John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Alarmtimer interface |
| 3 | * |
| 4 | * This interface provides a timer which is similarto hrtimers, |
| 5 | * but triggers a RTC alarm if the box is suspend. |
| 6 | * |
| 7 | * This interface is influenced by the Android RTC Alarm timer |
| 8 | * interface. |
| 9 | * |
| 10 | * Copyright (C) 2010 IBM Corperation |
| 11 | * |
| 12 | * Author: John Stultz <john.stultz@linaro.org> |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License version 2 as |
| 16 | * published by the Free Software Foundation. |
| 17 | */ |
| 18 | #include <linux/time.h> |
| 19 | #include <linux/hrtimer.h> |
| 20 | #include <linux/timerqueue.h> |
| 21 | #include <linux/rtc.h> |
| 22 | #include <linux/alarmtimer.h> |
| 23 | #include <linux/mutex.h> |
| 24 | #include <linux/platform_device.h> |
| 25 | #include <linux/posix-timers.h> |
| 26 | #include <linux/workqueue.h> |
| 27 | #include <linux/freezer.h> |
| 28 | |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 29 | /** |
| 30 | * struct alarm_base - Alarm timer bases |
| 31 | * @lock: Lock for syncrhonized access to the base |
| 32 | * @timerqueue: Timerqueue head managing the list of events |
| 33 | * @timer: hrtimer used to schedule events while running |
| 34 | * @gettime: Function to read the time correlating to the base |
| 35 | * @base_clockid: clockid for the base |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 36 | */ |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 37 | static struct alarm_base { |
| 38 | spinlock_t lock; |
| 39 | struct timerqueue_head timerqueue; |
| 40 | struct hrtimer timer; |
| 41 | ktime_t (*gettime)(void); |
| 42 | clockid_t base_clockid; |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 43 | } alarm_bases[ALARM_NUMTYPE]; |
| 44 | |
John Stultz | c008ba58 | 2011-06-16 18:27:09 -0700 | [diff] [blame] | 45 | /* freezer delta & lock used to handle clock_nanosleep triggered wakeups */ |
| 46 | static ktime_t freezer_delta; |
| 47 | static DEFINE_SPINLOCK(freezer_delta_lock); |
| 48 | |
John Stultz | 472647d | 2011-04-29 15:03:10 -0700 | [diff] [blame] | 49 | #ifdef CONFIG_RTC_CLASS |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 50 | /* rtc timer and device for setting alarm wakeups at suspend */ |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 51 | static struct rtc_timer rtctimer; |
| 52 | static struct rtc_device *rtcdev; |
John Stultz | c008ba58 | 2011-06-16 18:27:09 -0700 | [diff] [blame] | 53 | static DEFINE_SPINLOCK(rtcdev_lock); |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 54 | |
John Stultz | c008ba58 | 2011-06-16 18:27:09 -0700 | [diff] [blame] | 55 | /** |
| 56 | * has_wakealarm - check rtc device has wakealarm ability |
| 57 | * @dev: current device |
| 58 | * @name_ptr: name to be returned |
| 59 | * |
| 60 | * This helper function checks to see if the rtc device can wake |
| 61 | * from suspend. |
| 62 | */ |
| 63 | static int has_wakealarm(struct device *dev, void *name_ptr) |
| 64 | { |
| 65 | struct rtc_device *candidate = to_rtc_device(dev); |
| 66 | |
| 67 | if (!candidate->ops->set_alarm) |
| 68 | return 0; |
| 69 | if (!device_may_wakeup(candidate->dev.parent)) |
| 70 | return 0; |
| 71 | |
| 72 | *(const char **)name_ptr = dev_name(dev); |
| 73 | return 1; |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * alarmtimer_get_rtcdev - Return selected rtcdevice |
| 78 | * |
| 79 | * This function returns the rtc device to use for wakealarms. |
| 80 | * If one has not already been chosen, it checks to see if a |
| 81 | * functional rtc device is available. |
| 82 | */ |
| 83 | static struct rtc_device *alarmtimer_get_rtcdev(void) |
| 84 | { |
| 85 | struct device *dev; |
| 86 | char *str; |
| 87 | unsigned long flags; |
| 88 | struct rtc_device *ret; |
| 89 | |
| 90 | spin_lock_irqsave(&rtcdev_lock, flags); |
| 91 | if (!rtcdev) { |
| 92 | /* Find an rtc device and init the rtc_timer */ |
| 93 | dev = class_find_device(rtc_class, NULL, &str, has_wakealarm); |
| 94 | /* If we have a device then str is valid. See has_wakealarm() */ |
| 95 | if (dev) { |
| 96 | rtcdev = rtc_class_open(str); |
| 97 | /* |
| 98 | * Drop the reference we got in class_find_device, |
| 99 | * rtc_open takes its own. |
| 100 | */ |
| 101 | put_device(dev); |
| 102 | rtc_timer_init(&rtctimer, NULL, NULL); |
| 103 | } |
| 104 | } |
| 105 | ret = rtcdev; |
| 106 | spin_unlock_irqrestore(&rtcdev_lock, flags); |
| 107 | |
| 108 | return ret; |
| 109 | } |
John Stultz | 1c6b39a | 2011-06-16 18:47:37 -0700 | [diff] [blame] | 110 | #else |
| 111 | #define alarmtimer_get_rtcdev() (0) |
| 112 | #define rtcdev (0) |
John Stultz | c008ba58 | 2011-06-16 18:27:09 -0700 | [diff] [blame] | 113 | #endif |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 114 | |
| 115 | |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 116 | /** |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 117 | * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue |
| 118 | * @base: pointer to the base where the timer is being run |
| 119 | * @alarm: pointer to alarm being enqueued. |
| 120 | * |
| 121 | * Adds alarm to a alarm_base timerqueue and if necessary sets |
| 122 | * an hrtimer to run. |
| 123 | * |
| 124 | * Must hold base->lock when calling. |
| 125 | */ |
| 126 | static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm) |
| 127 | { |
| 128 | timerqueue_add(&base->timerqueue, &alarm->node); |
| 129 | if (&alarm->node == timerqueue_getnext(&base->timerqueue)) { |
| 130 | hrtimer_try_to_cancel(&base->timer); |
| 131 | hrtimer_start(&base->timer, alarm->node.expires, |
| 132 | HRTIMER_MODE_ABS); |
| 133 | } |
| 134 | } |
| 135 | |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 136 | /** |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 137 | * alarmtimer_remove - Removes an alarm timer from an alarm_base timerqueue |
| 138 | * @base: pointer to the base where the timer is running |
| 139 | * @alarm: pointer to alarm being removed |
| 140 | * |
| 141 | * Removes alarm to a alarm_base timerqueue and if necessary sets |
| 142 | * a new timer to run. |
| 143 | * |
| 144 | * Must hold base->lock when calling. |
| 145 | */ |
| 146 | static void alarmtimer_remove(struct alarm_base *base, struct alarm *alarm) |
| 147 | { |
| 148 | struct timerqueue_node *next = timerqueue_getnext(&base->timerqueue); |
| 149 | |
| 150 | timerqueue_del(&base->timerqueue, &alarm->node); |
| 151 | if (next == &alarm->node) { |
| 152 | hrtimer_try_to_cancel(&base->timer); |
| 153 | next = timerqueue_getnext(&base->timerqueue); |
| 154 | if (!next) |
| 155 | return; |
| 156 | hrtimer_start(&base->timer, next->expires, HRTIMER_MODE_ABS); |
| 157 | } |
| 158 | } |
| 159 | |
John Stultz | 7068b7a | 2011-04-28 13:29:18 -0700 | [diff] [blame] | 160 | |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 161 | /** |
John Stultz | 7068b7a | 2011-04-28 13:29:18 -0700 | [diff] [blame] | 162 | * alarmtimer_fired - Handles alarm hrtimer being fired. |
| 163 | * @timer: pointer to hrtimer being run |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 164 | * |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 165 | * When a alarm timer fires, this runs through the timerqueue to |
| 166 | * see which alarms expired, and runs those. If there are more alarm |
| 167 | * timers queued for the future, we set the hrtimer to fire when |
| 168 | * when the next future alarm timer expires. |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 169 | */ |
John Stultz | 7068b7a | 2011-04-28 13:29:18 -0700 | [diff] [blame] | 170 | static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 171 | { |
John Stultz | 7068b7a | 2011-04-28 13:29:18 -0700 | [diff] [blame] | 172 | struct alarm_base *base = container_of(timer, struct alarm_base, timer); |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 173 | struct timerqueue_node *next; |
| 174 | unsigned long flags; |
| 175 | ktime_t now; |
John Stultz | 7068b7a | 2011-04-28 13:29:18 -0700 | [diff] [blame] | 176 | int ret = HRTIMER_NORESTART; |
John Stultz | 54da23b | 2011-08-10 11:08:07 -0700 | [diff] [blame^] | 177 | int restart = ALARMTIMER_NORESTART; |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 178 | |
| 179 | spin_lock_irqsave(&base->lock, flags); |
| 180 | now = base->gettime(); |
| 181 | while ((next = timerqueue_getnext(&base->timerqueue))) { |
| 182 | struct alarm *alarm; |
| 183 | ktime_t expired = next->expires; |
| 184 | |
| 185 | if (expired.tv64 >= now.tv64) |
| 186 | break; |
| 187 | |
| 188 | alarm = container_of(next, struct alarm, node); |
| 189 | |
| 190 | timerqueue_del(&base->timerqueue, &alarm->node); |
| 191 | alarm->enabled = 0; |
John Stultz | 54da23b | 2011-08-10 11:08:07 -0700 | [diff] [blame^] | 192 | |
| 193 | spin_unlock_irqrestore(&base->lock, flags); |
| 194 | if (alarm->function) |
| 195 | restart = alarm->function(alarm, now); |
| 196 | spin_lock_irqsave(&base->lock, flags); |
| 197 | |
| 198 | if (restart != ALARMTIMER_NORESTART) { |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 199 | timerqueue_add(&base->timerqueue, &alarm->node); |
| 200 | alarm->enabled = 1; |
| 201 | } |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 202 | } |
| 203 | |
| 204 | if (next) { |
John Stultz | 7068b7a | 2011-04-28 13:29:18 -0700 | [diff] [blame] | 205 | hrtimer_set_expires(&base->timer, next->expires); |
| 206 | ret = HRTIMER_RESTART; |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 207 | } |
| 208 | spin_unlock_irqrestore(&base->lock, flags); |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 209 | |
John Stultz | 7068b7a | 2011-04-28 13:29:18 -0700 | [diff] [blame] | 210 | return ret; |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 211 | |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 212 | } |
| 213 | |
John Stultz | 472647d | 2011-04-29 15:03:10 -0700 | [diff] [blame] | 214 | #ifdef CONFIG_RTC_CLASS |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 215 | /** |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 216 | * alarmtimer_suspend - Suspend time callback |
| 217 | * @dev: unused |
| 218 | * @state: unused |
| 219 | * |
| 220 | * When we are going into suspend, we look through the bases |
| 221 | * to see which is the soonest timer to expire. We then |
| 222 | * set an rtc timer to fire that far into the future, which |
| 223 | * will wake us from suspend. |
| 224 | */ |
| 225 | static int alarmtimer_suspend(struct device *dev) |
| 226 | { |
| 227 | struct rtc_time tm; |
| 228 | ktime_t min, now; |
| 229 | unsigned long flags; |
John Stultz | c008ba58 | 2011-06-16 18:27:09 -0700 | [diff] [blame] | 230 | struct rtc_device *rtc; |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 231 | int i; |
| 232 | |
| 233 | spin_lock_irqsave(&freezer_delta_lock, flags); |
| 234 | min = freezer_delta; |
| 235 | freezer_delta = ktime_set(0, 0); |
| 236 | spin_unlock_irqrestore(&freezer_delta_lock, flags); |
| 237 | |
John Stultz | 1c6b39a | 2011-06-16 18:47:37 -0700 | [diff] [blame] | 238 | rtc = rtcdev; |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 239 | /* If we have no rtcdev, just return */ |
John Stultz | c008ba58 | 2011-06-16 18:27:09 -0700 | [diff] [blame] | 240 | if (!rtc) |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 241 | return 0; |
| 242 | |
| 243 | /* Find the soonest timer to expire*/ |
| 244 | for (i = 0; i < ALARM_NUMTYPE; i++) { |
| 245 | struct alarm_base *base = &alarm_bases[i]; |
| 246 | struct timerqueue_node *next; |
| 247 | ktime_t delta; |
| 248 | |
| 249 | spin_lock_irqsave(&base->lock, flags); |
| 250 | next = timerqueue_getnext(&base->timerqueue); |
| 251 | spin_unlock_irqrestore(&base->lock, flags); |
| 252 | if (!next) |
| 253 | continue; |
| 254 | delta = ktime_sub(next->expires, base->gettime()); |
| 255 | if (!min.tv64 || (delta.tv64 < min.tv64)) |
| 256 | min = delta; |
| 257 | } |
| 258 | if (min.tv64 == 0) |
| 259 | return 0; |
| 260 | |
| 261 | /* XXX - Should we enforce a minimum sleep time? */ |
| 262 | WARN_ON(min.tv64 < NSEC_PER_SEC); |
| 263 | |
| 264 | /* Setup an rtc timer to fire that far in the future */ |
John Stultz | c008ba58 | 2011-06-16 18:27:09 -0700 | [diff] [blame] | 265 | rtc_timer_cancel(rtc, &rtctimer); |
| 266 | rtc_read_time(rtc, &tm); |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 267 | now = rtc_tm_to_ktime(tm); |
| 268 | now = ktime_add(now, min); |
| 269 | |
John Stultz | c008ba58 | 2011-06-16 18:27:09 -0700 | [diff] [blame] | 270 | rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0)); |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 271 | |
| 272 | return 0; |
| 273 | } |
John Stultz | 472647d | 2011-04-29 15:03:10 -0700 | [diff] [blame] | 274 | #else |
| 275 | static int alarmtimer_suspend(struct device *dev) |
| 276 | { |
| 277 | return 0; |
| 278 | } |
| 279 | #endif |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 280 | |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 281 | static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) |
| 282 | { |
| 283 | ktime_t delta; |
| 284 | unsigned long flags; |
| 285 | struct alarm_base *base = &alarm_bases[type]; |
| 286 | |
| 287 | delta = ktime_sub(absexp, base->gettime()); |
| 288 | |
| 289 | spin_lock_irqsave(&freezer_delta_lock, flags); |
| 290 | if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64)) |
| 291 | freezer_delta = delta; |
| 292 | spin_unlock_irqrestore(&freezer_delta_lock, flags); |
| 293 | } |
| 294 | |
| 295 | |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 296 | /** |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 297 | * alarm_init - Initialize an alarm structure |
| 298 | * @alarm: ptr to alarm to be initialized |
| 299 | * @type: the type of the alarm |
| 300 | * @function: callback that is run when the alarm fires |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 301 | */ |
| 302 | void alarm_init(struct alarm *alarm, enum alarmtimer_type type, |
John Stultz | 4b41308 | 2011-08-10 10:37:59 -0700 | [diff] [blame] | 303 | enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 304 | { |
| 305 | timerqueue_init(&alarm->node); |
| 306 | alarm->period = ktime_set(0, 0); |
| 307 | alarm->function = function; |
| 308 | alarm->type = type; |
| 309 | alarm->enabled = 0; |
| 310 | } |
| 311 | |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 312 | /** |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 313 | * alarm_start - Sets an alarm to fire |
| 314 | * @alarm: ptr to alarm to set |
| 315 | * @start: time to run the alarm |
| 316 | * @period: period at which the alarm will recur |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 317 | */ |
| 318 | void alarm_start(struct alarm *alarm, ktime_t start, ktime_t period) |
| 319 | { |
| 320 | struct alarm_base *base = &alarm_bases[alarm->type]; |
| 321 | unsigned long flags; |
| 322 | |
| 323 | spin_lock_irqsave(&base->lock, flags); |
| 324 | if (alarm->enabled) |
| 325 | alarmtimer_remove(base, alarm); |
| 326 | alarm->node.expires = start; |
| 327 | alarm->period = period; |
| 328 | alarmtimer_enqueue(base, alarm); |
| 329 | alarm->enabled = 1; |
| 330 | spin_unlock_irqrestore(&base->lock, flags); |
| 331 | } |
| 332 | |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 333 | /** |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 334 | * alarm_cancel - Tries to cancel an alarm timer |
| 335 | * @alarm: ptr to alarm to be canceled |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 336 | */ |
| 337 | void alarm_cancel(struct alarm *alarm) |
| 338 | { |
| 339 | struct alarm_base *base = &alarm_bases[alarm->type]; |
| 340 | unsigned long flags; |
| 341 | |
| 342 | spin_lock_irqsave(&base->lock, flags); |
| 343 | if (alarm->enabled) |
| 344 | alarmtimer_remove(base, alarm); |
| 345 | alarm->enabled = 0; |
| 346 | spin_unlock_irqrestore(&base->lock, flags); |
| 347 | } |
| 348 | |
| 349 | |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 350 | /** |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 351 | * clock2alarm - helper that converts from clockid to alarmtypes |
| 352 | * @clockid: clockid. |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 353 | */ |
| 354 | static enum alarmtimer_type clock2alarm(clockid_t clockid) |
| 355 | { |
| 356 | if (clockid == CLOCK_REALTIME_ALARM) |
| 357 | return ALARM_REALTIME; |
| 358 | if (clockid == CLOCK_BOOTTIME_ALARM) |
| 359 | return ALARM_BOOTTIME; |
| 360 | return -1; |
| 361 | } |
| 362 | |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 363 | /** |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 364 | * alarm_handle_timer - Callback for posix timers |
| 365 | * @alarm: alarm that fired |
| 366 | * |
| 367 | * Posix timer callback for expired alarm timers. |
| 368 | */ |
John Stultz | 4b41308 | 2011-08-10 10:37:59 -0700 | [diff] [blame] | 369 | static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, |
| 370 | ktime_t now) |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 371 | { |
| 372 | struct k_itimer *ptr = container_of(alarm, struct k_itimer, |
| 373 | it.alarmtimer); |
| 374 | if (posix_timer_event(ptr, 0) != 0) |
| 375 | ptr->it_overrun++; |
John Stultz | 4b41308 | 2011-08-10 10:37:59 -0700 | [diff] [blame] | 376 | |
John Stultz | 54da23b | 2011-08-10 11:08:07 -0700 | [diff] [blame^] | 377 | /* Re-add periodic timers */ |
| 378 | if (alarm->period.tv64) { |
| 379 | alarm->node.expires = ktime_add(now, alarm->period); |
| 380 | return ALARMTIMER_RESTART; |
| 381 | } |
John Stultz | 4b41308 | 2011-08-10 10:37:59 -0700 | [diff] [blame] | 382 | return ALARMTIMER_NORESTART; |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 383 | } |
| 384 | |
John Stultz | 180bf81 | 2011-04-28 12:58:11 -0700 | [diff] [blame] | 385 | /** |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 386 | * alarm_clock_getres - posix getres interface |
| 387 | * @which_clock: clockid |
| 388 | * @tp: timespec to fill |
| 389 | * |
| 390 | * Returns the granularity of underlying alarm base clock |
| 391 | */ |
| 392 | static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp) |
| 393 | { |
| 394 | clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid; |
| 395 | |
John Stultz | 1c6b39a | 2011-06-16 18:47:37 -0700 | [diff] [blame] | 396 | if (!alarmtimer_get_rtcdev()) |
| 397 | return -ENOTSUPP; |
| 398 | |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 399 | return hrtimer_get_res(baseid, tp); |
| 400 | } |
| 401 | |
| 402 | /** |
| 403 | * alarm_clock_get - posix clock_get interface |
| 404 | * @which_clock: clockid |
| 405 | * @tp: timespec to fill. |
| 406 | * |
| 407 | * Provides the underlying alarm base time. |
| 408 | */ |
| 409 | static int alarm_clock_get(clockid_t which_clock, struct timespec *tp) |
| 410 | { |
| 411 | struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)]; |
| 412 | |
John Stultz | 1c6b39a | 2011-06-16 18:47:37 -0700 | [diff] [blame] | 413 | if (!alarmtimer_get_rtcdev()) |
| 414 | return -ENOTSUPP; |
| 415 | |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 416 | *tp = ktime_to_timespec(base->gettime()); |
| 417 | return 0; |
| 418 | } |
| 419 | |
| 420 | /** |
| 421 | * alarm_timer_create - posix timer_create interface |
| 422 | * @new_timer: k_itimer pointer to manage |
| 423 | * |
| 424 | * Initializes the k_itimer structure. |
| 425 | */ |
| 426 | static int alarm_timer_create(struct k_itimer *new_timer) |
| 427 | { |
| 428 | enum alarmtimer_type type; |
| 429 | struct alarm_base *base; |
| 430 | |
John Stultz | 1c6b39a | 2011-06-16 18:47:37 -0700 | [diff] [blame] | 431 | if (!alarmtimer_get_rtcdev()) |
| 432 | return -ENOTSUPP; |
| 433 | |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 434 | if (!capable(CAP_WAKE_ALARM)) |
| 435 | return -EPERM; |
| 436 | |
| 437 | type = clock2alarm(new_timer->it_clock); |
| 438 | base = &alarm_bases[type]; |
| 439 | alarm_init(&new_timer->it.alarmtimer, type, alarm_handle_timer); |
| 440 | return 0; |
| 441 | } |
| 442 | |
| 443 | /** |
| 444 | * alarm_timer_get - posix timer_get interface |
| 445 | * @new_timer: k_itimer pointer |
| 446 | * @cur_setting: itimerspec data to fill |
| 447 | * |
| 448 | * Copies the itimerspec data out from the k_itimer |
| 449 | */ |
| 450 | static void alarm_timer_get(struct k_itimer *timr, |
| 451 | struct itimerspec *cur_setting) |
| 452 | { |
John Stultz | ea7802f | 2011-08-04 07:51:56 -0700 | [diff] [blame] | 453 | memset(cur_setting, 0, sizeof(struct itimerspec)); |
| 454 | |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 455 | cur_setting->it_interval = |
| 456 | ktime_to_timespec(timr->it.alarmtimer.period); |
| 457 | cur_setting->it_value = |
| 458 | ktime_to_timespec(timr->it.alarmtimer.node.expires); |
| 459 | return; |
| 460 | } |
| 461 | |
| 462 | /** |
| 463 | * alarm_timer_del - posix timer_del interface |
| 464 | * @timr: k_itimer pointer to be deleted |
| 465 | * |
| 466 | * Cancels any programmed alarms for the given timer. |
| 467 | */ |
| 468 | static int alarm_timer_del(struct k_itimer *timr) |
| 469 | { |
John Stultz | 1c6b39a | 2011-06-16 18:47:37 -0700 | [diff] [blame] | 470 | if (!rtcdev) |
| 471 | return -ENOTSUPP; |
| 472 | |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 473 | alarm_cancel(&timr->it.alarmtimer); |
| 474 | return 0; |
| 475 | } |
| 476 | |
| 477 | /** |
| 478 | * alarm_timer_set - posix timer_set interface |
| 479 | * @timr: k_itimer pointer to be deleted |
| 480 | * @flags: timer flags |
| 481 | * @new_setting: itimerspec to be used |
| 482 | * @old_setting: itimerspec being replaced |
| 483 | * |
| 484 | * Sets the timer to new_setting, and starts the timer. |
| 485 | */ |
| 486 | static int alarm_timer_set(struct k_itimer *timr, int flags, |
| 487 | struct itimerspec *new_setting, |
| 488 | struct itimerspec *old_setting) |
| 489 | { |
John Stultz | 1c6b39a | 2011-06-16 18:47:37 -0700 | [diff] [blame] | 490 | if (!rtcdev) |
| 491 | return -ENOTSUPP; |
| 492 | |
John Stultz | 6af7e47 | 2011-08-10 10:26:09 -0700 | [diff] [blame] | 493 | /* |
| 494 | * XXX HACK! Currently we can DOS a system if the interval |
| 495 | * period on alarmtimers is too small. Cap the interval here |
| 496 | * to 100us and solve this properly in a future patch! -jstultz |
| 497 | */ |
| 498 | if ((new_setting->it_interval.tv_sec == 0) && |
| 499 | (new_setting->it_interval.tv_nsec < 100000)) |
| 500 | new_setting->it_interval.tv_nsec = 100000; |
| 501 | |
John Stultz | 971c90b | 2011-08-04 07:25:35 -0700 | [diff] [blame] | 502 | if (old_setting) |
| 503 | alarm_timer_get(timr, old_setting); |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 504 | |
| 505 | /* If the timer was already set, cancel it */ |
| 506 | alarm_cancel(&timr->it.alarmtimer); |
| 507 | |
| 508 | /* start the timer */ |
| 509 | alarm_start(&timr->it.alarmtimer, |
| 510 | timespec_to_ktime(new_setting->it_value), |
| 511 | timespec_to_ktime(new_setting->it_interval)); |
| 512 | return 0; |
| 513 | } |
| 514 | |
| 515 | /** |
| 516 | * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep |
| 517 | * @alarm: ptr to alarm that fired |
| 518 | * |
| 519 | * Wakes up the task that set the alarmtimer |
| 520 | */ |
John Stultz | 4b41308 | 2011-08-10 10:37:59 -0700 | [diff] [blame] | 521 | static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm, |
| 522 | ktime_t now) |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 523 | { |
| 524 | struct task_struct *task = (struct task_struct *)alarm->data; |
| 525 | |
| 526 | alarm->data = NULL; |
| 527 | if (task) |
| 528 | wake_up_process(task); |
John Stultz | 4b41308 | 2011-08-10 10:37:59 -0700 | [diff] [blame] | 529 | return ALARMTIMER_NORESTART; |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 530 | } |
| 531 | |
| 532 | /** |
| 533 | * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation |
| 534 | * @alarm: ptr to alarmtimer |
| 535 | * @absexp: absolute expiration time |
| 536 | * |
| 537 | * Sets the alarm timer and sleeps until it is fired or interrupted. |
| 538 | */ |
| 539 | static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp) |
| 540 | { |
| 541 | alarm->data = (void *)current; |
| 542 | do { |
| 543 | set_current_state(TASK_INTERRUPTIBLE); |
| 544 | alarm_start(alarm, absexp, ktime_set(0, 0)); |
| 545 | if (likely(alarm->data)) |
| 546 | schedule(); |
| 547 | |
| 548 | alarm_cancel(alarm); |
| 549 | } while (alarm->data && !signal_pending(current)); |
| 550 | |
| 551 | __set_current_state(TASK_RUNNING); |
| 552 | |
| 553 | return (alarm->data == NULL); |
| 554 | } |
| 555 | |
| 556 | |
| 557 | /** |
| 558 | * update_rmtp - Update remaining timespec value |
| 559 | * @exp: expiration time |
| 560 | * @type: timer type |
| 561 | * @rmtp: user pointer to remaining timepsec value |
| 562 | * |
| 563 | * Helper function that fills in rmtp value with time between |
| 564 | * now and the exp value |
| 565 | */ |
| 566 | static int update_rmtp(ktime_t exp, enum alarmtimer_type type, |
| 567 | struct timespec __user *rmtp) |
| 568 | { |
| 569 | struct timespec rmt; |
| 570 | ktime_t rem; |
| 571 | |
| 572 | rem = ktime_sub(exp, alarm_bases[type].gettime()); |
| 573 | |
| 574 | if (rem.tv64 <= 0) |
| 575 | return 0; |
| 576 | rmt = ktime_to_timespec(rem); |
| 577 | |
| 578 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) |
| 579 | return -EFAULT; |
| 580 | |
| 581 | return 1; |
| 582 | |
| 583 | } |
| 584 | |
| 585 | /** |
| 586 | * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep |
| 587 | * @restart: ptr to restart block |
| 588 | * |
| 589 | * Handles restarted clock_nanosleep calls |
| 590 | */ |
| 591 | static long __sched alarm_timer_nsleep_restart(struct restart_block *restart) |
| 592 | { |
Thomas Gleixner | ab8177b | 2011-05-20 13:05:15 +0200 | [diff] [blame] | 593 | enum alarmtimer_type type = restart->nanosleep.clockid; |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 594 | ktime_t exp; |
| 595 | struct timespec __user *rmtp; |
| 596 | struct alarm alarm; |
| 597 | int ret = 0; |
| 598 | |
| 599 | exp.tv64 = restart->nanosleep.expires; |
| 600 | alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); |
| 601 | |
| 602 | if (alarmtimer_do_nsleep(&alarm, exp)) |
| 603 | goto out; |
| 604 | |
| 605 | if (freezing(current)) |
| 606 | alarmtimer_freezerset(exp, type); |
| 607 | |
| 608 | rmtp = restart->nanosleep.rmtp; |
| 609 | if (rmtp) { |
| 610 | ret = update_rmtp(exp, type, rmtp); |
| 611 | if (ret <= 0) |
| 612 | goto out; |
| 613 | } |
| 614 | |
| 615 | |
| 616 | /* The other values in restart are already filled in */ |
| 617 | ret = -ERESTART_RESTARTBLOCK; |
| 618 | out: |
| 619 | return ret; |
| 620 | } |
| 621 | |
| 622 | /** |
| 623 | * alarm_timer_nsleep - alarmtimer nanosleep |
| 624 | * @which_clock: clockid |
| 625 | * @flags: determins abstime or relative |
| 626 | * @tsreq: requested sleep time (abs or rel) |
| 627 | * @rmtp: remaining sleep time saved |
| 628 | * |
| 629 | * Handles clock_nanosleep calls against _ALARM clockids |
| 630 | */ |
| 631 | static int alarm_timer_nsleep(const clockid_t which_clock, int flags, |
| 632 | struct timespec *tsreq, struct timespec __user *rmtp) |
| 633 | { |
| 634 | enum alarmtimer_type type = clock2alarm(which_clock); |
| 635 | struct alarm alarm; |
| 636 | ktime_t exp; |
| 637 | int ret = 0; |
| 638 | struct restart_block *restart; |
| 639 | |
John Stultz | 1c6b39a | 2011-06-16 18:47:37 -0700 | [diff] [blame] | 640 | if (!alarmtimer_get_rtcdev()) |
| 641 | return -ENOTSUPP; |
| 642 | |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 643 | if (!capable(CAP_WAKE_ALARM)) |
| 644 | return -EPERM; |
| 645 | |
| 646 | alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); |
| 647 | |
| 648 | exp = timespec_to_ktime(*tsreq); |
| 649 | /* Convert (if necessary) to absolute time */ |
| 650 | if (flags != TIMER_ABSTIME) { |
| 651 | ktime_t now = alarm_bases[type].gettime(); |
| 652 | exp = ktime_add(now, exp); |
| 653 | } |
| 654 | |
| 655 | if (alarmtimer_do_nsleep(&alarm, exp)) |
| 656 | goto out; |
| 657 | |
| 658 | if (freezing(current)) |
| 659 | alarmtimer_freezerset(exp, type); |
| 660 | |
| 661 | /* abs timers don't set remaining time or restart */ |
| 662 | if (flags == TIMER_ABSTIME) { |
| 663 | ret = -ERESTARTNOHAND; |
| 664 | goto out; |
| 665 | } |
| 666 | |
| 667 | if (rmtp) { |
| 668 | ret = update_rmtp(exp, type, rmtp); |
| 669 | if (ret <= 0) |
| 670 | goto out; |
| 671 | } |
| 672 | |
| 673 | restart = ¤t_thread_info()->restart_block; |
| 674 | restart->fn = alarm_timer_nsleep_restart; |
Thomas Gleixner | ab8177b | 2011-05-20 13:05:15 +0200 | [diff] [blame] | 675 | restart->nanosleep.clockid = type; |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 676 | restart->nanosleep.expires = exp.tv64; |
| 677 | restart->nanosleep.rmtp = rmtp; |
| 678 | ret = -ERESTART_RESTARTBLOCK; |
| 679 | |
| 680 | out: |
| 681 | return ret; |
| 682 | } |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 683 | |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 684 | |
| 685 | /* Suspend hook structures */ |
| 686 | static const struct dev_pm_ops alarmtimer_pm_ops = { |
| 687 | .suspend = alarmtimer_suspend, |
| 688 | }; |
| 689 | |
| 690 | static struct platform_driver alarmtimer_driver = { |
| 691 | .driver = { |
| 692 | .name = "alarmtimer", |
| 693 | .pm = &alarmtimer_pm_ops, |
| 694 | } |
| 695 | }; |
| 696 | |
| 697 | /** |
| 698 | * alarmtimer_init - Initialize alarm timer code |
| 699 | * |
| 700 | * This function initializes the alarm bases and registers |
| 701 | * the posix clock ids. |
| 702 | */ |
| 703 | static int __init alarmtimer_init(void) |
| 704 | { |
| 705 | int error = 0; |
| 706 | int i; |
John Stultz | 9a7adcf | 2011-01-11 09:54:33 -0800 | [diff] [blame] | 707 | struct k_clock alarm_clock = { |
| 708 | .clock_getres = alarm_clock_getres, |
| 709 | .clock_get = alarm_clock_get, |
| 710 | .timer_create = alarm_timer_create, |
| 711 | .timer_set = alarm_timer_set, |
| 712 | .timer_del = alarm_timer_del, |
| 713 | .timer_get = alarm_timer_get, |
| 714 | .nsleep = alarm_timer_nsleep, |
| 715 | }; |
| 716 | |
| 717 | posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock); |
| 718 | posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock); |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 719 | |
| 720 | /* Initialize alarm bases */ |
| 721 | alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME; |
| 722 | alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real; |
| 723 | alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME; |
| 724 | alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime; |
| 725 | for (i = 0; i < ALARM_NUMTYPE; i++) { |
| 726 | timerqueue_init_head(&alarm_bases[i].timerqueue); |
| 727 | spin_lock_init(&alarm_bases[i].lock); |
| 728 | hrtimer_init(&alarm_bases[i].timer, |
| 729 | alarm_bases[i].base_clockid, |
| 730 | HRTIMER_MODE_ABS); |
| 731 | alarm_bases[i].timer.function = alarmtimer_fired; |
John Stultz | ff3ead9 | 2011-01-11 09:42:13 -0800 | [diff] [blame] | 732 | } |
| 733 | error = platform_driver_register(&alarmtimer_driver); |
| 734 | platform_device_register_simple("alarmtimer", -1, NULL, 0); |
| 735 | |
| 736 | return error; |
| 737 | } |
| 738 | device_initcall(alarmtimer_init); |
| 739 | |