1/*
2 * Helper functions for indirect PCM data transfer to a simple FIFO in
3 * hardware (small, no possibility to read "hardware io position",
4 * updating position done by interrupt, ...)
5 *
6 *  Copyright (c) by 2007  Joachim Foerster <JOFT@gmx.de>
7 *
8 *  Based on "pcm-indirect.h" (alsa-driver-1.0.13) by
9 *
10 *  Copyright (c) by Takashi Iwai <tiwai@suse.de>
11 *                   Jaroslav Kysela <perex@suse.cz>
12 *
13 *   This program is free software; you can redistribute it and/or modify
14 *   it under the terms of the GNU General Public License as published by
15 *   the Free Software Foundation; either version 2 of the License, or
16 *   (at your option) any later version.
17 *
18 *   This program is distributed in the hope that it will be useful,
19 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
20 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21 *   GNU General Public License for more details.
22 *
23 *   You should have received a copy of the GNU General Public License
24 *   along with this program; if not, write to the Free Software
25 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
27
28/* snd_printk/d() */
29#include <sound/core.h>
30/* struct snd_pcm_substream, struct snd_pcm_runtime, snd_pcm_uframes_t
31 * snd_pcm_period_elapsed() */
32#include <sound/pcm.h>
33
34#include "pcm-indirect2.h"
35
36#ifdef SND_PCM_INDIRECT2_STAT
37/* jiffies */
38#include <linux/jiffies.h>
39
40void snd_pcm_indirect2_stat(struct snd_pcm_substream *substream,
41			    struct snd_pcm_indirect2 *rec)
42{
43	struct snd_pcm_runtime *runtime = substream->runtime;
44	int i;
45	int j;
46	int k;
47	int seconds = (rec->lastbytetime - rec->firstbytetime) / HZ;
48
49	snd_printk(KERN_DEBUG "STAT: mul_elapsed: %u, mul_elapsed_real: %d, "
50		   "irq_occured: %d\n",
51		   rec->mul_elapsed, rec->mul_elapsed_real, rec->irq_occured);
52	snd_printk(KERN_DEBUG "STAT: min_multiple: %d (irqs/period)\n",
53		   rec->min_multiple);
54	snd_printk(KERN_DEBUG "STAT: firstbytetime: %lu, lastbytetime: %lu, "
55		   "firstzerotime: %lu\n",
56		 rec->firstbytetime, rec->lastbytetime, rec->firstzerotime);
57	snd_printk(KERN_DEBUG "STAT: bytes2hw: %u Bytes => (by runtime->rate) "
58		   "length: %d s\n",
59		 rec->bytes2hw, rec->bytes2hw / 2 / 2 / runtime->rate);
60	snd_printk(KERN_DEBUG "STAT: (by measurement) length: %d => "
61		   "rate: %d Bytes/s = %d Frames/s|Hz\n",
62		   seconds, rec->bytes2hw / seconds,
63		   rec->bytes2hw / 2 / 2 / seconds);
64	snd_printk(KERN_DEBUG
65		   "STAT: zeros2hw: %u = %d ms ~ %d * %d zero copies\n",
66		   rec->zeros2hw, ((rec->zeros2hw / 2 / 2) * 1000) /
67		   runtime->rate,
68		   rec->zeros2hw / (rec->hw_buffer_size / 2),
69		   (rec->hw_buffer_size / 2));
70	snd_printk(KERN_DEBUG "STAT: pointer_calls: %u, lastdifftime: %u\n",
71		   rec->pointer_calls, rec->lastdifftime);
72	snd_printk(KERN_DEBUG "STAT: sw_io: %d, sw_data: %d\n", rec->sw_io,
73		   rec->sw_data);
74	snd_printk(KERN_DEBUG "STAT: byte_sizes[]:\n");
75	k = 0;
76	for (j = 0; j < 8; j++) {
77		for (i = j * 8; i < (j + 1) * 8; i++)
78			if (rec->byte_sizes[i] != 0) {
79				snd_printk(KERN_DEBUG "%u: %u",
80					   i, rec->byte_sizes[i]);
81				k++;
82			}
83		if (((k % 8) == 0) && (k != 0)) {
84			snd_printk(KERN_DEBUG "\n");
85			k = 0;
86		}
87	}
88	snd_printk(KERN_DEBUG "\n");
89	snd_printk(KERN_DEBUG "STAT: zero_sizes[]:\n");
90	for (j = 0; j < 8; j++) {
91		k = 0;
92		for (i = j * 8; i < (j + 1) * 8; i++)
93			if (rec->zero_sizes[i] != 0)
94				snd_printk(KERN_DEBUG "%u: %u",
95					   i, rec->zero_sizes[i]);
96			else
97				k++;
98		if (!k)
99			snd_printk(KERN_DEBUG "\n");
100	}
101	snd_printk(KERN_DEBUG "\n");
102	snd_printk(KERN_DEBUG "STAT: min_adds[]:\n");
103	for (j = 0; j < 8; j++) {
104		if (rec->min_adds[j] != 0)
105			snd_printk(KERN_DEBUG "%u: %u", j, rec->min_adds[j]);
106	}
107	snd_printk(KERN_DEBUG "\n");
108	snd_printk(KERN_DEBUG "STAT: mul_adds[]:\n");
109	for (j = 0; j < 8; j++) {
110		if (rec->mul_adds[j] != 0)
111			snd_printk(KERN_DEBUG "%u: %u", j, rec->mul_adds[j]);
112	}
113	snd_printk(KERN_DEBUG "\n");
114	snd_printk(KERN_DEBUG
115		   "STAT: zero_times_saved: %d, zero_times_notsaved: %d\n",
116		   rec->zero_times_saved, rec->zero_times_notsaved);
117	/* snd_printk(KERN_DEBUG "STAT: zero_times[]\n");
118	i = 0;
119	for (j = 0; j < 3750; j++) {
120		if (rec->zero_times[j] != 0) {
121			snd_printk(KERN_DEBUG "%u: %u", j, rec->zero_times[j]);
122			i++;
123		}
124		if (((i % 8) == 0) && (i != 0))
125			snd_printk(KERN_DEBUG "\n");
126	}
127	snd_printk(KERN_DEBUG "\n"); */
128	return;
129}
130#endif
131
132/*
133 * _internal_ helper function for playback/capture transfer function
134 */
135static void
136snd_pcm_indirect2_increase_min_periods(struct snd_pcm_substream *substream,
137				       struct snd_pcm_indirect2 *rec,
138				       int isplay, int iscopy,
139				       unsigned int bytes)
140{
141	if (rec->min_periods >= 0) {
142		if (iscopy) {
143			rec->sw_io += bytes;
144			if (rec->sw_io >= rec->sw_buffer_size)
145				rec->sw_io -= rec->sw_buffer_size;
146		} else if (isplay) {
147			/* If application does not write data in multiples of
148			 * a period, move sw_data to the next correctly aligned
149			 * position, so that sw_io can converge to it (in the
150			 * next step).
151			 */
152			if (!rec->check_alignment) {
153				if (rec->bytes2hw %
154				    snd_pcm_lib_period_bytes(substream)) {
155					unsigned bytes2hw_aligned =
156					    (1 +
157					     (rec->bytes2hw /
158					      snd_pcm_lib_period_bytes
159					      (substream))) *
160					    snd_pcm_lib_period_bytes
161					    (substream);
162					rec->sw_data =
163					    bytes2hw_aligned %
164					    rec->sw_buffer_size;
165#ifdef SND_PCM_INDIRECT2_STAT
166					snd_printk(KERN_DEBUG
167						   "STAT: @re-align: aligned "
168						   "bytes2hw to next period "
169						   "size boundary: %d "
170						   "(instead of %d)\n",
171						   bytes2hw_aligned,
172						   rec->bytes2hw);
173					snd_printk(KERN_DEBUG
174						   "STAT: @re-align: sw_data "
175						   "moves to: %d\n",
176						   rec->sw_data);
177#endif
178				}
179				rec->check_alignment = 1;
180			}
181			/* We are at the end and are copying zeros into the
182			 * fifo.
183			 * Now, we have to make sure that sw_io is increased
184			 * until the position of sw_data: Filling the fifo with
185			 * the first zeros means, the last bytes were played.
186			 */
187			if (rec->sw_io != rec->sw_data) {
188				unsigned int diff;
189				if (rec->sw_data > rec->sw_io)
190					diff = rec->sw_data - rec->sw_io;
191				else
192					diff = (rec->sw_buffer_size -
193						rec->sw_io) +
194						rec->sw_data;
195				if (bytes >= diff)
196					rec->sw_io = rec->sw_data;
197				else {
198					rec->sw_io += bytes;
199					if (rec->sw_io >= rec->sw_buffer_size)
200						rec->sw_io -=
201						    rec->sw_buffer_size;
202				}
203			}
204		}
205		rec->min_period_count += bytes;
206		if (rec->min_period_count >= (rec->hw_buffer_size / 2)) {
207			rec->min_periods += (rec->min_period_count /
208					     (rec->hw_buffer_size / 2));
209#ifdef SND_PCM_INDIRECT2_STAT
210			if ((rec->min_period_count /
211			     (rec->hw_buffer_size / 2)) > 7)
212				snd_printk(KERN_DEBUG
213					   "STAT: more than 7 (%d) min_adds "
214					   "at once - too big to save!\n",
215					   (rec->min_period_count /
216					    (rec->hw_buffer_size / 2)));
217			else
218				rec->min_adds[(rec->min_period_count /
219					       (rec->hw_buffer_size / 2))]++;
220#endif
221			rec->min_period_count = (rec->min_period_count %
222						 (rec->hw_buffer_size / 2));
223		}
224	} else if (isplay && iscopy)
225		rec->min_periods = 0;
226}
227
228/*
229 * helper function for playback/capture pointer callback
230 */
231snd_pcm_uframes_t
232snd_pcm_indirect2_pointer(struct snd_pcm_substream *substream,
233			  struct snd_pcm_indirect2 *rec)
234{
235#ifdef SND_PCM_INDIRECT2_STAT
236	rec->pointer_calls++;
237#endif
238	return bytes_to_frames(substream->runtime, rec->sw_io);
239}
240
241/*
242 * _internal_ helper function for playback interrupt callback
243 */
244static void
245snd_pcm_indirect2_playback_transfer(struct snd_pcm_substream *substream,
246				    struct snd_pcm_indirect2 *rec,
247				    snd_pcm_indirect2_copy_t copy,
248				    snd_pcm_indirect2_zero_t zero)
249{
250	struct snd_pcm_runtime *runtime = substream->runtime;
251	snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr;
252
253	/* runtime->control->appl_ptr: position where ALSA will write next time
254	 * rec->appl_ptr: position where ALSA was last time
255	 * diff: obviously ALSA wrote that much bytes into the intermediate
256	 * buffer since we checked last time
257	 */
258	snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr;
259
260	if (diff) {
261#ifdef SND_PCM_INDIRECT2_STAT
262		rec->lastdifftime = jiffies;
263#endif
264		if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2))
265			diff += runtime->boundary;
266		/* number of bytes "added" by ALSA increases the number of
267		 * bytes which are ready to "be transferred to HW"/"played"
268		 * Then, set rec->appl_ptr to not count bytes twice next time.
269		 */
270		rec->sw_ready += (int)frames_to_bytes(runtime, diff);
271		rec->appl_ptr = appl_ptr;
272	}
273	if (rec->hw_ready && (rec->sw_ready <= 0)) {
274		unsigned int bytes;
275
276#ifdef SND_PCM_INDIRECT2_STAT
277		if (rec->firstzerotime == 0) {
278			rec->firstzerotime = jiffies;
279			snd_printk(KERN_DEBUG
280				   "STAT: @firstzerotime: mul_elapsed: %d, "
281				   "min_period_count: %d\n",
282				   rec->mul_elapsed, rec->min_period_count);
283			snd_printk(KERN_DEBUG
284				   "STAT: @firstzerotime: sw_io: %d, "
285				   "sw_data: %d, appl_ptr: %u\n",
286				   rec->sw_io, rec->sw_data,
287				   (unsigned int)appl_ptr);
288		}
289		if ((jiffies - rec->firstzerotime) < 3750) {
290			rec->zero_times[(jiffies - rec->firstzerotime)]++;
291			rec->zero_times_saved++;
292		} else
293			rec->zero_times_notsaved++;
294#endif
295		bytes = zero(substream, rec);
296
297#ifdef SND_PCM_INDIRECT2_STAT
298		rec->zeros2hw += bytes;
299		if (bytes < 64)
300			rec->zero_sizes[bytes]++;
301		else
302			snd_printk(KERN_DEBUG
303				   "STAT: %d zero Bytes copied to hardware at "
304				   "once - too big to save!\n",
305				   bytes);
306#endif
307		snd_pcm_indirect2_increase_min_periods(substream, rec, 1, 0,
308						       bytes);
309		return;
310	}
311	while (rec->hw_ready && (rec->sw_ready > 0)) {
312		/* sw_to_end: max. number of bytes that can be read/take from
313		 * the current position (sw_data) in _one_ step
314		 */
315		unsigned int sw_to_end = rec->sw_buffer_size - rec->sw_data;
316
317		/* bytes: number of bytes we have available (for reading) */
318		unsigned int bytes = rec->sw_ready;
319
320		if (sw_to_end < bytes)
321			bytes = sw_to_end;
322		if (!bytes)
323			break;
324
325#ifdef SND_PCM_INDIRECT2_STAT
326		if (rec->firstbytetime == 0)
327			rec->firstbytetime = jiffies;
328		rec->lastbytetime = jiffies;
329#endif
330		/* copy bytes from intermediate buffer position sw_data to the
331		 * HW and return number of bytes actually written
332		 * Furthermore, set hw_ready to 0, if the fifo isn't empty
333		 * now => more could be transferred to fifo
334		 */
335		bytes = copy(substream, rec, bytes);
336		rec->bytes2hw += bytes;
337
338#ifdef SND_PCM_INDIRECT2_STAT
339		if (bytes < 64)
340			rec->byte_sizes[bytes]++;
341		else
342			snd_printk(KERN_DEBUG
343				   "STAT: %d Bytes copied to hardware at once "
344				   "- too big to save!\n",
345				   bytes);
346#endif
347		/* increase sw_data by the number of actually written bytes
348		 * (= number of taken bytes from intermediate buffer)
349		 */
350		rec->sw_data += bytes;
351		if (rec->sw_data == rec->sw_buffer_size)
352			rec->sw_data = 0;
353		/* now sw_data is the position where ALSA is going to write
354		 * in the intermediate buffer next time = position we are going
355		 * to read from next time
356		 */
357
358		snd_pcm_indirect2_increase_min_periods(substream, rec, 1, 1,
359						       bytes);
360
361		/* we read bytes from intermediate buffer, so we need to say
362		 * that the number of bytes ready for transfer are decreased
363		 * now
364		 */
365		rec->sw_ready -= bytes;
366	}
367	return;
368}
369
370/*
371 * helper function for playback interrupt routine
372 */
373void
374snd_pcm_indirect2_playback_interrupt(struct snd_pcm_substream *substream,
375				     struct snd_pcm_indirect2 *rec,
376				     snd_pcm_indirect2_copy_t copy,
377				     snd_pcm_indirect2_zero_t zero)
378{
379#ifdef SND_PCM_INDIRECT2_STAT
380	rec->irq_occured++;
381#endif
382	/* hardware played some bytes, so there is room again (in fifo) */
383	rec->hw_ready = 1;
384
385	/* don't call ack() now, instead call transfer() function directly
386	 * (normally called by ack() )
387	 */
388	snd_pcm_indirect2_playback_transfer(substream, rec, copy, zero);
389
390	if (rec->min_periods >= rec->min_multiple) {
391#ifdef SND_PCM_INDIRECT2_STAT
392		if ((rec->min_periods / rec->min_multiple) > 7)
393			snd_printk(KERN_DEBUG
394				   "STAT: more than 7 (%d) mul_adds - too big "
395				   "to save!\n",
396				   (rec->min_periods / rec->min_multiple));
397		else
398			rec->mul_adds[(rec->min_periods /
399				       rec->min_multiple)]++;
400		rec->mul_elapsed_real += (rec->min_periods /
401					  rec->min_multiple);
402		rec->mul_elapsed++;
403#endif
404		rec->min_periods = (rec->min_periods % rec->min_multiple);
405		snd_pcm_period_elapsed(substream);
406	}
407}
408
409/*
410 * _internal_ helper function for capture interrupt callback
411 */
412static void
413snd_pcm_indirect2_capture_transfer(struct snd_pcm_substream *substream,
414				   struct snd_pcm_indirect2 *rec,
415				   snd_pcm_indirect2_copy_t copy,
416				   snd_pcm_indirect2_zero_t null)
417{
418	struct snd_pcm_runtime *runtime = substream->runtime;
419	snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr;
420	snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr;
421
422	if (diff) {
423#ifdef SND_PCM_INDIRECT2_STAT
424		rec->lastdifftime = jiffies;
425#endif
426		if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2))
427			diff += runtime->boundary;
428		rec->sw_ready -= frames_to_bytes(runtime, diff);
429		rec->appl_ptr = appl_ptr;
430	}
431	/* if hardware has something, but the intermediate buffer is full
432	 * => skip contents of buffer
433	 */
434	if (rec->hw_ready && (rec->sw_ready >= (int)rec->sw_buffer_size)) {
435		unsigned int bytes;
436
437#ifdef SND_PCM_INDIRECT2_STAT
438		if (rec->firstzerotime == 0) {
439			rec->firstzerotime = jiffies;
440			snd_printk(KERN_DEBUG "STAT: (capture) "
441				   "@firstzerotime: mul_elapsed: %d, "
442				   "min_period_count: %d\n",
443				   rec->mul_elapsed, rec->min_period_count);
444			snd_printk(KERN_DEBUG "STAT: (capture) "
445				   "@firstzerotime: sw_io: %d, sw_data: %d, "
446				   "appl_ptr: %u\n",
447				   rec->sw_io, rec->sw_data,
448				   (unsigned int)appl_ptr);
449		}
450		if ((jiffies - rec->firstzerotime) < 3750) {
451			rec->zero_times[(jiffies - rec->firstzerotime)]++;
452			rec->zero_times_saved++;
453		} else
454			rec->zero_times_notsaved++;
455#endif
456		bytes = null(substream, rec);
457
458#ifdef SND_PCM_INDIRECT2_STAT
459		rec->zeros2hw += bytes;
460		if (bytes < 64)
461			rec->zero_sizes[bytes]++;
462		else
463			snd_printk(KERN_DEBUG
464				   "STAT: (capture) %d zero Bytes copied to "
465				   "hardware at once - too big to save!\n",
466				   bytes);
467#endif
468		snd_pcm_indirect2_increase_min_periods(substream, rec, 0, 0,
469						       bytes);
470		/* report an overrun */
471		rec->sw_io = SNDRV_PCM_POS_XRUN;
472		return;
473	}
474	while (rec->hw_ready && (rec->sw_ready < (int)rec->sw_buffer_size)) {
475		/* sw_to_end: max. number of bytes that we can write to the
476		 *  intermediate buffer (until it's end)
477		 */
478		size_t sw_to_end = rec->sw_buffer_size - rec->sw_data;
479
480		/* bytes: max. number of bytes, which may be copied to the
481		 *  intermediate buffer without overflow (in _one_ step)
482		 */
483		size_t bytes = rec->sw_buffer_size - rec->sw_ready;
484
485		/* limit number of bytes (for transfer) by available room in
486		 * the intermediate buffer
487		 */
488		if (sw_to_end < bytes)
489			bytes = sw_to_end;
490		if (!bytes)
491			break;
492
493#ifdef SND_PCM_INDIRECT2_STAT
494		if (rec->firstbytetime == 0)
495			rec->firstbytetime = jiffies;
496		rec->lastbytetime = jiffies;
497#endif
498		/* copy bytes from the intermediate buffer (position sw_data)
499		 * to the HW at most and return number of bytes actually copied
500		 * from HW
501		 * Furthermore, set hw_ready to 0, if the fifo is empty now.
502		 */
503		bytes = copy(substream, rec, bytes);
504		rec->bytes2hw += bytes;
505
506#ifdef SND_PCM_INDIRECT2_STAT
507		if (bytes < 64)
508			rec->byte_sizes[bytes]++;
509		else
510			snd_printk(KERN_DEBUG
511				   "STAT: (capture) %d Bytes copied to "
512				   "hardware at once - too big to save!\n",
513				   bytes);
514#endif
515		/* increase sw_data by the number of actually copied bytes from
516		 * HW
517		 */
518		rec->sw_data += bytes;
519		if (rec->sw_data == rec->sw_buffer_size)
520			rec->sw_data = 0;
521
522		snd_pcm_indirect2_increase_min_periods(substream, rec, 0, 1,
523						       bytes);
524
525		/* number of bytes in the intermediate buffer, which haven't
526		 * been fetched by ALSA yet.
527		 */
528		rec->sw_ready += bytes;
529	}
530	return;
531}
532
533/*
534 * helper function for capture interrupt routine
535 */
536void
537snd_pcm_indirect2_capture_interrupt(struct snd_pcm_substream *substream,
538				    struct snd_pcm_indirect2 *rec,
539				    snd_pcm_indirect2_copy_t copy,
540				    snd_pcm_indirect2_zero_t null)
541{
542#ifdef SND_PCM_INDIRECT2_STAT
543	rec->irq_occured++;
544#endif
545	/* hardware recorded some bytes, so there is something to read from the
546	 * record fifo:
547	 */
548	rec->hw_ready = 1;
549
550	/* don't call ack() now, instead call transfer() function directly
551	 * (normally called by ack() )
552	 */
553	snd_pcm_indirect2_capture_transfer(substream, rec, copy, null);
554
555	if (rec->min_periods >= rec->min_multiple) {
556
557#ifdef SND_PCM_INDIRECT2_STAT
558		if ((rec->min_periods / rec->min_multiple) > 7)
559			snd_printk(KERN_DEBUG
560				   "STAT: more than 7 (%d) mul_adds - "
561				   "too big to save!\n",
562				   (rec->min_periods / rec->min_multiple));
563		else
564			rec->mul_adds[(rec->min_periods /
565				       rec->min_multiple)]++;
566		rec->mul_elapsed_real += (rec->min_periods /
567					  rec->min_multiple);
568		rec->mul_elapsed++;
569#endif
570		rec->min_periods = (rec->min_periods % rec->min_multiple);
571		snd_pcm_period_elapsed(substream);
572	}
573}
574