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 int use_system_timer;
  19 MODULE_PARM_DESC(use_system_timer, "Foce 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         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 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)
 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->frag_count < min_intr)
 220                         min_intr = ti->frag_count;
 221         }
 222
 223         if (min_intr < MIN_TICKS)
 224                 min_intr = MIN_TICKS;
 225         ct_xfitimer_irq_rearm(atimer, min_intr);
 226         atimer->reprogram = 0; /* clear flag */
 227         return updates;
 228 }
 229
 230 /* look through the instance list and call period_elapsed if needed */
 231 static void ct_xfitimer_check_period(struct ct_timer *atimer)
 232 {
 233         struct ct_timer_instance *ti;
 234         unsigned long flags;
 235
 236         spin_lock_irqsave(&atimer->list_lock, flags);
 237         list_for_each_entry(ti, &atimer->instance_head, instance_list) {
 238                 if (ti->need_update) {
 239                         ti->need_update = 0;
 240                         ti->apcm->interrupt(ti->apcm);
 241                 }
 242         }
 243         spin_unlock_irqrestore(&atimer->list_lock, flags);
 244 }
 245
 246 /* Handle timer-interrupt */
 247 static void ct_xfitimer_callback(struct ct_timer *atimer)
 248 {
 249         int update;
 250         unsigned long flags;
 251
 252         spin_lock_irqsave(&atimer->lock, flags);
 253         atimer->irq_handling = 1;
 254         do {
 255                 update = ct_xfitimer_reprogram(atimer);
 256                 spin_unlock(&atimer->lock);
 257                 if (update)
 258                         ct_xfitimer_check_period(atimer);
 259                 spin_lock(&atimer->lock);
 260         } while (atimer->reprogram);
 261         atimer->irq_handling = 0;
 262         spin_unlock_irqrestore(&atimer->lock, flags);
 263 }
 264
 265 static void ct_xfitimer_prepare(struct ct_timer_instance *ti)
 266 {
 267         ti->frag_count = ti->substream->runtime->period_size;
 268         ti->need_update = 0;
 269 }
 270
 271
 272 /* start/stop the timer */
 273 static void ct_xfitimer_update(struct ct_timer *atimer)
 274 {
 275         unsigned long flags;
 276         int update;
 277
 278         spin_lock_irqsave(&atimer->lock, flags);
 279         if (atimer->irq_handling) {
 280                 /* reached from IRQ handler; let it handle later */
 281                 atimer->reprogram = 1;
 282                 spin_unlock_irqrestore(&atimer->lock, flags);
 283                 return;
 284         }
 285
 286         ct_xfitimer_irq_stop(atimer);
 287         update = ct_xfitimer_reprogram(atimer);
 288         spin_unlock_irqrestore(&atimer->lock, flags);
 289         if (update)
 290                 ct_xfitimer_check_period(atimer);
 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         list_add(&ti->running_list, &atimer->running_head);
 302         spin_unlock_irqrestore(&atimer->lock, flags);
 303         ct_xfitimer_update(atimer);
 304 }
 305
 306 static void ct_xfitimer_stop(struct ct_timer_instance *ti)
 307 {
 308         struct ct_timer *atimer = ti->timer_base;
 309         unsigned long flags;
 310
 311         spin_lock_irqsave(&atimer->lock, flags);
 312         list_del_init(&ti->running_list);
 313         ti->need_update = 0;
 314         spin_unlock_irqrestore(&atimer->lock, flags);
 315         ct_xfitimer_update(atimer);
 316 }
 317
 318 static void ct_xfitimer_free_global(struct ct_timer *atimer)
 319 {
 320         ct_xfitimer_irq_stop(atimer);
 321 }
 322
 323 static struct ct_timer_ops ct_xfitimer_ops = {
 324         .prepare = ct_xfitimer_prepare,
 325         .start = ct_xfitimer_start,
 326         .stop = ct_xfitimer_stop,
 327         .interrupt = ct_xfitimer_callback,
 328         .free_global = ct_xfitimer_free_global,
 329 };
 330
 331 /*
 332  * timer instance
 333  */
 334
 335 struct ct_timer_instance *
 336 ct_timer_instance_new(struct ct_timer *atimer, struct ct_atc_pcm *apcm)
 337 {
 338         struct ct_timer_instance *ti;
 339
 340         ti = kzalloc(sizeof(*ti), GFP_KERNEL);
 341         if (!ti)
 342                 return NULL;
 343         spin_lock_init(&ti->lock);
 344         INIT_LIST_HEAD(&ti->instance_list);
 345         INIT_LIST_HEAD(&ti->running_list);
 346         ti->timer_base = atimer;
 347         ti->apcm = apcm;
 348         ti->substream = apcm->substream;
 349         if (atimer->ops->init)
 350                 atimer->ops->init(ti);
 351
 352         spin_lock_irq(&atimer->list_lock);
 353         list_add(&ti->instance_list, &atimer->instance_head);
 354         spin_unlock_irq(&atimer->list_lock);
 355
 356         return ti;
 357 }
 358
 359 void ct_timer_prepare(struct ct_timer_instance *ti)
 360 {
 361         if (ti->timer_base->ops->prepare)
 362                 ti->timer_base->ops->prepare(ti);
 363         ti->position = 0;
 364         ti->running = 0;
 365 }
 366
 367 void ct_timer_start(struct ct_timer_instance *ti)
 368 {
 369         struct ct_timer *atimer = ti->timer_base;
 370         atimer->ops->start(ti);
 371 }
 372
 373 void ct_timer_stop(struct ct_timer_instance *ti)
 374 {
 375         struct ct_timer *atimer = ti->timer_base;
 376         atimer->ops->stop(ti);
 377 }
 378
 379 void ct_timer_instance_free(struct ct_timer_instance *ti)
 380 {
 381         struct ct_timer *atimer = ti->timer_base;
 382
 383         atimer->ops->stop(ti); /* to be sure */
 384         if (atimer->ops->free_instance)
 385                 atimer->ops->free_instance(ti);
 386
 387         spin_lock_irq(&atimer->list_lock);
 388         list_del(&ti->instance_list);
 389         spin_unlock_irq(&atimer->list_lock);
 390
 391         kfree(ti);
 392 }
 393
 394 /*
 395  * timer manager
 396  */
 397
 398 static void ct_timer_interrupt(void *data, unsigned int status)
 399 {
 400         struct ct_timer *timer = data;
 401
 402         /* Interval timer interrupt */
 403         if ((status & IT_INT) && timer->ops->interrupt)
 404                 timer->ops->interrupt(timer);
 405 }
 406
 407 struct ct_timer *ct_timer_new(struct ct_atc *atc)
 408 {
 409         struct ct_timer *atimer;
 410         struct hw *hw;
 411
 412         atimer = kzalloc(sizeof(*atimer), GFP_KERNEL);
 413         if (!atimer)
 414                 return NULL;
 415         spin_lock_init(&atimer->lock);
 416         spin_lock_init(&atimer->list_lock);
 417         INIT_LIST_HEAD(&atimer->instance_head);
 418         INIT_LIST_HEAD(&atimer->running_head);
 419         atimer->atc = atc;
 420         hw = atc->hw;
 421         if (!use_system_timer && hw->set_timer_irq) {
 422                 snd_printd(KERN_INFO "ctxfi: Use xfi-native timer\n");
 423                 atimer->ops = &ct_xfitimer_ops;
 424                 hw->irq_callback_data = atimer;
 425                 hw->irq_callback = ct_timer_interrupt;
 426         } else {
 427                 snd_printd(KERN_INFO "ctxfi: Use system timer\n");
 428                 atimer->ops = &ct_systimer_ops;
 429         }
 430         return atimer;
 431 }
 432
 433 void ct_timer_free(struct ct_timer *atimer)
 434 {
 435         struct hw *hw = atimer->atc->hw;
 436         hw->irq_callback = NULL;
 437         if (atimer->ops->free_global)
 438                 atimer->ops->free_global(atimer);
 439         kfree(atimer);
 440 }
 441