[PATCH v4 0/2] leds: Add a driver for the BD2606MVV

[PATCH v4 0/2] leds: Add a driver for the BD2606MVV

[Andreas Kemnade]

Add the binding description and the corresponding driver for
the BD2606.

Changes in V4:
- minor tuning of description in bindings
 
Changes in V3:
- binding cleanup
- move active variable from long-living struct onto stack

Changes in V2:
- Add Datasheet link
- use fwnode api
- remove childnode count check, that will bail out
  anyways later.
- add enable-gpios to binding but not to driver due to lack of
  testing ability

Andreas Kemnade (2):
  dt-bindings: leds: Add ROHM BD2606MVV LED driver
  leds: bd2606mvv: Driver for the Rohm 6 Channel i2c LED driver

 .../bindings/leds/rohm,bd2606mvv.yaml         |  81 ++++++++++
 drivers/leds/Kconfig                          |  11 ++
 drivers/leds/Makefile                         |   1 +
 drivers/leds/leds-bd2606mvv.c                 | 143 ++++++++++++++++++
 4 files changed, 236 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/rohm,bd2606mvv.yaml
 create mode 100644 drivers/leds/leds-bd2606mvv.c

-- 
2.39.2

[PATCH v4 1/2] dt-bindings: leds: Add ROHM BD2606MVV LED driver

[Andreas Kemnade]

Document ROHM BD2606MVV LED driver devicetree bindings.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
 .../bindings/leds/rohm,bd2606mvv.yaml         | 81 +++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/rohm,bd2606mvv.yaml

diff --git a/Documentation/devicetree/bindings/leds/rohm,bd2606mvv.yaml b/Documentation/devicetree/bindings/leds/rohm,bd2606mvv.yaml
new file mode 100644
index 0000000000000..14700a2e5feaa
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/rohm,bd2606mvv.yaml
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/rohm,bd2606mvv.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ROHM BD2606MVV LED controller
+
+maintainers:
+  - Andreas Kemnade <andreas@kemnade.info>
+
+description:
+  The BD2606 MVV is a programmable LED controller connected via I2C that can
+  drive 6 separate lines. Each of them can be individually switched on and off,
+  but the brightness setting is shared between pairs of them.
+
+  Datasheet is available at
+  https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/led_driver/bd2606mvv_1-e.pdf
+
+properties:
+  compatible:
+    const: rohm,bd2606mvv
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  enable-gpios:
+    maxItems: 1
+    description: GPIO pin to enable/disable the device.
+
+patternProperties:
+  "^led@[0-6]$":
+    type: object
+    $ref: common.yaml#
+    unevaluatedProperties: false
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 6
+
+    required:
+      - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/leds/common.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        led-controller@66 {
+            compatible = "rohm,bd2606mvv";
+            reg = <0x66>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            led@0 {
+                reg = <0x0>;
+                color = <LED_COLOR_ID_RED>;
+                function = LED_FUNCTION_POWER;
+            };
+
+            led@2 {
+                reg = <0x2>;
+                color = <LED_COLOR_ID_WHITE>;
+                function = LED_FUNCTION_STATUS;
+            };
+        };
+    };
+
+...
-- 
2.39.2

Re: [PATCH v4 1/2] dt-bindings: leds: Add ROHM BD2606MVV LED driver

[Krzysztof Kozlowski]

On 14/04/2023 07:53, Andreas Kemnade wrote:
> Document ROHM BD2606MVV LED driver devicetree bindings.

Subject: no improvements and no comments from your side. Why?

> 
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
> ---
>  .../bindings/leds/rohm,bd2606mvv.yaml         | 81 +++++++++++++++++++
>  1 file changed, 81 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/rohm,bd2606mvv.yaml
> 
> diff --git a/Documentation/devicetree/bindings/leds/rohm,bd2606mvv.yaml b/Documentation/devicetree/bindings/leds/rohm,bd2606mvv.yaml
> new file mode 100644
> index 0000000000000..14700a2e5feaa
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/rohm,bd2606mvv.yaml
> @@ -0,0 +1,81 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/rohm,bd2606mvv.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ROHM BD2606MVV LED controller
> +
> +maintainers:
> +  - Andreas Kemnade <andreas@kemnade.info>
> +
> +description:
> +  The BD2606 MVV is a programmable LED controller connected via I2C that can
> +  drive 6 separate lines. Each of them can be individually switched on and off,
> +  but the brightness setting is shared between pairs of them.
> +
> +  Datasheet is available at
> +  https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/led_driver/bd2606mvv_1-e.pdf
> +
> +properties:
> +  compatible:
> +    const: rohm,bd2606mvv
> +
> +  reg:
> +    maxItems: 1
> +
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 0
> +
> +  enable-gpios:
> +    maxItems: 1

Drop maxItems. It cannot be different.

> +    description: GPIO pin to enable/disable the device.
> +
Best regards,
Krzysztof

Re: [PATCH v4 1/2] dt-bindings: leds: Add ROHM BD2606MVV LED driver

[Andreas Kemnade]

On Fri, 14 Apr 2023 17:28:49 +0200
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:

> On 14/04/2023 07:53, Andreas Kemnade wrote:
> > Document ROHM BD2606MVV LED driver devicetree bindings.  
> 
> Subject: no improvements and no comments from your side. Why?
> 
old subject (v2):

dt-bindings: leds: ROHM BD2606MVV LED driver

Your comment:
Subject: maybe drop "driver" (suggests it is for Linux drivers, although
maybe it matches the actual hardware here?) and add missing verb, e.g.
"Add ROHM ..."

New Subject (v3/4):
dt-bindings: leds: Add ROHM BD2606MVV LED driver

What is still missing?

Regards,
Andreas

Re: [PATCH v4 1/2] dt-bindings: leds: Add ROHM BD2606MVV LED driver

[Andreas Kemnade]

On Fri, 14 Apr 2023 17:54:12 +0200
Andreas Kemnade <andreas@kemnade.info> wrote:

> On Fri, 14 Apr 2023 17:28:49 +0200
> Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:
> 
> > On 14/04/2023 07:53, Andreas Kemnade wrote:  
> > > Document ROHM BD2606MVV LED driver devicetree bindings.    
> > 
> > Subject: no improvements and no comments from your side. Why?
> >   
> old subject (v2):
> 
> dt-bindings: leds: ROHM BD2606MVV LED driver
> 
> Your comment:
> Subject: maybe drop "driver" (suggests it is for Linux drivers, although
> maybe it matches the actual hardware here?) and add missing verb, e.g.
> "Add ROHM ..."
> 
> New Subject (v3/4):
> dt-bindings: leds: Add ROHM BD2606MVV LED driver
> 
> What is still missing?
> 
ok, answering myself:
missing verb was added ("Add")

but
s/driver//
is missing

Sorry.

Regards,
Andreas

Re: [PATCH v4 1/2] dt-bindings: leds: Add ROHM BD2606MVV LED driver

[Krzysztof Kozlowski]

On 14/04/2023 17:54, Andreas Kemnade wrote:
> On Fri, 14 Apr 2023 17:28:49 +0200
> Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:
> 
>> On 14/04/2023 07:53, Andreas Kemnade wrote:
>>> Document ROHM BD2606MVV LED driver devicetree bindings.  
>>
>> Subject: no improvements and no comments from your side. Why?
>>
> old subject (v2):
> 
> dt-bindings: leds: ROHM BD2606MVV LED driver
> 
> Your comment:
> Subject: maybe drop "driver" (suggests it is for Linux drivers, although
> maybe it matches the actual hardware here?) and add missing verb, e.g.
> "Add ROHM ..."
> 
> New Subject (v3/4):
> dt-bindings: leds: Add ROHM BD2606MVV LED driver
> 
> What is still missing?

There is still "driver". Comment was: drop "driver". Where is it dropped?

If you do not agree, sure, just respond with something.

Best regards,
Krzysztof

Re: [PATCH v4 1/2] dt-bindings: leds: Add ROHM BD2606MVV LED driver

[Andreas Kemnade]

Hi,

On Fri, 14 Apr 2023 23:17:56 +0200
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:

> On 14/04/2023 17:54, Andreas Kemnade wrote:
> > On Fri, 14 Apr 2023 17:28:49 +0200
> > Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:
> >   
> >> On 14/04/2023 07:53, Andreas Kemnade wrote:  
> >>> Document ROHM BD2606MVV LED driver devicetree bindings.    
> >>
> >> Subject: no improvements and no comments from your side. Why?
> >>  
> > old subject (v2):
> > 
> > dt-bindings: leds: ROHM BD2606MVV LED driver
> > 
> > Your comment:
> > Subject: maybe drop "driver" (suggests it is for Linux drivers, although
> > maybe it matches the actual hardware here?) and add missing verb, e.g.
> > "Add ROHM ..."
> > 
> > New Subject (v3/4):
> > dt-bindings: leds: Add ROHM BD2606MVV LED driver
> > 
> > What is still missing?  
> 
> There is still "driver". Comment was: drop "driver". Where is it dropped?
> 
> If you do not agree, sure, just respond with something.
> 
I am fine with both. On one hand BD2606MVV is not a LED by itself
but LEDs can be connected to it. so the chip itself can be called LED driver.

But on the other hand I think that holds true for everything in drivers/leds
and binding/leds and we do not call the subsystem leddriver.
So there are reasons for and against "driver" in the subject line.

Regards,
Andreas

[PATCH v4 2/2] leds: bd2606mvv: Driver for the Rohm 6 Channel i2c LED driver

[Andreas Kemnade]

The device provides 6 channels which can be individually
turned off and on but groups of two channels share a common brightness
register.

Limitation: The GPIO to enable the device is not used yet.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
 drivers/leds/Kconfig          |  11 +++
 drivers/leds/Makefile         |   1 +
 drivers/leds/leds-bd2606mvv.c | 143 ++++++++++++++++++++++++++++++++++
 3 files changed, 155 insertions(+)
 create mode 100644 drivers/leds/leds-bd2606mvv.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 9dbce09eabacf..cc4eadbb2542e 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -551,6 +551,17 @@ config LEDS_REGULATOR
 	help
 	  This option enables support for regulator driven LEDs.
 
+config LEDS_BD2606MVV
+	tristate "LED driver for BD2606MVV"
+	depends on LEDS_CLASS
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  This option enables support for BD2606MVV LED driver chips
+	  accessed via the I2C bus. It supports setting brightness, with
+	  the limitiation that there are groups of two channels sharing
+	  a brightness setting, but not the on/off setting.
+
 config LEDS_BD2802
 	tristate "LED driver for BD2802 RGB LED"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index d30395d11fd84..c07d1512c745a 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_LEDS_ARIEL)		+= leds-ariel.o
 obj-$(CONFIG_LEDS_AW2013)		+= leds-aw2013.o
 obj-$(CONFIG_LEDS_BCM6328)		+= leds-bcm6328.o
 obj-$(CONFIG_LEDS_BCM6358)		+= leds-bcm6358.o
+obj-$(CONFIG_LEDS_BD2606MVV)		+= leds-bd2606mvv.o
 obj-$(CONFIG_LEDS_BD2802)		+= leds-bd2802.o
 obj-$(CONFIG_LEDS_BLINKM)		+= leds-blinkm.o
 obj-$(CONFIG_LEDS_CLEVO_MAIL)		+= leds-clevo-mail.o
diff --git a/drivers/leds/leds-bd2606mvv.c b/drivers/leds/leds-bd2606mvv.c
new file mode 100644
index 0000000000000..81ceeaa434494
--- /dev/null
+++ b/drivers/leds/leds-bd2606mvv.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Andreas Kemnade
+ *
+ * Datasheet:
+ * https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/led_driver/bd2606mvv_1-e.pdf
+ */
+
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define BD2606_MAX_LEDS 6
+#define BD2606_MAX_BRIGHTNESS 63
+#define BD2606_REG_PWRCNT 3
+#define ldev_to_led(c)	container_of(c, struct bd2606mvv_led, ldev)
+
+struct bd2606mvv_led {
+	unsigned int led_no;
+	struct led_classdev ldev;
+	struct bd2606mvv_priv *priv;
+};
+
+struct bd2606mvv_priv {
+	struct bd2606mvv_led leds[BD2606_MAX_LEDS];
+	struct regmap *regmap;
+};
+
+static int
+bd2606mvv_brightness_set(struct led_classdev *led_cdev,
+		      enum led_brightness brightness)
+{
+	struct bd2606mvv_led *led = ldev_to_led(led_cdev);
+	struct bd2606mvv_priv *priv = led->priv;
+	int err;
+
+	if (brightness == 0)
+		return regmap_update_bits(priv->regmap,
+					  BD2606_REG_PWRCNT,
+					  1 << led->led_no,
+					  0);
+
+	/* shared brightness register */
+	err = regmap_write(priv->regmap, led->led_no / 2,
+			   brightness);
+	if (err)
+		return err;
+
+	return regmap_update_bits(priv->regmap,
+				  BD2606_REG_PWRCNT,
+				  1 << led->led_no,
+				  1 << led->led_no);
+}
+
+static const struct regmap_config bd2606mvv_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x3,
+};
+
+static int bd2606mvv_probe(struct i2c_client *client)
+{
+	struct fwnode_handle *np, *child;
+	struct device *dev = &client->dev;
+	struct bd2606mvv_priv *priv;
+	bool active[BD2606_MAX_LEDS] = { 0 };
+	int err, reg;
+
+	np = dev_fwnode(dev);
+	if (!np)
+		return -ENODEV;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->regmap = devm_regmap_init_i2c(client, &bd2606mvv_regmap);
+	if (IS_ERR(priv->regmap)) {
+		err = PTR_ERR(priv->regmap);
+		dev_err(dev, "Failed to allocate register map: %d\n", err);
+		return err;
+	}
+
+	i2c_set_clientdata(client, priv);
+
+	fwnode_for_each_available_child_node(np, child) {
+		struct bd2606mvv_led *led;
+		struct led_init_data init_data = {};
+
+		init_data.fwnode = child;
+
+		err = fwnode_property_read_u32(child, "reg", &reg);
+		if (err) {
+			fwnode_handle_put(child);
+			return err;
+		}
+		if (reg < 0 || reg >= BD2606_MAX_LEDS ||
+		    active[reg]) {
+			fwnode_handle_put(child);
+			return -EINVAL;
+		}
+		led = &priv->leds[reg];
+
+		active[reg] = true;
+		led->priv = priv;
+		led->led_no = reg;
+		led->ldev.brightness_set_blocking = bd2606mvv_brightness_set;
+		led->ldev.max_brightness = BD2606_MAX_BRIGHTNESS;
+		err = devm_led_classdev_register_ext(dev, &led->ldev,
+						     &init_data);
+		if (err < 0) {
+			fwnode_handle_put(child);
+			return dev_err_probe(dev, err,
+					     "couldn't register LED %s\n",
+					     led->ldev.name);
+		}
+	}
+	return 0;
+}
+
+static const struct of_device_id __maybe_unused of_bd2606mvv_leds_match[] = {
+	{ .compatible = "rohm,bd2606mvv", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_bd2606mvv_leds_match);
+
+static struct i2c_driver bd2606mvv_driver = {
+	.driver   = {
+		.name    = "leds-bd2606mvv",
+		.of_match_table = of_match_ptr(of_bd2606mvv_leds_match),
+	},
+	.probe_new = bd2606mvv_probe,
+};
+
+module_i2c_driver(bd2606mvv_driver);
+
+MODULE_AUTHOR("Andreas Kemnade <andreas@kemnade.info>");
+MODULE_DESCRIPTION("BD2606 LED driver");
+MODULE_LICENSE("GPL");
-- 
2.39.2

Re: [PATCH v4 2/2] leds: bd2606mvv: Driver for the Rohm 6 Channel i2c LED driver

[Pavel Machek]

[-- Attachment #1: Type: text/plain, Size: 1559 bytes --]

Hi!

> The device provides 6 channels which can be individually
> turned off and on but groups of two channels share a common brightness
> register.

Yeah, well.. Turn it into 3-channel controller with brightness or
6-channel on/off one... You can't really share brightness.

> +++ b/drivers/leds/Kconfig
> @@ -551,6 +551,17 @@ config LEDS_REGULATOR
>  	help
>  	  This option enables support for regulator driven LEDs.
>  
> +config LEDS_BD2606MVV
> +	tristate "LED driver for BD2606MVV"
> +	depends on LEDS_CLASS
> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	  This option enables support for BD2606MVV LED driver chips
> +	  accessed via the I2C bus. It supports setting brightness, with
> +	  the limitiation that there are groups of two channels sharing
> +	  a brightness setting, but not the on/off setting.
> +

This driver can be used as a module...


> +static int
> +bd2606mvv_brightness_set(struct led_classdev *led_cdev,
> +		      enum led_brightness brightness)
> +{
> +	struct bd2606mvv_led *led = ldev_to_led(led_cdev);
> +	struct bd2606mvv_priv *priv = led->priv;
> +	int err;
> +
> +	if (brightness == 0)
> +		return regmap_update_bits(priv->regmap,
> +					  BD2606_REG_PWRCNT,
> +					  1 << led->led_no,
> +					  0);
> +
> +	/* shared brightness register */
> +	err = regmap_write(priv->regmap, led->led_no / 2,
> +			   brightness);
> +	if (err)
> +		return err;

Yeah. No.

Best regards,
							Pavel
-- 
People of Russia, stop Putin before his war on Ukraine escalates.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]

Re: [PATCH v4 2/2] leds: bd2606mvv: Driver for the Rohm 6 Channel i2c LED driver

[Andreas Kemnade]

Hi Pavel,

On Fri, 14 Apr 2023 14:18:56 +0200
Pavel Machek <pavel@ucw.cz> wrote:

> Hi!
> 
> > The device provides 6 channels which can be individually
> > turned off and on but groups of two channels share a common brightness
> > register.  
> 
> Yeah, well.. Turn it into 3-channel controller with brightness or
> 6-channel on/off one... You can't really share brightness.
> 
No, I cannot change the hardware, so it is a 6-channel with limitations.
And the devicetree has to describe the hardware and not the driver.

What is discussable is just how the driver should deal with that:

I see 5 possibilities.
a) ignore the shared brightness problem (status quo)
b) never set a brightness other than full on/off
c) ignore one led of each pair (not register it at all{
d) couple also the on/off of the pairs, so present to
   userspace only max. 3 leds.
e) allow full brightness control where independently possible,
   if LEDs are defined where that leads to conflicts,
   register them with max_brightness=1 and use them
   in on/off mode.

My preference were a) or e), the most possible usages.
e) has a cleaner interface to the userspace.

I would not upstream b)

Regards,
Andreas

> > +++ b/drivers/leds/Kconfig
> > @@ -551,6 +551,17 @@ config LEDS_REGULATOR
> >  	help
> >  	  This option enables support for regulator driven LEDs.
> >  
> > +config LEDS_BD2606MVV
> > +	tristate "LED driver for BD2606MVV"
> > +	depends on LEDS_CLASS
> > +	depends on I2C
> > +	select REGMAP_I2C
> > +	help
> > +	  This option enables support for BD2606MVV LED driver chips
> > +	  accessed via the I2C bus. It supports setting brightness, with
> > +	  the limitiation that there are groups of two channels sharing
> > +	  a brightness setting, but not the on/off setting.
> > +  
> 
> This driver can be used as a module...
> 
> 
> > +static int
> > +bd2606mvv_brightness_set(struct led_classdev *led_cdev,
> > +		      enum led_brightness brightness)
> > +{
> > +	struct bd2606mvv_led *led = ldev_to_led(led_cdev);
> > +	struct bd2606mvv_priv *priv = led->priv;
> > +	int err;
> > +
> > +	if (brightness == 0)
> > +		return regmap_update_bits(priv->regmap,
> > +					  BD2606_REG_PWRCNT,
> > +					  1 << led->led_no,
> > +					  0);
> > +
> > +	/* shared brightness register */
> > +	err = regmap_write(priv->regmap, led->led_no / 2,
> > +			   brightness);
> > +	if (err)
> > +		return err;  
> 
> Yeah. No.
> 
> Best regards,
> 							Pavel

Re: [PATCH v4 2/2] leds: bd2606mvv: Driver for the Rohm 6 Channel i2c LED driver

[Pavel Machek]

[-- Attachment #1: Type: text/plain, Size: 1335 bytes --]

Hi!

> > > The device provides 6 channels which can be individually
> > > turned off and on but groups of two channels share a common brightness
> > > register.  
> > 
> > Yeah, well.. Turn it into 3-channel controller with brightness or
> > 6-channel on/off one... You can't really share brightness.
> > 
> No, I cannot change the hardware, so it is a 6-channel with limitations.
> And the devicetree has to describe the hardware and not the driver.

Device tree is okay, I commented on the driver.

> What is discussable is just how the driver should deal with that:
> 
> I see 5 possibilities.
> a) ignore the shared brightness problem (status quo)
> b) never set a brightness other than full on/off
> c) ignore one led of each pair (not register it at all{
> d) couple also the on/off of the pairs, so present to
>    userspace only max. 3 leds.
> e) allow full brightness control where independently possible,
>    if LEDs are defined where that leads to conflicts,
>    register them with max_brightness=1 and use them
>    in on/off mode.
> 
> My preference were a) or e), the most possible usages.
> e) has a cleaner interface to the userspace.

b) c) e) are acceptable to me. So I guess e) is preffered.

BR,							Pavel
-- 
People of Russia, stop Putin before his war on Ukraine escalates.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]

Re: [PATCH v4 2/2] leds: bd2606mvv: Driver for the Rohm 6 Channel i2c LED driver

[Pavel Machek]

[-- Attachment #1: Type: text/plain, Size: 653 bytes --]

Hi!

> > > +config LEDS_BD2606MVV
> > > +	tristate "LED driver for BD2606MVV"
> > > +	depends on LEDS_CLASS
> > > +	depends on I2C
> > > +	select REGMAP_I2C
> > > +	help
> > > +	  This option enables support for BD2606MVV LED driver chips
> > > +	  accessed via the I2C bus. It supports setting brightness, with
> > > +	  the limitiation that there are groups of two channels sharing
> > > +	  a brightness setting, but not the on/off setting.
> > > +  
> > 
> > This driver can be used as a module...

And I was pointing this out before...

BR,
									Pavel
-- 
People of Russia, stop Putin before his war on Ukraine escalates.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]