xref: /linux/sound/aoa/soundbus/i2sbus/pcm.c (revision 0add53713b1c07a1c71e27a20e21eb7c180b4e7b)
1 /*
2  * i2sbus driver -- pcm routines
3  *
4  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
5  *
6  * GPL v2, can be found in COPYING.
7  */
8 
9 #include <linux/io.h>
10 #include <linux/delay.h>
11 #include <linux/slab.h>
12 #include <sound/core.h>
13 #include <asm/macio.h>
14 #include <linux/pci.h>
15 #include <linux/module.h>
16 #include "../soundbus.h"
17 #include "i2sbus.h"
18 
19 static inline void get_pcm_info(struct i2sbus_dev *i2sdev, int in,
20 				struct pcm_info **pi, struct pcm_info **other)
21 {
22 	if (in) {
23 		if (pi)
24 			*pi = &i2sdev->in;
25 		if (other)
26 			*other = &i2sdev->out;
27 	} else {
28 		if (pi)
29 			*pi = &i2sdev->out;
30 		if (other)
31 			*other = &i2sdev->in;
32 	}
33 }
34 
35 static int clock_and_divisors(int mclk, int sclk, int rate, int *out)
36 {
37 	/* sclk must be derived from mclk! */
38 	if (mclk % sclk)
39 		return -1;
40 	/* derive sclk register value */
41 	if (i2s_sf_sclkdiv(mclk / sclk, out))
42 		return -1;
43 
44 	if (I2S_CLOCK_SPEED_18MHz % (rate * mclk) == 0) {
45 		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_18MHz / (rate * mclk), out)) {
46 			*out |= I2S_SF_CLOCK_SOURCE_18MHz;
47 			return 0;
48 		}
49 	}
50 	if (I2S_CLOCK_SPEED_45MHz % (rate * mclk) == 0) {
51 		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_45MHz / (rate * mclk), out)) {
52 			*out |= I2S_SF_CLOCK_SOURCE_45MHz;
53 			return 0;
54 		}
55 	}
56 	if (I2S_CLOCK_SPEED_49MHz % (rate * mclk) == 0) {
57 		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_49MHz / (rate * mclk), out)) {
58 			*out |= I2S_SF_CLOCK_SOURCE_49MHz;
59 			return 0;
60 		}
61 	}
62 	return -1;
63 }
64 
65 #define CHECK_RATE(rate)						\
66 	do { if (rates & SNDRV_PCM_RATE_ ##rate) {			\
67 		int dummy;						\
68 		if (clock_and_divisors(sysclock_factor,			\
69 				       bus_factor, rate, &dummy))	\
70 			rates &= ~SNDRV_PCM_RATE_ ##rate;		\
71 	} } while (0)
72 
73 static int i2sbus_pcm_open(struct i2sbus_dev *i2sdev, int in)
74 {
75 	struct pcm_info *pi, *other;
76 	struct soundbus_dev *sdev;
77 	int masks_inited = 0, err;
78 	struct codec_info_item *cii, *rev;
79 	struct snd_pcm_hardware *hw;
80 	u64 formats = 0;
81 	unsigned int rates = 0;
82 	struct transfer_info v;
83 	int result = 0;
84 	int bus_factor = 0, sysclock_factor = 0;
85 	int found_this;
86 
87 	mutex_lock(&i2sdev->lock);
88 
89 	get_pcm_info(i2sdev, in, &pi, &other);
90 
91 	hw = &pi->substream->runtime->hw;
92 	sdev = &i2sdev->sound;
93 
94 	if (pi->active) {
95 		/* alsa messed up */
96 		result = -EBUSY;
97 		goto out_unlock;
98 	}
99 
100 	/* we now need to assign the hw */
101 	list_for_each_entry(cii, &sdev->codec_list, list) {
102 		struct transfer_info *ti = cii->codec->transfers;
103 		bus_factor = cii->codec->bus_factor;
104 		sysclock_factor = cii->codec->sysclock_factor;
105 		while (ti->formats && ti->rates) {
106 			v = *ti;
107 			if (ti->transfer_in == in
108 			    && cii->codec->usable(cii, ti, &v)) {
109 				if (masks_inited) {
110 					formats &= v.formats;
111 					rates &= v.rates;
112 				} else {
113 					formats = v.formats;
114 					rates = v.rates;
115 					masks_inited = 1;
116 				}
117 			}
118 			ti++;
119 		}
120 	}
121 	if (!masks_inited || !bus_factor || !sysclock_factor) {
122 		result = -ENODEV;
123 		goto out_unlock;
124 	}
125 	/* bus dependent stuff */
126 	hw->info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
127 		   SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_RESUME |
128 		   SNDRV_PCM_INFO_JOINT_DUPLEX;
129 
130 	CHECK_RATE(5512);
131 	CHECK_RATE(8000);
132 	CHECK_RATE(11025);
133 	CHECK_RATE(16000);
134 	CHECK_RATE(22050);
135 	CHECK_RATE(32000);
136 	CHECK_RATE(44100);
137 	CHECK_RATE(48000);
138 	CHECK_RATE(64000);
139 	CHECK_RATE(88200);
140 	CHECK_RATE(96000);
141 	CHECK_RATE(176400);
142 	CHECK_RATE(192000);
143 	hw->rates = rates;
144 
145 	/* well. the codec might want 24 bits only, and we'll
146 	 * ever only transfer 24 bits, but they are top-aligned!
147 	 * So for alsa, we claim that we're doing full 32 bit
148 	 * while in reality we'll ignore the lower 8 bits of
149 	 * that when doing playback (they're transferred as 0
150 	 * as far as I know, no codecs we have are 32-bit capable
151 	 * so I can't really test) and when doing recording we'll
152 	 * always have those lower 8 bits recorded as 0 */
153 	if (formats & SNDRV_PCM_FMTBIT_S24_BE)
154 		formats |= SNDRV_PCM_FMTBIT_S32_BE;
155 	if (formats & SNDRV_PCM_FMTBIT_U24_BE)
156 		formats |= SNDRV_PCM_FMTBIT_U32_BE;
157 	/* now mask off what we can support. I suppose we could
158 	 * also support S24_3LE and some similar formats, but I
159 	 * doubt there's a codec that would be able to use that,
160 	 * so we don't support it here. */
161 	hw->formats = formats & (SNDRV_PCM_FMTBIT_S16_BE |
162 				 SNDRV_PCM_FMTBIT_U16_BE |
163 				 SNDRV_PCM_FMTBIT_S32_BE |
164 				 SNDRV_PCM_FMTBIT_U32_BE);
165 
166 	/* we need to set the highest and lowest rate possible.
167 	 * These are the highest and lowest rates alsa can
168 	 * support properly in its bitfield.
169 	 * Below, we'll use that to restrict to the rate
170 	 * currently in use (if any). */
171 	hw->rate_min = 5512;
172 	hw->rate_max = 192000;
173 	/* if the other stream is active, then we can only
174 	 * support what it is currently using.
175 	 * FIXME: I lied. This comment is wrong. We can support
176 	 * anything that works with the same serial format, ie.
177 	 * when recording 24 bit sound we can well play 16 bit
178 	 * sound at the same time iff using the same transfer mode.
179 	 */
180 	if (other->active) {
181 		/* FIXME: is this guaranteed by the alsa api? */
182 		hw->formats &= pcm_format_to_bits(i2sdev->format);
183 		/* see above, restrict rates to the one we already have */
184 		hw->rate_min = i2sdev->rate;
185 		hw->rate_max = i2sdev->rate;
186 	}
187 
188 	hw->channels_min = 2;
189 	hw->channels_max = 2;
190 	/* these are somewhat arbitrary */
191 	hw->buffer_bytes_max = 131072;
192 	hw->period_bytes_min = 256;
193 	hw->period_bytes_max = 16384;
194 	hw->periods_min = 3;
195 	hw->periods_max = MAX_DBDMA_COMMANDS;
196 	err = snd_pcm_hw_constraint_integer(pi->substream->runtime,
197 					    SNDRV_PCM_HW_PARAM_PERIODS);
198 	if (err < 0) {
199 		result = err;
200 		goto out_unlock;
201 	}
202 	list_for_each_entry(cii, &sdev->codec_list, list) {
203 		if (cii->codec->open) {
204 			err = cii->codec->open(cii, pi->substream);
205 			if (err) {
206 				result = err;
207 				/* unwind */
208 				found_this = 0;
209 				list_for_each_entry_reverse(rev,
210 				    &sdev->codec_list, list) {
211 					if (found_this && rev->codec->close) {
212 						rev->codec->close(rev,
213 								pi->substream);
214 					}
215 					if (rev == cii)
216 						found_this = 1;
217 				}
218 				goto out_unlock;
219 			}
220 		}
221 	}
222 
223  out_unlock:
224 	mutex_unlock(&i2sdev->lock);
225 	return result;
226 }
227 
228 #undef CHECK_RATE
229 
230 static int i2sbus_pcm_close(struct i2sbus_dev *i2sdev, int in)
231 {
232 	struct codec_info_item *cii;
233 	struct pcm_info *pi;
234 	int err = 0, tmp;
235 
236 	mutex_lock(&i2sdev->lock);
237 
238 	get_pcm_info(i2sdev, in, &pi, NULL);
239 
240 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
241 		if (cii->codec->close) {
242 			tmp = cii->codec->close(cii, pi->substream);
243 			if (tmp)
244 				err = tmp;
245 		}
246 	}
247 
248 	pi->substream = NULL;
249 	pi->active = 0;
250 	mutex_unlock(&i2sdev->lock);
251 	return err;
252 }
253 
254 static void i2sbus_wait_for_stop(struct i2sbus_dev *i2sdev,
255 				 struct pcm_info *pi)
256 {
257 	unsigned long flags;
258 	struct completion done;
259 	long timeout;
260 
261 	spin_lock_irqsave(&i2sdev->low_lock, flags);
262 	if (pi->dbdma_ring.stopping) {
263 		init_completion(&done);
264 		pi->stop_completion = &done;
265 		spin_unlock_irqrestore(&i2sdev->low_lock, flags);
266 		timeout = wait_for_completion_timeout(&done, HZ);
267 		spin_lock_irqsave(&i2sdev->low_lock, flags);
268 		pi->stop_completion = NULL;
269 		if (timeout == 0) {
270 			/* timeout expired, stop dbdma forcefully */
271 			printk(KERN_ERR "i2sbus_wait_for_stop: timed out\n");
272 			/* make sure RUN, PAUSE and S0 bits are cleared */
273 			out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
274 			pi->dbdma_ring.stopping = 0;
275 			timeout = 10;
276 			while (in_le32(&pi->dbdma->status) & ACTIVE) {
277 				if (--timeout <= 0)
278 					break;
279 				udelay(1);
280 			}
281 		}
282 	}
283 	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
284 }
285 
286 #ifdef CONFIG_PM
287 void i2sbus_wait_for_stop_both(struct i2sbus_dev *i2sdev)
288 {
289 	struct pcm_info *pi;
290 
291 	get_pcm_info(i2sdev, 0, &pi, NULL);
292 	i2sbus_wait_for_stop(i2sdev, pi);
293 	get_pcm_info(i2sdev, 1, &pi, NULL);
294 	i2sbus_wait_for_stop(i2sdev, pi);
295 }
296 #endif
297 
298 static int i2sbus_hw_params(struct snd_pcm_substream *substream,
299 			    struct snd_pcm_hw_params *params)
300 {
301 	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
302 }
303 
304 static inline int i2sbus_hw_free(struct snd_pcm_substream *substream, int in)
305 {
306 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
307 	struct pcm_info *pi;
308 
309 	get_pcm_info(i2sdev, in, &pi, NULL);
310 	if (pi->dbdma_ring.stopping)
311 		i2sbus_wait_for_stop(i2sdev, pi);
312 	snd_pcm_lib_free_pages(substream);
313 	return 0;
314 }
315 
316 static int i2sbus_playback_hw_free(struct snd_pcm_substream *substream)
317 {
318 	return i2sbus_hw_free(substream, 0);
319 }
320 
321 static int i2sbus_record_hw_free(struct snd_pcm_substream *substream)
322 {
323 	return i2sbus_hw_free(substream, 1);
324 }
325 
326 static int i2sbus_pcm_prepare(struct i2sbus_dev *i2sdev, int in)
327 {
328 	/* whee. Hard work now. The user has selected a bitrate
329 	 * and bit format, so now we have to program our
330 	 * I2S controller appropriately. */
331 	struct snd_pcm_runtime *runtime;
332 	struct dbdma_cmd *command;
333 	int i, periodsize, nperiods;
334 	dma_addr_t offset;
335 	struct bus_info bi;
336 	struct codec_info_item *cii;
337 	int sfr = 0;		/* serial format register */
338 	int dws = 0;		/* data word sizes reg */
339 	int input_16bit;
340 	struct pcm_info *pi, *other;
341 	int cnt;
342 	int result = 0;
343 	unsigned int cmd, stopaddr;
344 
345 	mutex_lock(&i2sdev->lock);
346 
347 	get_pcm_info(i2sdev, in, &pi, &other);
348 
349 	if (pi->dbdma_ring.running) {
350 		result = -EBUSY;
351 		goto out_unlock;
352 	}
353 	if (pi->dbdma_ring.stopping)
354 		i2sbus_wait_for_stop(i2sdev, pi);
355 
356 	if (!pi->substream || !pi->substream->runtime) {
357 		result = -EINVAL;
358 		goto out_unlock;
359 	}
360 
361 	runtime = pi->substream->runtime;
362 	pi->active = 1;
363 	if (other->active &&
364 	    ((i2sdev->format != runtime->format)
365 	     || (i2sdev->rate != runtime->rate))) {
366 		result = -EINVAL;
367 		goto out_unlock;
368 	}
369 
370 	i2sdev->format = runtime->format;
371 	i2sdev->rate = runtime->rate;
372 
373 	periodsize = snd_pcm_lib_period_bytes(pi->substream);
374 	nperiods = pi->substream->runtime->periods;
375 	pi->current_period = 0;
376 
377 	/* generate dbdma command ring first */
378 	command = pi->dbdma_ring.cmds;
379 	memset(command, 0, (nperiods + 2) * sizeof(struct dbdma_cmd));
380 
381 	/* commands to DMA to/from the ring */
382 	/*
383 	 * For input, we need to do a graceful stop; if we abort
384 	 * the DMA, we end up with leftover bytes that corrupt
385 	 * the next recording.  To do this we set the S0 status
386 	 * bit and wait for the DMA controller to stop.  Each
387 	 * command has a branch condition to
388 	 * make it branch to a stop command if S0 is set.
389 	 * On input we also need to wait for the S7 bit to be
390 	 * set before turning off the DMA controller.
391 	 * In fact we do the graceful stop for output as well.
392 	 */
393 	offset = runtime->dma_addr;
394 	cmd = (in? INPUT_MORE: OUTPUT_MORE) | BR_IFSET | INTR_ALWAYS;
395 	stopaddr = pi->dbdma_ring.bus_cmd_start +
396 		(nperiods + 1) * sizeof(struct dbdma_cmd);
397 	for (i = 0; i < nperiods; i++, command++, offset += periodsize) {
398 		command->command = cpu_to_le16(cmd);
399 		command->cmd_dep = cpu_to_le32(stopaddr);
400 		command->phy_addr = cpu_to_le32(offset);
401 		command->req_count = cpu_to_le16(periodsize);
402 	}
403 
404 	/* branch back to beginning of ring */
405 	command->command = cpu_to_le16(DBDMA_NOP | BR_ALWAYS);
406 	command->cmd_dep = cpu_to_le32(pi->dbdma_ring.bus_cmd_start);
407 	command++;
408 
409 	/* set stop command */
410 	command->command = cpu_to_le16(DBDMA_STOP);
411 
412 	/* ok, let's set the serial format and stuff */
413 	switch (runtime->format) {
414 	/* 16 bit formats */
415 	case SNDRV_PCM_FORMAT_S16_BE:
416 	case SNDRV_PCM_FORMAT_U16_BE:
417 		/* FIXME: if we add different bus factors we need to
418 		 * do more here!! */
419 		bi.bus_factor = 0;
420 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
421 			bi.bus_factor = cii->codec->bus_factor;
422 			break;
423 		}
424 		if (!bi.bus_factor) {
425 			result = -ENODEV;
426 			goto out_unlock;
427 		}
428 		input_16bit = 1;
429 		break;
430 	case SNDRV_PCM_FORMAT_S32_BE:
431 	case SNDRV_PCM_FORMAT_U32_BE:
432 		/* force 64x bus speed, otherwise the data cannot be
433 		 * transferred quickly enough! */
434 		bi.bus_factor = 64;
435 		input_16bit = 0;
436 		break;
437 	default:
438 		result = -EINVAL;
439 		goto out_unlock;
440 	}
441 	/* we assume all sysclocks are the same! */
442 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
443 		bi.sysclock_factor = cii->codec->sysclock_factor;
444 		break;
445 	}
446 
447 	if (clock_and_divisors(bi.sysclock_factor,
448 			       bi.bus_factor,
449 			       runtime->rate,
450 			       &sfr) < 0) {
451 		result = -EINVAL;
452 		goto out_unlock;
453 	}
454 	switch (bi.bus_factor) {
455 	case 32:
456 		sfr |= I2S_SF_SERIAL_FORMAT_I2S_32X;
457 		break;
458 	case 64:
459 		sfr |= I2S_SF_SERIAL_FORMAT_I2S_64X;
460 		break;
461 	}
462 	/* FIXME: THIS ASSUMES MASTER ALL THE TIME */
463 	sfr |= I2S_SF_SCLK_MASTER;
464 
465 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
466 		int err = 0;
467 		if (cii->codec->prepare)
468 			err = cii->codec->prepare(cii, &bi, pi->substream);
469 		if (err) {
470 			result = err;
471 			goto out_unlock;
472 		}
473 	}
474 	/* codecs are fine with it, so set our clocks */
475 	if (input_16bit)
476 		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
477 			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
478 			I2S_DWS_DATA_IN_16BIT | I2S_DWS_DATA_OUT_16BIT;
479 	else
480 		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
481 			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
482 			I2S_DWS_DATA_IN_24BIT | I2S_DWS_DATA_OUT_24BIT;
483 
484 	/* early exit if already programmed correctly */
485 	/* not locking these is fine since we touch them only in this function */
486 	if (in_le32(&i2sdev->intfregs->serial_format) == sfr
487 	 && in_le32(&i2sdev->intfregs->data_word_sizes) == dws)
488 		goto out_unlock;
489 
490 	/* let's notify the codecs about clocks going away.
491 	 * For now we only do mastering on the i2s cell... */
492 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
493 		if (cii->codec->switch_clock)
494 			cii->codec->switch_clock(cii, CLOCK_SWITCH_PREPARE_SLAVE);
495 
496 	i2sbus_control_enable(i2sdev->control, i2sdev);
497 	i2sbus_control_cell(i2sdev->control, i2sdev, 1);
498 
499 	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);
500 
501 	i2sbus_control_clock(i2sdev->control, i2sdev, 0);
502 
503 	msleep(1);
504 
505 	/* wait for clock stopped. This can apparently take a while... */
506 	cnt = 100;
507 	while (cnt-- &&
508 	    !(in_le32(&i2sdev->intfregs->intr_ctl) & I2S_PENDING_CLOCKS_STOPPED)) {
509 		msleep(5);
510 	}
511 	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);
512 
513 	/* not locking these is fine since we touch them only in this function */
514 	out_le32(&i2sdev->intfregs->serial_format, sfr);
515 	out_le32(&i2sdev->intfregs->data_word_sizes, dws);
516 
517         i2sbus_control_enable(i2sdev->control, i2sdev);
518         i2sbus_control_cell(i2sdev->control, i2sdev, 1);
519         i2sbus_control_clock(i2sdev->control, i2sdev, 1);
520 	msleep(1);
521 
522 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
523 		if (cii->codec->switch_clock)
524 			cii->codec->switch_clock(cii, CLOCK_SWITCH_SLAVE);
525 
526  out_unlock:
527 	mutex_unlock(&i2sdev->lock);
528 	return result;
529 }
530 
531 #ifdef CONFIG_PM
532 void i2sbus_pcm_prepare_both(struct i2sbus_dev *i2sdev)
533 {
534 	i2sbus_pcm_prepare(i2sdev, 0);
535 	i2sbus_pcm_prepare(i2sdev, 1);
536 }
537 #endif
538 
539 static int i2sbus_pcm_trigger(struct i2sbus_dev *i2sdev, int in, int cmd)
540 {
541 	struct codec_info_item *cii;
542 	struct pcm_info *pi;
543 	int result = 0;
544 	unsigned long flags;
545 
546 	spin_lock_irqsave(&i2sdev->low_lock, flags);
547 
548 	get_pcm_info(i2sdev, in, &pi, NULL);
549 
550 	switch (cmd) {
551 	case SNDRV_PCM_TRIGGER_START:
552 	case SNDRV_PCM_TRIGGER_RESUME:
553 		if (pi->dbdma_ring.running) {
554 			result = -EALREADY;
555 			goto out_unlock;
556 		}
557 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
558 			if (cii->codec->start)
559 				cii->codec->start(cii, pi->substream);
560 		pi->dbdma_ring.running = 1;
561 
562 		if (pi->dbdma_ring.stopping) {
563 			/* Clear the S0 bit, then see if we stopped yet */
564 			out_le32(&pi->dbdma->control, 1 << 16);
565 			if (in_le32(&pi->dbdma->status) & ACTIVE) {
566 				/* possible race here? */
567 				udelay(10);
568 				if (in_le32(&pi->dbdma->status) & ACTIVE) {
569 					pi->dbdma_ring.stopping = 0;
570 					goto out_unlock; /* keep running */
571 				}
572 			}
573 		}
574 
575 		/* make sure RUN, PAUSE and S0 bits are cleared */
576 		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
577 
578 		/* set branch condition select register */
579 		out_le32(&pi->dbdma->br_sel, (1 << 16) | 1);
580 
581 		/* write dma command buffer address to the dbdma chip */
582 		out_le32(&pi->dbdma->cmdptr, pi->dbdma_ring.bus_cmd_start);
583 
584 		/* initialize the frame count and current period */
585 		pi->current_period = 0;
586 		pi->frame_count = in_le32(&i2sdev->intfregs->frame_count);
587 
588 		/* set the DMA controller running */
589 		out_le32(&pi->dbdma->control, (RUN << 16) | RUN);
590 
591 		/* off you go! */
592 		break;
593 
594 	case SNDRV_PCM_TRIGGER_STOP:
595 	case SNDRV_PCM_TRIGGER_SUSPEND:
596 		if (!pi->dbdma_ring.running) {
597 			result = -EALREADY;
598 			goto out_unlock;
599 		}
600 		pi->dbdma_ring.running = 0;
601 
602 		/* Set the S0 bit to make the DMA branch to the stop cmd */
603 		out_le32(&pi->dbdma->control, (1 << 16) | 1);
604 		pi->dbdma_ring.stopping = 1;
605 
606 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
607 			if (cii->codec->stop)
608 				cii->codec->stop(cii, pi->substream);
609 		break;
610 	default:
611 		result = -EINVAL;
612 		goto out_unlock;
613 	}
614 
615  out_unlock:
616 	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
617 	return result;
618 }
619 
620 static snd_pcm_uframes_t i2sbus_pcm_pointer(struct i2sbus_dev *i2sdev, int in)
621 {
622 	struct pcm_info *pi;
623 	u32 fc;
624 
625 	get_pcm_info(i2sdev, in, &pi, NULL);
626 
627 	fc = in_le32(&i2sdev->intfregs->frame_count);
628 	fc = fc - pi->frame_count;
629 
630 	if (fc >= pi->substream->runtime->buffer_size)
631 		fc %= pi->substream->runtime->buffer_size;
632 	return fc;
633 }
634 
635 static inline void handle_interrupt(struct i2sbus_dev *i2sdev, int in)
636 {
637 	struct pcm_info *pi;
638 	u32 fc, nframes;
639 	u32 status;
640 	int timeout, i;
641 	int dma_stopped = 0;
642 	struct snd_pcm_runtime *runtime;
643 
644 	spin_lock(&i2sdev->low_lock);
645 	get_pcm_info(i2sdev, in, &pi, NULL);
646 	if (!pi->dbdma_ring.running && !pi->dbdma_ring.stopping)
647 		goto out_unlock;
648 
649 	i = pi->current_period;
650 	runtime = pi->substream->runtime;
651 	while (pi->dbdma_ring.cmds[i].xfer_status) {
652 		if (le16_to_cpu(pi->dbdma_ring.cmds[i].xfer_status) & BT)
653 			/*
654 			 * BT is the branch taken bit.  If it took a branch
655 			 * it is because we set the S0 bit to make it
656 			 * branch to the stop command.
657 			 */
658 			dma_stopped = 1;
659 		pi->dbdma_ring.cmds[i].xfer_status = 0;
660 
661 		if (++i >= runtime->periods) {
662 			i = 0;
663 			pi->frame_count += runtime->buffer_size;
664 		}
665 		pi->current_period = i;
666 
667 		/*
668 		 * Check the frame count.  The DMA tends to get a bit
669 		 * ahead of the frame counter, which confuses the core.
670 		 */
671 		fc = in_le32(&i2sdev->intfregs->frame_count);
672 		nframes = i * runtime->period_size;
673 		if (fc < pi->frame_count + nframes)
674 			pi->frame_count = fc - nframes;
675 	}
676 
677 	if (dma_stopped) {
678 		timeout = 1000;
679 		for (;;) {
680 			status = in_le32(&pi->dbdma->status);
681 			if (!(status & ACTIVE) && (!in || (status & 0x80)))
682 				break;
683 			if (--timeout <= 0) {
684 				printk(KERN_ERR "i2sbus: timed out "
685 				       "waiting for DMA to stop!\n");
686 				break;
687 			}
688 			udelay(1);
689 		}
690 
691 		/* Turn off DMA controller, clear S0 bit */
692 		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
693 
694 		pi->dbdma_ring.stopping = 0;
695 		if (pi->stop_completion)
696 			complete(pi->stop_completion);
697 	}
698 
699 	if (!pi->dbdma_ring.running)
700 		goto out_unlock;
701 	spin_unlock(&i2sdev->low_lock);
702 	/* may call _trigger again, hence needs to be unlocked */
703 	snd_pcm_period_elapsed(pi->substream);
704 	return;
705 
706  out_unlock:
707 	spin_unlock(&i2sdev->low_lock);
708 }
709 
710 irqreturn_t i2sbus_tx_intr(int irq, void *devid)
711 {
712 	handle_interrupt((struct i2sbus_dev *)devid, 0);
713 	return IRQ_HANDLED;
714 }
715 
716 irqreturn_t i2sbus_rx_intr(int irq, void *devid)
717 {
718 	handle_interrupt((struct i2sbus_dev *)devid, 1);
719 	return IRQ_HANDLED;
720 }
721 
722 static int i2sbus_playback_open(struct snd_pcm_substream *substream)
723 {
724 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
725 
726 	if (!i2sdev)
727 		return -EINVAL;
728 	i2sdev->out.substream = substream;
729 	return i2sbus_pcm_open(i2sdev, 0);
730 }
731 
732 static int i2sbus_playback_close(struct snd_pcm_substream *substream)
733 {
734 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
735 	int err;
736 
737 	if (!i2sdev)
738 		return -EINVAL;
739 	if (i2sdev->out.substream != substream)
740 		return -EINVAL;
741 	err = i2sbus_pcm_close(i2sdev, 0);
742 	if (!err)
743 		i2sdev->out.substream = NULL;
744 	return err;
745 }
746 
747 static int i2sbus_playback_prepare(struct snd_pcm_substream *substream)
748 {
749 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
750 
751 	if (!i2sdev)
752 		return -EINVAL;
753 	if (i2sdev->out.substream != substream)
754 		return -EINVAL;
755 	return i2sbus_pcm_prepare(i2sdev, 0);
756 }
757 
758 static int i2sbus_playback_trigger(struct snd_pcm_substream *substream, int cmd)
759 {
760 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
761 
762 	if (!i2sdev)
763 		return -EINVAL;
764 	if (i2sdev->out.substream != substream)
765 		return -EINVAL;
766 	return i2sbus_pcm_trigger(i2sdev, 0, cmd);
767 }
768 
769 static snd_pcm_uframes_t i2sbus_playback_pointer(struct snd_pcm_substream
770 						 *substream)
771 {
772 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
773 
774 	if (!i2sdev)
775 		return -EINVAL;
776 	if (i2sdev->out.substream != substream)
777 		return 0;
778 	return i2sbus_pcm_pointer(i2sdev, 0);
779 }
780 
781 static const struct snd_pcm_ops i2sbus_playback_ops = {
782 	.open =		i2sbus_playback_open,
783 	.close =	i2sbus_playback_close,
784 	.ioctl =	snd_pcm_lib_ioctl,
785 	.hw_params =	i2sbus_hw_params,
786 	.hw_free =	i2sbus_playback_hw_free,
787 	.prepare =	i2sbus_playback_prepare,
788 	.trigger =	i2sbus_playback_trigger,
789 	.pointer =	i2sbus_playback_pointer,
790 };
791 
792 static int i2sbus_record_open(struct snd_pcm_substream *substream)
793 {
794 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
795 
796 	if (!i2sdev)
797 		return -EINVAL;
798 	i2sdev->in.substream = substream;
799 	return i2sbus_pcm_open(i2sdev, 1);
800 }
801 
802 static int i2sbus_record_close(struct snd_pcm_substream *substream)
803 {
804 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
805 	int err;
806 
807 	if (!i2sdev)
808 		return -EINVAL;
809 	if (i2sdev->in.substream != substream)
810 		return -EINVAL;
811 	err = i2sbus_pcm_close(i2sdev, 1);
812 	if (!err)
813 		i2sdev->in.substream = NULL;
814 	return err;
815 }
816 
817 static int i2sbus_record_prepare(struct snd_pcm_substream *substream)
818 {
819 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
820 
821 	if (!i2sdev)
822 		return -EINVAL;
823 	if (i2sdev->in.substream != substream)
824 		return -EINVAL;
825 	return i2sbus_pcm_prepare(i2sdev, 1);
826 }
827 
828 static int i2sbus_record_trigger(struct snd_pcm_substream *substream, int cmd)
829 {
830 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
831 
832 	if (!i2sdev)
833 		return -EINVAL;
834 	if (i2sdev->in.substream != substream)
835 		return -EINVAL;
836 	return i2sbus_pcm_trigger(i2sdev, 1, cmd);
837 }
838 
839 static snd_pcm_uframes_t i2sbus_record_pointer(struct snd_pcm_substream
840 					       *substream)
841 {
842 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
843 
844 	if (!i2sdev)
845 		return -EINVAL;
846 	if (i2sdev->in.substream != substream)
847 		return 0;
848 	return i2sbus_pcm_pointer(i2sdev, 1);
849 }
850 
851 static const struct snd_pcm_ops i2sbus_record_ops = {
852 	.open =		i2sbus_record_open,
853 	.close =	i2sbus_record_close,
854 	.ioctl =	snd_pcm_lib_ioctl,
855 	.hw_params =	i2sbus_hw_params,
856 	.hw_free =	i2sbus_record_hw_free,
857 	.prepare =	i2sbus_record_prepare,
858 	.trigger =	i2sbus_record_trigger,
859 	.pointer =	i2sbus_record_pointer,
860 };
861 
862 static void i2sbus_private_free(struct snd_pcm *pcm)
863 {
864 	struct i2sbus_dev *i2sdev = snd_pcm_chip(pcm);
865 	struct codec_info_item *p, *tmp;
866 
867 	i2sdev->sound.pcm = NULL;
868 	i2sdev->out.created = 0;
869 	i2sdev->in.created = 0;
870 	list_for_each_entry_safe(p, tmp, &i2sdev->sound.codec_list, list) {
871 		printk(KERN_ERR "i2sbus: a codec didn't unregister!\n");
872 		list_del(&p->list);
873 		module_put(p->codec->owner);
874 		kfree(p);
875 	}
876 	soundbus_dev_put(&i2sdev->sound);
877 	module_put(THIS_MODULE);
878 }
879 
880 int
881 i2sbus_attach_codec(struct soundbus_dev *dev, struct snd_card *card,
882 		    struct codec_info *ci, void *data)
883 {
884 	int err, in = 0, out = 0;
885 	struct transfer_info *tmp;
886 	struct i2sbus_dev *i2sdev = soundbus_dev_to_i2sbus_dev(dev);
887 	struct codec_info_item *cii;
888 
889 	if (!dev->pcmname || dev->pcmid == -1) {
890 		printk(KERN_ERR "i2sbus: pcm name and id must be set!\n");
891 		return -EINVAL;
892 	}
893 
894 	list_for_each_entry(cii, &dev->codec_list, list) {
895 		if (cii->codec_data == data)
896 			return -EALREADY;
897 	}
898 
899 	if (!ci->transfers || !ci->transfers->formats
900 	    || !ci->transfers->rates || !ci->usable)
901 		return -EINVAL;
902 
903 	/* we currently code the i2s transfer on the clock, and support only
904 	 * 32 and 64 */
905 	if (ci->bus_factor != 32 && ci->bus_factor != 64)
906 		return -EINVAL;
907 
908 	/* If you want to fix this, you need to keep track of what transport infos
909 	 * are to be used, which codecs they belong to, and then fix all the
910 	 * sysclock/busclock stuff above to depend on which is usable */
911 	list_for_each_entry(cii, &dev->codec_list, list) {
912 		if (cii->codec->sysclock_factor != ci->sysclock_factor) {
913 			printk(KERN_DEBUG
914 			       "cannot yet handle multiple different sysclocks!\n");
915 			return -EINVAL;
916 		}
917 		if (cii->codec->bus_factor != ci->bus_factor) {
918 			printk(KERN_DEBUG
919 			       "cannot yet handle multiple different bus clocks!\n");
920 			return -EINVAL;
921 		}
922 	}
923 
924 	tmp = ci->transfers;
925 	while (tmp->formats && tmp->rates) {
926 		if (tmp->transfer_in)
927 			in = 1;
928 		else
929 			out = 1;
930 		tmp++;
931 	}
932 
933 	cii = kzalloc(sizeof(struct codec_info_item), GFP_KERNEL);
934 	if (!cii) {
935 		printk(KERN_DEBUG "i2sbus: failed to allocate cii\n");
936 		return -ENOMEM;
937 	}
938 
939 	/* use the private data to point to the codec info */
940 	cii->sdev = soundbus_dev_get(dev);
941 	cii->codec = ci;
942 	cii->codec_data = data;
943 
944 	if (!cii->sdev) {
945 		printk(KERN_DEBUG
946 		       "i2sbus: failed to get soundbus dev reference\n");
947 		err = -ENODEV;
948 		goto out_free_cii;
949 	}
950 
951 	if (!try_module_get(THIS_MODULE)) {
952 		printk(KERN_DEBUG "i2sbus: failed to get module reference!\n");
953 		err = -EBUSY;
954 		goto out_put_sdev;
955 	}
956 
957 	if (!try_module_get(ci->owner)) {
958 		printk(KERN_DEBUG
959 		       "i2sbus: failed to get module reference to codec owner!\n");
960 		err = -EBUSY;
961 		goto out_put_this_module;
962 	}
963 
964 	if (!dev->pcm) {
965 		err = snd_pcm_new(card, dev->pcmname, dev->pcmid, 0, 0,
966 				  &dev->pcm);
967 		if (err) {
968 			printk(KERN_DEBUG "i2sbus: failed to create pcm\n");
969 			goto out_put_ci_module;
970 		}
971 	}
972 
973 	/* ALSA yet again sucks.
974 	 * If it is ever fixed, remove this line. See below. */
975 	out = in = 1;
976 
977 	if (!i2sdev->out.created && out) {
978 		if (dev->pcm->card != card) {
979 			/* eh? */
980 			printk(KERN_ERR
981 			       "Can't attach same bus to different cards!\n");
982 			err = -EINVAL;
983 			goto out_put_ci_module;
984 		}
985 		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK, 1);
986 		if (err)
987 			goto out_put_ci_module;
988 		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK,
989 				&i2sbus_playback_ops);
990 		dev->pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].dev.parent =
991 			&dev->ofdev.dev;
992 		i2sdev->out.created = 1;
993 	}
994 
995 	if (!i2sdev->in.created && in) {
996 		if (dev->pcm->card != card) {
997 			printk(KERN_ERR
998 			       "Can't attach same bus to different cards!\n");
999 			err = -EINVAL;
1000 			goto out_put_ci_module;
1001 		}
1002 		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_CAPTURE, 1);
1003 		if (err)
1004 			goto out_put_ci_module;
1005 		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_CAPTURE,
1006 				&i2sbus_record_ops);
1007 		dev->pcm->streams[SNDRV_PCM_STREAM_CAPTURE].dev.parent =
1008 			&dev->ofdev.dev;
1009 		i2sdev->in.created = 1;
1010 	}
1011 
1012 	/* so we have to register the pcm after adding any substream
1013 	 * to it because alsa doesn't create the devices for the
1014 	 * substreams when we add them later.
1015 	 * Therefore, force in and out on both busses (above) and
1016 	 * register the pcm now instead of just after creating it.
1017 	 */
1018 	err = snd_device_register(card, dev->pcm);
1019 	if (err) {
1020 		printk(KERN_ERR "i2sbus: error registering new pcm\n");
1021 		goto out_put_ci_module;
1022 	}
1023 	/* no errors any more, so let's add this to our list */
1024 	list_add(&cii->list, &dev->codec_list);
1025 
1026 	dev->pcm->private_data = i2sdev;
1027 	dev->pcm->private_free = i2sbus_private_free;
1028 
1029 	/* well, we really should support scatter/gather DMA */
1030 	snd_pcm_lib_preallocate_pages_for_all(
1031 		dev->pcm, SNDRV_DMA_TYPE_DEV,
1032 		snd_dma_pci_data(macio_get_pci_dev(i2sdev->macio)),
1033 		64 * 1024, 64 * 1024);
1034 
1035 	return 0;
1036  out_put_ci_module:
1037 	module_put(ci->owner);
1038  out_put_this_module:
1039 	module_put(THIS_MODULE);
1040  out_put_sdev:
1041 	soundbus_dev_put(dev);
1042  out_free_cii:
1043 	kfree(cii);
1044 	return err;
1045 }
1046 
1047 void i2sbus_detach_codec(struct soundbus_dev *dev, void *data)
1048 {
1049 	struct codec_info_item *cii = NULL, *i;
1050 
1051 	list_for_each_entry(i, &dev->codec_list, list) {
1052 		if (i->codec_data == data) {
1053 			cii = i;
1054 			break;
1055 		}
1056 	}
1057 	if (cii) {
1058 		list_del(&cii->list);
1059 		module_put(cii->codec->owner);
1060 		kfree(cii);
1061 	}
1062 	/* no more codecs, but still a pcm? */
1063 	if (list_empty(&dev->codec_list) && dev->pcm) {
1064 		/* the actual cleanup is done by the callback above! */
1065 		snd_device_free(dev->pcm->card, dev->pcm);
1066 	}
1067 }
1068