Date:   Sun, 6 Oct 2019 21:52:17 +0200
From:   Jacek Anaszewski <jacek.anaszewski@...il.com>
To:     Dan Murphy <dmurphy@...com>, pavel@....cz
Cc:     linux-leds@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v10 12/16] leds: lp55xx: Add multicolor framework support
 to lp55xx

Dan,

On 10/1/19 4:56 PM, Dan Murphy wrote:
> Add multicolor framework support for the lp55xx family.
> 
> Signed-off-by: Dan Murphy <dmurphy@...com>
> ---
>  drivers/leds/Kconfig                      |   1 +
>  drivers/leds/leds-lp55xx-common.c         | 169 +++++++++++++++++++---
>  drivers/leds/leds-lp55xx-common.h         |  11 ++
>  include/linux/platform_data/leds-lp55xx.h |   6 +
>  4 files changed, 163 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-lp55xx-common.c b/drivers/leds/leds-lp55xx-common.c
> index 44ced02b49f9..5de4f1789a44 100644
> --- a/drivers/leds/leds-lp55xx-common.c
> +++ b/drivers/leds/leds-lp55xx-common.c
> @@ -131,14 +131,50 @@ static struct attribute *lp55xx_led_attrs[] = {
>  };
>  ATTRIBUTE_GROUPS(lp55xx_led);
>  
> +struct led_mc_color_conversion color_component[LP55XX_MAX_GROUPED_CHAN];

Why is this global? Please move it to lp55xx_set_brightness().

> +
> +static int lp55xx_get_channel(struct lp55xx_led *led, int color_id)
> +{
> +	int i;
> +
> +	for (i = 0; i < led->mc_cdev.num_leds; i++) {
> +		if (led->channel_color[i] == color_id)
> +			return led->grouped_channels[i];
> +	}
> +
> +	return -EINVAL;
> +}
> +
>  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;
> +	int channel_num;
> +	int ret;
> +	int i;
>  
> -	led->brightness = (u8)brightness;
> -	return cfg->brightness_fn(led);
> +	if (led->mc_cdev.num_leds > 1) {
> +		led_mc_calc_brightness(&led->mc_cdev, brightness,
> +				       &color_component[0]);

s/&color_component[0]/color_component/

> +
> +		for (i = 0; i < led->mc_cdev.num_leds; i++) {
> +			channel_num = lp55xx_get_channel(led,
> +						color_component[i].color_id);
> +			if (channel_num < 0)
> +				return channel_num;
> +
> +			ret = cfg->color_intensity_fn(led, channel_num,
> +						 color_component[i].brightness);

If you passed struct led_mc_color_conversion instead of brightness,
then in the color_intensity_fn op you could obtain channel numbers
by calling lp55xx_get_channel in a loop. And you could setup the whole
cluster in a single call.

> +			if (ret)
> +				return ret;
> +		}
> +	} else {
> +		led->brightness = (u8)brightness;
> +		ret = cfg->brightness_fn(led);
> +	}
> +
> +	return ret;
>  }
>  
>  static int lp55xx_init_led(struct lp55xx_led *led,
> @@ -147,9 +183,9 @@ 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 +195,37 @@ 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->channel_color,
> +		       pdata->led_config[chan].channel_color,
> +		       sizeof(led->channel_color));
> +		memcpy(led->grouped_channels,
> +		       pdata->led_config[chan].grouped_channels,
> +		       sizeof(led->grouped_channels));
> +	} 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 +233,11 @@ 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].num_colors > 1)
> +		ret = led_classdev_multicolor_register(dev, &led->mc_cdev);
> +	else
> +		ret = led_classdev_register(dev, &led->cdev);
>  
> -	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;
> -	}
> -
> -	ret = led_classdev_register(dev, &led->cdev);
>  	if (ret) {
>  		dev_err(dev, "led register err: %d\n", ret);
>  		return ret;
> @@ -466,7 +522,6 @@ int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
>  		dev_err(&chip->cl->dev, "empty brightness configuration\n");
>  		return -EINVAL;
>  	}
> -
>  	for (i = 0; i < num_channels; i++) {
>  
>  		/* do not initialize channels that are not connected */
> @@ -538,6 +593,76 @@ 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)
> +{
> +	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].grouped_channels[cfg[chan_num].num_colors]

Please pass the index for grouped channels as an argument to this
function. Referring here directly to a temporary state of num_colors
that is incremented in the loop from which this function is called
is ugly IMO.

> +				= 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;
> +	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);
> +			if (ret)
> +				return ret;
> +			ret = of_property_read_u32(child, "color", &color_id);
> +			if (ret)
> +				return ret;
> +
> +			cfg[child_number].channel_color[cfg[child_number].num_colors] =
> +				color_id;
> +			set_bit(color_id, &cfg[child_number].available_colors);
> +
> +			cfg[child_number].num_colors++;
> +		}
> +	} else {
> +		return lp5xx_parse_common_child(np, cfg, child_number, false);
> +	}
> +
> +	return 0;
> +}
> +
>  struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
>  						      struct device_node *np)
>  {
> @@ -546,6 +671,7 @@ 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)
> @@ -565,14 +691,9 @@ 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);
> +		if (ret)
> +			return ERR_PTR(-EINVAL);
>  		i++;
>  	}
>  
> diff --git a/drivers/leds/leds-lp55xx-common.h b/drivers/leds/leds-lp55xx-common.h
> index 783ed5103ce5..5ea2a292a97e 100644
> --- a/drivers/leds/leds-lp55xx-common.h
> +++ b/drivers/leds/leds-lp55xx-common.h
> @@ -12,6 +12,10 @@
>  #ifndef _LEDS_LP55XX_COMMON_H
>  #define _LEDS_LP55XX_COMMON_H
>  
> +#include <linux/led-class-multicolor.h>
> +
> +#define LP55XX_MAX_GROUPED_CHAN	4
> +
>  enum lp55xx_engine_index {
>  	LP55XX_ENGINE_INVALID,
>  	LP55XX_ENGINE_1,
> @@ -109,6 +113,9 @@ struct lp55xx_device_config {
>  	/* access brightness register */
>  	int (*brightness_fn)(struct lp55xx_led *led);
>  
> +	/* access specific brightness register */
> +	int (*color_intensity_fn)(struct lp55xx_led *led, int chan_num, int brightness);
> +
>  	/* current setting function */
>  	void (*set_led_current) (struct lp55xx_led *led, u8 led_current);
>  
> @@ -159,6 +166,7 @@ struct lp55xx_chip {
>   * struct lp55xx_led
>   * @chan_nr         : Channel number
>   * @cdev            : LED class device
> + * @mc_cdev	    : Multi color class device
>   * @led_current     : Current setting at each led channel
>   * @max_current     : Maximun current at each led channel
>   * @brightness      : Brightness value

Documentation for channel_color and grouped_channels is missing.

> @@ -167,9 +175,12 @@ struct lp55xx_chip {
>  struct lp55xx_led {
>  	int chan_nr;
>  	struct led_classdev cdev;
> +	struct led_classdev_mc mc_cdev;
>  	u8 led_current;
>  	u8 max_current;
>  	u8 brightness;
> +	int channel_color[LP55XX_MAX_GROUPED_CHAN];
> +	int grouped_channels[LP55XX_MAX_GROUPED_CHAN];

I propose to create structure:

struct lp55xx_mc_cluster {
	int channel_color;
	int channel_id;
};

and instead of the above two arrays create one

struct lp55xx_mc_cluster mc_cluster[LP55XX_MAX_GROUPED_CHAN];

>  	struct lp55xx_chip *chip;
>  };
>  
> diff --git a/include/linux/platform_data/leds-lp55xx.h b/include/linux/platform_data/leds-lp55xx.h
> index 96a787100fda..0ac29f537ab6 100644
> --- a/include/linux/platform_data/leds-lp55xx.h
> +++ b/include/linux/platform_data/leds-lp55xx.h
> @@ -12,6 +12,8 @@
>  #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
> @@ -23,6 +25,10 @@ struct lp55xx_led_config {
>  	u8 chan_nr;
>  	u8 led_current; /* mA x10, 0 if led is not connected */
>  	u8 max_current;
> +	int num_colors;
> +	unsigned long available_colors;
> +	u32 channel_color[LED_COLOR_ID_MAX];

channel_color array is redundant if you have available_colors flags.

> +	int grouped_channels[LED_COLOR_ID_MAX];
>  };
>  
>  struct lp55xx_predef_pattern {
> 

-- 
Best regards,
Jacek Anaszewski

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