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, S_IRUGO);
  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(unsigned long data)
  67 {
  68         struct ct_timer_instance *ti = (struct ct_timer_instance *)data;
  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         setup_timer(&ti->timer, ct_systimer_callback,
  97                     (unsigned long)ti);
  98 }
  99
 100 static void ct_systimer_start(struct ct_timer_instance *ti)
 101 {
 102         struct snd_pcm_runtime *runtime = ti->substream->runtime;
 103         unsigned long flags;
 104
 105         spin_lock_irqsave(&ti->lock, flags);
 106         ti->running = 1;
 107         mod_timer(&ti->timer,
 108                   jiffies + (runtime->period_size * HZ +
 109                              (runtime->rate - 1)) / runtime->rate);
 110         spin_unlock_irqrestore(&ti->lock, flags);
 111 }
 112
 113 static void ct_systimer_stop(struct ct_timer_instance *ti)
 114 {
 115         unsigned long flags;
 116
 117         spin_lock_irqsave(&ti->lock, flags);
 118         ti->running = 0;
 119         del_timer(&ti->timer);
 120         spin_unlock_irqrestore(&ti->lock, flags);
 121 }
 122
 123 static void ct_systimer_prepare(struct ct_timer_instance *ti)
 124 {
 125         ct_systimer_stop(ti);
 126         try_to_del_timer_sync(&ti->timer);
 127 }
 128
 129 #define ct_systimer_free        ct_systimer_prepare
 130
 131 static const struct ct_timer_ops ct_systimer_ops = {
 132         .init = ct_systimer_init,
 133         .free_instance = ct_systimer_free,
 134         .prepare = ct_systimer_prepare,
 135         .start = ct_systimer_start,
 136         .stop = ct_systimer_stop,
 137 };
 138
 139
 140 /*
 141  * Handling multiple streams using a global emu20k1 timer irq
 142  */
 143
 144 #define CT_TIMER_FREQ   48000
 145 #define MIN_TICKS       1
 146 #define MAX_TICKS       ((1 << 13) - 1)
 147
 148 static void ct_xfitimer_irq_rearm(struct ct_timer *atimer, int ticks)
 149 {
 150         struct hw *hw = atimer->atc->hw;
 151         if (ticks > MAX_TICKS)
 152                 ticks = MAX_TICKS;
 153         hw->set_timer_tick(hw, ticks);
 154         if (!atimer->running)
 155                 hw->set_timer_irq(hw, 1);
 156         atimer->running = 1;
 157 }
 158
 159 static void ct_xfitimer_irq_stop(struct ct_timer *atimer)
 160 {
 161         if (atimer->running) {
 162                 struct hw *hw = atimer->atc->hw;
 163                 hw->set_timer_irq(hw, 0);
 164                 hw->set_timer_tick(hw, 0);
 165                 atimer->running = 0;
 166         }
 167 }
 168
 169 static inline unsigned int ct_xfitimer_get_wc(struct ct_timer *atimer)
 170 {
 171         struct hw *hw = atimer->atc->hw;
 172         return hw->get_wc(hw);
 173 }
 174
 175 /*
 176  * reprogram the timer interval;
 177  * checks the running instance list and determines the next timer interval.
 178  * also updates the each stream position, returns the number of streams
 179  * to call snd_pcm_period_elapsed() appropriately
 180  *
 181  * call this inside the lock and irq disabled
 182  */
 183 static int ct_xfitimer_reprogram(struct ct_timer *atimer, int can_update)
 184 {
 185         struct ct_timer_instance *ti;
 186         unsigned int min_intr = (unsigned int)-1;
 187         int updates = 0;
 188         unsigned int wc, diff;
 189
 190         if (list_empty(&atimer->running_head)) {
 191                 ct_xfitimer_irq_stop(atimer);
 192                 atimer->reprogram = 0; /* clear flag */
 193                 return 0;
 194         }
 195
 196         wc = ct_xfitimer_get_wc(atimer);
 197         diff = wc - atimer->wc;
 198         atimer->wc = wc;
 199         list_for_each_entry(ti, &atimer->running_head, running_list) {
 200                 if (ti->frag_count > diff)
 201                         ti->frag_count -= diff;
 202                 else {
 203                         unsigned int pos;
 204                         unsigned int period_size, rate;
 205
 206                         period_size = ti->substream->runtime->period_size;
 207                         rate = ti->substream->runtime->rate;
 208                         pos = ti->substream->ops->pointer(ti->substream);
 209                         if (pos / period_size != ti->position / period_size) {
 210                                 ti->need_update = 1;
 211                                 ti->position = pos;
 212                                 updates++;
 213                         }
 214                         pos %= period_size;
 215                         pos = period_size - pos;
 216                         ti->frag_count = div_u64((u64)pos * CT_TIMER_FREQ +
 217                                                  rate - 1, rate);
 218                 }
 219                 if (ti->need_update && !can_update)
 220                         min_intr = 0; /* pending to the next irq */
 221                 if (ti->frag_count < min_intr)
 222                         min_intr = ti->frag_count;
 223         }
 224
 225         if (min_intr < MIN_TICKS)
 226                 min_intr = MIN_TICKS;
 227         ct_xfitimer_irq_rearm(atimer, min_intr);
 228         atimer->reprogram = 0; /* clear flag */
 229         return updates;
 230 }
 231
 232 /* look through the instance list and call period_elapsed if needed */
 233 static void ct_xfitimer_check_period(struct ct_timer *atimer)
 234 {
 235         struct ct_timer_instance *ti;
 236         unsigned long flags;
 237
 238         spin_lock_irqsave(&atimer->list_lock, flags);
 239         list_for_each_entry(ti, &atimer->instance_head, instance_list) {
 240                 if (ti->running && ti->need_update) {
 241                         ti->need_update = 0;
 242                         ti->apcm->interrupt(ti->apcm);
 243                 }
 244         }
 245         spin_unlock_irqrestore(&atimer->list_lock, flags);
 246 }
 247
 248 /* Handle timer-interrupt */
 249 static void ct_xfitimer_callback(struct ct_timer *atimer)
 250 {
 251         int update;
 252         unsigned long flags;
 253
 254         spin_lock_irqsave(&atimer->lock, flags);
 255         atimer->irq_handling = 1;
 256         do {
 257                 update = ct_xfitimer_reprogram(atimer, 1);
 258                 spin_unlock(&atimer->lock);
 259                 if (update)
 260                         ct_xfitimer_check_period(atimer);
 261                 spin_lock(&atimer->lock);
 262         } while (atimer->reprogram);
 263         atimer->irq_handling = 0;
 264         spin_unlock_irqrestore(&atimer->lock, flags);
 265 }
 266
 267 static void ct_xfitimer_prepare(struct ct_timer_instance *ti)
 268 {
 269         ti->frag_count = ti->substream->runtime->period_size;
 270         ti->running = 0;
 271         ti->need_update = 0;
 272 }
 273
 274
 275 /* start/stop the timer */
 276 static void ct_xfitimer_update(struct ct_timer *atimer)
 277 {
 278         unsigned long flags;
 279
 280         spin_lock_irqsave(&atimer->lock, flags);
 281         if (atimer->irq_handling) {
 282                 /* reached from IRQ handler; let it handle later */
 283                 atimer->reprogram = 1;
 284                 spin_unlock_irqrestore(&atimer->lock, flags);
 285                 return;
 286         }
 287
 288         ct_xfitimer_irq_stop(atimer);
 289         ct_xfitimer_reprogram(atimer, 0);
 290         spin_unlock_irqrestore(&atimer->lock, flags);
 291 }
 292
 293 static void ct_xfitimer_start(struct ct_timer_instance *ti)
 294 {
 295         struct ct_timer *atimer = ti->timer_base;
 296         unsigned long flags;
 297
 298         spin_lock_irqsave(&atimer->lock, flags);
 299         if (list_empty(&ti->running_list))
 300                 atimer->wc = ct_xfitimer_get_wc(atimer);
 301         ti->running = 1;
 302         ti->need_update = 0;
 303         list_add(&ti->running_list, &atimer->running_head);
 304         spin_unlock_irqrestore(&atimer->lock, flags);
 305         ct_xfitimer_update(atimer);
 306 }
 307
 308 static void ct_xfitimer_stop(struct ct_timer_instance *ti)
 309 {
 310         struct ct_timer *atimer = ti->timer_base;
 311         unsigned long flags;
 312
 313         spin_lock_irqsave(&atimer->lock, flags);
 314         list_del_init(&ti->running_list);
 315         ti->running = 0;
 316         spin_unlock_irqrestore(&atimer->lock, flags);
 317         ct_xfitimer_update(atimer);
 318 }
 319
 320 static void ct_xfitimer_free_global(struct ct_timer *atimer)
 321 {
 322         ct_xfitimer_irq_stop(atimer);
 323 }
 324
 325 static const struct ct_timer_ops ct_xfitimer_ops = {
 326         .prepare = ct_xfitimer_prepare,
 327         .start = ct_xfitimer_start,
 328         .stop = ct_xfitimer_stop,
 329         .interrupt = ct_xfitimer_callback,
 330         .free_global = ct_xfitimer_free_global,
 331 };
 332
 333 /*
 334  * timer instance
 335  */
 336
 337 struct ct_timer_instance *
 338 ct_timer_instance_new(struct ct_timer *atimer, struct ct_atc_pcm *apcm)
 339 {
 340         struct ct_timer_instance *ti;
 341
 342         ti = kzalloc(sizeof(*ti), GFP_KERNEL);
 343         if (!ti)
 344                 return NULL;
 345         spin_lock_init(&ti->lock);
 346         INIT_LIST_HEAD(&ti->instance_list);
 347         INIT_LIST_HEAD(&ti->running_list);
 348         ti->timer_base = atimer;
 349         ti->apcm = apcm;
 350         ti->substream = apcm->substream;
 351         if (atimer->ops->init)
 352                 atimer->ops->init(ti);
 353
 354         spin_lock_irq(&atimer->list_lock);
 355         list_add(&ti->instance_list, &atimer->instance_head);
 356         spin_unlock_irq(&atimer->list_lock);
 357
 358         return ti;
 359 }
 360
 361 void ct_timer_prepare(struct ct_timer_instance *ti)
 362 {
 363         if (ti->timer_base->ops->prepare)
 364                 ti->timer_base->ops->prepare(ti);
 365         ti->position = 0;
 366         ti->running = 0;
 367 }
 368
 369 void ct_timer_start(struct ct_timer_instance *ti)
 370 {
 371         struct ct_timer *atimer = ti->timer_base;
 372         atimer->ops->start(ti);
 373 }
 374
 375 void ct_timer_stop(struct ct_timer_instance *ti)
 376 {
 377         struct ct_timer *atimer = ti->timer_base;
 378         atimer->ops->stop(ti);
 379 }
 380
 381 void ct_timer_instance_free(struct ct_timer_instance *ti)
 382 {
 383         struct ct_timer *atimer = ti->timer_base;
 384
 385         atimer->ops->stop(ti); /* to be sure */
 386         if (atimer->ops->free_instance)
 387                 atimer->ops->free_instance(ti);
 388
 389         spin_lock_irq(&atimer->list_lock);
 390         list_del(&ti->instance_list);
 391         spin_unlock_irq(&atimer->list_lock);
 392
 393         kfree(ti);
 394 }
 395
 396 /*
 397  * timer manager
 398  */
 399
 400 static void ct_timer_interrupt(void *data, unsigned int status)
 401 {
 402         struct ct_timer *timer = data;
 403
 404         /* Interval timer interrupt */
 405         if ((status & IT_INT) && timer->ops->interrupt)
 406                 timer->ops->interrupt(timer);
 407 }
 408
 409 struct ct_timer *ct_timer_new(struct ct_atc *atc)
 410 {
 411         struct ct_timer *atimer;
 412         struct hw *hw;
 413
 414         atimer = kzalloc(sizeof(*atimer), GFP_KERNEL);
 415         if (!atimer)
 416                 return NULL;
 417         spin_lock_init(&atimer->lock);
 418         spin_lock_init(&atimer->list_lock);
 419         INIT_LIST_HEAD(&atimer->instance_head);
 420         INIT_LIST_HEAD(&atimer->running_head);
 421         atimer->atc = atc;
 422         hw = atc->hw;
 423         if (!use_system_timer && hw->set_timer_irq) {
 424                 dev_info(atc->card->dev, "Use xfi-native timer\n");
 425                 atimer->ops = &ct_xfitimer_ops;
 426                 hw->irq_callback_data = atimer;
 427                 hw->irq_callback = ct_timer_interrupt;
 428         } else {
 429                 dev_info(atc->card->dev, "Use system timer\n");
 430                 atimer->ops = &ct_systimer_ops;
 431         }
 432         return atimer;
 433 }
 434
 435 void ct_timer_free(struct ct_timer *atimer)
 436 {
 437         struct hw *hw = atimer->atc->hw;
 438         hw->irq_callback = NULL;
 439         if (atimer->ops->free_global)
 440                 atimer->ops->free_global(atimer);
 441         kfree(atimer);
 442 }
 443