1c72a1d60SRichard Purdie /* 2c72a1d60SRichard Purdie * LED Class Core 3c72a1d60SRichard Purdie * 4c72a1d60SRichard Purdie * Copyright 2005-2006 Openedhand Ltd. 5c72a1d60SRichard Purdie * 6c72a1d60SRichard Purdie * Author: Richard Purdie <rpurdie@openedhand.com> 7c72a1d60SRichard Purdie * 8c72a1d60SRichard Purdie * This program is free software; you can redistribute it and/or modify 9c72a1d60SRichard Purdie * it under the terms of the GNU General Public License version 2 as 10c72a1d60SRichard Purdie * published by the Free Software Foundation. 11c72a1d60SRichard Purdie * 12c72a1d60SRichard Purdie */ 13c72a1d60SRichard Purdie 14c72a1d60SRichard Purdie #include <linux/kernel.h> 1504713306SJacek Anaszewski #include <linux/leds.h> 16c72a1d60SRichard Purdie #include <linux/list.h> 17c72a1d60SRichard Purdie #include <linux/module.h> 1804713306SJacek Anaszewski #include <linux/mutex.h> 1972f8da32SRichard Purdie #include <linux/rwsem.h> 20c72a1d60SRichard Purdie #include "leds.h" 21c72a1d60SRichard Purdie 2272f8da32SRichard Purdie DECLARE_RWSEM(leds_list_lock); 23c72a1d60SRichard Purdie EXPORT_SYMBOL_GPL(leds_list_lock); 244d404fd5SNémeth Márton 254d404fd5SNémeth Márton LIST_HEAD(leds_list); 264d404fd5SNémeth Márton EXPORT_SYMBOL_GPL(leds_list); 27a403d930SBryan Wu 28757b06aeSJacek Anaszewski static void led_timer_function(unsigned long data) 29757b06aeSJacek Anaszewski { 30757b06aeSJacek Anaszewski struct led_classdev *led_cdev = (void *)data; 31757b06aeSJacek Anaszewski unsigned long brightness; 32757b06aeSJacek Anaszewski unsigned long delay; 33757b06aeSJacek Anaszewski 34757b06aeSJacek Anaszewski if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) { 3581fe8e5bSJacek Anaszewski led_set_brightness_nosleep(led_cdev, LED_OFF); 36757b06aeSJacek Anaszewski return; 37757b06aeSJacek Anaszewski } 38757b06aeSJacek Anaszewski 39757b06aeSJacek Anaszewski if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) { 40757b06aeSJacek Anaszewski led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP; 41757b06aeSJacek Anaszewski return; 42757b06aeSJacek Anaszewski } 43757b06aeSJacek Anaszewski 44757b06aeSJacek Anaszewski brightness = led_get_brightness(led_cdev); 45757b06aeSJacek Anaszewski if (!brightness) { 46757b06aeSJacek Anaszewski /* Time to switch the LED on. */ 47757b06aeSJacek Anaszewski brightness = led_cdev->blink_brightness; 48757b06aeSJacek Anaszewski delay = led_cdev->blink_delay_on; 49757b06aeSJacek Anaszewski } else { 50757b06aeSJacek Anaszewski /* Store the current brightness value to be able 51757b06aeSJacek Anaszewski * to restore it when the delay_off period is over. 52f1e80c07SJacek Anaszewski * Do it only if there is no pending blink brightness 53f1e80c07SJacek Anaszewski * change, to avoid overwriting the new value. 54757b06aeSJacek Anaszewski */ 55f1e80c07SJacek Anaszewski if (!(led_cdev->flags & LED_BLINK_BRIGHTNESS_CHANGE)) 56757b06aeSJacek Anaszewski led_cdev->blink_brightness = brightness; 57f1e80c07SJacek Anaszewski else 58f1e80c07SJacek Anaszewski led_cdev->flags &= ~LED_BLINK_BRIGHTNESS_CHANGE; 59757b06aeSJacek Anaszewski brightness = LED_OFF; 60757b06aeSJacek Anaszewski delay = led_cdev->blink_delay_off; 61757b06aeSJacek Anaszewski } 62757b06aeSJacek Anaszewski 6381fe8e5bSJacek Anaszewski led_set_brightness_nosleep(led_cdev, brightness); 64757b06aeSJacek Anaszewski 65757b06aeSJacek Anaszewski /* Return in next iteration if led is in one-shot mode and we are in 66757b06aeSJacek Anaszewski * the final blink state so that the led is toggled each delay_on + 67757b06aeSJacek Anaszewski * delay_off milliseconds in worst case. 68757b06aeSJacek Anaszewski */ 69757b06aeSJacek Anaszewski if (led_cdev->flags & LED_BLINK_ONESHOT) { 70757b06aeSJacek Anaszewski if (led_cdev->flags & LED_BLINK_INVERT) { 71757b06aeSJacek Anaszewski if (brightness) 72757b06aeSJacek Anaszewski led_cdev->flags |= LED_BLINK_ONESHOT_STOP; 73757b06aeSJacek Anaszewski } else { 74757b06aeSJacek Anaszewski if (!brightness) 75757b06aeSJacek Anaszewski led_cdev->flags |= LED_BLINK_ONESHOT_STOP; 76757b06aeSJacek Anaszewski } 77757b06aeSJacek Anaszewski } 78757b06aeSJacek Anaszewski 79757b06aeSJacek Anaszewski mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay)); 80757b06aeSJacek Anaszewski } 81757b06aeSJacek Anaszewski 82757b06aeSJacek Anaszewski static void set_brightness_delayed(struct work_struct *ws) 83757b06aeSJacek Anaszewski { 84757b06aeSJacek Anaszewski struct led_classdev *led_cdev = 85757b06aeSJacek Anaszewski container_of(ws, struct led_classdev, set_brightness_work); 86*1afcadfcSJacek Anaszewski int ret = 0; 87757b06aeSJacek Anaszewski 88f1e80c07SJacek Anaszewski if (led_cdev->flags & LED_BLINK_DISABLE) { 89f1e80c07SJacek Anaszewski led_cdev->delayed_set_value = LED_OFF; 90757b06aeSJacek Anaszewski led_stop_software_blink(led_cdev); 91f1e80c07SJacek Anaszewski led_cdev->flags &= ~LED_BLINK_DISABLE; 92f1e80c07SJacek Anaszewski } 93757b06aeSJacek Anaszewski 94*1afcadfcSJacek Anaszewski if (led_cdev->brightness_set) 95*1afcadfcSJacek Anaszewski led_cdev->brightness_set(led_cdev, led_cdev->delayed_set_value); 96*1afcadfcSJacek Anaszewski else if (led_cdev->brightness_set_blocking) 97*1afcadfcSJacek Anaszewski ret = led_cdev->brightness_set_blocking(led_cdev, 98*1afcadfcSJacek Anaszewski led_cdev->delayed_set_value); 99*1afcadfcSJacek Anaszewski else 100*1afcadfcSJacek Anaszewski ret = -ENOTSUPP; 101*1afcadfcSJacek Anaszewski if (ret < 0) 102*1afcadfcSJacek Anaszewski dev_err(led_cdev->dev, 103*1afcadfcSJacek Anaszewski "Setting an LED's brightness failed (%d)\n", ret); 104757b06aeSJacek Anaszewski } 105757b06aeSJacek Anaszewski 106a403d930SBryan Wu static void led_set_software_blink(struct led_classdev *led_cdev, 107a403d930SBryan Wu unsigned long delay_on, 108a403d930SBryan Wu unsigned long delay_off) 109a403d930SBryan Wu { 110a403d930SBryan Wu int current_brightness; 111a403d930SBryan Wu 112a403d930SBryan Wu current_brightness = led_get_brightness(led_cdev); 113a403d930SBryan Wu if (current_brightness) 114a403d930SBryan Wu led_cdev->blink_brightness = current_brightness; 115a403d930SBryan Wu if (!led_cdev->blink_brightness) 116a403d930SBryan Wu led_cdev->blink_brightness = led_cdev->max_brightness; 117a403d930SBryan Wu 118a403d930SBryan Wu led_cdev->blink_delay_on = delay_on; 119a403d930SBryan Wu led_cdev->blink_delay_off = delay_off; 120a403d930SBryan Wu 1218d82fef8SStefan Sørensen /* never on - just set to off */ 1228d82fef8SStefan Sørensen if (!delay_on) { 12381fe8e5bSJacek Anaszewski led_set_brightness_nosleep(led_cdev, LED_OFF); 124a403d930SBryan Wu return; 1258d82fef8SStefan Sørensen } 126a403d930SBryan Wu 127a403d930SBryan Wu /* never off - just set to brightness */ 128a403d930SBryan Wu if (!delay_off) { 12981fe8e5bSJacek Anaszewski led_set_brightness_nosleep(led_cdev, 13081fe8e5bSJacek Anaszewski led_cdev->blink_brightness); 131a403d930SBryan Wu return; 132a403d930SBryan Wu } 133a403d930SBryan Wu 1349067359fSJiri Kosina mod_timer(&led_cdev->blink_timer, jiffies + 1); 135a403d930SBryan Wu } 136a403d930SBryan Wu 137a403d930SBryan Wu 13820c0e6b8SBryan Wu static void led_blink_setup(struct led_classdev *led_cdev, 139a403d930SBryan Wu unsigned long *delay_on, 140a403d930SBryan Wu unsigned long *delay_off) 141a403d930SBryan Wu { 1425bb629c5SFabio Baltieri if (!(led_cdev->flags & LED_BLINK_ONESHOT) && 1435bb629c5SFabio Baltieri led_cdev->blink_set && 144a403d930SBryan Wu !led_cdev->blink_set(led_cdev, delay_on, delay_off)) 145a403d930SBryan Wu return; 146a403d930SBryan Wu 147a403d930SBryan Wu /* blink with 1 Hz as default if nothing specified */ 148a403d930SBryan Wu if (!*delay_on && !*delay_off) 149a403d930SBryan Wu *delay_on = *delay_off = 500; 150a403d930SBryan Wu 151a403d930SBryan Wu led_set_software_blink(led_cdev, *delay_on, *delay_off); 152a403d930SBryan Wu } 1535bb629c5SFabio Baltieri 154757b06aeSJacek Anaszewski void led_init_core(struct led_classdev *led_cdev) 155757b06aeSJacek Anaszewski { 156757b06aeSJacek Anaszewski INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed); 157757b06aeSJacek Anaszewski 158757b06aeSJacek Anaszewski setup_timer(&led_cdev->blink_timer, led_timer_function, 159757b06aeSJacek Anaszewski (unsigned long)led_cdev); 160757b06aeSJacek Anaszewski } 161757b06aeSJacek Anaszewski EXPORT_SYMBOL_GPL(led_init_core); 162757b06aeSJacek Anaszewski 1635bb629c5SFabio Baltieri void led_blink_set(struct led_classdev *led_cdev, 1645bb629c5SFabio Baltieri unsigned long *delay_on, 1655bb629c5SFabio Baltieri unsigned long *delay_off) 1665bb629c5SFabio Baltieri { 1679067359fSJiri Kosina del_timer_sync(&led_cdev->blink_timer); 1685bb629c5SFabio Baltieri 1695bb629c5SFabio Baltieri led_cdev->flags &= ~LED_BLINK_ONESHOT; 1705bb629c5SFabio Baltieri led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP; 1715bb629c5SFabio Baltieri 1725bb629c5SFabio Baltieri led_blink_setup(led_cdev, delay_on, delay_off); 1735bb629c5SFabio Baltieri } 1742806e2ffSJacek Anaszewski EXPORT_SYMBOL_GPL(led_blink_set); 175a403d930SBryan Wu 1765bb629c5SFabio Baltieri void led_blink_set_oneshot(struct led_classdev *led_cdev, 1775bb629c5SFabio Baltieri unsigned long *delay_on, 1785bb629c5SFabio Baltieri unsigned long *delay_off, 1795bb629c5SFabio Baltieri int invert) 1805bb629c5SFabio Baltieri { 1815bb629c5SFabio Baltieri if ((led_cdev->flags & LED_BLINK_ONESHOT) && 1829067359fSJiri Kosina timer_pending(&led_cdev->blink_timer)) 1835bb629c5SFabio Baltieri return; 1845bb629c5SFabio Baltieri 1855bb629c5SFabio Baltieri led_cdev->flags |= LED_BLINK_ONESHOT; 1865bb629c5SFabio Baltieri led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP; 1875bb629c5SFabio Baltieri 1885bb629c5SFabio Baltieri if (invert) 1895bb629c5SFabio Baltieri led_cdev->flags |= LED_BLINK_INVERT; 1905bb629c5SFabio Baltieri else 1915bb629c5SFabio Baltieri led_cdev->flags &= ~LED_BLINK_INVERT; 1925bb629c5SFabio Baltieri 1935bb629c5SFabio Baltieri led_blink_setup(led_cdev, delay_on, delay_off); 1945bb629c5SFabio Baltieri } 1952806e2ffSJacek Anaszewski EXPORT_SYMBOL_GPL(led_blink_set_oneshot); 1965bb629c5SFabio Baltieri 197d23a22a7SFabio Baltieri void led_stop_software_blink(struct led_classdev *led_cdev) 198a403d930SBryan Wu { 1999067359fSJiri Kosina del_timer_sync(&led_cdev->blink_timer); 20043786482SFabio Baltieri led_cdev->blink_delay_on = 0; 20143786482SFabio Baltieri led_cdev->blink_delay_off = 0; 202d23a22a7SFabio Baltieri } 203d23a22a7SFabio Baltieri EXPORT_SYMBOL_GPL(led_stop_software_blink); 204d23a22a7SFabio Baltieri 205d23a22a7SFabio Baltieri void led_set_brightness(struct led_classdev *led_cdev, 206d23a22a7SFabio Baltieri enum led_brightness brightness) 207d23a22a7SFabio Baltieri { 2084d71a4a1SJacek Anaszewski int ret = 0; 2094d71a4a1SJacek Anaszewski 210f1e80c07SJacek Anaszewski /* 211f1e80c07SJacek Anaszewski * In case blinking is on delay brightness setting 212f1e80c07SJacek Anaszewski * until the next timer tick. 213f1e80c07SJacek Anaszewski */ 214d23a22a7SFabio Baltieri if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) { 215f1e80c07SJacek Anaszewski /* 216f1e80c07SJacek Anaszewski * If we need to disable soft blinking delegate this to the 217f1e80c07SJacek Anaszewski * work queue task to avoid problems in case we are called 218f1e80c07SJacek Anaszewski * from hard irq context. 219f1e80c07SJacek Anaszewski */ 220f1e80c07SJacek Anaszewski if (brightness == LED_OFF) { 221f1e80c07SJacek Anaszewski led_cdev->flags |= LED_BLINK_DISABLE; 222d23a22a7SFabio Baltieri schedule_work(&led_cdev->set_brightness_work); 223f1e80c07SJacek Anaszewski } else { 224f1e80c07SJacek Anaszewski led_cdev->flags |= LED_BLINK_BRIGHTNESS_CHANGE; 225f1e80c07SJacek Anaszewski led_cdev->blink_brightness = brightness; 226f1e80c07SJacek Anaszewski } 227d23a22a7SFabio Baltieri return; 228d23a22a7SFabio Baltieri } 22943786482SFabio Baltieri 2304d71a4a1SJacek Anaszewski if (led_cdev->flags & SET_BRIGHTNESS_ASYNC) { 23181fe8e5bSJacek Anaszewski led_set_brightness_nosleep(led_cdev, brightness); 2324d71a4a1SJacek Anaszewski return; 2334d71a4a1SJacek Anaszewski } else if (led_cdev->flags & SET_BRIGHTNESS_SYNC) 2344d71a4a1SJacek Anaszewski ret = led_set_brightness_sync(led_cdev, brightness); 2354d71a4a1SJacek Anaszewski else 2364d71a4a1SJacek Anaszewski ret = -EINVAL; 2374d71a4a1SJacek Anaszewski 2384d71a4a1SJacek Anaszewski if (ret < 0) 2394d71a4a1SJacek Anaszewski dev_dbg(led_cdev->dev, "Setting LED brightness failed (%d)\n", 2404d71a4a1SJacek Anaszewski ret); 241a403d930SBryan Wu } 2422806e2ffSJacek Anaszewski EXPORT_SYMBOL_GPL(led_set_brightness); 2433ef7de53SJacek Anaszewski 24481fe8e5bSJacek Anaszewski void led_set_brightness_nopm(struct led_classdev *led_cdev, 24581fe8e5bSJacek Anaszewski enum led_brightness value) 24681fe8e5bSJacek Anaszewski { 24781fe8e5bSJacek Anaszewski /* Use brightness_set op if available, it is guaranteed not to sleep */ 24881fe8e5bSJacek Anaszewski if (led_cdev->brightness_set) { 24981fe8e5bSJacek Anaszewski led_cdev->brightness_set(led_cdev, value); 25081fe8e5bSJacek Anaszewski return; 25181fe8e5bSJacek Anaszewski } 25281fe8e5bSJacek Anaszewski 25381fe8e5bSJacek Anaszewski /* If brightness setting can sleep, delegate it to a work queue task */ 25481fe8e5bSJacek Anaszewski led_cdev->delayed_set_value = value; 25581fe8e5bSJacek Anaszewski schedule_work(&led_cdev->set_brightness_work); 25681fe8e5bSJacek Anaszewski } 25781fe8e5bSJacek Anaszewski EXPORT_SYMBOL_GPL(led_set_brightness_nopm); 25881fe8e5bSJacek Anaszewski 25981fe8e5bSJacek Anaszewski void led_set_brightness_nosleep(struct led_classdev *led_cdev, 26081fe8e5bSJacek Anaszewski enum led_brightness value) 26181fe8e5bSJacek Anaszewski { 26281fe8e5bSJacek Anaszewski led_cdev->brightness = min(value, led_cdev->max_brightness); 26381fe8e5bSJacek Anaszewski 26481fe8e5bSJacek Anaszewski if (led_cdev->flags & LED_SUSPENDED) 26581fe8e5bSJacek Anaszewski return; 26681fe8e5bSJacek Anaszewski 26781fe8e5bSJacek Anaszewski led_set_brightness_nopm(led_cdev, led_cdev->brightness); 26881fe8e5bSJacek Anaszewski } 26981fe8e5bSJacek Anaszewski EXPORT_SYMBOL_GPL(led_set_brightness_nosleep); 27081fe8e5bSJacek Anaszewski 2713ef7de53SJacek Anaszewski int led_update_brightness(struct led_classdev *led_cdev) 2723ef7de53SJacek Anaszewski { 2733ef7de53SJacek Anaszewski int ret = 0; 2743ef7de53SJacek Anaszewski 2753ef7de53SJacek Anaszewski if (led_cdev->brightness_get) { 2763ef7de53SJacek Anaszewski ret = led_cdev->brightness_get(led_cdev); 2773ef7de53SJacek Anaszewski if (ret >= 0) { 2783ef7de53SJacek Anaszewski led_cdev->brightness = ret; 2793ef7de53SJacek Anaszewski return 0; 2803ef7de53SJacek Anaszewski } 2813ef7de53SJacek Anaszewski } 2823ef7de53SJacek Anaszewski 2833ef7de53SJacek Anaszewski return ret; 2843ef7de53SJacek Anaszewski } 2852806e2ffSJacek Anaszewski EXPORT_SYMBOL_GPL(led_update_brightness); 286acd899e4SJacek Anaszewski 287acd899e4SJacek Anaszewski /* Caller must ensure led_cdev->led_access held */ 288acd899e4SJacek Anaszewski void led_sysfs_disable(struct led_classdev *led_cdev) 289acd899e4SJacek Anaszewski { 290acd899e4SJacek Anaszewski lockdep_assert_held(&led_cdev->led_access); 291acd899e4SJacek Anaszewski 292acd899e4SJacek Anaszewski led_cdev->flags |= LED_SYSFS_DISABLE; 293acd899e4SJacek Anaszewski } 294acd899e4SJacek Anaszewski EXPORT_SYMBOL_GPL(led_sysfs_disable); 295acd899e4SJacek Anaszewski 296acd899e4SJacek Anaszewski /* Caller must ensure led_cdev->led_access held */ 297acd899e4SJacek Anaszewski void led_sysfs_enable(struct led_classdev *led_cdev) 298acd899e4SJacek Anaszewski { 299acd899e4SJacek Anaszewski lockdep_assert_held(&led_cdev->led_access); 300acd899e4SJacek Anaszewski 301acd899e4SJacek Anaszewski led_cdev->flags &= ~LED_SYSFS_DISABLE; 302acd899e4SJacek Anaszewski } 303acd899e4SJacek Anaszewski EXPORT_SYMBOL_GPL(led_sysfs_enable); 304