[PWM PATCH 4/7] Implements PWM-based LED control
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From: Bill Gatliff on 9 Feb 2010 15:50 Signed-off-by: Bill Gatliff <bgat(a)billgatliff.com> --- drivers/leds/leds-pwm.c | 224 ++++++++++++++++++++++++------------------- include/linux/pwm/pwm-led.h | 33 +++++++ 2 files changed, 157 insertions(+), 100 deletions(-) create mode 100644 include/linux/pwm/pwm-led.h diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index 88b1dd0..7877af8 100644 --- a/drivers/leds/leds-pwm.c +++ b/drivers/leds/leds-pwm.c @@ -1,152 +1,176 @@ /* - * linux/drivers/leds-pwm.c + * drivers/leds/leds-pwm.c * - * simple PWM based LED control + * Copyright (C) 2010 Bill Gatliff <bgat(a)billgatliff.com> + * Copyright (C) 2009 Loutao Fu, Pengutronix <l.fu(a)pengutronix.de> * - * Copyright 2009 Luotao Fu @ Pengutronix (l.fu(a)pengutronix.de) + * Based on leds-gpio.c by Raphael Assenat <raph(a)8d.com> * - * based on leds-gpio.c by Raphael Assenat <raph(a)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 + * This program is Free Software. You may redistribute and/or modify + * it under the terms of the GNU General Public License version 2, as * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + * USA */ - -#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; +#include <linux/io.h> +#include <linux/pwm/pwm.h> +#include <linux/pwm/pwm-led.h> + +struct led_pwm { + struct led_classdev led; + struct pwm_channel *pwm; + int percent; }; -static void led_pwm_set(struct led_classdev *led_cdev, - enum led_brightness brightness) +static inline struct led_pwm *to_led_pwm(const struct led_classdev *c) +{ + return container_of(c, struct led_pwm, led); +} + +static void +led_pwm_brightness_set(struct led_classdev *c, + enum led_brightness b) +{ + struct led_pwm *led = to_led_pwm(c); + int percent; + + percent = (b * 100) / (LED_FULL - LED_OFF); + led->percent = percent; + pwm_set_duty_percent(led->pwm, percent); +} + +static enum led_brightness +led_pwm_brightness_get(struct led_classdev *c) +{ + struct led_pwm *led = to_led_pwm(c); + return led->percent; +} + +static int +led_pwm_blink_set(struct led_classdev *c, + unsigned long *on_ms, + unsigned long *off_ms) { - struct led_pwm_data *led_dat = - container_of(led_cdev, struct led_pwm_data, cdev); - unsigned int max = led_dat->cdev.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); + struct led_pwm *led = to_led_pwm(c); + struct pwm_channel_config cfg; + + if (*on_ms == 0 && *off_ms == 0) { + *on_ms = 1000UL; + *off_ms = 1000UL; } + + cfg.config_mask = PWM_CONFIG_DUTY_NS + | PWM_CONFIG_PERIOD_NS; + + cfg.duty_ns = *on_ms * 1000000UL; + cfg.period_ns = (*on_ms + *off_ms) * 1000000UL; + + return pwm_config(led->pwm, &cfg); } -static int led_pwm_probe(struct platform_device *pdev) +static int __devinit +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; + struct pwm_led_platform_data *pdata = pdev->dev.platform_data; + struct led_pwm *led; + struct device *d = &pdev->dev; + int ret; - if (!pdata) - return -EBUSY; + if (!pdata || !pdata->led_info) + return -EINVAL; - leds_data = kzalloc(sizeof(struct led_pwm_data) * pdata->num_leds, - GFP_KERNEL); - if (!leds_data) + led = kzalloc(sizeof(*led), GFP_KERNEL); + if (!led) 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->period = cur_led->pwm_period_ns; - led_dat->cdev.brightness_set = led_pwm_set; - led_dat->cdev.brightness = LED_OFF; - led_dat->cdev.max_brightness = cur_led->max_brightness; - 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; - } + led->pwm = pwm_request(pdata->bus_id, pdata->chan, + pdata->led_info->name); + if (!led->pwm) { + ret = -EINVAL; + goto err_pwm_request; } - platform_set_drvdata(pdev, leds_data); + platform_set_drvdata(pdev, led); - return 0; + led->led.name = pdata->led_info->name; + led->led.default_trigger = pdata->led_info->default_trigger; + led->led.brightness_set = led_pwm_brightness_set; + led->led.brightness_get = led_pwm_brightness_get; + led->led.blink_set = led_pwm_blink_set; + led->led.brightness = LED_OFF; -err: - if (i > 0) { - for (i = i - 1; i >= 0; i--) { - led_classdev_unregister(&leds_data[i].cdev); - pwm_free(leds_data[i].pwm); - } - } + ret = pwm_config(led->pwm, pdata->config); + if (ret) + goto err_pwm_config; + pwm_start(led->pwm); + + ret = led_classdev_register(&pdev->dev, &led->led); + if (ret < 0) + goto err_classdev_register; - kfree(leds_data); + return 0; + +err_classdev_register: + pwm_stop(led->pwm); +err_pwm_config: + pwm_free(led->pwm); +err_pwm_request: + kfree(led); return ret; } -static int __devexit led_pwm_remove(struct platform_device *pdev) +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; + struct led_pwm *led = platform_get_drvdata(pdev); + struct device *d = &pdev->dev; - leds_data = platform_get_drvdata(pdev); + led_classdev_unregister(&led->led); - for (i = 0; i < pdata->num_leds; i++) { - led_classdev_unregister(&leds_data[i].cdev); - pwm_free(leds_data[i].pwm); + if (led->pwm) { + pwm_stop(led->pwm); + pwm_free(led->pwm); } - kfree(leds_data); + kfree(led); 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, + .driver = { + .name = "leds-pwm", + .owner = THIS_MODULE, }, + .probe = led_pwm_probe, + .remove = led_pwm_remove, }; -static int __init led_pwm_init(void) +static int __init led_pwm_modinit(void) { return platform_driver_register(&led_pwm_driver); } +module_init(led_pwm_modinit); -static void __exit led_pwm_exit(void) +static void __exit led_pwm_modexit(void) { platform_driver_unregister(&led_pwm_driver); } +module_exit(led_pwm_modexit); -module_init(led_pwm_init); -module_exit(led_pwm_exit); - -MODULE_AUTHOR("Luotao Fu <l.fu(a)pengutronix.de>"); -MODULE_DESCRIPTION("PWM LED driver for PXA"); +MODULE_AUTHOR("Bill Gatliff <bgat(a)billgatliff.com>"); +MODULE_DESCRIPTION("Driver for LEDs with PWM-controlled brightness"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:leds-pwm"); diff --git a/include/linux/pwm/pwm-led.h b/include/linux/pwm/pwm-led.h new file mode 100644 index 0000000..8ffeecc --- /dev/null +++ b/include/linux/pwm/pwm-led.h @@ -0,0 +1,33 @@ +/* + * include/linux/pwm-led.h + * + * Copyright (C) 2008 Bill Gatliff <bgat(a)billgatliff.com> + * + * This program is free software; you may redistribute and/or modify + * it under the terms of the GNU General Public License version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + * USA + */ +#ifndef __LINUX_PWM_LED_H +#define __LINUX_PWM_LED_H + +struct led_info; +struct pwm_channel_config; + +struct pwm_led_platform_data { + const char *bus_id; + int chan; + struct pwm_channel_config *config; + struct led_info *led_info; +}; + +#endif /* __LINUX_PWM_LED_H */ -- 1.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |