Re: [PATCH] cap11xx: add LED support

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

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