From: Sven Schwermer <sven.schwermer@xxxxxxxxxxxxxxxxxxxxxxxxxxx> By allowing to group multiple monochrome PWM LEDs into multicolor LEDs, all involved LEDs can be controlled in-sync. This enables using effects using triggers, etc. Signed-off-by: Sven Schwermer <sven.schwermer@xxxxxxxxxxxxxxxxxxxxxxxxxxx> --- drivers/leds/Kconfig | 8 ++ drivers/leds/Makefile | 1 + drivers/leds/leds-pwm-multicolor.c | 184 +++++++++++++++++++++++++++++ 3 files changed, 193 insertions(+) create mode 100644 drivers/leds/leds-pwm-multicolor.c diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index b6742b4231bf..2e5058696fa6 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -586,6 +586,14 @@ config LEDS_PWM help This option enables support for pwm driven LEDs +config LEDS_PWM_MULTICOLOR + tristate "PWM driven multi-color LED Support" + depends on LEDS_CLASS_MULTICOLOR + depends on PWM + help + This option enables support for PWM driven monochrome LEDs that are + grouped into multicolor LEDs. + config LEDS_REGULATOR tristate "REGULATOR driven LED support" depends on LEDS_CLASS diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index 2a698df9da57..152f69374632 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -79,6 +79,7 @@ obj-$(CONFIG_LEDS_PCA963X) += leds-pca963x.o obj-$(CONFIG_LEDS_PM8058) += leds-pm8058.o obj-$(CONFIG_LEDS_POWERNV) += leds-powernv.o obj-$(CONFIG_LEDS_PWM) += leds-pwm.o +obj-$(CONFIG_LEDS_PWM_MULTICOLOR) += leds-pwm-multicolor.o obj-$(CONFIG_LEDS_REGULATOR) += leds-regulator.o obj-$(CONFIG_LEDS_S3C24XX) += leds-s3c24xx.o obj-$(CONFIG_LEDS_SC27XX_BLTC) += leds-sc27xx-bltc.o diff --git a/drivers/leds/leds-pwm-multicolor.c b/drivers/leds/leds-pwm-multicolor.c new file mode 100644 index 000000000000..c54bed4536d3 --- /dev/null +++ b/drivers/leds/leds-pwm-multicolor.c @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * PWM-based multi-color LED control + * + * Copyright 2022 Sven Schwermer <sven.schwermer@xxxxxxxxxxxxxxxxxxxxxxxxxxx> + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/led-class-multicolor.h> +#include <linux/leds.h> +#include <linux/err.h> +#include <linux/pwm.h> +#include <linux/mutex.h> + +struct pwm_led { + struct pwm_device *pwm; + struct pwm_state pwmstate; +}; + +struct pwm_mc_led { + struct led_classdev_mc mc_cdev; + struct mutex lock; + struct pwm_led leds[]; +}; + +static int led_pwm_mc_set(struct led_classdev *cdev, + enum led_brightness brightness) +{ + int i; + unsigned long long duty; + int ret = 0; + struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev); + struct pwm_mc_led *priv = container_of(mc_cdev, struct pwm_mc_led, mc_cdev); + + led_mc_calc_color_components(mc_cdev, brightness); + + mutex_lock(&priv->lock); + + for (i = 0; i < mc_cdev->num_colors; ++i) { + duty = priv->leds[i].pwmstate.period; + duty *= mc_cdev->subled_info[i].brightness; + do_div(duty, cdev->max_brightness); + + priv->leds[i].pwmstate.duty_cycle = duty; + priv->leds[i].pwmstate.enabled = duty > 0; + ret = pwm_apply_state(priv->leds[i].pwm, + &priv->leds[i].pwmstate); + if (ret) + break; + } + + mutex_unlock(&priv->lock); + + return ret; +} + +static int led_pwm_mc_probe(struct platform_device *pdev) +{ + struct fwnode_handle *mcnode, *fwnode; + int count = 0; + struct pwm_mc_led *priv; + struct mc_subled *subled; + struct led_classdev *cdev; + struct pwm_led *pwmled; + u32 color; + int ret = 0; + struct led_init_data init_data = {}; + + mcnode = device_get_named_child_node(&pdev->dev, "multi-led"); + if (!mcnode) { + dev_err(&pdev->dev, "expected multi-led node\n"); + ret = -ENODEV; + goto out; + } + + /* count the nodes inside the multi-led node */ + fwnode_for_each_child_node(mcnode, fwnode) + ++count; + + priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, count), + GFP_KERNEL); + if (!priv) { + ret = -ENOMEM; + goto out; + } + mutex_init(&priv->lock); + + subled = devm_kcalloc(&pdev->dev, count, sizeof(*subled), GFP_KERNEL); + if (!subled) { + ret = -ENOMEM; + goto destroy_mutex; + } + priv->mc_cdev.subled_info = subled; + + /* init the multicolor's LED class device */ + cdev = &priv->mc_cdev.led_cdev; + fwnode_property_read_string(mcnode, "label", &cdev->name); + cdev->brightness = LED_OFF; + fwnode_property_read_u32(mcnode, "max-brightness", + &cdev->max_brightness); + cdev->flags = LED_CORE_SUSPENDRESUME; + cdev->brightness_set_blocking = led_pwm_mc_set; + + /* iterate over the nodes inside the multi-led node */ + fwnode_for_each_child_node(mcnode, fwnode) { + pwmled = &priv->leds[priv->mc_cdev.num_colors]; + pwmled->pwm = devm_fwnode_pwm_get(&pdev->dev, fwnode, NULL); + if (IS_ERR(pwmled->pwm)) { + ret = PTR_ERR(pwmled->pwm); + dev_err(&pdev->dev, "unable to request PWM: %d\n", ret); + goto destroy_mutex; + } + pwm_init_state(pwmled->pwm, &pwmled->pwmstate); + + ret = fwnode_property_read_u32(fwnode, "color", &color); + if (ret) { + dev_err(&pdev->dev, "cannot read color: %d\n", ret); + goto destroy_mutex; + } + + subled[priv->mc_cdev.num_colors].color_index = color; + subled[priv->mc_cdev.num_colors].channel = + priv->mc_cdev.num_colors; + ++priv->mc_cdev.num_colors; + } + + init_data.fwnode = mcnode; + ret = devm_led_classdev_multicolor_register_ext(&pdev->dev, + &priv->mc_cdev, + &init_data); + if (ret) { + dev_err(&pdev->dev, + "failed to register multicolor PWM led for %s: %d\n", + cdev->name, ret); + goto destroy_mutex; + } + + ret = led_pwm_mc_set(cdev, cdev->brightness); + if (ret) { + dev_err(&pdev->dev, "failed to set led PWM value for %s: %d", + cdev->name, ret); + goto destroy_mutex; + } + + platform_set_drvdata(pdev, priv); + return 0; + +destroy_mutex: + mutex_destroy(&priv->lock); +out: + return ret; +} + +static int led_pwm_mc_remove(struct platform_device *pdev) +{ + struct pwm_mc_led *priv = platform_get_drvdata(pdev); + + mutex_destroy(&priv->lock); + return 0; +} + +static const struct of_device_id of_pwm_leds_mc_match[] = { + { .compatible = "pwm-leds-multicolor", }, + {}, +}; +MODULE_DEVICE_TABLE(of, of_pwm_leds_mc_match); + +static struct platform_driver led_pwm_mc_driver = { + .probe = led_pwm_mc_probe, + .remove = led_pwm_mc_remove, + .driver = { + .name = "leds_pwm_multicolor", + .of_match_table = of_pwm_leds_mc_match, + }, +}; + +module_platform_driver(led_pwm_mc_driver); + +MODULE_AUTHOR("Sven Schwermer <sven.schwermer@xxxxxxxxxxxxxxxxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("multi-color PWM LED driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:leds-pwm-multicolor"); -- 2.35.0