[PATCH 0/2] leds: Add support for the is31fl3206 LED driver

[PATCH 0/2] leds: Add support for the is31fl3206 LED driver

[Flavio Amieiro]

This patch series adds support for the is31fl3206 LED driver to the
already existing is31fl32xx driver.

The main difference between this specific variant and the others in
the series is that the LED Control Register controls not only the
enable status of the channel, but also the maximum output current for
it.

Because the layout of the register is very different from the
previously supported variants, this patch follows the same pattern
present in the driver for paths that deviated from the norm: the
chipdef can define a pointer to an extra function that (if non-NULL)
will be called during probing. This was already done for reset_func
and for sw_shutdown_func in order to support other chips in the same
family.

The patches keep the previous behavior of using only the PWM registers
to control the state of the LEDs. For that reason, the current output
is always set to the maximum value.

This is my first attempt at a patch for the linux kernel, so please
let me know how I can improve it.

Signed-off-by: Flavio Amieiro <flavio@amieiro.net>
---
Flavio Amieiro (2):
      leds: is31f132xx: Add support for is31fl3206
      dt-bindings: leds: Add issi,is31fl3206 to leds-is31fl32xx

 .../devicetree/bindings/leds/leds-is31fl32xx.txt   |  1 +
 drivers/leds/leds-is31fl32xx.c                     | 89 ++++++++++++++++++----
 2 files changed, 74 insertions(+), 16 deletions(-)
---
base-commit: 05b4738b0078f7d6f154f68068a11c8a0635e9df
change-id: 20261012-add-is31fl3206-support-d557f863a97a

Best regards,
--  
Flavio Amieiro <flavio@amieiro.net>

[PATCH 1/2] leds: is31f132xx: Add support for is31fl3206

[Flavio Amieiro]

This chip has a different layout for the LED Control Register when
compared to the other variants. This register contains the enable bit
(in the highest nibble) but also the current control.

According to the datasheet, a value of 010000 (0x10) in the register
enables an LED with the output current set to maximum.

This commit adds support for this IC following the previous limitation
of the other variants: all LEDs are enabled and set with maximum
current, letting brightness be controlled by the PWM registers.

Signed-off-by: Flavio Amieiro <flavio@amieiro.net>
---
 drivers/leds/leds-is31fl32xx.c | 89 ++++++++++++++++++++++++++++++++++--------
 1 file changed, 73 insertions(+), 16 deletions(-)

diff --git a/drivers/leds/leds-is31fl32xx.c b/drivers/leds/leds-is31fl32xx.c
index 285085d27453..9c09548acabf 100644
--- a/drivers/leds/leds-is31fl32xx.c
+++ b/drivers/leds/leds-is31fl32xx.c
@@ -49,6 +49,9 @@
 #define IS31FL3293_RESET_MAGIC 0xc5
 #define IS31FL3293_MAX_MICROAMP 20000
 
+/* Custom LED Control enable value for IS31FL3206 */
+#define IS31FL3206_CONTROL_ENABLE_WITH_IMAX BIT(4)
+
 struct is31fl32xx_priv;
 struct is31fl32xx_led_data {
 	struct led_classdev cdev;
@@ -79,6 +82,7 @@ struct is31fl32xx_priv {
  * @enable_bits_per_led_control_register: number of LEDs enable bits in each
  * @brightness_steps    : number of brightness steps supported by the chip
  * @reset_func          : pointer to reset function
+ * @enable_all_channels_func  : pointer to enable all channels function
  * @sw_shutdown_func    : pointer to software shutdown function
  *
  * For all optional register addresses, the sentinel value %IS31FL32XX_REG_NONE
@@ -105,6 +109,7 @@ struct is31fl32xx_chipdef {
 	u8	enable_bits_per_led_control_register;
 	u16	brightness_steps;
 	int (*reset_func)(struct is31fl32xx_priv *priv);
+	int (*enable_all_channels_func)(struct is31fl32xx_priv *priv);
 	int (*sw_shutdown_func)(struct is31fl32xx_priv *priv, bool enable);
 };
 
@@ -228,6 +233,28 @@ static int is31fl3293_software_shutdown(struct is31fl32xx_priv *priv,
 	return is31fl32xx_write(priv, IS31FL3293_SHUTDOWN_REG, value);
 }
 
+/*
+ * Custom enable_all_channels function for IS31FL3206 because this
+ * variant has only one bit in the higher nibble for enable, and the
+ * lower nibble controls output current.
+ */
+static int is31fl3206_enable_all_channels(struct is31fl32xx_priv *priv)
+{
+	const struct is31fl32xx_chipdef *cdef = priv->cdef;
+	u8 num_regs = cdef->channels / cdef->enable_bits_per_led_control_register;
+	int i, ret;
+
+	for (i = 0; i < num_regs; i++) {
+		ret = is31fl32xx_write(priv,
+				       cdef->led_control_register_base+i,
+				       IS31FL3206_CONTROL_ENABLE_WITH_IMAX);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 /*
  * NOTE: A mutex is not needed in this function because:
  * - All referenced data is read-only after probe()
@@ -315,6 +342,33 @@ static int is31fl32xx_reset_regs(struct is31fl32xx_priv *priv)
 	return 0;
 }
 
+static int is31fl32xx_enable_all_channels(struct is31fl32xx_priv *priv)
+{
+	const struct is31fl32xx_chipdef *cdef = priv->cdef;
+	int ret;
+
+	if (cdef->led_control_register_base != IS31FL32XX_REG_NONE) {
+		u8 value =
+			GENMASK(cdef->enable_bits_per_led_control_register-1, 0);
+		u8 num_regs = cdef->channels /
+			cdef->enable_bits_per_led_control_register;
+		int i;
+
+		for (i = 0; i < num_regs; i++) {
+			ret = is31fl32xx_write(priv,
+					       cdef->led_control_register_base+i,
+					       value);
+			if (ret)
+				return ret;
+		}
+	}
+
+	if (cdef->enable_all_channels_func)
+		return cdef->enable_all_channels_func(priv);
+
+	return 0;
+}
+
 static int is31fl32xx_software_shutdown(struct is31fl32xx_priv *priv,
 					bool enable)
 {
@@ -345,24 +399,12 @@ static int is31fl32xx_init_regs(struct is31fl32xx_priv *priv)
 		return ret;
 
 	/*
-	 * Set enable bit for all channels.
+	 * Enable all channels.
 	 * We will control state with PWM registers alone.
 	 */
-	if (cdef->led_control_register_base != IS31FL32XX_REG_NONE) {
-		u8 value =
-		    GENMASK(cdef->enable_bits_per_led_control_register-1, 0);
-		u8 num_regs = cdef->channels /
-				cdef->enable_bits_per_led_control_register;
-		int i;
-
-		for (i = 0; i < num_regs; i++) {
-			ret = is31fl32xx_write(priv,
-					       cdef->led_control_register_base+i,
-					       value);
-			if (ret)
-				return ret;
-		}
-	}
+	ret = is31fl32xx_enable_all_channels(priv);
+	if (ret)
+		return ret;
 
 	ret = is31fl32xx_software_shutdown(priv, false);
 	if (ret)
@@ -552,7 +594,22 @@ static const struct is31fl32xx_chipdef is31fl3293_cdef = {
 	.sw_shutdown_func			= is31fl3293_software_shutdown,
 };
 
+static const struct is31fl32xx_chipdef is31fl3206_cdef = {
+	.channels				= 12,
+	.shutdown_reg				= 0x00,
+	.pwm_update_reg			= 0x13,
+	.global_control_reg			= 0x26,
+	.reset_reg				= 0x2f,
+	.output_frequency_setting_reg		= 0x27,
+	.pwm_register_base			= 0x04,
+	.led_control_register_base		= 0x17,
+	.enable_bits_per_led_control_register	= 1,
+	.brightness_steps			= 256,
+	.enable_all_channels_func		= is31fl3206_enable_all_channels,
+};
+
 static const struct of_device_id of_is31fl32xx_match[] = {
+	{ .compatible = "issi,is31fl3206",  .data = &is31fl3206_cdef, },
 	{ .compatible = "issi,is31fl3293",  .data = &is31fl3293_cdef, },
 	{ .compatible = "issi,is31fl3236",  .data = &is31fl3236_cdef, },
 	{ .compatible = "issi,is31fl3236a", .data = &is31fl3236a_cdef, },

-- 
2.53.0

[PATCH 2/2] dt-bindings: leds: Add issi,is31fl3206 to leds-is31fl32xx

[Flavio Amieiro]

This is a 12 channel variant of the is31fl32xx led driver series.

Signed-off-by: Flavio Amieiro <flavio@amieiro.net>
---
 Documentation/devicetree/bindings/leds/leds-is31fl32xx.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/leds/leds-is31fl32xx.txt b/Documentation/devicetree/bindings/leds/leds-is31fl32xx.txt
index 7082ed186dd9..06f85a1c6aaf 100644
--- a/Documentation/devicetree/bindings/leds/leds-is31fl32xx.txt
+++ b/Documentation/devicetree/bindings/leds/leds-is31fl32xx.txt
@@ -11,6 +11,7 @@ Required properties:
 	issi,is31fl3218
 	issi,is31fl3216
 	issi,is31fl3293
+	issi,is31fl3206
 	si-en,sn3218
 	si-en,sn3216
 - reg: I2C slave address

-- 
2.53.0

Re: [PATCH 2/2] dt-bindings: leds: Add issi,is31fl3206 to leds-is31fl32xx

[Krzysztof Kozlowski]

On Tue, Oct 13, 2026 at 12:33:15AM -0300, Flavio Amieiro wrote:
> This is a 12 channel variant of the is31fl32xx led driver series.
> 
> Signed-off-by: Flavio Amieiro <flavio@amieiro.net>
> ---
>  Documentation/devicetree/bindings/leds/leds-is31fl32xx.txt | 1 +
>  1 file changed, 1 insertion(+)

Please organize the patch documenting the compatible (DT bindings)
before the patch using that compatible.
See also: https://elixir.bootlin.com/linux/v6.14-rc6/source/Documentation/devicetree/bindings/submitting-patches.rst#L46

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Best regards,
Krzysztof

Re: [PATCH 2/2] dt-bindings: leds: Add issi,is31fl3206 to leds-is31fl32xx

[Flávio Amieiro]

Krzysztof Kozlowski <krzk@kernel.org> writes:
> Please organize the patch documenting the compatible (DT bindings)
> before the patch using that compatible.

I'm sorry, I read this e-mail after sending v2 of the patch series. I
will organize the commits and send v3.

Thank you for your review!

Best regards,
Flávio Amieiro

Re: [PATCH 2/2] dt-bindings: leds: Add issi,is31fl3206 to leds-is31fl32xx

[Krzysztof Kozlowski]

On 13/10/2026 11:58, Flávio Amieiro wrote:
> Krzysztof Kozlowski <krzk@kernel.org> writes:
>> Please organize the patch documenting the compatible (DT bindings)
>> before the patch using that compatible.
> 
> I'm sorry, I read this e-mail after sending v2 of the patch series. I
> will organize the commits and send v3.

v1 was sent today, so how could review be after v2?

One version per 24h, so you actually allow people to look at this code.

Best regards,
Krzysztof

Re: [PATCH 2/2] dt-bindings: leds: Add issi,is31fl3206 to leds-is31fl32xx

[Flávio Amieiro]

Krzysztof Kozlowski <krzk@kernel.org> writes:
> v1 was sent today, so how could review be after v2?

I sent it last night (in my timezone) and saw Shashiko reviews that
needed addressing in the morning. That's why I sent v2.

>
> One version per 24h, so you actually allow people to look at this code.
>

I didn't know about this rule, but of course it makes a lot of
sense. I'm sorry about the noise in the list, and I will for sure keep
this in mind for the future.

Best regards,
Flavio Amieiro