diff options
Diffstat (limited to 'drivers/leds/leds-pwm.c')
| -rw-r--r-- | drivers/leds/leds-pwm.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c new file mode 100644 index 000000000000..fe2477e777e2 --- /dev/null +++ b/drivers/leds/leds-pwm.c @@ -0,0 +1,189 @@ +/* + * drivers/leds/leds-pwm.c + * + * Copyright (C) 2009 by Digi International Inc. + * All rights reserved. + * + * Code rebased on original leds-pwm.c from Bill Gatliff + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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/kernel.h> +#include <linux/platform_device.h> +#include <linux/leds.h> +#include <linux/io.h> +#include <linux/pwm.h> +#include <linux/pwm-led.h> +#include <linux/err.h> +#include <linux/delay.h> + + +struct led_pwm { + struct led_classdev led; + struct pwm_channel *pwm; + unsigned long period; +}; + +static void +led_pwm_brightness_set(struct led_classdev *c, + enum led_brightness b) +{ + struct led_pwm *led; + unsigned long period; + + period = 1000000000UL; + led = container_of(c, struct led_pwm, led); + led->period = period; + pwm_set_period_ns(led->pwm, period); +} + + +static enum led_brightness +led_pwm_brightness_get(struct led_classdev *c) +{ + struct led_pwm *led; + led = container_of(c, struct led_pwm, led); + return led->period; +} + +static int +led_pwm_blink_set(struct led_classdev *c, + unsigned long *on_ms, + unsigned long *off_ms) +{ + struct led_pwm *led; + struct pwm_channel_config cfg; + + led = container_of(c, struct led_pwm, led); + + 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 * 1000000000UL; + cfg.period_ns = (*on_ms + *off_ms) * 1000000000UL; + + return pwm_config(led->pwm, &cfg); +} + + +static int __init +led_pwm_probe(struct platform_device *pdev) +{ + struct pwm_led_platform_data *pdata = pdev->dev.platform_data; + struct led_pwm *led; + int ret; + + if (!pdata || !pdata->led_info) { + return -EINVAL; + } + + led = kzalloc(sizeof(*led), GFP_KERNEL); + if (!led) + return -ENOMEM; + + 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, led); + + 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; + + 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; + + 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 +led_pwm_remove(struct platform_device *pdev) +{ + struct led_pwm *led = platform_get_drvdata(pdev); + + led_classdev_unregister(&led->led); + + if (led->pwm) { + pwm_stop(led->pwm); + pwm_free(led->pwm); + } + + kfree(led); + platform_set_drvdata(pdev, NULL); + + return 0; +} + + +static struct platform_driver led_pwm_driver = { + .driver = { + .name = "leds-pwm", + .owner = THIS_MODULE, + }, + .probe = led_pwm_probe, + .remove = led_pwm_remove, +}; + + +static int __init led_pwm_modinit(void) +{ + return platform_driver_register(&led_pwm_driver); +} +late_initcall(led_pwm_modinit); + + +static void __exit led_pwm_modexit(void) +{ + platform_driver_unregister(&led_pwm_driver); +} +module_exit(led_pwm_modexit); + + +MODULE_AUTHOR("Hector Oron <Hector.Oron <at> digi.com>"); +MODULE_DESCRIPTION("Driver for LEDs with PWM-controlled brightness"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:leds-pwm"); + |