xref: /openbmc/linux/sound/aoa/soundbus/i2sbus/pcm.c (revision 888dcb7c)
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 <asm/io.h>
10 #include <linux/delay.h>
11 #include <sound/core.h>
12 #include <asm/macio.h>
13 #include <linux/pci.h>
14 #include "../soundbus.h"
15 #include "i2sbus.h"
16 
17 static inline void get_pcm_info(struct i2sbus_dev *i2sdev, int in,
18 				struct pcm_info **pi, struct pcm_info **other)
19 {
20 	if (in) {
21 		if (pi)
22 			*pi = &i2sdev->in;
23 		if (other)
24 			*other = &i2sdev->out;
25 	} else {
26 		if (pi)
27 			*pi = &i2sdev->out;
28 		if (other)
29 			*other = &i2sdev->in;
30 	}
31 }
32 
33 static int clock_and_divisors(int mclk, int sclk, int rate, int *out)
34 {
35 	/* sclk must be derived from mclk! */
36 	if (mclk % sclk)
37 		return -1;
38 	/* derive sclk register value */
39 	if (i2s_sf_sclkdiv(mclk / sclk, out))
40 		return -1;
41 
42 	if (I2S_CLOCK_SPEED_18MHz % (rate * mclk) == 0) {
43 		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_18MHz / (rate * mclk), out)) {
44 			*out |= I2S_SF_CLOCK_SOURCE_18MHz;
45 			return 0;
46 		}
47 	}
48 	if (I2S_CLOCK_SPEED_45MHz % (rate * mclk) == 0) {
49 		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_45MHz / (rate * mclk), out)) {
50 			*out |= I2S_SF_CLOCK_SOURCE_45MHz;
51 			return 0;
52 		}
53 	}
54 	if (I2S_CLOCK_SPEED_49MHz % (rate * mclk) == 0) {
55 		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_49MHz / (rate * mclk), out)) {
56 			*out |= I2S_SF_CLOCK_SOURCE_49MHz;
57 			return 0;
58 		}
59 	}
60 	return -1;
61 }
62 
63 #define CHECK_RATE(rate)						\
64 	do { if (rates & SNDRV_PCM_RATE_ ##rate) {			\
65 		int dummy;						\
66 		if (clock_and_divisors(sysclock_factor,			\
67 				       bus_factor, rate, &dummy))	\
68 			rates &= ~SNDRV_PCM_RATE_ ##rate;		\
69 	} } while (0)
70 
71 static int i2sbus_pcm_open(struct i2sbus_dev *i2sdev, int in)
72 {
73 	struct pcm_info *pi, *other;
74 	struct soundbus_dev *sdev;
75 	int masks_inited = 0, err;
76 	struct codec_info_item *cii, *rev;
77 	struct snd_pcm_hardware *hw;
78 	u64 formats = 0;
79 	unsigned int rates = 0;
80 	struct transfer_info v;
81 	int result = 0;
82 	int bus_factor = 0, sysclock_factor = 0;
83 	int found_this;
84 
85 	mutex_lock(&i2sdev->lock);
86 
87 	get_pcm_info(i2sdev, in, &pi, &other);
88 
89 	hw = &pi->substream->runtime->hw;
90 	sdev = &i2sdev->sound;
91 
92 	if (pi->active) {
93 		/* alsa messed up */
94 		result = -EBUSY;
95 		goto out_unlock;
96 	}
97 
98 	/* we now need to assign the hw */
99 	list_for_each_entry(cii, &sdev->codec_list, list) {
100 		struct transfer_info *ti = cii->codec->transfers;
101 		bus_factor = cii->codec->bus_factor;
102 		sysclock_factor = cii->codec->sysclock_factor;
103 		while (ti->formats && ti->rates) {
104 			v = *ti;
105 			if (ti->transfer_in == in
106 			    && cii->codec->usable(cii, ti, &v)) {
107 				if (masks_inited) {
108 					formats &= v.formats;
109 					rates &= v.rates;
110 				} else {
111 					formats = v.formats;
112 					rates = v.rates;
113 					masks_inited = 1;
114 				}
115 			}
116 			ti++;
117 		}
118 	}
119 	if (!masks_inited || !bus_factor || !sysclock_factor) {
120 		result = -ENODEV;
121 		goto out_unlock;
122 	}
123 	/* bus dependent stuff */
124 	hw->info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
125 		   SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_RESUME |
126 		   SNDRV_PCM_INFO_JOINT_DUPLEX;
127 
128 	CHECK_RATE(5512);
129 	CHECK_RATE(8000);
130 	CHECK_RATE(11025);
131 	CHECK_RATE(16000);
132 	CHECK_RATE(22050);
133 	CHECK_RATE(32000);
134 	CHECK_RATE(44100);
135 	CHECK_RATE(48000);
136 	CHECK_RATE(64000);
137 	CHECK_RATE(88200);
138 	CHECK_RATE(96000);
139 	CHECK_RATE(176400);
140 	CHECK_RATE(192000);
141 	hw->rates = rates;
142 
143 	/* well. the codec might want 24 bits only, and we'll
144 	 * ever only transfer 24 bits, but they are top-aligned!
145 	 * So for alsa, we claim that we're doing full 32 bit
146 	 * while in reality we'll ignore the lower 8 bits of
147 	 * that when doing playback (they're transferred as 0
148 	 * as far as I know, no codecs we have are 32-bit capable
149 	 * so I can't really test) and when doing recording we'll
150 	 * always have those lower 8 bits recorded as 0 */
151 	if (formats & SNDRV_PCM_FMTBIT_S24_BE)
152 		formats |= SNDRV_PCM_FMTBIT_S32_BE;
153 	if (formats & SNDRV_PCM_FMTBIT_U24_BE)
154 		formats |= SNDRV_PCM_FMTBIT_U32_BE;
155 	/* now mask off what we can support. I suppose we could
156 	 * also support S24_3LE and some similar formats, but I
157 	 * doubt there's a codec that would be able to use that,
158 	 * so we don't support it here. */
159 	hw->formats = formats & (SNDRV_PCM_FMTBIT_S16_BE |
160 				 SNDRV_PCM_FMTBIT_U16_BE |
161 				 SNDRV_PCM_FMTBIT_S32_BE |
162 				 SNDRV_PCM_FMTBIT_U32_BE);
163 
164 	/* we need to set the highest and lowest rate possible.
165 	 * These are the highest and lowest rates alsa can
166 	 * support properly in its bitfield.
167 	 * Below, we'll use that to restrict to the rate
168 	 * currently in use (if any). */
169 	hw->rate_min = 5512;
170 	hw->rate_max = 192000;
171 	/* if the other stream is active, then we can only
172 	 * support what it is currently using.
173 	 * FIXME: I lied. This comment is wrong. We can support
174 	 * anything that works with the same serial format, ie.
175 	 * when recording 24 bit sound we can well play 16 bit
176 	 * sound at the same time iff using the same transfer mode.
177 	 */
178 	if (other->active) {
179 		/* FIXME: is this guaranteed by the alsa api? */
180 		hw->formats &= (1ULL << i2sdev->format);
181 		/* see above, restrict rates to the one we already have */
182 		hw->rate_min = i2sdev->rate;
183 		hw->rate_max = i2sdev->rate;
184 	}
185 
186 	hw->channels_min = 2;
187 	hw->channels_max = 2;
188 	/* these are somewhat arbitrary */
189 	hw->buffer_bytes_max = 131072;
190 	hw->period_bytes_min = 256;
191 	hw->period_bytes_max = 16384;
192 	hw->periods_min = 3;
193 	hw->periods_max = MAX_DBDMA_COMMANDS;
194 	err = snd_pcm_hw_constraint_integer(pi->substream->runtime,
195 					    SNDRV_PCM_HW_PARAM_PERIODS);
196 	if (err < 0) {
197 		result = err;
198 		goto out_unlock;
199 	}
200 	list_for_each_entry(cii, &sdev->codec_list, list) {
201 		if (cii->codec->open) {
202 			err = cii->codec->open(cii, pi->substream);
203 			if (err) {
204 				result = err;
205 				/* unwind */
206 				found_this = 0;
207 				list_for_each_entry_reverse(rev,
208 				    &sdev->codec_list, list) {
209 					if (found_this && rev->codec->close) {
210 						rev->codec->close(rev,
211 								pi->substream);
212 					}
213 					if (rev == cii)
214 						found_this = 1;
215 				}
216 				goto out_unlock;
217 			}
218 		}
219 	}
220 
221  out_unlock:
222 	mutex_unlock(&i2sdev->lock);
223 	return result;
224 }
225 
226 #undef CHECK_RATE
227 
228 static int i2sbus_pcm_close(struct i2sbus_dev *i2sdev, int in)
229 {
230 	struct codec_info_item *cii;
231 	struct pcm_info *pi;
232 	int err = 0, tmp;
233 
234 	mutex_lock(&i2sdev->lock);
235 
236 	get_pcm_info(i2sdev, in, &pi, NULL);
237 
238 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
239 		if (cii->codec->close) {
240 			tmp = cii->codec->close(cii, pi->substream);
241 			if (tmp)
242 				err = tmp;
243 		}
244 	}
245 
246 	pi->substream = NULL;
247 	pi->active = 0;
248 	mutex_unlock(&i2sdev->lock);
249 	return err;
250 }
251 
252 static void i2sbus_wait_for_stop(struct i2sbus_dev *i2sdev,
253 				 struct pcm_info *pi)
254 {
255 	unsigned long flags;
256 	struct completion done;
257 	long timeout;
258 
259 	spin_lock_irqsave(&i2sdev->low_lock, flags);
260 	if (pi->dbdma_ring.stopping) {
261 		init_completion(&done);
262 		pi->stop_completion = &done;
263 		spin_unlock_irqrestore(&i2sdev->low_lock, flags);
264 		timeout = wait_for_completion_timeout(&done, HZ);
265 		spin_lock_irqsave(&i2sdev->low_lock, flags);
266 		pi->stop_completion = NULL;
267 		if (timeout == 0) {
268 			/* timeout expired, stop dbdma forcefully */
269 			printk(KERN_ERR "i2sbus_wait_for_stop: timed out\n");
270 			/* make sure RUN, PAUSE and S0 bits are cleared */
271 			out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
272 			pi->dbdma_ring.stopping = 0;
273 			timeout = 10;
274 			while (in_le32(&pi->dbdma->status) & ACTIVE) {
275 				if (--timeout <= 0)
276 					break;
277 				udelay(1);
278 			}
279 		}
280 	}
281 	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
282 }
283 
284 #ifdef CONFIG_PM
285 void i2sbus_wait_for_stop_both(struct i2sbus_dev *i2sdev)
286 {
287 	struct pcm_info *pi;
288 
289 	get_pcm_info(i2sdev, 0, &pi, NULL);
290 	i2sbus_wait_for_stop(i2sdev, pi);
291 	get_pcm_info(i2sdev, 1, &pi, NULL);
292 	i2sbus_wait_for_stop(i2sdev, pi);
293 }
294 #endif
295 
296 static int i2sbus_hw_params(struct snd_pcm_substream *substream,
297 			    struct snd_pcm_hw_params *params)
298 {
299 	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
300 }
301 
302 static inline int i2sbus_hw_free(struct snd_pcm_substream *substream, int in)
303 {
304 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
305 	struct pcm_info *pi;
306 
307 	get_pcm_info(i2sdev, in, &pi, NULL);
308 	if (pi->dbdma_ring.stopping)
309 		i2sbus_wait_for_stop(i2sdev, pi);
310 	snd_pcm_lib_free_pages(substream);
311 	return 0;
312 }
313 
314 static int i2sbus_playback_hw_free(struct snd_pcm_substream *substream)
315 {
316 	return i2sbus_hw_free(substream, 0);
317 }
318 
319 static int i2sbus_record_hw_free(struct snd_pcm_substream *substream)
320 {
321 	return i2sbus_hw_free(substream, 1);
322 }
323 
324 static int i2sbus_pcm_prepare(struct i2sbus_dev *i2sdev, int in)
325 {
326 	/* whee. Hard work now. The user has selected a bitrate
327 	 * and bit format, so now we have to program our
328 	 * I2S controller appropriately. */
329 	struct snd_pcm_runtime *runtime;
330 	struct dbdma_cmd *command;
331 	int i, periodsize, nperiods;
332 	dma_addr_t offset;
333 	struct bus_info bi;
334 	struct codec_info_item *cii;
335 	int sfr = 0;		/* serial format register */
336 	int dws = 0;		/* data word sizes reg */
337 	int input_16bit;
338 	struct pcm_info *pi, *other;
339 	int cnt;
340 	int result = 0;
341 	unsigned int cmd, stopaddr;
342 
343 	mutex_lock(&i2sdev->lock);
344 
345 	get_pcm_info(i2sdev, in, &pi, &other);
346 
347 	if (pi->dbdma_ring.running) {
348 		result = -EBUSY;
349 		goto out_unlock;
350 	}
351 	if (pi->dbdma_ring.stopping)
352 		i2sbus_wait_for_stop(i2sdev, pi);
353 
354 	if (!pi->substream || !pi->substream->runtime) {
355 		result = -EINVAL;
356 		goto out_unlock;
357 	}
358 
359 	runtime = pi->substream->runtime;
360 	pi->active = 1;
361 	if (other->active &&
362 	    ((i2sdev->format != runtime->format)
363 	     || (i2sdev->rate != runtime->rate))) {
364 		result = -EINVAL;
365 		goto out_unlock;
366 	}
367 
368 	i2sdev->format = runtime->format;
369 	i2sdev->rate = runtime->rate;
370 
371 	periodsize = snd_pcm_lib_period_bytes(pi->substream);
372 	nperiods = pi->substream->runtime->periods;
373 	pi->current_period = 0;
374 
375 	/* generate dbdma command ring first */
376 	command = pi->dbdma_ring.cmds;
377 	memset(command, 0, (nperiods + 2) * sizeof(struct dbdma_cmd));
378 
379 	/* commands to DMA to/from the ring */
380 	/*
381 	 * For input, we need to do a graceful stop; if we abort
382 	 * the DMA, we end up with leftover bytes that corrupt
383 	 * the next recording.  To do this we set the S0 status
384 	 * bit and wait for the DMA controller to stop.  Each
385 	 * command has a branch condition to
386 	 * make it branch to a stop command if S0 is set.
387 	 * On input we also need to wait for the S7 bit to be
388 	 * set before turning off the DMA controller.
389 	 * In fact we do the graceful stop for output as well.
390 	 */
391 	offset = runtime->dma_addr;
392 	cmd = (in? INPUT_MORE: OUTPUT_MORE) | BR_IFSET | INTR_ALWAYS;
393 	stopaddr = pi->dbdma_ring.bus_cmd_start +
394 		(nperiods + 1) * sizeof(struct dbdma_cmd);
395 	for (i = 0; i < nperiods; i++, command++, offset += periodsize) {
396 		command->command = cpu_to_le16(cmd);
397 		command->cmd_dep = cpu_to_le32(stopaddr);
398 		command->phy_addr = cpu_to_le32(offset);
399 		command->req_count = cpu_to_le16(periodsize);
400 	}
401 
402 	/* branch back to beginning of ring */
403 	command->command = cpu_to_le16(DBDMA_NOP | BR_ALWAYS);
404 	command->cmd_dep = cpu_to_le32(pi->dbdma_ring.bus_cmd_start);
405 	command++;
406 
407 	/* set stop command */
408 	command->command = cpu_to_le16(DBDMA_STOP);
409 
410 	/* ok, let's set the serial format and stuff */
411 	switch (runtime->format) {
412 	/* 16 bit formats */
413 	case SNDRV_PCM_FORMAT_S16_BE:
414 	case SNDRV_PCM_FORMAT_U16_BE:
415 		/* FIXME: if we add different bus factors we need to
416 		 * do more here!! */
417 		bi.bus_factor = 0;
418 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
419 			bi.bus_factor = cii->codec->bus_factor;
420 			break;
421 		}
422 		if (!bi.bus_factor) {
423 			result = -ENODEV;
424 			goto out_unlock;
425 		}
426 		input_16bit = 1;
427 		break;
428 	case SNDRV_PCM_FORMAT_S32_BE:
429 	case SNDRV_PCM_FORMAT_U32_BE:
430 		/* force 64x bus speed, otherwise the data cannot be
431 		 * transferred quickly enough! */
432 		bi.bus_factor = 64;
433 		input_16bit = 0;
434 		break;
435 	default:
436 		result = -EINVAL;
437 		goto out_unlock;
438 	}
439 	/* we assume all sysclocks are the same! */
440 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
441 		bi.sysclock_factor = cii->codec->sysclock_factor;
442 		break;
443 	}
444 
445 	if (clock_and_divisors(bi.sysclock_factor,
446 			       bi.bus_factor,
447 			       runtime->rate,
448 			       &sfr) < 0) {
449 		result = -EINVAL;
450 		goto out_unlock;
451 	}
452 	switch (bi.bus_factor) {
453 	case 32:
454 		sfr |= I2S_SF_SERIAL_FORMAT_I2S_32X;
455 		break;
456 	case 64:
457 		sfr |= I2S_SF_SERIAL_FORMAT_I2S_64X;
458 		break;
459 	}
460 	/* FIXME: THIS ASSUMES MASTER ALL THE TIME */
461 	sfr |= I2S_SF_SCLK_MASTER;
462 
463 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
464 		int err = 0;
465 		if (cii->codec->prepare)
466 			err = cii->codec->prepare(cii, &bi, pi->substream);
467 		if (err) {
468 			result = err;
469 			goto out_unlock;
470 		}
471 	}
472 	/* codecs are fine with it, so set our clocks */
473 	if (input_16bit)
474 		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
475 			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
476 			I2S_DWS_DATA_IN_16BIT | I2S_DWS_DATA_OUT_16BIT;
477 	else
478 		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
479 			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
480 			I2S_DWS_DATA_IN_24BIT | I2S_DWS_DATA_OUT_24BIT;
481 
482 	/* early exit if already programmed correctly */
483 	/* not locking these is fine since we touch them only in this function */
484 	if (in_le32(&i2sdev->intfregs->serial_format) == sfr
485 	 && in_le32(&i2sdev->intfregs->data_word_sizes) == dws)
486 		goto out_unlock;
487 
488 	/* let's notify the codecs about clocks going away.
489 	 * For now we only do mastering on the i2s cell... */
490 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
491 		if (cii->codec->switch_clock)
492 			cii->codec->switch_clock(cii, CLOCK_SWITCH_PREPARE_SLAVE);
493 
494 	i2sbus_control_enable(i2sdev->control, i2sdev);
495 	i2sbus_control_cell(i2sdev->control, i2sdev, 1);
496 
497 	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);
498 
499 	i2sbus_control_clock(i2sdev->control, i2sdev, 0);
500 
501 	msleep(1);
502 
503 	/* wait for clock stopped. This can apparently take a while... */
504 	cnt = 100;
505 	while (cnt-- &&
506 	    !(in_le32(&i2sdev->intfregs->intr_ctl) & I2S_PENDING_CLOCKS_STOPPED)) {
507 		msleep(5);
508 	}
509 	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);
510 
511 	/* not locking these is fine since we touch them only in this function */
512 	out_le32(&i2sdev->intfregs->serial_format, sfr);
513 	out_le32(&i2sdev->intfregs->data_word_sizes, dws);
514 
515         i2sbus_control_enable(i2sdev->control, i2sdev);
516         i2sbus_control_cell(i2sdev->control, i2sdev, 1);
517         i2sbus_control_clock(i2sdev->control, i2sdev, 1);
518 	msleep(1);
519 
520 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
521 		if (cii->codec->switch_clock)
522 			cii->codec->switch_clock(cii, CLOCK_SWITCH_SLAVE);
523 
524  out_unlock:
525 	mutex_unlock(&i2sdev->lock);
526 	return result;
527 }
528 
529 #ifdef CONFIG_PM
530 void i2sbus_pcm_prepare_both(struct i2sbus_dev *i2sdev)
531 {
532 	i2sbus_pcm_prepare(i2sdev, 0);
533 	i2sbus_pcm_prepare(i2sdev, 1);
534 }
535 #endif
536 
537 static int i2sbus_pcm_trigger(struct i2sbus_dev *i2sdev, int in, int cmd)
538 {
539 	struct codec_info_item *cii;
540 	struct pcm_info *pi;
541 	int result = 0;
542 	unsigned long flags;
543 
544 	spin_lock_irqsave(&i2sdev->low_lock, flags);
545 
546 	get_pcm_info(i2sdev, in, &pi, NULL);
547 
548 	switch (cmd) {
549 	case SNDRV_PCM_TRIGGER_START:
550 	case SNDRV_PCM_TRIGGER_RESUME:
551 		if (pi->dbdma_ring.running) {
552 			result = -EALREADY;
553 			goto out_unlock;
554 		}
555 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
556 			if (cii->codec->start)
557 				cii->codec->start(cii, pi->substream);
558 		pi->dbdma_ring.running = 1;
559 
560 		if (pi->dbdma_ring.stopping) {
561 			/* Clear the S0 bit, then see if we stopped yet */
562 			out_le32(&pi->dbdma->control, 1 << 16);
563 			if (in_le32(&pi->dbdma->status) & ACTIVE) {
564 				/* possible race here? */
565 				udelay(10);
566 				if (in_le32(&pi->dbdma->status) & ACTIVE) {
567 					pi->dbdma_ring.stopping = 0;
568 					goto out_unlock; /* keep running */
569 				}
570 			}
571 		}
572 
573 		/* make sure RUN, PAUSE and S0 bits are cleared */
574 		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
575 
576 		/* set branch condition select register */
577 		out_le32(&pi->dbdma->br_sel, (1 << 16) | 1);
578 
579 		/* write dma command buffer address to the dbdma chip */
580 		out_le32(&pi->dbdma->cmdptr, pi->dbdma_ring.bus_cmd_start);
581 
582 		/* initialize the frame count and current period */
583 		pi->current_period = 0;
584 		pi->frame_count = in_le32(&i2sdev->intfregs->frame_count);
585 
586 		/* set the DMA controller running */
587 		out_le32(&pi->dbdma->control, (RUN << 16) | RUN);
588 
589 		/* off you go! */
590 		break;
591 
592 	case SNDRV_PCM_TRIGGER_STOP:
593 	case SNDRV_PCM_TRIGGER_SUSPEND:
594 		if (!pi->dbdma_ring.running) {
595 			result = -EALREADY;
596 			goto out_unlock;
597 		}
598 		pi->dbdma_ring.running = 0;
599 
600 		/* Set the S0 bit to make the DMA branch to the stop cmd */
601 		out_le32(&pi->dbdma->control, (1 << 16) | 1);
602 		pi->dbdma_ring.stopping = 1;
603 
604 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
605 			if (cii->codec->stop)
606 				cii->codec->stop(cii, pi->substream);
607 		break;
608 	default:
609 		result = -EINVAL;
610 		goto out_unlock;
611 	}
612 
613  out_unlock:
614 	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
615 	return result;
616 }
617 
618 static snd_pcm_uframes_t i2sbus_pcm_pointer(struct i2sbus_dev *i2sdev, int in)
619 {
620 	struct pcm_info *pi;
621 	u32 fc;
622 
623 	get_pcm_info(i2sdev, in, &pi, NULL);
624 
625 	fc = in_le32(&i2sdev->intfregs->frame_count);
626 	fc = fc - pi->frame_count;
627 
628 	if (fc >= pi->substream->runtime->buffer_size)
629 		fc %= pi->substream->runtime->buffer_size;
630 	return fc;
631 }
632 
633 static inline void handle_interrupt(struct i2sbus_dev *i2sdev, int in)
634 {
635 	struct pcm_info *pi;
636 	u32 fc, nframes;
637 	u32 status;
638 	int timeout, i;
639 	int dma_stopped = 0;
640 	struct snd_pcm_runtime *runtime;
641 
642 	spin_lock(&i2sdev->low_lock);
643 	get_pcm_info(i2sdev, in, &pi, NULL);
644 	if (!pi->dbdma_ring.running && !pi->dbdma_ring.stopping)
645 		goto out_unlock;
646 
647 	i = pi->current_period;
648 	runtime = pi->substream->runtime;
649 	while (pi->dbdma_ring.cmds[i].xfer_status) {
650 		if (le16_to_cpu(pi->dbdma_ring.cmds[i].xfer_status) & BT)
651 			/*
652 			 * BT is the branch taken bit.  If it took a branch
653 			 * it is because we set the S0 bit to make it
654 			 * branch to the stop command.
655 			 */
656 			dma_stopped = 1;
657 		pi->dbdma_ring.cmds[i].xfer_status = 0;
658 
659 		if (++i >= runtime->periods) {
660 			i = 0;
661 			pi->frame_count += runtime->buffer_size;
662 		}
663 		pi->current_period = i;
664 
665 		/*
666 		 * Check the frame count.  The DMA tends to get a bit
667 		 * ahead of the frame counter, which confuses the core.
668 		 */
669 		fc = in_le32(&i2sdev->intfregs->frame_count);
670 		nframes = i * runtime->period_size;
671 		if (fc < pi->frame_count + nframes)
672 			pi->frame_count = fc - nframes;
673 	}
674 
675 	if (dma_stopped) {
676 		timeout = 1000;
677 		for (;;) {
678 			status = in_le32(&pi->dbdma->status);
679 			if (!(status & ACTIVE) && (!in || (status & 0x80)))
680 				break;
681 			if (--timeout <= 0) {
682 				printk(KERN_ERR "i2sbus: timed out "
683 				       "waiting for DMA to stop!\n");
684 				break;
685 			}
686 			udelay(1);
687 		}
688 
689 		/* Turn off DMA controller, clear S0 bit */
690 		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
691 
692 		pi->dbdma_ring.stopping = 0;
693 		if (pi->stop_completion)
694 			complete(pi->stop_completion);
695 	}
696 
697 	if (!pi->dbdma_ring.running)
698 		goto out_unlock;
699 	spin_unlock(&i2sdev->low_lock);
700 	/* may call _trigger again, hence needs to be unlocked */
701 	snd_pcm_period_elapsed(pi->substream);
702 	return;
703 
704  out_unlock:
705 	spin_unlock(&i2sdev->low_lock);
706 }
707 
708 irqreturn_t i2sbus_tx_intr(int irq, void *devid)
709 {
710 	handle_interrupt((struct i2sbus_dev *)devid, 0);
711 	return IRQ_HANDLED;
712 }
713 
714 irqreturn_t i2sbus_rx_intr(int irq, void *devid)
715 {
716 	handle_interrupt((struct i2sbus_dev *)devid, 1);
717 	return IRQ_HANDLED;
718 }
719 
720 static int i2sbus_playback_open(struct snd_pcm_substream *substream)
721 {
722 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
723 
724 	if (!i2sdev)
725 		return -EINVAL;
726 	i2sdev->out.substream = substream;
727 	return i2sbus_pcm_open(i2sdev, 0);
728 }
729 
730 static int i2sbus_playback_close(struct snd_pcm_substream *substream)
731 {
732 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
733 	int err;
734 
735 	if (!i2sdev)
736 		return -EINVAL;
737 	if (i2sdev->out.substream != substream)
738 		return -EINVAL;
739 	err = i2sbus_pcm_close(i2sdev, 0);
740 	if (!err)
741 		i2sdev->out.substream = NULL;
742 	return err;
743 }
744 
745 static int i2sbus_playback_prepare(struct snd_pcm_substream *substream)
746 {
747 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
748 
749 	if (!i2sdev)
750 		return -EINVAL;
751 	if (i2sdev->out.substream != substream)
752 		return -EINVAL;
753 	return i2sbus_pcm_prepare(i2sdev, 0);
754 }
755 
756 static int i2sbus_playback_trigger(struct snd_pcm_substream *substream, int cmd)
757 {
758 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
759 
760 	if (!i2sdev)
761 		return -EINVAL;
762 	if (i2sdev->out.substream != substream)
763 		return -EINVAL;
764 	return i2sbus_pcm_trigger(i2sdev, 0, cmd);
765 }
766 
767 static snd_pcm_uframes_t i2sbus_playback_pointer(struct snd_pcm_substream
768 						 *substream)
769 {
770 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
771 
772 	if (!i2sdev)
773 		return -EINVAL;
774 	if (i2sdev->out.substream != substream)
775 		return 0;
776 	return i2sbus_pcm_pointer(i2sdev, 0);
777 }
778 
779 static struct snd_pcm_ops i2sbus_playback_ops = {
780 	.open =		i2sbus_playback_open,
781 	.close =	i2sbus_playback_close,
782 	.ioctl =	snd_pcm_lib_ioctl,
783 	.hw_params =	i2sbus_hw_params,
784 	.hw_free =	i2sbus_playback_hw_free,
785 	.prepare =	i2sbus_playback_prepare,
786 	.trigger =	i2sbus_playback_trigger,
787 	.pointer =	i2sbus_playback_pointer,
788 };
789 
790 static int i2sbus_record_open(struct snd_pcm_substream *substream)
791 {
792 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
793 
794 	if (!i2sdev)
795 		return -EINVAL;
796 	i2sdev->in.substream = substream;
797 	return i2sbus_pcm_open(i2sdev, 1);
798 }
799 
800 static int i2sbus_record_close(struct snd_pcm_substream *substream)
801 {
802 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
803 	int err;
804 
805 	if (!i2sdev)
806 		return -EINVAL;
807 	if (i2sdev->in.substream != substream)
808 		return -EINVAL;
809 	err = i2sbus_pcm_close(i2sdev, 1);
810 	if (!err)
811 		i2sdev->in.substream = NULL;
812 	return err;
813 }
814 
815 static int i2sbus_record_prepare(struct snd_pcm_substream *substream)
816 {
817 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
818 
819 	if (!i2sdev)
820 		return -EINVAL;
821 	if (i2sdev->in.substream != substream)
822 		return -EINVAL;
823 	return i2sbus_pcm_prepare(i2sdev, 1);
824 }
825 
826 static int i2sbus_record_trigger(struct snd_pcm_substream *substream, int cmd)
827 {
828 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
829 
830 	if (!i2sdev)
831 		return -EINVAL;
832 	if (i2sdev->in.substream != substream)
833 		return -EINVAL;
834 	return i2sbus_pcm_trigger(i2sdev, 1, cmd);
835 }
836 
837 static snd_pcm_uframes_t i2sbus_record_pointer(struct snd_pcm_substream
838 					       *substream)
839 {
840 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
841 
842 	if (!i2sdev)
843 		return -EINVAL;
844 	if (i2sdev->in.substream != substream)
845 		return 0;
846 	return i2sbus_pcm_pointer(i2sdev, 1);
847 }
848 
849 static struct snd_pcm_ops i2sbus_record_ops = {
850 	.open =		i2sbus_record_open,
851 	.close =	i2sbus_record_close,
852 	.ioctl =	snd_pcm_lib_ioctl,
853 	.hw_params =	i2sbus_hw_params,
854 	.hw_free =	i2sbus_record_hw_free,
855 	.prepare =	i2sbus_record_prepare,
856 	.trigger =	i2sbus_record_trigger,
857 	.pointer =	i2sbus_record_pointer,
858 };
859 
860 static void i2sbus_private_free(struct snd_pcm *pcm)
861 {
862 	struct i2sbus_dev *i2sdev = snd_pcm_chip(pcm);
863 	struct codec_info_item *p, *tmp;
864 
865 	i2sdev->sound.pcm = NULL;
866 	i2sdev->out.created = 0;
867 	i2sdev->in.created = 0;
868 	list_for_each_entry_safe(p, tmp, &i2sdev->sound.codec_list, list) {
869 		printk(KERN_ERR "i2sbus: a codec didn't unregister!\n");
870 		list_del(&p->list);
871 		module_put(p->codec->owner);
872 		kfree(p);
873 	}
874 	soundbus_dev_put(&i2sdev->sound);
875 	module_put(THIS_MODULE);
876 }
877 
878 int
879 i2sbus_attach_codec(struct soundbus_dev *dev, struct snd_card *card,
880 		    struct codec_info *ci, void *data)
881 {
882 	int err, in = 0, out = 0;
883 	struct transfer_info *tmp;
884 	struct i2sbus_dev *i2sdev = soundbus_dev_to_i2sbus_dev(dev);
885 	struct codec_info_item *cii;
886 
887 	if (!dev->pcmname || dev->pcmid == -1) {
888 		printk(KERN_ERR "i2sbus: pcm name and id must be set!\n");
889 		return -EINVAL;
890 	}
891 
892 	list_for_each_entry(cii, &dev->codec_list, list) {
893 		if (cii->codec_data == data)
894 			return -EALREADY;
895 	}
896 
897 	if (!ci->transfers || !ci->transfers->formats
898 	    || !ci->transfers->rates || !ci->usable)
899 		return -EINVAL;
900 
901 	/* we currently code the i2s transfer on the clock, and support only
902 	 * 32 and 64 */
903 	if (ci->bus_factor != 32 && ci->bus_factor != 64)
904 		return -EINVAL;
905 
906 	/* If you want to fix this, you need to keep track of what transport infos
907 	 * are to be used, which codecs they belong to, and then fix all the
908 	 * sysclock/busclock stuff above to depend on which is usable */
909 	list_for_each_entry(cii, &dev->codec_list, list) {
910 		if (cii->codec->sysclock_factor != ci->sysclock_factor) {
911 			printk(KERN_DEBUG
912 			       "cannot yet handle multiple different sysclocks!\n");
913 			return -EINVAL;
914 		}
915 		if (cii->codec->bus_factor != ci->bus_factor) {
916 			printk(KERN_DEBUG
917 			       "cannot yet handle multiple different bus clocks!\n");
918 			return -EINVAL;
919 		}
920 	}
921 
922 	tmp = ci->transfers;
923 	while (tmp->formats && tmp->rates) {
924 		if (tmp->transfer_in)
925 			in = 1;
926 		else
927 			out = 1;
928 		tmp++;
929 	}
930 
931 	cii = kzalloc(sizeof(struct codec_info_item), GFP_KERNEL);
932 	if (!cii) {
933 		printk(KERN_DEBUG "i2sbus: failed to allocate cii\n");
934 		return -ENOMEM;
935 	}
936 
937 	/* use the private data to point to the codec info */
938 	cii->sdev = soundbus_dev_get(dev);
939 	cii->codec = ci;
940 	cii->codec_data = data;
941 
942 	if (!cii->sdev) {
943 		printk(KERN_DEBUG
944 		       "i2sbus: failed to get soundbus dev reference\n");
945 		err = -ENODEV;
946 		goto out_free_cii;
947 	}
948 
949 	if (!try_module_get(THIS_MODULE)) {
950 		printk(KERN_DEBUG "i2sbus: failed to get module reference!\n");
951 		err = -EBUSY;
952 		goto out_put_sdev;
953 	}
954 
955 	if (!try_module_get(ci->owner)) {
956 		printk(KERN_DEBUG
957 		       "i2sbus: failed to get module reference to codec owner!\n");
958 		err = -EBUSY;
959 		goto out_put_this_module;
960 	}
961 
962 	if (!dev->pcm) {
963 		err = snd_pcm_new(card, dev->pcmname, dev->pcmid, 0, 0,
964 				  &dev->pcm);
965 		if (err) {
966 			printk(KERN_DEBUG "i2sbus: failed to create pcm\n");
967 			goto out_put_ci_module;
968 		}
969 		dev->pcm->dev = &dev->ofdev.dev;
970 	}
971 
972 	/* ALSA yet again sucks.
973 	 * If it is ever fixed, remove this line. See below. */
974 	out = in = 1;
975 
976 	if (!i2sdev->out.created && out) {
977 		if (dev->pcm->card != card) {
978 			/* eh? */
979 			printk(KERN_ERR
980 			       "Can't attach same bus to different cards!\n");
981 			err = -EINVAL;
982 			goto out_put_ci_module;
983 		}
984 		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK, 1);
985 		if (err)
986 			goto out_put_ci_module;
987 		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK,
988 				&i2sbus_playback_ops);
989 		i2sdev->out.created = 1;
990 	}
991 
992 	if (!i2sdev->in.created && in) {
993 		if (dev->pcm->card != card) {
994 			printk(KERN_ERR
995 			       "Can't attach same bus to different cards!\n");
996 			err = -EINVAL;
997 			goto out_put_ci_module;
998 		}
999 		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_CAPTURE, 1);
1000 		if (err)
1001 			goto out_put_ci_module;
1002 		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_CAPTURE,
1003 				&i2sbus_record_ops);
1004 		i2sdev->in.created = 1;
1005 	}
1006 
1007 	/* so we have to register the pcm after adding any substream
1008 	 * to it because alsa doesn't create the devices for the
1009 	 * substreams when we add them later.
1010 	 * Therefore, force in and out on both busses (above) and
1011 	 * register the pcm now instead of just after creating it.
1012 	 */
1013 	err = snd_device_register(card, dev->pcm);
1014 	if (err) {
1015 		printk(KERN_ERR "i2sbus: error registering new pcm\n");
1016 		goto out_put_ci_module;
1017 	}
1018 	/* no errors any more, so let's add this to our list */
1019 	list_add(&cii->list, &dev->codec_list);
1020 
1021 	dev->pcm->private_data = i2sdev;
1022 	dev->pcm->private_free = i2sbus_private_free;
1023 
1024 	/* well, we really should support scatter/gather DMA */
1025 	snd_pcm_lib_preallocate_pages_for_all(
1026 		dev->pcm, SNDRV_DMA_TYPE_DEV,
1027 		snd_dma_pci_data(macio_get_pci_dev(i2sdev->macio)),
1028 		64 * 1024, 64 * 1024);
1029 
1030 	return 0;
1031  out_put_ci_module:
1032 	module_put(ci->owner);
1033  out_put_this_module:
1034 	module_put(THIS_MODULE);
1035  out_put_sdev:
1036 	soundbus_dev_put(dev);
1037  out_free_cii:
1038 	kfree(cii);
1039 	return err;
1040 }
1041 
1042 void i2sbus_detach_codec(struct soundbus_dev *dev, void *data)
1043 {
1044 	struct codec_info_item *cii = NULL, *i;
1045 
1046 	list_for_each_entry(i, &dev->codec_list, list) {
1047 		if (i->codec_data == data) {
1048 			cii = i;
1049 			break;
1050 		}
1051 	}
1052 	if (cii) {
1053 		list_del(&cii->list);
1054 		module_put(cii->codec->owner);
1055 		kfree(cii);
1056 	}
1057 	/* no more codecs, but still a pcm? */
1058 	if (list_empty(&dev->codec_list) && dev->pcm) {
1059 		/* the actual cleanup is done by the callback above! */
1060 		snd_device_free(dev->pcm->card, dev->pcm);
1061 	}
1062 }
1063