1 /* 2 * LED Class Core 3 * 4 * Copyright 2005-2006 Openedhand Ltd. 5 * 6 * Author: Richard Purdie <rpurdie@openedhand.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/list.h> 16 #include <linux/module.h> 17 #include <linux/rwsem.h> 18 #include <linux/leds.h> 19 #include "leds.h" 20 21 DECLARE_RWSEM(leds_list_lock); 22 EXPORT_SYMBOL_GPL(leds_list_lock); 23 24 LIST_HEAD(leds_list); 25 EXPORT_SYMBOL_GPL(leds_list); 26 27 static void led_stop_software_blink(struct led_classdev *led_cdev) 28 { 29 /* deactivate previous settings */ 30 del_timer_sync(&led_cdev->blink_timer); 31 led_cdev->blink_delay_on = 0; 32 led_cdev->blink_delay_off = 0; 33 } 34 35 static void led_set_software_blink(struct led_classdev *led_cdev, 36 unsigned long delay_on, 37 unsigned long delay_off) 38 { 39 int current_brightness; 40 41 current_brightness = led_get_brightness(led_cdev); 42 if (current_brightness) 43 led_cdev->blink_brightness = current_brightness; 44 if (!led_cdev->blink_brightness) 45 led_cdev->blink_brightness = led_cdev->max_brightness; 46 47 led_cdev->blink_delay_on = delay_on; 48 led_cdev->blink_delay_off = delay_off; 49 50 /* never on - don't blink */ 51 if (!delay_on) 52 return; 53 54 /* never off - just set to brightness */ 55 if (!delay_off) { 56 led_set_brightness(led_cdev, led_cdev->blink_brightness); 57 return; 58 } 59 60 mod_timer(&led_cdev->blink_timer, jiffies + 1); 61 } 62 63 64 void led_blink_set(struct led_classdev *led_cdev, 65 unsigned long *delay_on, 66 unsigned long *delay_off) 67 { 68 del_timer_sync(&led_cdev->blink_timer); 69 70 if (led_cdev->blink_set && 71 !led_cdev->blink_set(led_cdev, delay_on, delay_off)) 72 return; 73 74 /* blink with 1 Hz as default if nothing specified */ 75 if (!*delay_on && !*delay_off) 76 *delay_on = *delay_off = 500; 77 78 led_set_software_blink(led_cdev, *delay_on, *delay_off); 79 } 80 EXPORT_SYMBOL(led_blink_set); 81 82 void led_brightness_set(struct led_classdev *led_cdev, 83 enum led_brightness brightness) 84 { 85 led_stop_software_blink(led_cdev); 86 led_cdev->brightness_set(led_cdev, brightness); 87 } 88 EXPORT_SYMBOL(led_brightness_set); 89