Re: [PATCH v14 13/19] leds: lp55xx: Add multicolor framework support to lp55xx

[Jacek Anaszewski]

Dan,

On 10/18/19 2:25 PM, Dan Murphy wrote:
> Add multicolor framework support for the lp55xx family.
> 
> Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
> ---
>  drivers/leds/Kconfig                      |   1 +
>  drivers/leds/leds-lp55xx-common.c         | 185 +++++++++++++++++++---
>  drivers/leds/leds-lp55xx-common.h         |   9 ++
>  include/linux/platform_data/leds-lp55xx.h |   7 +
>  4 files changed, 179 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index fb614a6b9afa..5706bf8d8bd1 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 OF
>  	select FW_LOADER
>  	select FW_LOADER_USER_HELPER
>  	help
> diff --git a/drivers/leds/leds-lp55xx-common.c b/drivers/leds/leds-lp55xx-common.c
> index 882ef39e4965..197b87ca5ca2 100644
> --- a/drivers/leds/leds-lp55xx-common.c
> +++ b/drivers/leds/leds-lp55xx-common.c
> @@ -131,14 +131,62 @@ static struct attribute *lp55xx_led_attrs[] = {
>  };
>  ATTRIBUTE_GROUPS(lp55xx_led);
>  
> +#if IS_ENABLED(CONFIG_LEDS_CLASS_MULTI_COLOR)
> +static int lp55xx_map_channel(struct lp55xx_led *led, int color_id,
> +			      enum led_brightness brightness)

If you changed the type of the first parameter to
struct led_mc_color_conversion* then you could make this function local
in LED mc class and call it in led_mc_calc_color_components() after
calculating brightness components.

> +{
> +	int i;
> +
> +	for (i = 0; i < led->mc_cdev.num_leds; i++) {
> +		if (led->color_components[i].color_id == color_id) {
> +			led->color_components[i].brightness = brightness;
> +			return 0;
> +		}
> +	}
> +
> +	return -EINVAL;
> +}
> +#endif
> +
> +static int lp55xx_set_mc_brightness(struct lp55xx_led *led,
> +				    struct lp55xx_device_config *cfg,
> +				     enum led_brightness brightness)
> +{
> +	int ret = -EINVAL;
> +#if IS_ENABLED(CONFIG_LEDS_CLASS_MULTI_COLOR)
> +	struct led_mc_color_conversion color_components[LP55XX_MAX_GROUPED_CHAN];

You wouldn't need this local variable then.

> +	int i;
> +
> +	if (!cfg->multicolor_brightness_fn)
> +		return -EINVAL;
> +
> +	led_mc_calc_color_components(&led->mc_cdev, brightness,
> +				     color_components);

Because you could pass what you already have in the struct lp55xx_led:

led_mc_calc_color_components(&led->mc_cdev, brightness,
                             led->color_components);


> +
> +	for (i = 0; i < led->mc_cdev.num_leds; i++) {
> +		ret = lp55xx_map_channel(led, color_components[i].color_id,
> +					 color_components[i].brightness);
> +		if (ret)
> +			return ret;
> +	}

And this loop would execute inside the previous call, thus it is to be
optimized out from here.

> +
> +	ret = cfg->multicolor_brightness_fn(led);
> +#endif
> +	return ret;
> +}
> +
>  static int lp55xx_set_brightness(struct led_classdev *cdev,
>  			     enum led_brightness brightness)
>  {
>  	struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
>  	struct lp55xx_device_config *cfg = led->chip->cfg;
>  
> -	led->brightness = (u8)brightness;
> -	return cfg->brightness_fn(led);
> +	if (led->mc_cdev.num_leds > 1) {
> +		return lp55xx_set_mc_brightness(led, cfg, brightness);
> +	} else {
> +		led->brightness = (u8)brightness;
> +		return cfg->brightness_fn(led);
> +	}
>  }
>  
>  static int lp55xx_init_led(struct lp55xx_led *led,
> @@ -147,9 +195,9 @@ static int lp55xx_init_led(struct lp55xx_led *led,
>  	struct lp55xx_platform_data *pdata = chip->pdata;
>  	struct lp55xx_device_config *cfg = chip->cfg;
>  	struct device *dev = &chip->cl->dev;
> +	int max_channel = cfg->max_channel;
>  	char name[32];
>  	int ret;
> -	int max_channel = cfg->max_channel;
>  
>  	if (chan >= max_channel) {
>  		dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel);
> @@ -159,10 +207,34 @@ static int lp55xx_init_led(struct lp55xx_led *led,
>  	if (pdata->led_config[chan].led_current == 0)
>  		return 0;
>  
> +	if (pdata->led_config[chan].name) {
> +		led->cdev.name = pdata->led_config[chan].name;
> +	} else {
> +		snprintf(name, sizeof(name), "%s:channel%d",
> +			pdata->label ? : chip->cl->name, chan);
> +		led->cdev.name = name;
> +	}
> +
> +	if (pdata->led_config[chan].num_colors > 1) {
> +		led->mc_cdev.led_cdev = &led->cdev;
> +		led->cdev.brightness_set_blocking = lp55xx_set_brightness;
> +		led->cdev.groups = lp55xx_led_groups;
> +		led->mc_cdev.num_leds = pdata->led_config[chan].num_colors;
> +		led->mc_cdev.available_colors =
> +			pdata->led_config[chan].available_colors;
> +		memcpy(led->color_components,
> +		       pdata->led_config[chan].color_components,
> +		       sizeof(led->color_components));
> +	} else {
> +
> +		led->cdev.default_trigger =
> +			pdata->led_config[chan].default_trigger;
> +		led->cdev.brightness_set_blocking = lp55xx_set_brightness;
> +	}	led->cdev.groups = lp55xx_led_groups;
> +
>  	led->led_current = pdata->led_config[chan].led_current;
>  	led->max_current = pdata->led_config[chan].max_current;
>  	led->chan_nr = pdata->led_config[chan].chan_nr;
> -	led->cdev.default_trigger = pdata->led_config[chan].default_trigger;
>  
>  	if (led->chan_nr >= max_channel) {
>  		dev_err(dev, "Use channel numbers between 0 and %d\n",
> @@ -170,18 +242,13 @@ static int lp55xx_init_led(struct lp55xx_led *led,
>  		return -EINVAL;
>  	}
>  
> -	led->cdev.brightness_set_blocking = lp55xx_set_brightness;
> -	led->cdev.groups = lp55xx_led_groups;
> -
> -	if (pdata->led_config[chan].name) {
> -		led->cdev.name = pdata->led_config[chan].name;
> -	} else {
> -		snprintf(name, sizeof(name), "%s:channel%d",
> -			pdata->label ? : chip->cl->name, chan);
> -		led->cdev.name = name;
> -	}
> +#if IS_ENABLED(CONFIG_LEDS_CLASS_MULTI_COLOR)
> +	if (pdata->led_config[chan].num_colors > 1)
> +		ret = devm_led_classdev_multicolor_register(dev, &led->mc_cdev);
> +	else
> +#endif
> +		ret = devm_led_classdev_register(dev, &led->cdev);
>  
> -	ret = devm_led_classdev_register(dev, &led->cdev);
>  	if (ret) {
>  		dev_err(dev, "led register err: %d\n", ret);
>  		return ret;
> @@ -525,6 +592,82 @@ void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
>  }
>  EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
>  
> +static int lp5xx_parse_common_child(struct device_node *np,
> +				    struct lp55xx_led_config *cfg,
> +				    int chan_num, bool is_multicolor,
> +				    int color_num)
> +{
> +	u32 led_number;
> +	int ret;
> +
> +	of_property_read_string(np, "chan-name",
> +				&cfg[chan_num].name);
> +	of_property_read_u8(np, "led-cur",
> +			    &cfg[chan_num].led_current);
> +	of_property_read_u8(np, "max-cur",
> +			    &cfg[chan_num].max_current);
> +
> +	ret = of_property_read_u32(np, "reg", &led_number);
> +	if (ret)
> +		return ret;
> +
> +	if (led_number < 0 || led_number > 6)
> +		return -EINVAL;
> +
> +	if (is_multicolor)
> +		cfg[chan_num].color_components[color_num].output_num =
> +								led_number;
> +	else
> +		cfg[chan_num].chan_nr = led_number;
> +
> +	return 0;
> +}
> +
> +static int lp5xx_parse_channel_child(struct device_node *np,
> +				     struct lp55xx_led_config *cfg,
> +				     int child_number)
> +{
> +	struct device_node *child;
> +	int channel_color;
> +	int num_colors = 0;
> +	u32 color_id;
> +	int ret;
> +
> +	cfg[child_number].default_trigger =
> +			of_get_property(np, "linux,default-trigger", NULL);
> +
> +	ret = of_property_read_u32(np, "color", &channel_color);
> +	if (ret)
> +		channel_color = ret;
> +
> +
> +	if (channel_color == LED_COLOR_ID_MULTI) {
> +		for_each_child_of_node(np, child) {
> +			ret = lp5xx_parse_common_child(child, cfg,
> +						       child_number, true,
> +						       num_colors);
> +			if (ret)
> +				return ret;
> +
> +			ret = of_property_read_u32(child, "color", &color_id);
> +			if (ret)
> +				return ret;
> +
> +			cfg[child_number].color_components[num_colors].color_id =
> +						color_id;
> +			set_bit(color_id, &cfg[child_number].available_colors);
> +			num_colors++;
> +		}
> +
> +		cfg[child_number].num_colors = num_colors;
> +	} else {
> +		return lp5xx_parse_common_child(np, cfg, child_number, false,
> +						num_colors);
> +	}
> +
> +	return 0;
> +}
> +
>  struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
>  						      struct device_node *np)
>  {
> @@ -533,6 +676,7 @@ struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
>  	struct lp55xx_led_config *cfg;
>  	int num_channels;
>  	int i = 0;
> +	int ret;
>  
>  	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
>  	if (!pdata)
> @@ -552,14 +696,9 @@ struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
>  	pdata->num_channels = num_channels;
>  
>  	for_each_child_of_node(np, child) {
> -		cfg[i].chan_nr = i;
> -
> -		of_property_read_string(child, "chan-name", &cfg[i].name);
> -		of_property_read_u8(child, "led-cur", &cfg[i].led_current);
> -		of_property_read_u8(child, "max-cur", &cfg[i].max_current);
> -		cfg[i].default_trigger =
> -			of_get_property(child, "linux,default-trigger", NULL);
> -
> +		ret = lp5xx_parse_channel_child(child, cfg, i);

I went into details of this parsing and finally came up with
the code which is a bit greater in size, but IMHO cleaner.
Note changes in variable naming. It is not even compile-tested.

static int lp55xx_parse_common_child(struct device_node *np,
                                    struct lp55xx_led_config *cfg,
                                    int led_number, int *chan_nr)
{
        int ret;

        of_property_read_string(np, "chan-name",
                                &cfg[led_number].name);
        of_property_read_u8(np, "led-cur",
                            &cfg[led_number].led_current);
        of_property_read_u8(np, "max-cur",
                            &cfg[led_number].max_current);

        ret = of_property_read_u32(np, "reg", chan_nr);
        if (ret)
                return ret;

        if (chan_nr < 0 || chan_nr > cfg->max_chan_nr) /* side note: new
max_chan_nr property needed in cfg */
                return -EINVAL;

        return 0;
}

static int lp55xx_parse_mutli_led_child(struct device_node *np,
                                        struct lp55xx_led_config *cfg,
                                        int child_number,
                                        int color_number)
{
        int chan_nr, color_id;

        ret = lp55xx_parse_common_child(child, cfg, child_number,
color_number,
                                        &chan_nr);
        if (ret)
                return ret;

        ret = of_property_read_u32(child, "color", &color_id);
        if (ret)
               return ret;

        cfg[child_number].color_components[color_number].color_id =
color_id;
        cfg[child_number].color_components[color_number].output_num =
chan_nr;
        set_bit(color_id, &cfg[child_number].available_colors);

        return 0;
}

staitc int lp55xx_parse_mutli_led(struct device_node *np,
                                  struct lp55xx_led_config *cfg,
                                  int child_number)
{
        struct device_node *child;
        int num_colors = 0, i = 0;

        for_each_child_of_node(np, child) {
                ret = lp55xx_parse_mutli_led_child(child, cfg, num_colors,
                                                   child_number, i))
                if (ret)
                        return ret;
                num_colors++;
        }
}

static int lp5xx_parse_logical_led(struct device_node *np,
                                   struct lp55xx_led_config *cfg,
                                   int child_number)
{
        int led_color, ret;

        cfg[child_number].default_trigger =
                of_get_property(np, "linux,default-trigger", NULL);

        ret = of_property_read_u32(np, "color", &led_color);

        if (ret) {
                int chan_nr;
                ret =  lp55xx_parse_common_child(np, cfg, child_number,
                                                 &chan_nr);
                if (ret < 0)
                       return ret;
                cfg[child_number].chan_nr = chan_nr;
        } else if (led_color == LED_COLOR_ID_MULTI) {
                return lp55xx_parse_mutli_led(np, cfg, child_number);
        } else
                return ret;

        return 0;
}


for_each_child_of_node(np, child) {
        ret = lp55xx_parse_logical_led(child, cfg, i);
        if (ret)
                return ERR_PTR(-EINVAL);
        i++;
}


It maybe worth also to check if channel has not been already taken.


> +		if (ret)
> +			return ERR_PTR(-EINVAL);
>  		i++;
>  	}
>  
> diff --git a/drivers/leds/leds-lp55xx-common.h b/drivers/leds/leds-lp55xx-common.h
> index b9b1041e8143..4a0cdbfe54a6 100644
> --- a/drivers/leds/leds-lp55xx-common.h
> +++ b/drivers/leds/leds-lp55xx-common.h
> @@ -12,6 +12,8 @@
>  #ifndef _LEDS_LP55XX_COMMON_H
>  #define _LEDS_LP55XX_COMMON_H
>  
> +#include <linux/led-class-multicolor.h>
> +
>  enum lp55xx_engine_index {
>  	LP55XX_ENGINE_INVALID,
>  	LP55XX_ENGINE_1,
> @@ -109,6 +111,9 @@ struct lp55xx_device_config {
>  	/* access brightness register */
>  	int (*brightness_fn)(struct lp55xx_led *led);
>  
> +	/* perform brightness value to multiple LEDs */
> +	int (*multicolor_brightness_fn)(struct lp55xx_led *led);
> +
>  	/* current setting function */
>  	void (*set_led_current) (struct lp55xx_led *led, u8 led_current);
>  
> @@ -159,6 +164,8 @@ struct lp55xx_chip {
>   * struct lp55xx_led
>   * @chan_nr         : Channel number
>   * @cdev            : LED class device
> + * @mc_cdev	    : Multi color class device
> + * @color_components: Multi color LED map information
>   * @led_current     : Current setting at each led channel
>   * @max_current     : Maximun current at each led channel
>   * @brightness      : Brightness value
> @@ -167,6 +174,8 @@ struct lp55xx_chip {
>  struct lp55xx_led {
>  	int chan_nr;
>  	struct led_classdev cdev;
> +	struct led_classdev_mc mc_cdev;
> +	struct led_mc_color_conversion color_components[LP55XX_MAX_GROUPED_CHAN];
>  	u8 led_current;
>  	u8 max_current;
>  	u8 brightness;
> diff --git a/include/linux/platform_data/leds-lp55xx.h b/include/linux/platform_data/leds-lp55xx.h
> index 96a787100fda..ead9d145de0d 100644
> --- a/include/linux/platform_data/leds-lp55xx.h
> +++ b/include/linux/platform_data/leds-lp55xx.h
> @@ -12,17 +12,24 @@
>  #ifndef _LEDS_LP55XX_H
>  #define _LEDS_LP55XX_H
>  
> +#include <linux/led-class-multicolor.h>
> +
>  /* Clock configuration */
>  #define LP55XX_CLOCK_AUTO	0
>  #define LP55XX_CLOCK_INT	1
>  #define LP55XX_CLOCK_EXT	2
>  
> +#define LP55XX_MAX_GROUPED_CHAN	4
> +
>  struct lp55xx_led_config {
>  	const char *name;
>  	const char *default_trigger;
>  	u8 chan_nr;
>  	u8 led_current; /* mA x10, 0 if led is not connected */
>  	u8 max_current;
> +	int num_colors;
> +	unsigned long available_colors;
> +	struct led_mc_color_conversion color_components[LP55XX_MAX_GROUPED_CHAN];
>  };
>  
>  struct lp55xx_predef_pattern {
> 

-- 
Best regards,
Jacek Anaszewski