Re: [PATCH v8 9/9] leds: Update the lp55xx to use the multi color framework

Jacek Anaszewski
2019-09-21T18:06:27Z

Dan,

On 9/20/19 7:41 PM, Dan Murphy wrote:
> Update the lp5523 to use the multi color framework.
>
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
> drivers/leds/leds-lp5523.c | 13 +++
> drivers/leds/leds-lp55xx-common.c | 131 ++++++++++++++++++----
> drivers/leds/leds-lp55xx-common.h | 9 ++
> include/linux/platform_data/leds-lp55xx.h | 6 +
> 4 files changed, 137 insertions(+), 22 deletions(-)
>
> 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)
> +{
> + 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..a5efe2407832 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 adj_value[LED_COLOR_ID_MAX];

This looks suboptimal. This array should have only the number
of elements equal to the number of requested colors.

> + int ret;
> + int i;
> +
> + if (led->mc_cdev.num_leds > 1) {
> + led_mc_calc_brightness(&led->mc_cdev,
> + brightness, adj_value);

I still feel uncomfortable with the name of the third
argument for led_mc_calc_brightness().

In the function definition I proposed brightness_val instead of
adj_value, but this is not too informative either.
How about brightness_dimmed ? If you agree then let's change it
also in the definition. Also the type should be enum led_brightness.

Here we would have the following call:

led_mc_calc_brightness(&led->mc_cdev, brightness, brightness_dimmed);

> + for (i = 0; i < led->mc_cdev.num_leds; i++) {
> + led->brightness = adj_value[i];
> + ret = cfg->color_intensity_fn(led,
> + led->grouped_channels[i]);
> + if (ret)
> + break;
> + }
> + } else {
> + led->brightness = (u8)brightness;
> + ret = cfg->brightness_fn(led);
> + }
>
> - led->brightness = (u8)brightness;
> - return cfg->brightness_fn(led);
> + return ret;
> }
>
> static int lp55xx_init_led(struct lp55xx_led *led,
> @@ -147,9 +164,9 @@ 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 +176,35 @@ 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 +212,11 @@ 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 +501,6 @@ 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 +572,38 @@ void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
> }
> EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
>
> +static int lp5xx_parse_channel_child(struct device_node *np,
> + struct lp55xx_led_config *cfg,
> + int chan_num)
> +{
> + struct device_node *child;
> + int num_colors = 0;
> + u32 color_id;
> + u32 led_number;
> + int ret;
> +
> + cfg[chan_num].default_trigger =
> + of_get_property(np, "linux,default-trigger", NULL);
> +
> + for_each_child_of_node(np, child) {
> + of_property_read_string(child, "chan-name",
> + &cfg[chan_num].name);
> + of_property_read_u8(child, "led-cur",
> + &cfg[chan_num].led_current);
> + of_property_read_u8(child, "max-cur",
> + &cfg[chan_num].max_current);
> + of_property_read_u32(child, "color", &color_id);
> + cfg[chan_num].channel_color[num_colors] = color_id;
> + set_bit(color_id, &cfg[chan_num].available_colors);
> + ret = of_property_read_u32(child, "reg", &led_number);
> + cfg[chan_num].grouped_channels[num_colors] = led_number;
> + num_colors++;

We have similar parser snippet below in lp55xx_of_populate_pdata().
Why this duplication is needed? We also need an update to DT bindings.
Now I don't know what's the multicolor DT design for this driver
family.

> + }
> + cfg[chan_num].num_colors = num_colors;
> +
> + return 0;
> +}
> +
> struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
> struct device_node *np)
> {
> @@ -545,7 +611,10 @@ struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
> struct lp55xx_platform_data *pdata;
> struct lp55xx_led_config *cfg;
> int num_channels;
> + int channel_color;
> + u32 led_number;
> int i = 0;
> + int ret;
>
> pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> if (!pdata)
> @@ -565,13 +634,31 @@ 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;
> + ret = of_property_read_u32(child, "color", &channel_color);
> + if (ret) {
> + dev_err(dev,"Missing color property setting white\n");
> + channel_color = LED_COLOR_ID_WHITE;
> + }
>
> - 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);
> + if (channel_color == LED_COLOR_ID_MULTI)
> + lp5xx_parse_channel_child(child, cfg, i);
> + else {
> + 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);
> + of_property_read_u32(child, "reg", &led_number);
> +
> + if (led_number < 0 || led_number > 6)
> + return ERR_PTR(EINVAL);
> +
> + cfg[i].chan_nr = led_number;
> + }
>
> i++;
> }
> diff --git a/drivers/leds/leds-lp55xx-common.h b/drivers/leds/leds-lp55xx-common.h
> index 783ed5103ce5..d9c114259dcb 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);
>
> + /* access specific brightness register */
> + int (*color_intensity_fn)(struct lp55xx_led *led, int chan_num);
> +
> /* current setting function */
> void (*set_led_current) (struct lp55xx_led *led, u8 led_current);
>
> @@ -159,6 +164,7 @@ 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
> @@ -167,9 +173,12 @@ 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[LED_COLOR_ID_MAX];
> + int grouped_channels[LED_COLOR_ID_MAX];
> 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];
> + int grouped_channels[LED_COLOR_ID_MAX];

We can do with three-element arrays here.

> };
>
> struct lp55xx_predef_pattern {
>

--
Best regards,
Jacek Anaszewski