Re: [PATCH v9 13/15] leds: lp55xx: Update the lp55xx to use the multi color framework

[Dan Murphy]

Jacek

On 9/25/19 5:00 PM, Jacek Anaszewski wrote:
> Dan,
>
> On 9/25/19 7:46 PM, Dan Murphy wrote:
> > Update the lp5523 to allow the use of the multi color framework.
> >
> > Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
> > ---
> >   drivers/leds/Kconfig                      |   1 +
> >   drivers/leds/leds-lp5523.c                |  13 ++
> >   drivers/leds/leds-lp55xx-common.c         | 150 ++++++++++++++++++----
> >   drivers/leds/leds-lp55xx-common.h         |  11 ++
> >   include/linux/platform_data/leds-lp55xx.h |   6 +
> >   5 files changed, 157 insertions(+), 24 deletions(-)
> >
> > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> > index 84f60e35c5ee..dc3d9f2194cd 100644
> > --- a/drivers/leds/Kconfig
> > +++ b/drivers/leds/Kconfig
> > @@ -377,6 +377,7 @@ config LEDS_LP50XX
> >   config LEDS_LP55XX_COMMON
> >   	tristate "Common Driver for TI/National LP5521/5523/55231/5562/8501"
> >   	depends on LEDS_LP5521 || LEDS_LP5523 || LEDS_LP5562 || LEDS_LP8501
> > +	depends on LEDS_CLASS_MULTI_COLOR && OF
> >   	select FW_LOADER
> >   	select FW_LOADER_USER_HELPER
> >   	help
> > diff --git a/drivers/leds/leds-lp5523.c b/drivers/leds/leds-lp5523.c
> > index d0b931a136b9..8b2cdb98fed6 100644
> > --- a/drivers/leds/leds-lp5523.c
> > +++ b/drivers/leds/leds-lp5523.c
> > @@ -791,6 +791,18 @@ static ssize_t store_master_fader_leds(struct device *dev,
> >   	return ret;
> >   }
> >   
> > +static int lp5523_led_intensity(struct lp55xx_led *led, int chan_num)
> Why do we need this function? brightness op will not suffice?

I looked at this before sending it in. This API adds the chan_num to 
write to.

The brightness_fn does not it takes it from the led structure.

> > +{
> > +	struct lp55xx_chip *chip = led->chip;
> > +	int ret;
> > +
> > +	mutex_lock(&chip->lock);
> > +	ret = lp55xx_write(chip, LP5523_REG_LED_PWM_BASE + chan_num,
> > +		     led->brightness);
> > +	mutex_unlock(&chip->lock);
> > +	return ret;
> > +}
> > +
> >   static int lp5523_led_brightness(struct lp55xx_led *led)
> >   {
> >   	struct lp55xx_chip *chip = led->chip;
> > @@ -857,6 +869,7 @@ static struct lp55xx_device_config lp5523_cfg = {
> >   	.max_channel  = LP5523_MAX_LEDS,
> >   	.post_init_device   = lp5523_post_init_device,
> >   	.brightness_fn      = lp5523_led_brightness,
> > +	.color_intensity_fn = lp5523_led_intensity,
> >   	.set_led_current    = lp5523_set_led_current,
> >   	.firmware_cb        = lp5523_firmware_loaded,
> >   	.run_engine         = lp5523_run_engine,
> > diff --git a/drivers/leds/leds-lp55xx-common.c b/drivers/leds/leds-lp55xx-common.c
> > index 44ced02b49f9..0e4b3a9d3047 100644
> > --- a/drivers/leds/leds-lp55xx-common.c
> > +++ b/drivers/leds/leds-lp55xx-common.c
> > @@ -136,9 +136,26 @@ static int lp55xx_set_brightness(struct led_classdev *cdev,
> >   {
> >   	struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
> >   	struct lp55xx_device_config *cfg = led->chip->cfg;
> > +	int brightness_val[LP55XX_MAX_GROUPED_CHAN];
> > +	int ret;
> > +	int i;
> > +
> > +	if (led->mc_cdev.num_leds > 1) {
> > +		led_mc_calc_brightness(&led->mc_cdev,
> > +				       brightness, brightness_val);
> > +		for (i = 0; i < led->mc_cdev.num_leds; i++) {
> > +			led->brightness = brightness_val[i];
> > +			ret = cfg->color_intensity_fn(led,
> > +						      led->grouped_channels[i]);
> Now we will have three separate calls for each color component
> (and possibly sleeping on mutex on contention).
>
> Probably LED mc class use case will need a bit different design.
>
> Also, instead of grouped_channels we could possibly have
>
> led_mc_get_color_id(&led->mc_dev, i)
color_id and grouped_channels are not a 1:1 mapping
> which would map entry position index to color_id.
>
> I will stop reviewing here and will continue after taking
> deeper look at this lp55xx design.

Dan