aboutsummaryrefslogtreecommitdiff
path: root/sound/pci/ctxfi/cttimer.c
blob: 03fb909085af375322d53f653496e5f56d94d162 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
/*
 * PCM timer handling on ctxfi
 *
 * This source file is released under GPL v2 license (no other versions).
 * See the COPYING file included in the main directory of this source
 * distribution for the license terms and conditions.
 */

#include <linux/slab.h>
#include <linux/math64.h>
#include <linux/moduleparam.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include "ctatc.h"
#include "cthardware.h"
#include "cttimer.h"

static bool use_system_timer;
MODULE_PARM_DESC(use_system_timer, "Force to use system-timer");
module_param(use_system_timer, bool, S_IRUGO);

struct ct_timer_ops {
	void (*init)(struct ct_timer_instance *);
	void (*prepare)(struct ct_timer_instance *);
	void (*start)(struct ct_timer_instance *);
	void (*stop)(struct ct_timer_instance *);
	void (*free_instance)(struct ct_timer_instance *);
	void (*interrupt)(struct ct_timer *);
	void (*free_global)(struct ct_timer *);
};

/* timer instance -- assigned to each PCM stream */
struct ct_timer_instance {
	spinlock_t lock;
	struct ct_timer *timer_base;
	struct ct_atc_pcm *apcm;
	struct snd_pcm_substream *substream;
	struct timer_list timer;
	struct list_head instance_list;
	struct list_head running_list;
	unsigned int position;
	unsigned int frag_count;
	unsigned int running:1;
	unsigned int need_update:1;
};

/* timer instance manager */
struct ct_timer {
	spinlock_t lock;		/* global timer lock (for xfitimer) */
	spinlock_t list_lock;		/* lock for instance list */
	struct ct_atc *atc;
	struct ct_timer_ops *ops;
	struct list_head instance_head;
	struct list_head running_head;
	unsigned int wc;		/* current wallclock */
	unsigned int irq_handling:1;	/* in IRQ handling */
	unsigned int reprogram:1;	/* need to reprogram the internval */
	unsigned int running:1;		/* global timer running */
};


/*
 * system-timer-based updates
 */

static void ct_systimer_callback(unsigned long data)
{
	struct ct_timer_instance *ti = (struct ct_timer_instance *)data;
	struct snd_pcm_substream *substream = ti->substream;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct ct_atc_pcm *apcm = ti->apcm;
	unsigned int period_size = runtime->period_size;
	unsigned int buffer_size = runtime->buffer_size;
	unsigned long flags;
	unsigned int position, dist, interval;

	position = substream->ops->pointer(substream);
	dist = (position + buffer_size - ti->position) % buffer_size;
	if (dist >= period_size ||
	    position / period_size != ti->position / period_size) {
		apcm->interrupt(apcm);
		ti->position = position;
	}
	/* Add extra HZ*5/1000 to avoid overrun issue when recording
	 * at 8kHz in 8-bit format or at 88kHz in 24-bit format. */
	interval = ((period_size - (position % period_size))
		   * HZ + (runtime->rate - 1)) / runtime->rate + HZ * 5 / 1000;
	spin_lock_irqsave(&ti->lock, flags);
	if (ti->running)
		mod_timer(&ti->timer, jiffies + interval);
	spin_unlock_irqrestore(&ti->lock, flags);
}

static void ct_systimer_init(struct ct_timer_instance *ti)
{
	setup_timer(&ti->timer, ct_systimer_callback,
		    (unsigned long)ti);
}

static void ct_systimer_start(struct ct_timer_instance *ti)
{
	struct snd_pcm_runtime *runtime = ti->substream->runtime;
	unsigned long flags;

	spin_lock_irqsave(&ti->lock, flags);
	ti->running = 1;
	mod_timer(&ti->timer,
		  jiffies + (runtime->period_size * HZ +
			     (runtime->rate - 1)) / runtime->rate);
	spin_unlock_irqrestore(&ti->lock, flags);
}

static void ct_systimer_stop(struct ct_timer_instance *ti)
{
	unsigned long flags;

	spin_lock_irqsave(&ti->lock, flags);
	ti->running = 0;
	del_timer(&ti->timer);
	spin_unlock_irqrestore(&ti->lock, flags);
}

static void ct_systimer_prepare(struct ct_timer_instance *ti)
{
	ct_systimer_stop(ti);
	try_to_del_timer_sync(&ti->timer);
}

#define ct_systimer_free	ct_systimer_prepare

static struct ct_timer_ops ct_systimer_ops = {
	.init = ct_systimer_init,
	.free_instance = ct_systimer_free,
	.prepare = ct_systimer_prepare,
	.start = ct_systimer_start,
	.stop = ct_systimer_stop,
};


/*
 * Handling multiple streams using a global emu20k1 timer irq
 */

#define CT_TIMER_FREQ	48000
#define MIN_TICKS	1
#define MAX_TICKS	((1 << 13) - 1)

static void ct_xfitimer_irq_rearm(struct ct_timer *atimer, int ticks)
{
	struct hw *hw = atimer->atc->hw;
	if (ticks > MAX_TICKS)
		ticks = MAX_TICKS;
	hw->set_timer_tick(hw, ticks);
	if (!atimer->running)
		hw->set_timer_irq(hw, 1);
	atimer->running = 1;
}

static void ct_xfitimer_irq_stop(struct ct_timer *atimer)
{
	if (atimer->running) {
		struct hw *hw = atimer->atc->hw;
		hw->set_timer_irq(hw, 0);
		hw->set_timer_tick(hw, 0);
		atimer->running = 0;
	}
}

static inline unsigned int ct_xfitimer_get_wc(struct ct_timer *atimer)
{
	struct hw *hw = atimer->atc->hw;
	return hw->get_wc(hw);
}

/*
 * reprogram the timer interval;
 * checks the running instance list and determines the next timer interval.
 * also updates the each stream position, returns the number of streams
 * to call snd_pcm_period_elapsed() appropriately
 *
 * call this inside the lock and irq disabled
 */
static int ct_xfitimer_reprogram(struct ct_timer *atimer, int can_update)
{
	struct ct_timer_instance *ti;
	unsigned int min_intr = (unsigned int)-1;
	int updates = 0;
	unsigned int wc, diff;

	if (list_empty(&atimer->running_head)) {
		ct_xfitimer_irq_stop(atimer);
		atimer->reprogram = 0; /* clear flag */
		return 0;
	}

	wc = ct_xfitimer_get_wc(atimer);
	diff = wc - atimer->wc;
	atimer->wc = wc;
	list_for_each_entry(ti, &atimer->running_head, running_list) {
		if (ti->frag_count > diff)
			ti->frag_count -= diff;
		else {
			unsigned int pos;
			unsigned int period_size, rate;

			period_size = ti->substream->runtime->period_size;
			rate = ti->substream->runtime->rate;
			pos = ti->substream->ops->pointer(ti->substream);
			if (pos / period_size != ti->position / period_size) {
				ti->need_update = 1;
				ti->position = pos;
				updates++;
			}
			pos %= period_size;
			pos = period_size - pos;
			ti->frag_count = div_u64((u64)pos * CT_TIMER_FREQ +
						 rate - 1, rate);
		}
		if (ti->need_update && !can_update)
			min_intr = 0; /* pending to the next irq */
		if (ti->frag_count < min_intr)
			min_intr = ti->frag_count;
	}

	if (min_intr < MIN_TICKS)
		min_intr = MIN_TICKS;
	ct_xfitimer_irq_rearm(atimer, min_intr);
	atimer->reprogram = 0; /* clear flag */
	return updates;
}

/* look through the instance list and call period_elapsed if needed */
static void ct_xfitimer_check_period(struct ct_timer *atimer)
{
	struct ct_timer_instance *ti;
	unsigned long flags;

	spin_lock_irqsave(&atimer->list_lock, flags);
	list_for_each_entry(ti, &atimer->instance_head, instance_list) {
		if (ti->running && ti->need_update) {
			ti->need_update = 0;
			ti->apcm->interrupt(ti->apcm);
		}
	}
	spin_unlock_irqrestore(&atimer->list_lock, flags);
}

/* Handle timer-interrupt */
static void ct_xfitimer_callback(struct ct_timer *atimer)
{
	int update;
	unsigned long flags;

	spin_lock_irqsave(&atimer->lock, flags);
	atimer->irq_handling = 1;
	do {
		update = ct_xfitimer_reprogram(atimer, 1);
		spin_unlock(&atimer->lock);
		if (update)
			ct_xfitimer_check_period(atimer);
		spin_lock(&atimer->lock);
	} while (atimer->reprogram);
	atimer->irq_handling = 0;
	spin_unlock_irqrestore(&atimer->lock, flags);
}

static void ct_xfitimer_prepare(struct ct_timer_instance *ti)
{
	ti->frag_count = ti->substream->runtime->period_size;
	ti->running = 0;
	ti->need_update = 0;
}


/* start/stop the timer */
static void ct_xfitimer_update(struct ct_timer *atimer)
{
	unsigned long flags;

	spin_lock_irqsave(&atimer->lock, flags);
	if (atimer->irq_handling) {
		/* reached from IRQ handler; let it handle later */
		atimer->reprogram = 1;
		spin_unlock_irqrestore(&atimer->lock, flags);
		return;
	}

	ct_xfitimer_irq_stop(atimer);
	ct_xfitimer_reprogram(atimer, 0);
	spin_unlock_irqrestore(&atimer->lock, flags);
}

static void ct_xfitimer_start(struct ct_timer_instance *ti)
{
	struct ct_timer *atimer = ti->timer_base;
	unsigned long flags;

	spin_lock_irqsave(&atimer->lock, flags);
	if (list_empty(&ti->running_list))
		atimer->wc = ct_xfitimer_get_wc(atimer);
	ti->running = 1;
	ti->need_update = 0;
	list_add(&ti->running_list, &atimer->running_head);
	spin_unlock_irqrestore(&atimer->lock, flags);
	ct_xfitimer_update(atimer);
}

static void ct_xfitimer_stop(struct ct_timer_instance *ti)
{
	struct ct_timer *atimer = ti->timer_base;
	unsigned long flags;

	spin_lock_irqsave(&atimer->lock, flags);
	list_del_init(&ti->running_list);
	ti->running = 0;
	spin_unlock_irqrestore(&atimer->lock, flags);
	ct_xfitimer_update(atimer);
}

static void ct_xfitimer_free_global(struct ct_timer *atimer)
{
	ct_xfitimer_irq_stop(atimer);
}

static struct ct_timer_ops ct_xfitimer_ops = {
	.prepare = ct_xfitimer_prepare,
	.start = ct_xfitimer_start,
	.stop = ct_xfitimer_stop,
	.interrupt = ct_xfitimer_callback,
	.free_global = ct_xfitimer_free_global,
};

/*
 * timer instance
 */

struct ct_timer_instance *
ct_timer_instance_new(struct ct_timer *atimer, struct ct_atc_pcm *apcm)
{
	struct ct_timer_instance *ti;

	ti = kzalloc(sizeof(*ti), GFP_KERNEL);
	if (!ti)
		return NULL;
	spin_lock_init(&ti->lock);
	INIT_LIST_HEAD(&ti->instance_list);
	INIT_LIST_HEAD(&ti->running_list);
	ti->timer_base = atimer;
	ti->apcm = apcm;
	ti->substream = apcm->substream;
	if (atimer->ops->init)
		atimer->ops->init(ti);

	spin_lock_irq(&atimer->list_lock);
	list_add(&ti->instance_list, &atimer->instance_head);
	spin_unlock_irq(&atimer->list_lock);

	return ti;
}

void ct_timer_prepare(struct ct_timer_instance *ti)
{
	if (ti->timer_base->ops->prepare)
		ti->timer_base->ops->prepare(ti);
	ti->position = 0;
	ti->running = 0;
}

void ct_timer_start(struct ct_timer_instance *ti)
{
	struct ct_timer *atimer = ti->timer_base;
	atimer->ops->start(ti);
}

void ct_timer_stop(struct ct_timer_instance *ti)
{
	struct ct_timer *atimer = ti->timer_base;
	atimer->ops->stop(ti);
}

void ct_timer_instance_free(struct ct_timer_instance *ti)
{
	struct ct_timer *atimer = ti->timer_base;

	atimer->ops->stop(ti); /* to be sure */
	if (atimer->ops->free_instance)
		atimer->ops->free_instance(ti);

	spin_lock_irq(&atimer->list_lock);
	list_del(&ti->instance_list);
	spin_unlock_irq(&atimer->list_lock);

	kfree(ti);
}

/*
 * timer manager
 */

static void ct_timer_interrupt(void *data, unsigned int status)
{
	struct ct_timer *timer = data;

	/* Interval timer interrupt */
	if ((status & IT_INT) && timer->ops->interrupt)
		timer->ops->interrupt(timer);
}

struct ct_timer *ct_timer_new(struct ct_atc *atc)
{
	struct ct_timer *atimer;
	struct hw *hw;

	atimer = kzalloc(sizeof(*atimer), GFP_KERNEL);
	if (!atimer)
		return NULL;
	spin_lock_init(&atimer->lock);
	spin_lock_init(&atimer->list_lock);
	INIT_LIST_HEAD(&atimer->instance_head);
	INIT_LIST_HEAD(&atimer->running_head);
	atimer->atc = atc;
	hw = atc->hw;
	if (!use_system_timer && hw->set_timer_irq) {
		snd_printd(KERN_INFO "ctxfi: Use xfi-native timer\n");
		atimer->ops = &ct_xfitimer_ops;
		hw->irq_callback_data = atimer;
		hw->irq_callback = ct_timer_interrupt;
	} else {
		snd_printd(KERN_INFO "ctxfi: Use system timer\n");
		atimer->ops = &ct_systimer_ops;
	}
	return atimer;
}

void ct_timer_free(struct ct_timer *atimer)
{
	struct hw *hw = atimer->atc->hw;
	hw->irq_callback = NULL;
	if (atimer->ops->free_global)
		atimer->ops->free_global(atimer);
	kfree(atimer);
}