function.
> Not sure how the sharing is relevant.  Even if shared with nothing
> else we need to turn it on.  So just mention that on some boards it
> isn't always on.
> 
> The only reason this would be optional in the binding is if there
> was internal routing in some packaging or similar that meant there
> was no pin to connect.
>
> Upshot, make this required in the binding. Note that doesn't mean
> the driver must require it - we are simply documenting that the
> device needs power.
> 

I agree this should be required, but that would break dt_binding_check
for existing boards. I don't have their schematic nor boards themselves
to verify the regulator for the power supply.

Best regards,
Roman

Re: [PATCH 1/4] dt-bindings: iio: light: stk33xx: add power supply support

[Jonathan Cameron]

On Sat, 07 Nov 2026 22:45:45 +0000
Roman Vivchar <rva333@protonmail.com> wrote:

> Hi Jonathan,
> 
> On Sunday, November 8th, 2026 at 12:36 AM, Jonathan Cameron <jic23@kernel.org> wrote:
> 
> > On Sun, 08 Nov 2026 00:15:03 +0200
> > Roman Vivchar via B4 Relay <devnull+rva333.protonmail.com@kernel.org> wrote:
> >   
> > > From: Roman Vivchar <rva333@protonmail.com>
> > >
> > > On some boards, the chip shares a power rail with other components. If
> > > that rail is turned off, the chip can't function.  
> > Not sure how the sharing is relevant.  Even if shared with nothing
> > else we need to turn it on.  So just mention that on some boards it
> > isn't always on.
> > 
> > The only reason this would be optional in the binding is if there
> > was internal routing in some packaging or similar that meant there
> > was no pin to connect.
> >
> > Upshot, make this required in the binding. Note that doesn't mean
> > the driver must require it - we are simply documenting that the
> > device needs power.
> >   
> 
> I agree this should be required, but that would break dt_binding_check
> for existing boards. I don't have their schematic nor boards themselves
> to verify the regulator for the power supply.

There aren't any upstream (from a quick grep) and so not your problem
unless you have some in a downstream tree that need fixing.
If you do then there is the option of a fixed regulator to close
the gap.  I consider a missing supply a bug that we should fix but maybe
others disagree.

Jonathan


> 
> Best regards,
> Roman

Re: [PATCH 1/4] dt-bindings: iio: light: stk33xx: add power supply support

[Roman Vivchar]

On Sunday, November 8th, 2026 at 1:53 AM, Jonathan Cameron <jic23@kernel.org> wrote:

> On Sat, 07 Nov 2026 22:45:45 +0000
> Roman Vivchar <rva333@protonmail.com> wrote:
> 
> > Hi Jonathan,
> >
> > On Sunday, November 8th, 2026 at 12:36 AM, Jonathan Cameron <jic23@kernel.org> wrote:
> >
> > > On Sun, 08 Nov 2026 00:15:03 +0200
> > > Roman Vivchar via B4 Relay <devnull+rva333.protonmail.com@kernel.org> wrote:
> > >
> > > > From: Roman Vivchar <rva333@protonmail.com>
> > > >
> > > > On some boards, the chip shares a power rail with other components. If
> > > > that rail is turned off, the chip can't function.
> > > Not sure how the sharing is relevant.  Even if shared with nothing
> > > else we need to turn it on.  So just mention that on some boards it
> > > isn't always on.
> > >
> > > The only reason this would be optional in the binding is if there
> > > was internal routing in some packaging or similar that meant there
> > > was no pin to connect.
> > >
> > > Upshot, make this required in the binding. Note that doesn't mean
> > > the driver must require it - we are simply documenting that the
> > > device needs power.
> > >
> >
> > I agree this should be required, but that would break dt_binding_check
> > for existing boards. I don't have their schematic nor boards themselves
> > to verify the regulator for the power supply.
> 
> There aren't any upstream (from a quick grep) and so not your problem
> unless you have some in a downstream tree that need fixing.

I found these (next-20261015, 7.3-rc7):
$ rg "sensortek,stk" arch/
arch/arm64/boot/dts/exynos/exynos7870-on7xelte.dts
467:		compatible = "sensortek,stk3013", "sensortek,stk3310";

arch/arm64/boot/dts/exynos/exynos7870-a2corelte.dts
412:		compatible = "sensortek,stk3013", "sensortek,stk3310";

arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts
526:		compatible = "sensortek,stk3311";

arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
219:		compatible = "sensortek,stk3311";

arch/arm64/boot/dts/mediatek/mt6768-xiaomi-merlin.dts
348:		compatible = "sensortek,stk3337", "sensortek,stk3310";

arch/arm64/boot/dts/mediatek/mt6795-sony-xperia-m5.dts
206:		compatible = "sensortek,stk3310";

arch/arm64/boot/dts/qcom/msm8916-wiko-chuppito.dts
91:		compatible = "sensortek,stk3310";

arch/arm64/boot/dts/qcom/msm8916-alcatel-idol347.dts
173:		compatible = "sensortek,stk3310";

arch/arm/boot/dts/qcom/msm8926-sony-xperia-yukon-eagle.dts
169:		compatible = "sensortek,stk3310";

> If you do then there is the option of a fixed regulator to close
> the gap.  I consider a missing supply a bug that we should fix but maybe
> others disagree.

Yeah in my tree I have added vdd-supply for my board :D

Best regards,
Roman

[PATCH 2/4] dt-bindings: iio: light: stk33xx: add stk3337

[Roman Vivchar via B4 Relay]

From: Roman Vivchar <rva333@protonmail.com>

Add compatible string for the stk3337 ALSPS sensor. Its core registers
are backwards compatible with the stk3310, while also providing a clear
light channel like the stk36c61, so document it with sensortek,stk3310
as a fallback.

Datasheet: https://www.bestmodulescorp.com/en/amfile/file/download/file/1699/product/1048/
Signed-off-by: Roman Vivchar <rva333@protonmail.com>
---
 Documentation/devicetree/bindings/iio/light/stk33xx.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/iio/light/stk33xx.yaml b/Documentation/devicetree/bindings/iio/light/stk33xx.yaml
index 114cf87eb54d..d5d7059fbc0f 100644
--- a/Documentation/devicetree/bindings/iio/light/stk33xx.yaml
+++ b/Documentation/devicetree/bindings/iio/light/stk33xx.yaml
@@ -26,6 +26,7 @@ properties:
       - items:
           - enum:
               - sensortek,stk3013
+              - sensortek,stk3337
               - sensortek,stk36c61
           - const: sensortek,stk3310
 

-- 
2.56.0

[PATCH 3/4] iio: light: stk3310: add vdd regulator support

[Roman Vivchar via B4 Relay]

From: Roman Vivchar <rva333@protonmail.com>

On some boards, the sensor is powered by shared power rail. If the rail
is powered down, the chip can't function.

Add optional regulator support to ensure the power supply is enabled for
the chip.

Signed-off-by: Roman Vivchar <rva333@protonmail.com>
---
 drivers/iio/light/stk3310.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/iio/light/stk3310.c b/drivers/iio/light/stk3310.c
index e751e7c97bc1..2f4747c06f43 100644
--- a/drivers/iio/light/stk3310.c
+++ b/drivers/iio/light/stk3310.c
@@ -18,6 +18,7 @@
 #include <linux/pm.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include <linux/sysfs.h>
 #include <linux/types.h>
 
@@ -745,6 +746,10 @@ static int stk3310_probe(struct i2c_client *client)
 	device_property_read_u32(&client->dev, "proximity-near-level",
 				 &data->ps_near_level);
 
+	ret = devm_regulator_get_enable(dev, "vdd");
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to get vdd supply\n");
+
 	mutex_init(&data->lock);
 
 	ret = stk3310_regmap_init(data);

-- 
2.56.0

[PATCH 4/4] iio: light: stk3310: add stk3337 support

[Roman Vivchar via B4 Relay]

From: Roman Vivchar <rva333@protonmail.com>

Add support for the stk3337 sensor, found in the Xiaomi Redmi Note 9
phone.

In addition to the standard stk3310 ambient light and proximity
channels, the stk3337 provides a clear intensity channel, matching the
layout already used by the stk36c61.

Datasheet: https://www.bestmodulescorp.com/en/amfile/file/download/file/1699/product/1048/
Signed-off-by: Roman Vivchar <rva333@protonmail.com>
---
 drivers/iio/light/stk3310.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/iio/light/stk3310.c b/drivers/iio/light/stk3310.c
index 2f4747c06f43..6d629ce726fc 100644
--- a/drivers/iio/light/stk3310.c
+++ b/drivers/iio/light/stk3310.c
@@ -60,6 +60,7 @@
 #define STK3311S34_CHIP_ID_VAL			0x1E
 #define STK3311X_CHIP_ID_VAL			0x12
 #define STK3335_CHIP_ID_VAL			0x51
+#define STK3337_CHIP_ID_VAL			0x5F
 #define STK36C61_CHIP_ID_VAL			0x95
 #define STK3310_PSINT_EN			0x01
 #define STK3310_PS_MAX_VAL			0xFFFF
@@ -111,6 +112,7 @@ static const u8 stk3310_chip_ids[] = {
 	STK3311X_CHIP_ID_VAL,
 	STK3311_CHIP_ID_VAL,
 	STK3335_CHIP_ID_VAL,
+	STK3337_CHIP_ID_VAL,
 	STK36C61_CHIP_ID_VAL,
 };
 
@@ -233,6 +235,12 @@ static const struct iio_chan_spec stk3310_channels[] = {
 	STK3310_PROXIMITY_CHANNEL,
 };
 
+static const struct iio_chan_spec stk3337_channels[] = {
+	STK3310_LIGHT_CHANNEL,
+	STK3310_PROXIMITY_CHANNEL,
+	STK36C61_INTENSITY_CHANNEL(CLEAR, STK36C61_REG_CLEAR_DATA_MSB),
+};
+
 static const struct iio_chan_spec stk36c61_channels[] = {
 	STK3310_LIGHT_CHANNEL,
 	STK3310_PROXIMITY_CHANNEL,
@@ -260,6 +268,12 @@ static const struct stk3310_chip_info stk3310_chip_info = {
 	.num_channels = ARRAY_SIZE(stk3310_channels),
 };
 
+static const struct stk3310_chip_info stk3337_chip_info = {
+	.name = "stk3337",
+	.channels = stk3337_channels,
+	.num_channels = ARRAY_SIZE(stk3337_channels),
+};
+
 static const struct stk3310_chip_info stk36c61_chip_info = {
 	.name = "stk36c61",
 	.channels = stk36c61_channels,
@@ -870,6 +884,7 @@ static const struct i2c_device_id stk3310_i2c_id[] = {
 	{ .name = "stk3310", .driver_data = (kernel_ulong_t)&stk3310_chip_info },
 	{ .name = "stk3311", .driver_data = (kernel_ulong_t)&stk3310_chip_info },
 	{ .name = "stk3335", .driver_data = (kernel_ulong_t)&stk3310_chip_info },
+	{ .name = "stk3337", .driver_data = (kernel_ulong_t)&stk3337_chip_info },
 	{ .name = "stk36c61", .driver_data = (kernel_ulong_t)&stk36c61_chip_info },
 	{ }
 };
@@ -888,6 +903,7 @@ static const struct of_device_id stk3310_of_match[] = {
 	{ .compatible = "sensortek,stk3310", .data = &stk3310_chip_info },
 	{ .compatible = "sensortek,stk3311", .data = &stk3310_chip_info },
 	{ .compatible = "sensortek,stk3335", .data = &stk3310_chip_info },
+	{ .compatible = "sensortek,stk3337", .data = &stk3337_chip_info },
 	{ .compatible = "sensortek,stk36c61", .data = &stk36c61_chip_info },
 	{ }
 };

-- 
2.56.0

Re: [PATCH 4/4] iio: light: stk3310: add stk3337 support

[Jonathan Cameron]

On Sun, 08 Nov 2026 00:15:06 +0200
Roman Vivchar via B4 Relay <devnull+rva333.protonmail.com@kernel.org> wrote:

> From: Roman Vivchar <rva333@protonmail.com>
> 
> Add support for the stk3337 sensor, found in the Xiaomi Redmi Note 9
> phone.
> 
> In addition to the standard stk3310 ambient light and proximity
> channels, the stk3337 provides a clear intensity channel, matching the
> layout already used by the stk36c61.

I think you should probably make it clear that this is a subset of
the stk36c61 channel spec as that also has other colour sensors.

I was briefly confused as to why you didn't just use the chan spec
from that given this description.

Other than that, looks good to me.

Thanks

Jonathan


> 
> Datasheet: https://www.bestmodulescorp.com/en/amfile/file/download/file/1699/product/1048/
> Signed-off-by: Roman Vivchar <rva333@protonmail.com>
> ---
>  drivers/iio/light/stk3310.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/iio/light/stk3310.c b/drivers/iio/light/stk3310.c
> index 2f4747c06f43..6d629ce726fc 100644
> --- a/drivers/iio/light/stk3310.c
> +++ b/drivers/iio/light/stk3310.c
> @@ -60,6 +60,7 @@
>  #define STK3311S34_CHIP_ID_VAL			0x1E
>  #define STK3311X_CHIP_ID_VAL			0x12
>  #define STK3335_CHIP_ID_VAL			0x51
> +#define STK3337_CHIP_ID_VAL			0x5F
>  #define STK36C61_CHIP_ID_VAL			0x95
>  #define STK3310_PSINT_EN			0x01
>  #define STK3310_PS_MAX_VAL			0xFFFF
> @@ -111,6 +112,7 @@ static const u8 stk3310_chip_ids[] = {
>  	STK3311X_CHIP_ID_VAL,
>  	STK3311_CHIP_ID_VAL,
>  	STK3335_CHIP_ID_VAL,
> +	STK3337_CHIP_ID_VAL,
>  	STK36C61_CHIP_ID_VAL,
>  };
>  
> @@ -233,6 +235,12 @@ static const struct iio_chan_spec stk3310_channels[] = {
>  	STK3310_PROXIMITY_CHANNEL,
>  };
>  
> +static const struct iio_chan_spec stk3337_channels[] = {
> +	STK3310_LIGHT_CHANNEL,
> +	STK3310_PROXIMITY_CHANNEL,
> +	STK36C61_INTENSITY_CHANNEL(CLEAR, STK36C61_REG_CLEAR_DATA_MSB),
> +};
> +
>  static const struct iio_chan_spec stk36c61_channels[] = {
>  	STK3310_LIGHT_CHANNEL,
>  	STK3310_PROXIMITY_CHANNEL,
> @@ -260,6 +268,12 @@ static const struct stk3310_chip_info stk3310_chip_info = {
>  	.num_channels = ARRAY_SIZE(stk3310_channels),
>  };
>  
> +static const struct stk3310_chip_info stk3337_chip_info = {
> +	.name = "stk3337",
> +	.channels = stk3337_channels,
> +	.num_channels = ARRAY_SIZE(stk3337_channels),
> +};
> +
>  static const struct stk3310_chip_info stk36c61_chip_info = {
>  	.name = "stk36c61",
>  	.channels = stk36c61_channels,
> @@ -870,6 +884,7 @@ static const struct i2c_device_id stk3310_i2c_id[] = {
>  	{ .name = "stk3310", .driver_data = (kernel_ulong_t)&stk3310_chip_info },
>  	{ .name = "stk3311", .driver_data = (kernel_ulong_t)&stk3310_chip_info },
>  	{ .name = "stk3335", .driver_data = (kernel_ulong_t)&stk3310_chip_info },
> +	{ .name = "stk3337", .driver_data = (kernel_ulong_t)&stk3337_chip_info },
>  	{ .name = "stk36c61", .driver_data = (kernel_ulong_t)&stk36c61_chip_info },
>  	{ }
>  };
> @@ -888,6 +903,7 @@ static const struct of_device_id stk3310_of_match[] = {
>  	{ .compatible = "sensortek,stk3310", .data = &stk3310_chip_info },
>  	{ .compatible = "sensortek,stk3311", .data = &stk3310_chip_info },
>  	{ .compatible = "sensortek,stk3335", .data = &stk3310_chip_info },
> +	{ .compatible = "sensortek,stk3337", .data = &stk3337_chip_info },
>  	{ .compatible = "sensortek,stk36c61", .data = &stk36c61_chip_info },
>  	{ }
>  };
>