sound/pci/ctxfi/cttimer.c

   1 /*
   2  * PCM timer handling on ctxfi
   3  *
   4  * This source file is released under GPL v2 license (no other versions).
   5  * See the COPYING file included in the main directory of this source
   6  * distribution for the license terms and conditions.
   7  */
   8
   9 #include <linux/slab.h>
  10 #include <linux/math64.h>
  11 #include <linux/moduleparam.h>
  12 #include <sound/core.h>
  13 #include <sound/pcm.h>
  14 #include "ctatc.h"
  15 #include "cthardware.h"
  16 #include "cttimer.h"
  17
  18 static bool use_system_timer;
  19 MODULE_PARM_DESC(use_system_timer, "Force to use system-timer");
  20 module_param(use_system_timer, bool, 0444);
  21
  22 struct ct_timer_ops {
  23         void (*init)(struct ct_timer_instance *);
  24         void (*prepare)(struct ct_timer_instance *);
  25         void (*start)(struct ct_timer_instance *);
  26         void (*stop)(struct ct_timer_instance *);
  27         void (*free_instance)(struct ct_timer_instance *);
  28         void (*interrupt)(struct ct_timer *);
  29         void (*free_global)(struct ct_timer *);
  30 };
  31
  32 /* timer instance -- assigned to each PCM stream */
  33 struct ct_timer_instance {
  34         spinlock_t lock;
  35         struct ct_timer *timer_base;
  36         struct ct_atc_pcm *apcm;
  37         struct snd_pcm_substream *substream;
  38         struct timer_list timer;
  39         struct list_head instance_list;
  40         struct list_head running_list;
  41         unsigned int position;
  42         unsigned int frag_count;
  43         unsigned int running:1;
  44         unsigned int need_update:1;
  45 };
  46
  47 /* timer instance manager */
  48 struct ct_timer {
  49         spinlock_t lock;                /* global timer lock (for xfitimer) */
  50         spinlock_t list_lock;           /* lock for instance list */
  51         struct ct_atc *atc;
  52         const struct ct_timer_ops *ops;
  53         struct list_head instance_head;
  54         struct list_head running_head;
  55         unsigned int wc;                /* current wallclock */
  56         unsigned int irq_handling:1;    /* in IRQ handling */
  57         unsigned int reprogram:1;       /* need to reprogram the internval */
  58         unsigned int running:1;         /* global timer running */
  59 };
  60
  61
  62 /*
  63  * system-timer-based updates
  64  */
  65
  66 static void ct_systimer_callback(struct timer_list *t)
  67 {
  68         struct ct_timer_instance *ti = from_timer(ti, t, timer);
  69         struct snd_pcm_substream *substream = ti->substream;
  70         struct snd_pcm_runtime *runtime = substream->runtime;
  71         struct ct_atc_pcm *apcm = ti->apcm;
  72         unsigned int period_size = runtime->period_size;
  73         unsigned int buffer_size = runtime->buffer_size;
  74         unsigned long flags;
  75         unsigned int position, dist, interval;
  76
  77         position = substream->ops->pointer(substream);
  78         dist = (position + buffer_size - ti->position) % buffer_size;
  79         if (dist >= period_size ||
  80             position / period_size != ti->position / period_size) {
  81                 apcm->interrupt(apcm);
  82                 ti->position = position;
  83         }
  84         /* Add extra HZ*5/1000 to avoid overrun issue when recording
  85          * at 8kHz in 8-bit format or at 88kHz in 24-bit format. */
  86         interval = ((period_size - (position % period_size))
  87                    * HZ + (runtime->rate - 1)) / runtime->rate + HZ * 5 / 1000;
  88         spin_lock_irqsave(&ti->lock, flags);
  89         if (ti->running)
  90                 mod_timer(&ti->timer, jiffies + interval);
  91         spin_unlock_irqrestore(&ti->lock, flags);
  92 }
  93
  94 static void ct_systimer_init(struct ct_timer_instance *ti)
  95 {
  96         timer_setup(&ti->timer, ct_systimer_callback, 0);
  97 }
  98
  99 static void ct_systimer_start(struct ct_timer_instance *ti)
 100 {
 101         struct snd_pcm_runtime *runtime = ti->substream->runtime;
 102         unsigned long flags;
 103
 104         spin_lock_irqsave(&ti->lock, flags);
 105         ti->running = 1;
 106         mod_timer(&ti->timer,
 107                   jiffies + (runtime->period_size * HZ +
 108                              (runtime->rate - 1)) / runtime->rate);
 109         spin_unlock_irqrestore(&ti->lock, flags);
 110 }
 111
 112 static void ct_systimer_stop(struct ct_timer_instance *ti)
 113 {
 114         unsigned long flags;
 115
 116         spin_lock_irqsave(&ti->lock, flags);
 117         ti->running = 0;
 118         del_timer(&ti->timer);
 119         spin_unlock_irqrestore(&ti->lock, flags);
 120 }
 121
 122 static void ct_systimer_prepare(struct ct_timer_instance *ti)
 123 {
 124         ct_systimer_stop(ti);
 125         try_to_del_timer_sync(&ti->timer);
 126 }
 127
 128 #define ct_systimer_free        ct_systimer_prepare
 129
 130 static const struct ct_timer_ops ct_systimer_ops = {
 131         .init = ct_systimer_init,
 132         .free_instance = ct_systimer_free,
 133         .prepare = ct_systimer_prepare,
 134         .start = ct_systimer_start,
 135         .stop = ct_systimer_stop,
 136 };
 137
 138
 139 /*
 140  * Handling multiple streams using a global emu20k1 timer irq
 141  */
 142
 143 #define CT_TIMER_FREQ   48000
 144 #define MIN_TICKS       1
 145 #define MAX_TICKS       ((1 << 13) - 1)
 146
 147 static void ct_xfitimer_irq_rearm(struct ct_timer *atimer, int ticks)
 148 {
 149         struct hw *hw = atimer->atc->hw;
 150         if (ticks > MAX_TICKS)
 151                 ticks = MAX_TICKS;
 152         hw->set_timer_tick(hw, ticks);
 153         if (!atimer->running)
 154                 hw->set_timer_irq(hw, 1);
 155         atimer->running = 1;
 156 }
 157
 158 static void ct_xfitimer_irq_stop(struct ct_timer *atimer)
 159 {
 160         if (atimer->running) {
 161                 struct hw *hw = atimer->atc->hw;
 162                 hw->set_timer_irq(hw, 0);
 163                 hw->set_timer_tick(hw, 0);
 164                 atimer->running = 0;
 165         }
 166 }
 167
 168 static inline unsigned int ct_xfitimer_get_wc(struct ct_timer *atimer)
 169 {
 170         struct hw *hw = atimer->atc->hw;
 171         return hw->get_wc(hw);
 172 }
 173
 174 /*
 175  * reprogram the timer interval;
 176  * checks the running instance list and determines the next timer interval.
 177  * also updates the each stream position, returns the number of streams
 178  * to call snd_pcm_period_elapsed() appropriately
 179  *
 180  * call this inside the lock and irq disabled
 181  */
 182 static int ct_xfitimer_reprogram(struct ct_timer *atimer, int can_update)
 183 {
 184         struct ct_timer_instance *ti;
 185         unsigned int min_intr = (unsigned int)-1;
 186         int updates = 0;
 187         unsigned int wc, diff;
 188
 189         if (list_empty(&atimer->running_head)) {
 190                 ct_xfitimer_irq_stop(atimer);
 191                 atimer->reprogram = 0; /* clear flag */
 192                 return 0;
 193         }
 194
 195         wc = ct_xfitimer_get_wc(atimer);
 196         diff = wc - atimer->wc;
 197         atimer->wc = wc;
 198         list_for_each_entry(ti, &atimer->running_head, running_list) {
 199                 if (ti->frag_count > diff)
 200                         ti->frag_count -= diff;
 201                 else {
 202                         unsigned int pos;
 203                         unsigned int period_size, rate;
 204
 205                         period_size = ti->substream->runtime->period_size;
 206                         rate = ti->substream->runtime->rate;
 207                         pos = ti->substream->ops->pointer(ti->substream);
 208                         if (pos / period_size != ti->position / period_size) {
 209                                 ti->need_update = 1;
 210                                 ti->position = pos;
 211                                 updates++;
 212                         }
 213                         pos %= period_size;
 214                         pos = period_size - pos;
 215                         ti->frag_count = div_u64((u64)pos * CT_TIMER_FREQ +
 216                                                  rate - 1, rate);
 217                 }
 218                 if (ti->need_update && !can_update)
 219                         min_intr = 0; /* pending to the next irq */
 220                 if (ti->frag_count < min_intr)
 221                         min_intr = ti->frag_count;
 222         }
 223
 224         if (min_intr < MIN_TICKS)
 225                 min_intr = MIN_TICKS;
 226         ct_xfitimer_irq_rearm(atimer, min_intr);
 227         atimer->reprogram = 0; /* clear flag */
 228         return updates;
 229 }
 230
 231 /* look through the instance list and call period_elapsed if needed */
 232 static void ct_xfitimer_check_period(struct ct_timer *atimer)
 233 {
 234         struct ct_timer_instance *ti;
 235         unsigned long flags;
 236
 237         spin_lock_irqsave(&atimer->list_lock, flags);
 238         list_for_each_entry(ti, &atimer->instance_head, instance_list) {
 239                 if (ti->running && ti->need_update) {
 240                         ti->need_update = 0;
 241                         ti->apcm->interrupt(ti->apcm);
 242                 }
 243         }
 244         spin_unlock_irqrestore(&atimer->list_lock, flags);
 245 }
 246
 247 /* Handle timer-interrupt */
 248 static void ct_xfitimer_callback(struct ct_timer *atimer)
 249 {
 250         int update;
 251         unsigned long flags;
 252
 253         spin_lock_irqsave(&atimer->lock, flags);
 254         atimer->irq_handling = 1;
 255         do {
 256                 update = ct_xfitimer_reprogram(atimer, 1);
 257                 spin_unlock(&atimer->lock);
 258                 if (update)
 259                         ct_xfitimer_check_period(atimer);
 260                 spin_lock(&atimer->lock);
 261         } while (atimer->reprogram);
 262         atimer->irq_handling = 0;
 263         spin_unlock_irqrestore(&atimer->lock, flags);
 264 }
 265
 266 static void ct_xfitimer_prepare(struct ct_timer_instance *ti)
 267 {
 268         ti->frag_count = ti->substream->runtime->period_size;
 269         ti->running = 0;
 270         ti->need_update = 0;
 271 }
 272
 273
 274 /* start/stop the timer */
 275 static void ct_xfitimer_update(struct ct_timer *atimer)
 276 {
 277         unsigned long flags;
 278
 279         spin_lock_irqsave(&atimer->lock, flags);
 280         if (atimer->irq_handling) {
 281                 /* reached from IRQ handler; let it handle later */
 282                 atimer->reprogram = 1;
 283                 spin_unlock_irqrestore(&atimer->lock, flags);
 284                 return;
 285         }
 286
 287         ct_xfitimer_irq_stop(atimer);
 288         ct_xfitimer_reprogram(atimer, 0);
 289         spin_unlock_irqrestore(&atimer->lock, flags);
 290 }
 291
 292 static void ct_xfitimer_start(struct ct_timer_instance *ti)
 293 {
 294         struct ct_timer *atimer = ti->timer_base;
 295         unsigned long flags;
 296
 297         spin_lock_irqsave(&atimer->lock, flags);
 298         if (list_empty(&ti->running_list))
 299                 atimer->wc = ct_xfitimer_get_wc(atimer);
 300         ti->running = 1;
 301         ti->need_update = 0;
 302         list_add(&ti->running_list, &atimer->running_head);
 303         spin_unlock_irqrestore(&atimer->lock, flags);
 304         ct_xfitimer_update(atimer);
 305 }
 306
 307 static void ct_xfitimer_stop(struct ct_timer_instance *ti)
 308 {
 309         struct ct_timer *atimer = ti->timer_base;
 310         unsigned long flags;
 311
 312         spin_lock_irqsave(&atimer->lock, flags);
 313         list_del_init(&ti->running_list);
 314         ti->running = 0;
 315         spin_unlock_irqrestore(&atimer->lock, flags);
 316         ct_xfitimer_update(atimer);
 317 }
 318
 319 static void ct_xfitimer_free_global(struct ct_timer *atimer)
 320 {
 321         ct_xfitimer_irq_stop(atimer);
 322 }
 323
 324 static const struct ct_timer_ops ct_xfitimer_ops = {
 325         .prepare = ct_xfitimer_prepare,
 326         .start = ct_xfitimer_start,
 327         .stop = ct_xfitimer_stop,
 328         .interrupt = ct_xfitimer_callback,
 329         .free_global = ct_xfitimer_free_global,
 330 };
 331
 332 /*
 333  * timer instance
 334  */
 335
 336 struct ct_timer_instance *
 337 ct_timer_instance_new(struct ct_timer *atimer, struct ct_atc_pcm *apcm)
 338 {
 339         struct ct_timer_instance *ti;
 340
 341         ti = kzalloc(sizeof(*ti), GFP_KERNEL);
 342         if (!ti)
 343                 return NULL;
 344         spin_lock_init(&ti->lock);
 345         INIT_LIST_HEAD(&ti->instance_list);
 346         INIT_LIST_HEAD(&ti->running_list);
 347         ti->timer_base = atimer;
 348         ti->apcm = apcm;
 349         ti->substream = apcm->substream;
 350         if (atimer->ops->init)
 351                 atimer->ops->init(ti);
 352
 353         spin_lock_irq(&atimer->list_lock);
 354         list_add(&ti->instance_list, &atimer->instance_head);
 355         spin_unlock_irq(&atimer->list_lock);
 356
 357         return ti;
 358 }
 359
 360 void ct_timer_prepare(struct ct_timer_instance *ti)
 361 {
 362         if (ti->timer_base->ops->prepare)
 363                 ti->timer_base->ops->prepare(ti);
 364         ti->position = 0;
 365         ti->running = 0;
 366 }
 367
 368 void ct_timer_start(struct ct_timer_instance *ti)
 369 {
 370         struct ct_timer *atimer = ti->timer_base;
 371         atimer->ops->start(ti);
 372 }
 373
 374 void ct_timer_stop(struct ct_timer_instance *ti)
 375 {
 376         struct ct_timer *atimer = ti->timer_base;
 377         atimer->ops->stop(ti);
 378 }
 379
 380 void ct_timer_instance_free(struct ct_timer_instance *ti)
 381 {
 382         struct ct_timer *atimer = ti->timer_base;
 383
 384         atimer->ops->stop(ti); /* to be sure */
 385         if (atimer->ops->free_instance)
 386                 atimer->ops->free_instance(ti);
 387
 388         spin_lock_irq(&atimer->list_lock);
 389         list_del(&ti->instance_list);
 390         spin_unlock_irq(&atimer->list_lock);
 391
 392         kfree(ti);
 393 }
 394
 395 /*
 396  * timer manager
 397  */
 398
 399 static void ct_timer_interrupt(void *data, unsigned int status)
 400 {
 401         struct ct_timer *timer = data;
 402
 403         /* Interval timer interrupt */
 404         if ((status & IT_INT) && timer->ops->interrupt)
 405                 timer->ops->interrupt(timer);
 406 }
 407
 408 struct ct_timer *ct_timer_new(struct ct_atc *atc)
 409 {
 410         struct ct_timer *atimer;
 411         struct hw *hw;
 412
 413         atimer = kzalloc(sizeof(*atimer), GFP_KERNEL);
 414         if (!atimer)
 415                 return NULL;
 416         spin_lock_init(&atimer->lock);
 417         spin_lock_init(&atimer->list_lock);
 418         INIT_LIST_HEAD(&atimer->instance_head);
 419         INIT_LIST_HEAD(&atimer->running_head);
 420         atimer->atc = atc;
 421         hw = atc->hw;
 422         if (!use_system_timer && hw->set_timer_irq) {
 423                 dev_info(atc->card->dev, "Use xfi-native timer\n");
 424                 atimer->ops = &ct_xfitimer_ops;
 425                 hw->irq_callback_data = atimer;
 426                 hw->irq_callback = ct_timer_interrupt;
 427         } else {
 428                 dev_info(atc->card->dev, "Use system timer\n");
 429                 atimer->ops = &ct_systimer_ops;
 430         }
 431         return atimer;
 432 }
 433
 434 void ct_timer_free(struct ct_timer *atimer)
 435 {
 436         struct hw *hw = atimer->atc->hw;
 437         hw->irq_callback = NULL;
 438         if (atimer->ops->free_global)
 439                 atimer->ops->free_global(atimer);
 440         kfree(atimer);
 441 }
 442