[PATCH] cap11xx: add LED support

[PATCH] cap11xx: add LED support

[Matt Ranostay]

Several cap11xx variants have LEDs that be can be controlled, this
patchset implements this functionality.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
---
 drivers/input/keyboard/cap11xx.c | 102 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 99 insertions(+), 3 deletions(-)

diff --git a/drivers/input/keyboard/cap11xx.c b/drivers/input/keyboard/cap11xx.c
index f07461a..dc48936 100644
--- a/drivers/input/keyboard/cap11xx.c
+++ b/drivers/input/keyboard/cap11xx.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/input.h>
+#include <linux/leds.h>
 #include <linux/of_irq.h>
 #include <linux/regmap.h>
 #include <linux/i2c.h>
@@ -47,6 +48,8 @@
 #define CAP11XX_REG_CONFIG2		0x44
 #define CAP11XX_REG_CONFIG2_ALT_POL	BIT(6)
 #define CAP11XX_REG_SENSOR_BASE_CNT(X)	(0x50 + (X))
+#define CAP11XX_REG_LED_POLARITY	0x73
+#define CAP11XX_REG_LED_OUTPUT_CONTROL	0x74
 #define CAP11XX_REG_SENSOR_CALIB	(0xb1 + (X))
 #define CAP11XX_REG_SENSOR_CALIB_LSB1	0xb9
 #define CAP11XX_REG_SENSOR_CALIB_LSB2	0xba
@@ -56,10 +59,25 @@
 
 #define CAP11XX_MANUFACTURER_ID	0x5d
 
+#ifdef CONFIG_LEDS_CLASS
+struct cap11xx_led {
+	struct cap11xx_priv *priv;
+	struct led_classdev cdev;
+	struct work_struct work;
+	char name[32];
+	int id;
+	enum led_brightness new_brightness;
+};
+#endif
+
 struct cap11xx_priv {
 	struct regmap *regmap;
 	struct input_dev *idev;
 
+#ifdef CONFIG_LEDS_CLASS
+	struct cap11xx_led *leds;
+	int num_leds;
+#endif
 	/* config */
 	u32 keycodes[];
 };
@@ -67,6 +85,7 @@ struct cap11xx_priv {
 struct cap11xx_hw_model {
 	u8 product_id;
 	unsigned int num_channels;
+	unsigned int num_leds;
 };
 
 enum {
@@ -76,9 +95,9 @@ enum {
 };
 
 static const struct cap11xx_hw_model cap11xx_devices[] = {
-	[CAP1106] = { .product_id = 0x55, .num_channels = 6 },
-	[CAP1126] = { .product_id = 0x53, .num_channels = 6 },
-	[CAP1188] = { .product_id = 0x50, .num_channels = 8 },
+	[CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0 },
+	[CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2 },
+	[CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8 },
 };
 
 static const struct reg_default cap11xx_reg_defaults[] = {
@@ -111,6 +130,8 @@ static const struct reg_default cap11xx_reg_defaults[] = {
 	{ CAP11XX_REG_STANDBY_SENSITIVITY,	0x02 },
 	{ CAP11XX_REG_STANDBY_THRESH,		0x40 },
 	{ CAP11XX_REG_CONFIG2,			0x40 },
+	{ CAP11XX_REG_LED_POLARITY,		0x00 },
+	{ CAP11XX_REG_LED_OUTPUT_CONTROL,	0x00 },
 	{ CAP11XX_REG_SENSOR_CALIB_LSB1,	0x00 },
 	{ CAP11XX_REG_SENSOR_CALIB_LSB2,	0x00 },
 };
@@ -196,6 +217,69 @@ static void cap11xx_input_close(struct input_dev *idev)
 	cap11xx_set_sleep(priv, true);
 }
 
+#ifdef CONFIG_LEDS_CLASS
+static void cap11xx_led_work(struct work_struct *work)
+{
+	struct cap11xx_led *led = container_of(work, struct cap11xx_led, work);
+	struct cap11xx_priv *priv = led->priv;
+	int value = led->new_brightness;
+
+	regmap_update_bits(priv->regmap, CAP11XX_REG_LED_OUTPUT_CONTROL,
+				BIT(led->id), !!value ? BIT(led->id) : 0);
+}
+
+static void cap11xx_led_set(struct led_classdev *cdev,
+			   enum led_brightness value)
+{
+	struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
+
+	led->new_brightness = value;
+	schedule_work(&led->work);
+}
+
+static int cap11xx_register_leds(struct device *dev, struct cap11xx_priv *priv)
+{
+	int ret;
+	int i;
+
+	for (i = 0; i < priv->num_leds; i++) {
+		struct cap11xx_led *led = &priv->leds[i];
+
+		snprintf(led->name, sizeof(led->name), "cap11xx:led%d", i + 1);
+		led->cdev.name = led->name;
+		led->cdev.brightness_set = cap11xx_led_set;
+		led->cdev.brightness = LED_OFF;
+		led->cdev.max_brightness = 1;
+		led->id = i;
+		led->priv = priv;
+
+		ret = led_classdev_register(dev, &led->cdev);
+		if (ret < 0)
+			return ret;
+
+		INIT_WORK(&led->work, cap11xx_led_work);
+	};
+	return 0;
+}
+
+static int cap11xx_i2c_remove(struct i2c_client *client)
+{
+	struct cap11xx_priv *priv = i2c_get_clientdata(client);
+	int i;
+
+	for (i = 0; i < priv->num_leds; i++) {
+		led_classdev_unregister(&priv->leds[i].cdev);
+		cancel_work_sync(&priv->leds[i].work);
+	}
+	regmap_update_bits(priv->regmap,
+		CAP11XX_REG_LED_OUTPUT_CONTROL, 0xff, 0);
+
+	return 0;
+}
+#else
+#define cap11xx_i2c_remove	NULL
+#endif
+
 static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
 			     const struct i2c_device_id *id)
 {
@@ -316,6 +400,17 @@ static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
 	priv->idev->open = cap11xx_input_open;
 	priv->idev->close = cap11xx_input_close;
 
+#ifdef CONFIG_LEDS_CLASS
+	if (cap->num_leds > 0) {
+		priv->leds = devm_kzalloc(dev,
+				cap->num_leds * sizeof(struct cap11xx_led),
+				GFP_KERNEL);
+		if (!priv->leds)
+			return -ENOMEM;
+		priv->num_leds = cap->num_leds;
+		cap11xx_register_leds(dev, priv);
+	}
+#endif
 	input_set_drvdata(priv->idev, priv);
 
 	/*
@@ -366,6 +461,7 @@ static struct i2c_driver cap11xx_i2c_driver = {
 	},
 	.id_table	= cap11xx_i2c_ids,
 	.probe		= cap11xx_i2c_probe,
+	.remove		= cap11xx_i2c_remove,
 };
 
 module_i2c_driver(cap11xx_i2c_driver);
-- 
1.9.1

Re: [PATCH] cap11xx: add LED support

[Daniel Mack]

Hi Matt,

On 06/09/2015 05:46 AM, Matt Ranostay wrote:
> Several cap11xx variants have LEDs that be can be controlled, this
> patchset implements this functionality.
> 
> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
> ---
>  drivers/input/keyboard/cap11xx.c | 102 +++++++++++++++++++++++++++++++++++++--
>  1 file changed, 99 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/input/keyboard/cap11xx.c b/drivers/input/keyboard/cap11xx.c
> index f07461a..dc48936 100644
> --- a/drivers/input/keyboard/cap11xx.c
> +++ b/drivers/input/keyboard/cap11xx.c
> @@ -12,6 +12,7 @@
>  #include <linux/module.h>
>  #include <linux/interrupt.h>
>  #include <linux/input.h>
> +#include <linux/leds.h>
>  #include <linux/of_irq.h>
>  #include <linux/regmap.h>
>  #include <linux/i2c.h>
> @@ -47,6 +48,8 @@
>  #define CAP11XX_REG_CONFIG2		0x44
>  #define CAP11XX_REG_CONFIG2_ALT_POL	BIT(6)
>  #define CAP11XX_REG_SENSOR_BASE_CNT(X)	(0x50 + (X))
> +#define CAP11XX_REG_LED_POLARITY	0x73
> +#define CAP11XX_REG_LED_OUTPUT_CONTROL	0x74
>  #define CAP11XX_REG_SENSOR_CALIB	(0xb1 + (X))
>  #define CAP11XX_REG_SENSOR_CALIB_LSB1	0xb9
>  #define CAP11XX_REG_SENSOR_CALIB_LSB2	0xba
> @@ -56,10 +59,25 @@
>  
>  #define CAP11XX_MANUFACTURER_ID	0x5d
>  
> +#ifdef CONFIG_LEDS_CLASS
> +struct cap11xx_led {
> +	struct cap11xx_priv *priv;
> +	struct led_classdev cdev;
> +	struct work_struct work;
> +	char name[32];
> +	int id;
> +	enum led_brightness new_brightness;
> +};
> +#endif
> +
>  struct cap11xx_priv {
>  	struct regmap *regmap;
>  	struct input_dev *idev;
>  
> +#ifdef CONFIG_LEDS_CLASS
> +	struct cap11xx_led *leds;
> +	int num_leds;
> +#endif
>  	/* config */
>  	u32 keycodes[];
>  };
> @@ -67,6 +85,7 @@ struct cap11xx_priv {
>  struct cap11xx_hw_model {
>  	u8 product_id;
>  	unsigned int num_channels;
> +	unsigned int num_leds;
>  };
>  
>  enum {
> @@ -76,9 +95,9 @@ enum {
>  };
>  
>  static const struct cap11xx_hw_model cap11xx_devices[] = {
> -	[CAP1106] = { .product_id = 0x55, .num_channels = 6 },
> -	[CAP1126] = { .product_id = 0x53, .num_channels = 6 },
> -	[CAP1188] = { .product_id = 0x50, .num_channels = 8 },
> +	[CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0 },
> +	[CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2 },
> +	[CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8 },
>  };
>  
>  static const struct reg_default cap11xx_reg_defaults[] = {
> @@ -111,6 +130,8 @@ static const struct reg_default cap11xx_reg_defaults[] = {
>  	{ CAP11XX_REG_STANDBY_SENSITIVITY,	0x02 },
>  	{ CAP11XX_REG_STANDBY_THRESH,		0x40 },
>  	{ CAP11XX_REG_CONFIG2,			0x40 },
> +	{ CAP11XX_REG_LED_POLARITY,		0x00 },
> +	{ CAP11XX_REG_LED_OUTPUT_CONTROL,	0x00 },
>  	{ CAP11XX_REG_SENSOR_CALIB_LSB1,	0x00 },
>  	{ CAP11XX_REG_SENSOR_CALIB_LSB2,	0x00 },
>  };
> @@ -196,6 +217,69 @@ static void cap11xx_input_close(struct input_dev *idev)
>  	cap11xx_set_sleep(priv, true);
>  }
>  
> +#ifdef CONFIG_LEDS_CLASS
> +static void cap11xx_led_work(struct work_struct *work)
> +{
> +	struct cap11xx_led *led = container_of(work, struct cap11xx_led, work);
> +	struct cap11xx_priv *priv = led->priv;
> +	int value = led->new_brightness;
> +
> +	regmap_update_bits(priv->regmap, CAP11XX_REG_LED_OUTPUT_CONTROL,
> +				BIT(led->id), !!value ? BIT(led->id) : 0);
> +}
> +
> +static void cap11xx_led_set(struct led_classdev *cdev,
> +			   enum led_brightness value)
> +{
> +	struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
> +
> +	led->new_brightness = value;
> +	schedule_work(&led->work);
> +}
> +
> +static int cap11xx_register_leds(struct device *dev, struct cap11xx_priv *priv)
> +{
> +	int ret;
> +	int i;
> +
> +	for (i = 0; i < priv->num_leds; i++) {
> +		struct cap11xx_led *led = &priv->leds[i];
> +
> +		snprintf(led->name, sizeof(led->name), "cap11xx:led%d", i + 1);
> +		led->cdev.name = led->name;
> +		led->cdev.brightness_set = cap11xx_led_set;

Use the .brightness_set_sync callback, so you don't have to dance around
with the workers at all.

> +		led->cdev.brightness = LED_OFF;
> +		led->cdev.max_brightness = 1;
> +		led->id = i;
> +		led->priv = priv;
> +
> +		ret = led_classdev_register(dev, &led->cdev);

You can use the devm_variant of this function. That will solve the
tricky part of unwinding if registration of only one LED fails.

> +		if (ret < 0)
> +			return ret;
> +
> +		INIT_WORK(&led->work, cap11xx_led_work);
> +	};
> +	return 0;
> +}
> +
> +static int cap11xx_i2c_remove(struct i2c_client *client)
> +{
> +	struct cap11xx_priv *priv = i2c_get_clientdata(client);
> +	int i;
> +
> +	for (i = 0; i < priv->num_leds; i++) {
> +		led_classdev_unregister(&priv->leds[i].cdev);
> +		cancel_work_sync(&priv->leds[i].work);
> +	}

With the two changes from above, this code can go away.

> +	regmap_update_bits(priv->regmap,
> +		CAP11XX_REG_LED_OUTPUT_CONTROL, 0xff, 0);

Well, we don't reset the other registers either, so I don't know if it's
worth it. After all, the entire function can go away if you left this
register untouched on removal time.

> +
> +	return 0;
> +}
> +#else
> +#define cap11xx_i2c_remove	NULL
> +#endif
> +
>  static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
>  			     const struct i2c_device_id *id)
>  {
> @@ -316,6 +400,17 @@ static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
>  	priv->idev->open = cap11xx_input_open;
>  	priv->idev->close = cap11xx_input_close;
>  
> +#ifdef CONFIG_LEDS_CLASS
> +	if (cap->num_leds > 0) {
> +		priv->leds = devm_kzalloc(dev,
> +				cap->num_leds * sizeof(struct cap11xx_led),
> +				GFP_KERNEL);

There's devm_kcalloc(), but that's nitpicking.

> +		if (!priv->leds)
> +			return -ENOMEM;
> +		priv->num_leds = cap->num_leds;
> +		cap11xx_register_leds(dev, priv);

You need to check the return value here and bail.



Thanks,
Daniel

Re: [PATCH] cap11xx: add LED support

[Daniel Mack]

On 06/09/2015 05:46 AM, Matt Ranostay wrote:
> Several cap11xx variants have LEDs that be can be controlled, this
> patchset implements this functionality.
> 
> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
> ---
>  drivers/input/keyboard/cap11xx.c | 102 +++++++++++++++++++++++++++++++++++++--
>  1 file changed, 99 insertions(+), 3 deletions(-)

Ah, and please include the LED maintainers in v2, they might spot other
details :)


Thanks,
Daniel

Re: [PATCH] cap11xx: add LED support

[Matt Ranostay]

On Mon, Jun 8, 2015 at 10:26 PM, Daniel Mack <daniel@zonque.org> wrote:
> On 06/09/2015 05:46 AM, Matt Ranostay wrote:
>> Several cap11xx variants have LEDs that be can be controlled, this
>> patchset implements this functionality.
>>
>> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
>> ---
>>  drivers/input/keyboard/cap11xx.c | 102 +++++++++++++++++++++++++++++++++++++--
>>  1 file changed, 99 insertions(+), 3 deletions(-)
>
> Ah, and please include the LED maintainers in v2, they might spot other
> details :)
>

Will do.

>
> Thanks,
> Daniel
>
>

Re: [PATCH] cap11xx: add LED support

[Dmitry Torokhov]

On Tue, Jun 09, 2015 at 07:25:42AM +0200, Daniel Mack wrote:
> Hi Matt,
> 
> On 06/09/2015 05:46 AM, Matt Ranostay wrote:
> > Several cap11xx variants have LEDs that be can be controlled, this
> > patchset implements this functionality.
> > 
> > Signed-off-by: Matt Ranostay <mranostay@gmail.com>
> > ---
> >  drivers/input/keyboard/cap11xx.c | 102 +++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 99 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/input/keyboard/cap11xx.c b/drivers/input/keyboard/cap11xx.c
> > index f07461a..dc48936 100644
> > --- a/drivers/input/keyboard/cap11xx.c
> > +++ b/drivers/input/keyboard/cap11xx.c
> > @@ -12,6 +12,7 @@
> >  #include <linux/module.h>
> >  #include <linux/interrupt.h>
> >  #include <linux/input.h>
> > +#include <linux/leds.h>
> >  #include <linux/of_irq.h>
> >  #include <linux/regmap.h>
> >  #include <linux/i2c.h>
> > @@ -47,6 +48,8 @@
> >  #define CAP11XX_REG_CONFIG2		0x44
> >  #define CAP11XX_REG_CONFIG2_ALT_POL	BIT(6)
> >  #define CAP11XX_REG_SENSOR_BASE_CNT(X)	(0x50 + (X))
> > +#define CAP11XX_REG_LED_POLARITY	0x73
> > +#define CAP11XX_REG_LED_OUTPUT_CONTROL	0x74
> >  #define CAP11XX_REG_SENSOR_CALIB	(0xb1 + (X))
> >  #define CAP11XX_REG_SENSOR_CALIB_LSB1	0xb9
> >  #define CAP11XX_REG_SENSOR_CALIB_LSB2	0xba
> > @@ -56,10 +59,25 @@
> >  
> >  #define CAP11XX_MANUFACTURER_ID	0x5d
> >  
> > +#ifdef CONFIG_LEDS_CLASS
> > +struct cap11xx_led {
> > +	struct cap11xx_priv *priv;
> > +	struct led_classdev cdev;
> > +	struct work_struct work;
> > +	char name[32];
> > +	int id;
> > +	enum led_brightness new_brightness;
> > +};
> > +#endif
> > +
> >  struct cap11xx_priv {
> >  	struct regmap *regmap;
> >  	struct input_dev *idev;
> >  
> > +#ifdef CONFIG_LEDS_CLASS
> > +	struct cap11xx_led *leds;
> > +	int num_leds;
> > +#endif
> >  	/* config */
> >  	u32 keycodes[];
> >  };
> > @@ -67,6 +85,7 @@ struct cap11xx_priv {
> >  struct cap11xx_hw_model {
> >  	u8 product_id;
> >  	unsigned int num_channels;
> > +	unsigned int num_leds;
> >  };
> >  
> >  enum {
> > @@ -76,9 +95,9 @@ enum {
> >  };
> >  
> >  static const struct cap11xx_hw_model cap11xx_devices[] = {
> > -	[CAP1106] = { .product_id = 0x55, .num_channels = 6 },
> > -	[CAP1126] = { .product_id = 0x53, .num_channels = 6 },
> > -	[CAP1188] = { .product_id = 0x50, .num_channels = 8 },
> > +	[CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0 },
> > +	[CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2 },
> > +	[CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8 },
> >  };
> >  
> >  static const struct reg_default cap11xx_reg_defaults[] = {
> > @@ -111,6 +130,8 @@ static const struct reg_default cap11xx_reg_defaults[] = {
> >  	{ CAP11XX_REG_STANDBY_SENSITIVITY,	0x02 },
> >  	{ CAP11XX_REG_STANDBY_THRESH,		0x40 },
> >  	{ CAP11XX_REG_CONFIG2,			0x40 },
> > +	{ CAP11XX_REG_LED_POLARITY,		0x00 },
> > +	{ CAP11XX_REG_LED_OUTPUT_CONTROL,	0x00 },
> >  	{ CAP11XX_REG_SENSOR_CALIB_LSB1,	0x00 },
> >  	{ CAP11XX_REG_SENSOR_CALIB_LSB2,	0x00 },
> >  };
> > @@ -196,6 +217,69 @@ static void cap11xx_input_close(struct input_dev *idev)
> >  	cap11xx_set_sleep(priv, true);
> >  }
> >  
> > +#ifdef CONFIG_LEDS_CLASS
> > +static void cap11xx_led_work(struct work_struct *work)
> > +{
> > +	struct cap11xx_led *led = container_of(work, struct cap11xx_led, work);
> > +	struct cap11xx_priv *priv = led->priv;
> > +	int value = led->new_brightness;
> > +
> > +	regmap_update_bits(priv->regmap, CAP11XX_REG_LED_OUTPUT_CONTROL,
> > +				BIT(led->id), !!value ? BIT(led->id) : 0);
> > +}
> > +
> > +static void cap11xx_led_set(struct led_classdev *cdev,
> > +			   enum led_brightness value)
> > +{
> > +	struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
> > +
> > +	led->new_brightness = value;
> > +	schedule_work(&led->work);
> > +}
> > +
> > +static int cap11xx_register_leds(struct device *dev, struct cap11xx_priv *priv)
> > +{
> > +	int ret;
> > +	int i;
> > +
> > +	for (i = 0; i < priv->num_leds; i++) {
> > +		struct cap11xx_led *led = &priv->leds[i];
> > +
> > +		snprintf(led->name, sizeof(led->name), "cap11xx:led%d", i + 1);
> > +		led->cdev.name = led->name;
> > +		led->cdev.brightness_set = cap11xx_led_set;
> 
> Use the .brightness_set_sync callback, so you don't have to dance around
> with the workers at all.

Umm, how will it help? You still can't sleep in set_brightness().
brightness_set_sync() just says that the driver guarantees that the LED
state will be set (or error returned) when the function returns.

Thanks.

-- 
Dmitry

Re: [PATCH] cap11xx: add LED support

[Matt Ranostay]

On Tue, Jun 9, 2015 at 10:12 AM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> On Tue, Jun 09, 2015 at 07:25:42AM +0200, Daniel Mack wrote:
>> Hi Matt,
>>
>> On 06/09/2015 05:46 AM, Matt Ranostay wrote:
>> > Several cap11xx variants have LEDs that be can be controlled, this
>> > patchset implements this functionality.
>> >
>> > Signed-off-by: Matt Ranostay <mranostay@gmail.com>
>> > ---
>> >  drivers/input/keyboard/cap11xx.c | 102 +++++++++++++++++++++++++++++++++++++--
>> >  1 file changed, 99 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/drivers/input/keyboard/cap11xx.c b/drivers/input/keyboard/cap11xx.c
>> > index f07461a..dc48936 100644
>> > --- a/drivers/input/keyboard/cap11xx.c
>> > +++ b/drivers/input/keyboard/cap11xx.c
>> > @@ -12,6 +12,7 @@
>> >  #include <linux/module.h>
>> >  #include <linux/interrupt.h>
>> >  #include <linux/input.h>
>> > +#include <linux/leds.h>
>> >  #include <linux/of_irq.h>
>> >  #include <linux/regmap.h>
>> >  #include <linux/i2c.h>
>> > @@ -47,6 +48,8 @@
>> >  #define CAP11XX_REG_CONFIG2                0x44
>> >  #define CAP11XX_REG_CONFIG2_ALT_POL        BIT(6)
>> >  #define CAP11XX_REG_SENSOR_BASE_CNT(X)     (0x50 + (X))
>> > +#define CAP11XX_REG_LED_POLARITY   0x73
>> > +#define CAP11XX_REG_LED_OUTPUT_CONTROL     0x74
>> >  #define CAP11XX_REG_SENSOR_CALIB   (0xb1 + (X))
>> >  #define CAP11XX_REG_SENSOR_CALIB_LSB1      0xb9
>> >  #define CAP11XX_REG_SENSOR_CALIB_LSB2      0xba
>> > @@ -56,10 +59,25 @@
>> >
>> >  #define CAP11XX_MANUFACTURER_ID    0x5d
>> >
>> > +#ifdef CONFIG_LEDS_CLASS
>> > +struct cap11xx_led {
>> > +   struct cap11xx_priv *priv;
>> > +   struct led_classdev cdev;
>> > +   struct work_struct work;
>> > +   char name[32];
>> > +   int id;
>> > +   enum led_brightness new_brightness;
>> > +};
>> > +#endif
>> > +
>> >  struct cap11xx_priv {
>> >     struct regmap *regmap;
>> >     struct input_dev *idev;
>> >
>> > +#ifdef CONFIG_LEDS_CLASS
>> > +   struct cap11xx_led *leds;
>> > +   int num_leds;
>> > +#endif
>> >     /* config */
>> >     u32 keycodes[];
>> >  };
>> > @@ -67,6 +85,7 @@ struct cap11xx_priv {
>> >  struct cap11xx_hw_model {
>> >     u8 product_id;
>> >     unsigned int num_channels;
>> > +   unsigned int num_leds;
>> >  };
>> >
>> >  enum {
>> > @@ -76,9 +95,9 @@ enum {
>> >  };
>> >
>> >  static const struct cap11xx_hw_model cap11xx_devices[] = {
>> > -   [CAP1106] = { .product_id = 0x55, .num_channels = 6 },
>> > -   [CAP1126] = { .product_id = 0x53, .num_channels = 6 },
>> > -   [CAP1188] = { .product_id = 0x50, .num_channels = 8 },
>> > +   [CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0 },
>> > +   [CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2 },
>> > +   [CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8 },
>> >  };
>> >
>> >  static const struct reg_default cap11xx_reg_defaults[] = {
>> > @@ -111,6 +130,8 @@ static const struct reg_default cap11xx_reg_defaults[] = {
>> >     { CAP11XX_REG_STANDBY_SENSITIVITY,      0x02 },
>> >     { CAP11XX_REG_STANDBY_THRESH,           0x40 },
>> >     { CAP11XX_REG_CONFIG2,                  0x40 },
>> > +   { CAP11XX_REG_LED_POLARITY,             0x00 },
>> > +   { CAP11XX_REG_LED_OUTPUT_CONTROL,       0x00 },
>> >     { CAP11XX_REG_SENSOR_CALIB_LSB1,        0x00 },
>> >     { CAP11XX_REG_SENSOR_CALIB_LSB2,        0x00 },
>> >  };
>> > @@ -196,6 +217,69 @@ static void cap11xx_input_close(struct input_dev *idev)
>> >     cap11xx_set_sleep(priv, true);
>> >  }
>> >
>> > +#ifdef CONFIG_LEDS_CLASS
>> > +static void cap11xx_led_work(struct work_struct *work)
>> > +{
>> > +   struct cap11xx_led *led = container_of(work, struct cap11xx_led, work);
>> > +   struct cap11xx_priv *priv = led->priv;
>> > +   int value = led->new_brightness;
>> > +
>> > +   regmap_update_bits(priv->regmap, CAP11XX_REG_LED_OUTPUT_CONTROL,
>> > +                           BIT(led->id), !!value ? BIT(led->id) : 0);
>> > +}
>> > +
>> > +static void cap11xx_led_set(struct led_classdev *cdev,
>> > +                      enum led_brightness value)
>> > +{
>> > +   struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
>> > +
>> > +   led->new_brightness = value;
>> > +   schedule_work(&led->work);
>> > +}
>> > +
>> > +static int cap11xx_register_leds(struct device *dev, struct cap11xx_priv *priv)
>> > +{
>> > +   int ret;
>> > +   int i;
>> > +
>> > +   for (i = 0; i < priv->num_leds; i++) {
>> > +           struct cap11xx_led *led = &priv->leds[i];
>> > +
>> > +           snprintf(led->name, sizeof(led->name), "cap11xx:led%d", i + 1);
>> > +           led->cdev.name = led->name;
>> > +           led->cdev.brightness_set = cap11xx_led_set;
>>
>> Use the .brightness_set_sync callback, so you don't have to dance around
>> with the workers at all.
>
> Umm, how will it help? You still can't sleep in set_brightness().
> brightness_set_sync() just says that the driver guarantees that the LED
> state will be set (or error returned) when the function returns.
>
Yeah the worker queues are for sure needed.

> Thanks.
>
> --
> Dmitry

Re: [PATCH] cap11xx: add LED support

[Daniel Mack]

On 06/09/2015 07:12 PM, Dmitry Torokhov wrote:
> On Tue, Jun 09, 2015 at 07:25:42AM +0200, Daniel Mack wrote:

>> Use the .brightness_set_sync callback, so you don't have to dance around
>> with the workers at all.
> 
> Umm, how will it help? You still can't sleep in set_brightness().
> brightness_set_sync() just says that the driver guarantees that the LED
> state will be set (or error returned) when the function returns.

Hmm, right. I was mislead by this comment in include/linux/leds.h:

   /*
    * Set LED brightness level immediately - it can block the caller for
    * the time required for accessing a LED device register.
    */

But I in fact don't see any wrapper logic that magically uses a worker
when called from interrupt context.


Thanks for the heads-up!
Daniel