xref: /openbmc/linux/sound/aoa/soundbus/i2sbus/pcm.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * i2sbus driver -- pcm routines
4  *
5  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
6  */
7 
8 #include <linux/io.h>
9 #include <linux/delay.h>
10 #include <linux/slab.h>
11 #include <sound/core.h>
12 #include <asm/macio.h>
13 #include <linux/pci.h>
14 #include <linux/module.h>
15 #include "../soundbus.h"
16 #include "i2sbus.h"
17 
18 static inline void get_pcm_info(struct i2sbus_dev *i2sdev, int in,
19 				struct pcm_info **pi, struct pcm_info **other)
20 {
21 	if (in) {
22 		if (pi)
23 			*pi = &i2sdev->in;
24 		if (other)
25 			*other = &i2sdev->out;
26 	} else {
27 		if (pi)
28 			*pi = &i2sdev->out;
29 		if (other)
30 			*other = &i2sdev->in;
31 	}
32 }
33 
34 static int clock_and_divisors(int mclk, int sclk, int rate, int *out)
35 {
36 	/* sclk must be derived from mclk! */
37 	if (mclk % sclk)
38 		return -1;
39 	/* derive sclk register value */
40 	if (i2s_sf_sclkdiv(mclk / sclk, out))
41 		return -1;
42 
43 	if (I2S_CLOCK_SPEED_18MHz % (rate * mclk) == 0) {
44 		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_18MHz / (rate * mclk), out)) {
45 			*out |= I2S_SF_CLOCK_SOURCE_18MHz;
46 			return 0;
47 		}
48 	}
49 	if (I2S_CLOCK_SPEED_45MHz % (rate * mclk) == 0) {
50 		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_45MHz / (rate * mclk), out)) {
51 			*out |= I2S_SF_CLOCK_SOURCE_45MHz;
52 			return 0;
53 		}
54 	}
55 	if (I2S_CLOCK_SPEED_49MHz % (rate * mclk) == 0) {
56 		if (!i2s_sf_mclkdiv(I2S_CLOCK_SPEED_49MHz / (rate * mclk), out)) {
57 			*out |= I2S_SF_CLOCK_SOURCE_49MHz;
58 			return 0;
59 		}
60 	}
61 	return -1;
62 }
63 
64 #define CHECK_RATE(rate)						\
65 	do { if (rates & SNDRV_PCM_RATE_ ##rate) {			\
66 		int dummy;						\
67 		if (clock_and_divisors(sysclock_factor,			\
68 				       bus_factor, rate, &dummy))	\
69 			rates &= ~SNDRV_PCM_RATE_ ##rate;		\
70 	} } while (0)
71 
72 static int i2sbus_pcm_open(struct i2sbus_dev *i2sdev, int in)
73 {
74 	struct pcm_info *pi, *other;
75 	struct soundbus_dev *sdev;
76 	int masks_inited = 0, err;
77 	struct codec_info_item *cii, *rev;
78 	struct snd_pcm_hardware *hw;
79 	u64 formats = 0;
80 	unsigned int rates = 0;
81 	struct transfer_info v;
82 	int result = 0;
83 	int bus_factor = 0, sysclock_factor = 0;
84 	int found_this;
85 
86 	mutex_lock(&i2sdev->lock);
87 
88 	get_pcm_info(i2sdev, in, &pi, &other);
89 
90 	hw = &pi->substream->runtime->hw;
91 	sdev = &i2sdev->sound;
92 
93 	if (pi->active) {
94 		/* alsa messed up */
95 		result = -EBUSY;
96 		goto out_unlock;
97 	}
98 
99 	/* we now need to assign the hw */
100 	list_for_each_entry(cii, &sdev->codec_list, list) {
101 		struct transfer_info *ti = cii->codec->transfers;
102 		bus_factor = cii->codec->bus_factor;
103 		sysclock_factor = cii->codec->sysclock_factor;
104 		while (ti->formats && ti->rates) {
105 			v = *ti;
106 			if (ti->transfer_in == in
107 			    && cii->codec->usable(cii, ti, &v)) {
108 				if (masks_inited) {
109 					formats &= v.formats;
110 					rates &= v.rates;
111 				} else {
112 					formats = v.formats;
113 					rates = v.rates;
114 					masks_inited = 1;
115 				}
116 			}
117 			ti++;
118 		}
119 	}
120 	if (!masks_inited || !bus_factor || !sysclock_factor) {
121 		result = -ENODEV;
122 		goto out_unlock;
123 	}
124 	/* bus dependent stuff */
125 	hw->info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
126 		   SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_RESUME |
127 		   SNDRV_PCM_INFO_JOINT_DUPLEX;
128 
129 	CHECK_RATE(5512);
130 	CHECK_RATE(8000);
131 	CHECK_RATE(11025);
132 	CHECK_RATE(16000);
133 	CHECK_RATE(22050);
134 	CHECK_RATE(32000);
135 	CHECK_RATE(44100);
136 	CHECK_RATE(48000);
137 	CHECK_RATE(64000);
138 	CHECK_RATE(88200);
139 	CHECK_RATE(96000);
140 	CHECK_RATE(176400);
141 	CHECK_RATE(192000);
142 	hw->rates = rates;
143 
144 	/* well. the codec might want 24 bits only, and we'll
145 	 * ever only transfer 24 bits, but they are top-aligned!
146 	 * So for alsa, we claim that we're doing full 32 bit
147 	 * while in reality we'll ignore the lower 8 bits of
148 	 * that when doing playback (they're transferred as 0
149 	 * as far as I know, no codecs we have are 32-bit capable
150 	 * so I can't really test) and when doing recording we'll
151 	 * always have those lower 8 bits recorded as 0 */
152 	if (formats & SNDRV_PCM_FMTBIT_S24_BE)
153 		formats |= SNDRV_PCM_FMTBIT_S32_BE;
154 	if (formats & SNDRV_PCM_FMTBIT_U24_BE)
155 		formats |= SNDRV_PCM_FMTBIT_U32_BE;
156 	/* now mask off what we can support. I suppose we could
157 	 * also support S24_3LE and some similar formats, but I
158 	 * doubt there's a codec that would be able to use that,
159 	 * so we don't support it here. */
160 	hw->formats = formats & (SNDRV_PCM_FMTBIT_S16_BE |
161 				 SNDRV_PCM_FMTBIT_U16_BE |
162 				 SNDRV_PCM_FMTBIT_S32_BE |
163 				 SNDRV_PCM_FMTBIT_U32_BE);
164 
165 	/* we need to set the highest and lowest rate possible.
166 	 * These are the highest and lowest rates alsa can
167 	 * support properly in its bitfield.
168 	 * Below, we'll use that to restrict to the rate
169 	 * currently in use (if any). */
170 	hw->rate_min = 5512;
171 	hw->rate_max = 192000;
172 	/* if the other stream is active, then we can only
173 	 * support what it is currently using.
174 	 * FIXME: I lied. This comment is wrong. We can support
175 	 * anything that works with the same serial format, ie.
176 	 * when recording 24 bit sound we can well play 16 bit
177 	 * sound at the same time iff using the same transfer mode.
178 	 */
179 	if (other->active) {
180 		/* FIXME: is this guaranteed by the alsa api? */
181 		hw->formats &= pcm_format_to_bits(i2sdev->format);
182 		/* see above, restrict rates to the one we already have */
183 		hw->rate_min = i2sdev->rate;
184 		hw->rate_max = i2sdev->rate;
185 	}
186 
187 	hw->channels_min = 2;
188 	hw->channels_max = 2;
189 	/* these are somewhat arbitrary */
190 	hw->buffer_bytes_max = 131072;
191 	hw->period_bytes_min = 256;
192 	hw->period_bytes_max = 16384;
193 	hw->periods_min = 3;
194 	hw->periods_max = MAX_DBDMA_COMMANDS;
195 	err = snd_pcm_hw_constraint_integer(pi->substream->runtime,
196 					    SNDRV_PCM_HW_PARAM_PERIODS);
197 	if (err < 0) {
198 		result = err;
199 		goto out_unlock;
200 	}
201 	list_for_each_entry(cii, &sdev->codec_list, list) {
202 		if (cii->codec->open) {
203 			err = cii->codec->open(cii, pi->substream);
204 			if (err) {
205 				result = err;
206 				/* unwind */
207 				found_this = 0;
208 				list_for_each_entry_reverse(rev,
209 				    &sdev->codec_list, list) {
210 					if (found_this && rev->codec->close) {
211 						rev->codec->close(rev,
212 								pi->substream);
213 					}
214 					if (rev == cii)
215 						found_this = 1;
216 				}
217 				goto out_unlock;
218 			}
219 		}
220 	}
221 
222  out_unlock:
223 	mutex_unlock(&i2sdev->lock);
224 	return result;
225 }
226 
227 #undef CHECK_RATE
228 
229 static int i2sbus_pcm_close(struct i2sbus_dev *i2sdev, int in)
230 {
231 	struct codec_info_item *cii;
232 	struct pcm_info *pi;
233 	int err = 0, tmp;
234 
235 	mutex_lock(&i2sdev->lock);
236 
237 	get_pcm_info(i2sdev, in, &pi, NULL);
238 
239 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
240 		if (cii->codec->close) {
241 			tmp = cii->codec->close(cii, pi->substream);
242 			if (tmp)
243 				err = tmp;
244 		}
245 	}
246 
247 	pi->substream = NULL;
248 	pi->active = 0;
249 	mutex_unlock(&i2sdev->lock);
250 	return err;
251 }
252 
253 static void i2sbus_wait_for_stop(struct i2sbus_dev *i2sdev,
254 				 struct pcm_info *pi)
255 {
256 	unsigned long flags;
257 	struct completion done;
258 	long timeout;
259 
260 	spin_lock_irqsave(&i2sdev->low_lock, flags);
261 	if (pi->dbdma_ring.stopping) {
262 		init_completion(&done);
263 		pi->stop_completion = &done;
264 		spin_unlock_irqrestore(&i2sdev->low_lock, flags);
265 		timeout = wait_for_completion_timeout(&done, HZ);
266 		spin_lock_irqsave(&i2sdev->low_lock, flags);
267 		pi->stop_completion = NULL;
268 		if (timeout == 0) {
269 			/* timeout expired, stop dbdma forcefully */
270 			printk(KERN_ERR "i2sbus_wait_for_stop: timed out\n");
271 			/* make sure RUN, PAUSE and S0 bits are cleared */
272 			out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
273 			pi->dbdma_ring.stopping = 0;
274 			timeout = 10;
275 			while (in_le32(&pi->dbdma->status) & ACTIVE) {
276 				if (--timeout <= 0)
277 					break;
278 				udelay(1);
279 			}
280 		}
281 	}
282 	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
283 }
284 
285 #ifdef CONFIG_PM
286 void i2sbus_wait_for_stop_both(struct i2sbus_dev *i2sdev)
287 {
288 	struct pcm_info *pi;
289 
290 	get_pcm_info(i2sdev, 0, &pi, NULL);
291 	i2sbus_wait_for_stop(i2sdev, pi);
292 	get_pcm_info(i2sdev, 1, &pi, NULL);
293 	i2sbus_wait_for_stop(i2sdev, pi);
294 }
295 #endif
296 
297 static int i2sbus_hw_params(struct snd_pcm_substream *substream,
298 			    struct snd_pcm_hw_params *params)
299 {
300 	return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
301 }
302 
303 static inline int i2sbus_hw_free(struct snd_pcm_substream *substream, int in)
304 {
305 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
306 	struct pcm_info *pi;
307 
308 	get_pcm_info(i2sdev, in, &pi, NULL);
309 	if (pi->dbdma_ring.stopping)
310 		i2sbus_wait_for_stop(i2sdev, pi);
311 	snd_pcm_lib_free_pages(substream);
312 	return 0;
313 }
314 
315 static int i2sbus_playback_hw_free(struct snd_pcm_substream *substream)
316 {
317 	return i2sbus_hw_free(substream, 0);
318 }
319 
320 static int i2sbus_record_hw_free(struct snd_pcm_substream *substream)
321 {
322 	return i2sbus_hw_free(substream, 1);
323 }
324 
325 static int i2sbus_pcm_prepare(struct i2sbus_dev *i2sdev, int in)
326 {
327 	/* whee. Hard work now. The user has selected a bitrate
328 	 * and bit format, so now we have to program our
329 	 * I2S controller appropriately. */
330 	struct snd_pcm_runtime *runtime;
331 	struct dbdma_cmd *command;
332 	int i, periodsize, nperiods;
333 	dma_addr_t offset;
334 	struct bus_info bi;
335 	struct codec_info_item *cii;
336 	int sfr = 0;		/* serial format register */
337 	int dws = 0;		/* data word sizes reg */
338 	int input_16bit;
339 	struct pcm_info *pi, *other;
340 	int cnt;
341 	int result = 0;
342 	unsigned int cmd, stopaddr;
343 
344 	mutex_lock(&i2sdev->lock);
345 
346 	get_pcm_info(i2sdev, in, &pi, &other);
347 
348 	if (pi->dbdma_ring.running) {
349 		result = -EBUSY;
350 		goto out_unlock;
351 	}
352 	if (pi->dbdma_ring.stopping)
353 		i2sbus_wait_for_stop(i2sdev, pi);
354 
355 	if (!pi->substream || !pi->substream->runtime) {
356 		result = -EINVAL;
357 		goto out_unlock;
358 	}
359 
360 	runtime = pi->substream->runtime;
361 	pi->active = 1;
362 	if (other->active &&
363 	    ((i2sdev->format != runtime->format)
364 	     || (i2sdev->rate != runtime->rate))) {
365 		result = -EINVAL;
366 		goto out_unlock;
367 	}
368 
369 	i2sdev->format = runtime->format;
370 	i2sdev->rate = runtime->rate;
371 
372 	periodsize = snd_pcm_lib_period_bytes(pi->substream);
373 	nperiods = pi->substream->runtime->periods;
374 	pi->current_period = 0;
375 
376 	/* generate dbdma command ring first */
377 	command = pi->dbdma_ring.cmds;
378 	memset(command, 0, (nperiods + 2) * sizeof(struct dbdma_cmd));
379 
380 	/* commands to DMA to/from the ring */
381 	/*
382 	 * For input, we need to do a graceful stop; if we abort
383 	 * the DMA, we end up with leftover bytes that corrupt
384 	 * the next recording.  To do this we set the S0 status
385 	 * bit and wait for the DMA controller to stop.  Each
386 	 * command has a branch condition to
387 	 * make it branch to a stop command if S0 is set.
388 	 * On input we also need to wait for the S7 bit to be
389 	 * set before turning off the DMA controller.
390 	 * In fact we do the graceful stop for output as well.
391 	 */
392 	offset = runtime->dma_addr;
393 	cmd = (in? INPUT_MORE: OUTPUT_MORE) | BR_IFSET | INTR_ALWAYS;
394 	stopaddr = pi->dbdma_ring.bus_cmd_start +
395 		(nperiods + 1) * sizeof(struct dbdma_cmd);
396 	for (i = 0; i < nperiods; i++, command++, offset += periodsize) {
397 		command->command = cpu_to_le16(cmd);
398 		command->cmd_dep = cpu_to_le32(stopaddr);
399 		command->phy_addr = cpu_to_le32(offset);
400 		command->req_count = cpu_to_le16(periodsize);
401 	}
402 
403 	/* branch back to beginning of ring */
404 	command->command = cpu_to_le16(DBDMA_NOP | BR_ALWAYS);
405 	command->cmd_dep = cpu_to_le32(pi->dbdma_ring.bus_cmd_start);
406 	command++;
407 
408 	/* set stop command */
409 	command->command = cpu_to_le16(DBDMA_STOP);
410 
411 	/* ok, let's set the serial format and stuff */
412 	switch (runtime->format) {
413 	/* 16 bit formats */
414 	case SNDRV_PCM_FORMAT_S16_BE:
415 	case SNDRV_PCM_FORMAT_U16_BE:
416 		/* FIXME: if we add different bus factors we need to
417 		 * do more here!! */
418 		bi.bus_factor = 0;
419 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
420 			bi.bus_factor = cii->codec->bus_factor;
421 			break;
422 		}
423 		if (!bi.bus_factor) {
424 			result = -ENODEV;
425 			goto out_unlock;
426 		}
427 		input_16bit = 1;
428 		break;
429 	case SNDRV_PCM_FORMAT_S32_BE:
430 	case SNDRV_PCM_FORMAT_U32_BE:
431 		/* force 64x bus speed, otherwise the data cannot be
432 		 * transferred quickly enough! */
433 		bi.bus_factor = 64;
434 		input_16bit = 0;
435 		break;
436 	default:
437 		result = -EINVAL;
438 		goto out_unlock;
439 	}
440 	/* we assume all sysclocks are the same! */
441 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
442 		bi.sysclock_factor = cii->codec->sysclock_factor;
443 		break;
444 	}
445 
446 	if (clock_and_divisors(bi.sysclock_factor,
447 			       bi.bus_factor,
448 			       runtime->rate,
449 			       &sfr) < 0) {
450 		result = -EINVAL;
451 		goto out_unlock;
452 	}
453 	switch (bi.bus_factor) {
454 	case 32:
455 		sfr |= I2S_SF_SERIAL_FORMAT_I2S_32X;
456 		break;
457 	case 64:
458 		sfr |= I2S_SF_SERIAL_FORMAT_I2S_64X;
459 		break;
460 	}
461 	/* FIXME: THIS ASSUMES MASTER ALL THE TIME */
462 	sfr |= I2S_SF_SCLK_MASTER;
463 
464 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
465 		int err = 0;
466 		if (cii->codec->prepare)
467 			err = cii->codec->prepare(cii, &bi, pi->substream);
468 		if (err) {
469 			result = err;
470 			goto out_unlock;
471 		}
472 	}
473 	/* codecs are fine with it, so set our clocks */
474 	if (input_16bit)
475 		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
476 			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
477 			I2S_DWS_DATA_IN_16BIT | I2S_DWS_DATA_OUT_16BIT;
478 	else
479 		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
480 			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
481 			I2S_DWS_DATA_IN_24BIT | I2S_DWS_DATA_OUT_24BIT;
482 
483 	/* early exit if already programmed correctly */
484 	/* not locking these is fine since we touch them only in this function */
485 	if (in_le32(&i2sdev->intfregs->serial_format) == sfr
486 	 && in_le32(&i2sdev->intfregs->data_word_sizes) == dws)
487 		goto out_unlock;
488 
489 	/* let's notify the codecs about clocks going away.
490 	 * For now we only do mastering on the i2s cell... */
491 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
492 		if (cii->codec->switch_clock)
493 			cii->codec->switch_clock(cii, CLOCK_SWITCH_PREPARE_SLAVE);
494 
495 	i2sbus_control_enable(i2sdev->control, i2sdev);
496 	i2sbus_control_cell(i2sdev->control, i2sdev, 1);
497 
498 	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);
499 
500 	i2sbus_control_clock(i2sdev->control, i2sdev, 0);
501 
502 	msleep(1);
503 
504 	/* wait for clock stopped. This can apparently take a while... */
505 	cnt = 100;
506 	while (cnt-- &&
507 	    !(in_le32(&i2sdev->intfregs->intr_ctl) & I2S_PENDING_CLOCKS_STOPPED)) {
508 		msleep(5);
509 	}
510 	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);
511 
512 	/* not locking these is fine since we touch them only in this function */
513 	out_le32(&i2sdev->intfregs->serial_format, sfr);
514 	out_le32(&i2sdev->intfregs->data_word_sizes, dws);
515 
516         i2sbus_control_enable(i2sdev->control, i2sdev);
517         i2sbus_control_cell(i2sdev->control, i2sdev, 1);
518         i2sbus_control_clock(i2sdev->control, i2sdev, 1);
519 	msleep(1);
520 
521 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
522 		if (cii->codec->switch_clock)
523 			cii->codec->switch_clock(cii, CLOCK_SWITCH_SLAVE);
524 
525  out_unlock:
526 	mutex_unlock(&i2sdev->lock);
527 	return result;
528 }
529 
530 #ifdef CONFIG_PM
531 void i2sbus_pcm_prepare_both(struct i2sbus_dev *i2sdev)
532 {
533 	i2sbus_pcm_prepare(i2sdev, 0);
534 	i2sbus_pcm_prepare(i2sdev, 1);
535 }
536 #endif
537 
538 static int i2sbus_pcm_trigger(struct i2sbus_dev *i2sdev, int in, int cmd)
539 {
540 	struct codec_info_item *cii;
541 	struct pcm_info *pi;
542 	int result = 0;
543 	unsigned long flags;
544 
545 	spin_lock_irqsave(&i2sdev->low_lock, flags);
546 
547 	get_pcm_info(i2sdev, in, &pi, NULL);
548 
549 	switch (cmd) {
550 	case SNDRV_PCM_TRIGGER_START:
551 	case SNDRV_PCM_TRIGGER_RESUME:
552 		if (pi->dbdma_ring.running) {
553 			result = -EALREADY;
554 			goto out_unlock;
555 		}
556 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
557 			if (cii->codec->start)
558 				cii->codec->start(cii, pi->substream);
559 		pi->dbdma_ring.running = 1;
560 
561 		if (pi->dbdma_ring.stopping) {
562 			/* Clear the S0 bit, then see if we stopped yet */
563 			out_le32(&pi->dbdma->control, 1 << 16);
564 			if (in_le32(&pi->dbdma->status) & ACTIVE) {
565 				/* possible race here? */
566 				udelay(10);
567 				if (in_le32(&pi->dbdma->status) & ACTIVE) {
568 					pi->dbdma_ring.stopping = 0;
569 					goto out_unlock; /* keep running */
570 				}
571 			}
572 		}
573 
574 		/* make sure RUN, PAUSE and S0 bits are cleared */
575 		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
576 
577 		/* set branch condition select register */
578 		out_le32(&pi->dbdma->br_sel, (1 << 16) | 1);
579 
580 		/* write dma command buffer address to the dbdma chip */
581 		out_le32(&pi->dbdma->cmdptr, pi->dbdma_ring.bus_cmd_start);
582 
583 		/* initialize the frame count and current period */
584 		pi->current_period = 0;
585 		pi->frame_count = in_le32(&i2sdev->intfregs->frame_count);
586 
587 		/* set the DMA controller running */
588 		out_le32(&pi->dbdma->control, (RUN << 16) | RUN);
589 
590 		/* off you go! */
591 		break;
592 
593 	case SNDRV_PCM_TRIGGER_STOP:
594 	case SNDRV_PCM_TRIGGER_SUSPEND:
595 		if (!pi->dbdma_ring.running) {
596 			result = -EALREADY;
597 			goto out_unlock;
598 		}
599 		pi->dbdma_ring.running = 0;
600 
601 		/* Set the S0 bit to make the DMA branch to the stop cmd */
602 		out_le32(&pi->dbdma->control, (1 << 16) | 1);
603 		pi->dbdma_ring.stopping = 1;
604 
605 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
606 			if (cii->codec->stop)
607 				cii->codec->stop(cii, pi->substream);
608 		break;
609 	default:
610 		result = -EINVAL;
611 		goto out_unlock;
612 	}
613 
614  out_unlock:
615 	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
616 	return result;
617 }
618 
619 static snd_pcm_uframes_t i2sbus_pcm_pointer(struct i2sbus_dev *i2sdev, int in)
620 {
621 	struct pcm_info *pi;
622 	u32 fc;
623 
624 	get_pcm_info(i2sdev, in, &pi, NULL);
625 
626 	fc = in_le32(&i2sdev->intfregs->frame_count);
627 	fc = fc - pi->frame_count;
628 
629 	if (fc >= pi->substream->runtime->buffer_size)
630 		fc %= pi->substream->runtime->buffer_size;
631 	return fc;
632 }
633 
634 static inline void handle_interrupt(struct i2sbus_dev *i2sdev, int in)
635 {
636 	struct pcm_info *pi;
637 	u32 fc, nframes;
638 	u32 status;
639 	int timeout, i;
640 	int dma_stopped = 0;
641 	struct snd_pcm_runtime *runtime;
642 
643 	spin_lock(&i2sdev->low_lock);
644 	get_pcm_info(i2sdev, in, &pi, NULL);
645 	if (!pi->dbdma_ring.running && !pi->dbdma_ring.stopping)
646 		goto out_unlock;
647 
648 	i = pi->current_period;
649 	runtime = pi->substream->runtime;
650 	while (pi->dbdma_ring.cmds[i].xfer_status) {
651 		if (le16_to_cpu(pi->dbdma_ring.cmds[i].xfer_status) & BT)
652 			/*
653 			 * BT is the branch taken bit.  If it took a branch
654 			 * it is because we set the S0 bit to make it
655 			 * branch to the stop command.
656 			 */
657 			dma_stopped = 1;
658 		pi->dbdma_ring.cmds[i].xfer_status = 0;
659 
660 		if (++i >= runtime->periods) {
661 			i = 0;
662 			pi->frame_count += runtime->buffer_size;
663 		}
664 		pi->current_period = i;
665 
666 		/*
667 		 * Check the frame count.  The DMA tends to get a bit
668 		 * ahead of the frame counter, which confuses the core.
669 		 */
670 		fc = in_le32(&i2sdev->intfregs->frame_count);
671 		nframes = i * runtime->period_size;
672 		if (fc < pi->frame_count + nframes)
673 			pi->frame_count = fc - nframes;
674 	}
675 
676 	if (dma_stopped) {
677 		timeout = 1000;
678 		for (;;) {
679 			status = in_le32(&pi->dbdma->status);
680 			if (!(status & ACTIVE) && (!in || (status & 0x80)))
681 				break;
682 			if (--timeout <= 0) {
683 				printk(KERN_ERR "i2sbus: timed out "
684 				       "waiting for DMA to stop!\n");
685 				break;
686 			}
687 			udelay(1);
688 		}
689 
690 		/* Turn off DMA controller, clear S0 bit */
691 		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
692 
693 		pi->dbdma_ring.stopping = 0;
694 		if (pi->stop_completion)
695 			complete(pi->stop_completion);
696 	}
697 
698 	if (!pi->dbdma_ring.running)
699 		goto out_unlock;
700 	spin_unlock(&i2sdev->low_lock);
701 	/* may call _trigger again, hence needs to be unlocked */
702 	snd_pcm_period_elapsed(pi->substream);
703 	return;
704 
705  out_unlock:
706 	spin_unlock(&i2sdev->low_lock);
707 }
708 
709 irqreturn_t i2sbus_tx_intr(int irq, void *devid)
710 {
711 	handle_interrupt((struct i2sbus_dev *)devid, 0);
712 	return IRQ_HANDLED;
713 }
714 
715 irqreturn_t i2sbus_rx_intr(int irq, void *devid)
716 {
717 	handle_interrupt((struct i2sbus_dev *)devid, 1);
718 	return IRQ_HANDLED;
719 }
720 
721 static int i2sbus_playback_open(struct snd_pcm_substream *substream)
722 {
723 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
724 
725 	if (!i2sdev)
726 		return -EINVAL;
727 	i2sdev->out.substream = substream;
728 	return i2sbus_pcm_open(i2sdev, 0);
729 }
730 
731 static int i2sbus_playback_close(struct snd_pcm_substream *substream)
732 {
733 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
734 	int err;
735 
736 	if (!i2sdev)
737 		return -EINVAL;
738 	if (i2sdev->out.substream != substream)
739 		return -EINVAL;
740 	err = i2sbus_pcm_close(i2sdev, 0);
741 	if (!err)
742 		i2sdev->out.substream = NULL;
743 	return err;
744 }
745 
746 static int i2sbus_playback_prepare(struct snd_pcm_substream *substream)
747 {
748 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
749 
750 	if (!i2sdev)
751 		return -EINVAL;
752 	if (i2sdev->out.substream != substream)
753 		return -EINVAL;
754 	return i2sbus_pcm_prepare(i2sdev, 0);
755 }
756 
757 static int i2sbus_playback_trigger(struct snd_pcm_substream *substream, int cmd)
758 {
759 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
760 
761 	if (!i2sdev)
762 		return -EINVAL;
763 	if (i2sdev->out.substream != substream)
764 		return -EINVAL;
765 	return i2sbus_pcm_trigger(i2sdev, 0, cmd);
766 }
767 
768 static snd_pcm_uframes_t i2sbus_playback_pointer(struct snd_pcm_substream
769 						 *substream)
770 {
771 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
772 
773 	if (!i2sdev)
774 		return -EINVAL;
775 	if (i2sdev->out.substream != substream)
776 		return 0;
777 	return i2sbus_pcm_pointer(i2sdev, 0);
778 }
779 
780 static const struct snd_pcm_ops i2sbus_playback_ops = {
781 	.open =		i2sbus_playback_open,
782 	.close =	i2sbus_playback_close,
783 	.ioctl =	snd_pcm_lib_ioctl,
784 	.hw_params =	i2sbus_hw_params,
785 	.hw_free =	i2sbus_playback_hw_free,
786 	.prepare =	i2sbus_playback_prepare,
787 	.trigger =	i2sbus_playback_trigger,
788 	.pointer =	i2sbus_playback_pointer,
789 };
790 
791 static int i2sbus_record_open(struct snd_pcm_substream *substream)
792 {
793 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
794 
795 	if (!i2sdev)
796 		return -EINVAL;
797 	i2sdev->in.substream = substream;
798 	return i2sbus_pcm_open(i2sdev, 1);
799 }
800 
801 static int i2sbus_record_close(struct snd_pcm_substream *substream)
802 {
803 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
804 	int err;
805 
806 	if (!i2sdev)
807 		return -EINVAL;
808 	if (i2sdev->in.substream != substream)
809 		return -EINVAL;
810 	err = i2sbus_pcm_close(i2sdev, 1);
811 	if (!err)
812 		i2sdev->in.substream = NULL;
813 	return err;
814 }
815 
816 static int i2sbus_record_prepare(struct snd_pcm_substream *substream)
817 {
818 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
819 
820 	if (!i2sdev)
821 		return -EINVAL;
822 	if (i2sdev->in.substream != substream)
823 		return -EINVAL;
824 	return i2sbus_pcm_prepare(i2sdev, 1);
825 }
826 
827 static int i2sbus_record_trigger(struct snd_pcm_substream *substream, int cmd)
828 {
829 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
830 
831 	if (!i2sdev)
832 		return -EINVAL;
833 	if (i2sdev->in.substream != substream)
834 		return -EINVAL;
835 	return i2sbus_pcm_trigger(i2sdev, 1, cmd);
836 }
837 
838 static snd_pcm_uframes_t i2sbus_record_pointer(struct snd_pcm_substream
839 					       *substream)
840 {
841 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
842 
843 	if (!i2sdev)
844 		return -EINVAL;
845 	if (i2sdev->in.substream != substream)
846 		return 0;
847 	return i2sbus_pcm_pointer(i2sdev, 1);
848 }
849 
850 static const struct snd_pcm_ops i2sbus_record_ops = {
851 	.open =		i2sbus_record_open,
852 	.close =	i2sbus_record_close,
853 	.ioctl =	snd_pcm_lib_ioctl,
854 	.hw_params =	i2sbus_hw_params,
855 	.hw_free =	i2sbus_record_hw_free,
856 	.prepare =	i2sbus_record_prepare,
857 	.trigger =	i2sbus_record_trigger,
858 	.pointer =	i2sbus_record_pointer,
859 };
860 
861 static void i2sbus_private_free(struct snd_pcm *pcm)
862 {
863 	struct i2sbus_dev *i2sdev = snd_pcm_chip(pcm);
864 	struct codec_info_item *p, *tmp;
865 
866 	i2sdev->sound.pcm = NULL;
867 	i2sdev->out.created = 0;
868 	i2sdev->in.created = 0;
869 	list_for_each_entry_safe(p, tmp, &i2sdev->sound.codec_list, list) {
870 		printk(KERN_ERR "i2sbus: a codec didn't unregister!\n");
871 		list_del(&p->list);
872 		module_put(p->codec->owner);
873 		kfree(p);
874 	}
875 	soundbus_dev_put(&i2sdev->sound);
876 	module_put(THIS_MODULE);
877 }
878 
879 int
880 i2sbus_attach_codec(struct soundbus_dev *dev, struct snd_card *card,
881 		    struct codec_info *ci, void *data)
882 {
883 	int err, in = 0, out = 0;
884 	struct transfer_info *tmp;
885 	struct i2sbus_dev *i2sdev = soundbus_dev_to_i2sbus_dev(dev);
886 	struct codec_info_item *cii;
887 
888 	if (!dev->pcmname || dev->pcmid == -1) {
889 		printk(KERN_ERR "i2sbus: pcm name and id must be set!\n");
890 		return -EINVAL;
891 	}
892 
893 	list_for_each_entry(cii, &dev->codec_list, list) {
894 		if (cii->codec_data == data)
895 			return -EALREADY;
896 	}
897 
898 	if (!ci->transfers || !ci->transfers->formats
899 	    || !ci->transfers->rates || !ci->usable)
900 		return -EINVAL;
901 
902 	/* we currently code the i2s transfer on the clock, and support only
903 	 * 32 and 64 */
904 	if (ci->bus_factor != 32 && ci->bus_factor != 64)
905 		return -EINVAL;
906 
907 	/* If you want to fix this, you need to keep track of what transport infos
908 	 * are to be used, which codecs they belong to, and then fix all the
909 	 * sysclock/busclock stuff above to depend on which is usable */
910 	list_for_each_entry(cii, &dev->codec_list, list) {
911 		if (cii->codec->sysclock_factor != ci->sysclock_factor) {
912 			printk(KERN_DEBUG
913 			       "cannot yet handle multiple different sysclocks!\n");
914 			return -EINVAL;
915 		}
916 		if (cii->codec->bus_factor != ci->bus_factor) {
917 			printk(KERN_DEBUG
918 			       "cannot yet handle multiple different bus clocks!\n");
919 			return -EINVAL;
920 		}
921 	}
922 
923 	tmp = ci->transfers;
924 	while (tmp->formats && tmp->rates) {
925 		if (tmp->transfer_in)
926 			in = 1;
927 		else
928 			out = 1;
929 		tmp++;
930 	}
931 
932 	cii = kzalloc(sizeof(struct codec_info_item), GFP_KERNEL);
933 	if (!cii) {
934 		printk(KERN_DEBUG "i2sbus: failed to allocate cii\n");
935 		return -ENOMEM;
936 	}
937 
938 	/* use the private data to point to the codec info */
939 	cii->sdev = soundbus_dev_get(dev);
940 	cii->codec = ci;
941 	cii->codec_data = data;
942 
943 	if (!cii->sdev) {
944 		printk(KERN_DEBUG
945 		       "i2sbus: failed to get soundbus dev reference\n");
946 		err = -ENODEV;
947 		goto out_free_cii;
948 	}
949 
950 	if (!try_module_get(THIS_MODULE)) {
951 		printk(KERN_DEBUG "i2sbus: failed to get module reference!\n");
952 		err = -EBUSY;
953 		goto out_put_sdev;
954 	}
955 
956 	if (!try_module_get(ci->owner)) {
957 		printk(KERN_DEBUG
958 		       "i2sbus: failed to get module reference to codec owner!\n");
959 		err = -EBUSY;
960 		goto out_put_this_module;
961 	}
962 
963 	if (!dev->pcm) {
964 		err = snd_pcm_new(card, dev->pcmname, dev->pcmid, 0, 0,
965 				  &dev->pcm);
966 		if (err) {
967 			printk(KERN_DEBUG "i2sbus: failed to create pcm\n");
968 			goto out_put_ci_module;
969 		}
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 		dev->pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].dev.parent =
990 			&dev->ofdev.dev;
991 		i2sdev->out.created = 1;
992 	}
993 
994 	if (!i2sdev->in.created && in) {
995 		if (dev->pcm->card != card) {
996 			printk(KERN_ERR
997 			       "Can't attach same bus to different cards!\n");
998 			err = -EINVAL;
999 			goto out_put_ci_module;
1000 		}
1001 		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_CAPTURE, 1);
1002 		if (err)
1003 			goto out_put_ci_module;
1004 		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_CAPTURE,
1005 				&i2sbus_record_ops);
1006 		dev->pcm->streams[SNDRV_PCM_STREAM_CAPTURE].dev.parent =
1007 			&dev->ofdev.dev;
1008 		i2sdev->in.created = 1;
1009 	}
1010 
1011 	/* so we have to register the pcm after adding any substream
1012 	 * to it because alsa doesn't create the devices for the
1013 	 * substreams when we add them later.
1014 	 * Therefore, force in and out on both busses (above) and
1015 	 * register the pcm now instead of just after creating it.
1016 	 */
1017 	err = snd_device_register(card, dev->pcm);
1018 	if (err) {
1019 		printk(KERN_ERR "i2sbus: error registering new pcm\n");
1020 		goto out_put_ci_module;
1021 	}
1022 	/* no errors any more, so let's add this to our list */
1023 	list_add(&cii->list, &dev->codec_list);
1024 
1025 	dev->pcm->private_data = i2sdev;
1026 	dev->pcm->private_free = i2sbus_private_free;
1027 
1028 	/* well, we really should support scatter/gather DMA */
1029 	snd_pcm_lib_preallocate_pages_for_all(
1030 		dev->pcm, SNDRV_DMA_TYPE_DEV,
1031 		snd_dma_pci_data(macio_get_pci_dev(i2sdev->macio)),
1032 		64 * 1024, 64 * 1024);
1033 
1034 	return 0;
1035  out_put_ci_module:
1036 	module_put(ci->owner);
1037  out_put_this_module:
1038 	module_put(THIS_MODULE);
1039  out_put_sdev:
1040 	soundbus_dev_put(dev);
1041  out_free_cii:
1042 	kfree(cii);
1043 	return err;
1044 }
1045 
1046 void i2sbus_detach_codec(struct soundbus_dev *dev, void *data)
1047 {
1048 	struct codec_info_item *cii = NULL, *i;
1049 
1050 	list_for_each_entry(i, &dev->codec_list, list) {
1051 		if (i->codec_data == data) {
1052 			cii = i;
1053 			break;
1054 		}
1055 	}
1056 	if (cii) {
1057 		list_del(&cii->list);
1058 		module_put(cii->codec->owner);
1059 		kfree(cii);
1060 	}
1061 	/* no more codecs, but still a pcm? */
1062 	if (list_empty(&dev->codec_list) && dev->pcm) {
1063 		/* the actual cleanup is done by the callback above! */
1064 		snd_device_free(dev->pcm->card, dev->pcm);
1065 	}
1066 }
1067