/* * linux/drivers/leds-pwm.c * * simple PWM based LED control * * Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de) * * based on leds-gpio.c by Raphael Assenat <raph@8d.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/platform_device.h> #include <linux/fb.h> #include <linux/leds.h> #include <linux/err.h> #include <linux/pwm.h> #include <linux/leds_pwm.h> struct led_pwm_data { struct led_classdev cdev; struct pwm_device *pwm; unsigned int active_low; unsigned int period; unsigned int max_brightness; }; static void led_pwm_set(struct led_classdev *led_cdev, enum led_brightness brightness) { struct led_pwm_data *led_dat = container_of(led_cdev, struct led_pwm_data, cdev); unsigned int max = led_dat->max_brightness; unsigned int period = led_dat->period; if (brightness == 0) { pwm_config(led_dat->pwm, 0, period); pwm_disable(led_dat->pwm); } else { pwm_config(led_dat->pwm, brightness * period / max, period); pwm_enable(led_dat->pwm); } } static int led_pwm_probe(struct platform_device *pdev) { struct led_pwm_platform_data *pdata = pdev->dev.platform_data; struct led_pwm *cur_led; struct led_pwm_data *leds_data, *led_dat; int i, ret = 0; if (!pdata) return -EBUSY; leds_data = kzalloc(sizeof(struct led_pwm_data) * pdata->num_leds, GFP_KERNEL); if (!leds_data) return -ENOMEM; for (i = 0; i < pdata->num_leds; i++) { cur_led = &pdata->leds[i]; led_dat = &leds_data[i]; led_dat->pwm = pwm_request(cur_led->pwm_id, cur_led->name); if (IS_ERR(led_dat->pwm)) { dev_err(&pdev->dev, "unable to request PWM %d\n", cur_led->pwm_id); goto err; } led_dat->cdev.name = cur_led->name; led_dat->cdev.default_trigger = cur_led->default_trigger; led_dat->active_low = cur_led->active_low; led_dat->max_brightness = cur_led->max_brightness; led_dat->period = cur_led->pwm_period_ns; led_dat->cdev.brightness_set = led_pwm_set; led_dat->cdev.brightness = LED_OFF; led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; ret = led_classdev_register(&pdev->dev, &led_dat->cdev); if (ret < 0) { pwm_free(led_dat->pwm); goto err; } } platform_set_drvdata(pdev, leds_data); return 0; err: if (i > 0) { for (i = i - 1; i >= 0; i--) { led_classdev_unregister(&leds_data[i].cdev); pwm_free(leds_data[i].pwm); } } kfree(leds_data); return ret; } static int __devexit led_pwm_remove(struct platform_device *pdev) { int i; struct led_pwm_platform_data *pdata = pdev->dev.platform_data; struct led_pwm_data *leds_data; leds_data = platform_get_drvdata(pdev); for (i = 0; i < pdata->num_leds; i++) { led_classdev_unregister(&leds_data[i].cdev); pwm_free(leds_data[i].pwm); } kfree(leds_data); return 0; } static struct platform_driver led_pwm_driver = { .probe = led_pwm_probe, .remove = __devexit_p(led_pwm_remove), .driver = { .name = "leds_pwm", .owner = THIS_MODULE, }, }; static int __init led_pwm_init(void) { return platform_driver_register(&led_pwm_driver); } static void __exit led_pwm_exit(void) { platform_driver_unregister(&led_pwm_driver); } module_init(led_pwm_init); module_exit(led_pwm_exit); MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); MODULE_DESCRIPTION("PWM LED driver for PXA"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:leds-pwm");