xref: /linux/sound/aoa/soundbus/i2sbus/pcm.c (revision ee8287e068a3995b0f8001dd6931e221dfb7c530)
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 	DECLARE_COMPLETION_ONSTACK(done);
258 	unsigned long time_left;
259 
260 	spin_lock_irqsave(&i2sdev->low_lock, flags);
261 	if (pi->dbdma_ring.stopping) {
262 		pi->stop_completion = &done;
263 		spin_unlock_irqrestore(&i2sdev->low_lock, flags);
264 		time_left = wait_for_completion_timeout(&done, HZ);
265 		spin_lock_irqsave(&i2sdev->low_lock, flags);
266 		pi->stop_completion = NULL;
267 		if (time_left == 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 			time_left = 10;
274 			while (in_le32(&pi->dbdma->status) & ACTIVE) {
275 				if (--time_left <= 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 inline int i2sbus_hw_free(struct snd_pcm_substream *substream, int in)
297 {
298 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
299 	struct pcm_info *pi;
300 
301 	get_pcm_info(i2sdev, in, &pi, NULL);
302 	if (pi->dbdma_ring.stopping)
303 		i2sbus_wait_for_stop(i2sdev, pi);
304 	return 0;
305 }
306 
307 static int i2sbus_playback_hw_free(struct snd_pcm_substream *substream)
308 {
309 	return i2sbus_hw_free(substream, 0);
310 }
311 
312 static int i2sbus_record_hw_free(struct snd_pcm_substream *substream)
313 {
314 	return i2sbus_hw_free(substream, 1);
315 }
316 
317 static int i2sbus_pcm_prepare(struct i2sbus_dev *i2sdev, int in)
318 {
319 	/* whee. Hard work now. The user has selected a bitrate
320 	 * and bit format, so now we have to program our
321 	 * I2S controller appropriately. */
322 	struct snd_pcm_runtime *runtime;
323 	struct dbdma_cmd *command;
324 	int i, periodsize, nperiods;
325 	dma_addr_t offset;
326 	struct bus_info bi;
327 	struct codec_info_item *cii;
328 	int sfr = 0;		/* serial format register */
329 	int dws = 0;		/* data word sizes reg */
330 	int input_16bit;
331 	struct pcm_info *pi, *other;
332 	int cnt;
333 	int result = 0;
334 	unsigned int cmd, stopaddr;
335 
336 	mutex_lock(&i2sdev->lock);
337 
338 	get_pcm_info(i2sdev, in, &pi, &other);
339 
340 	if (pi->dbdma_ring.running) {
341 		result = -EBUSY;
342 		goto out_unlock;
343 	}
344 	if (pi->dbdma_ring.stopping)
345 		i2sbus_wait_for_stop(i2sdev, pi);
346 
347 	if (!pi->substream || !pi->substream->runtime) {
348 		result = -EINVAL;
349 		goto out_unlock;
350 	}
351 
352 	runtime = pi->substream->runtime;
353 	pi->active = 1;
354 	if (other->active &&
355 	    ((i2sdev->format != runtime->format)
356 	     || (i2sdev->rate != runtime->rate))) {
357 		result = -EINVAL;
358 		goto out_unlock;
359 	}
360 
361 	i2sdev->format = runtime->format;
362 	i2sdev->rate = runtime->rate;
363 
364 	periodsize = snd_pcm_lib_period_bytes(pi->substream);
365 	nperiods = pi->substream->runtime->periods;
366 	pi->current_period = 0;
367 
368 	/* generate dbdma command ring first */
369 	command = pi->dbdma_ring.cmds;
370 	memset(command, 0, (nperiods + 2) * sizeof(struct dbdma_cmd));
371 
372 	/* commands to DMA to/from the ring */
373 	/*
374 	 * For input, we need to do a graceful stop; if we abort
375 	 * the DMA, we end up with leftover bytes that corrupt
376 	 * the next recording.  To do this we set the S0 status
377 	 * bit and wait for the DMA controller to stop.  Each
378 	 * command has a branch condition to
379 	 * make it branch to a stop command if S0 is set.
380 	 * On input we also need to wait for the S7 bit to be
381 	 * set before turning off the DMA controller.
382 	 * In fact we do the graceful stop for output as well.
383 	 */
384 	offset = runtime->dma_addr;
385 	cmd = (in? INPUT_MORE: OUTPUT_MORE) | BR_IFSET | INTR_ALWAYS;
386 	stopaddr = pi->dbdma_ring.bus_cmd_start +
387 		(nperiods + 1) * sizeof(struct dbdma_cmd);
388 	for (i = 0; i < nperiods; i++, command++, offset += periodsize) {
389 		command->command = cpu_to_le16(cmd);
390 		command->cmd_dep = cpu_to_le32(stopaddr);
391 		command->phy_addr = cpu_to_le32(offset);
392 		command->req_count = cpu_to_le16(periodsize);
393 	}
394 
395 	/* branch back to beginning of ring */
396 	command->command = cpu_to_le16(DBDMA_NOP | BR_ALWAYS);
397 	command->cmd_dep = cpu_to_le32(pi->dbdma_ring.bus_cmd_start);
398 	command++;
399 
400 	/* set stop command */
401 	command->command = cpu_to_le16(DBDMA_STOP);
402 
403 	/* ok, let's set the serial format and stuff */
404 	switch (runtime->format) {
405 	/* 16 bit formats */
406 	case SNDRV_PCM_FORMAT_S16_BE:
407 	case SNDRV_PCM_FORMAT_U16_BE:
408 		/* FIXME: if we add different bus factors we need to
409 		 * do more here!! */
410 		bi.bus_factor = 0;
411 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
412 			bi.bus_factor = cii->codec->bus_factor;
413 			break;
414 		}
415 		if (!bi.bus_factor) {
416 			result = -ENODEV;
417 			goto out_unlock;
418 		}
419 		input_16bit = 1;
420 		break;
421 	case SNDRV_PCM_FORMAT_S32_BE:
422 	case SNDRV_PCM_FORMAT_U32_BE:
423 		/* force 64x bus speed, otherwise the data cannot be
424 		 * transferred quickly enough! */
425 		bi.bus_factor = 64;
426 		input_16bit = 0;
427 		break;
428 	default:
429 		result = -EINVAL;
430 		goto out_unlock;
431 	}
432 	/* we assume all sysclocks are the same! */
433 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
434 		bi.sysclock_factor = cii->codec->sysclock_factor;
435 		break;
436 	}
437 
438 	if (clock_and_divisors(bi.sysclock_factor,
439 			       bi.bus_factor,
440 			       runtime->rate,
441 			       &sfr) < 0) {
442 		result = -EINVAL;
443 		goto out_unlock;
444 	}
445 	switch (bi.bus_factor) {
446 	case 32:
447 		sfr |= I2S_SF_SERIAL_FORMAT_I2S_32X;
448 		break;
449 	case 64:
450 		sfr |= I2S_SF_SERIAL_FORMAT_I2S_64X;
451 		break;
452 	}
453 	/* FIXME: THIS ASSUMES MASTER ALL THE TIME */
454 	sfr |= I2S_SF_SCLK_MASTER;
455 
456 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
457 		int err = 0;
458 		if (cii->codec->prepare)
459 			err = cii->codec->prepare(cii, &bi, pi->substream);
460 		if (err) {
461 			result = err;
462 			goto out_unlock;
463 		}
464 	}
465 	/* codecs are fine with it, so set our clocks */
466 	if (input_16bit)
467 		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
468 			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
469 			I2S_DWS_DATA_IN_16BIT | I2S_DWS_DATA_OUT_16BIT;
470 	else
471 		dws =	(2 << I2S_DWS_NUM_CHANNELS_IN_SHIFT) |
472 			(2 << I2S_DWS_NUM_CHANNELS_OUT_SHIFT) |
473 			I2S_DWS_DATA_IN_24BIT | I2S_DWS_DATA_OUT_24BIT;
474 
475 	/* early exit if already programmed correctly */
476 	/* not locking these is fine since we touch them only in this function */
477 	if (in_le32(&i2sdev->intfregs->serial_format) == sfr
478 	 && in_le32(&i2sdev->intfregs->data_word_sizes) == dws)
479 		goto out_unlock;
480 
481 	/* let's notify the codecs about clocks going away.
482 	 * For now we only do mastering on the i2s cell... */
483 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
484 		if (cii->codec->switch_clock)
485 			cii->codec->switch_clock(cii, CLOCK_SWITCH_PREPARE_SLAVE);
486 
487 	i2sbus_control_enable(i2sdev->control, i2sdev);
488 	i2sbus_control_cell(i2sdev->control, i2sdev, 1);
489 
490 	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);
491 
492 	i2sbus_control_clock(i2sdev->control, i2sdev, 0);
493 
494 	msleep(1);
495 
496 	/* wait for clock stopped. This can apparently take a while... */
497 	cnt = 100;
498 	while (cnt-- &&
499 	    !(in_le32(&i2sdev->intfregs->intr_ctl) & I2S_PENDING_CLOCKS_STOPPED)) {
500 		msleep(5);
501 	}
502 	out_le32(&i2sdev->intfregs->intr_ctl, I2S_PENDING_CLOCKS_STOPPED);
503 
504 	/* not locking these is fine since we touch them only in this function */
505 	out_le32(&i2sdev->intfregs->serial_format, sfr);
506 	out_le32(&i2sdev->intfregs->data_word_sizes, dws);
507 
508         i2sbus_control_enable(i2sdev->control, i2sdev);
509         i2sbus_control_cell(i2sdev->control, i2sdev, 1);
510         i2sbus_control_clock(i2sdev->control, i2sdev, 1);
511 	msleep(1);
512 
513 	list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
514 		if (cii->codec->switch_clock)
515 			cii->codec->switch_clock(cii, CLOCK_SWITCH_SLAVE);
516 
517  out_unlock:
518 	mutex_unlock(&i2sdev->lock);
519 	return result;
520 }
521 
522 #ifdef CONFIG_PM
523 void i2sbus_pcm_prepare_both(struct i2sbus_dev *i2sdev)
524 {
525 	i2sbus_pcm_prepare(i2sdev, 0);
526 	i2sbus_pcm_prepare(i2sdev, 1);
527 }
528 #endif
529 
530 static int i2sbus_pcm_trigger(struct i2sbus_dev *i2sdev, int in, int cmd)
531 {
532 	struct codec_info_item *cii;
533 	struct pcm_info *pi;
534 	int result = 0;
535 	unsigned long flags;
536 
537 	spin_lock_irqsave(&i2sdev->low_lock, flags);
538 
539 	get_pcm_info(i2sdev, in, &pi, NULL);
540 
541 	switch (cmd) {
542 	case SNDRV_PCM_TRIGGER_START:
543 	case SNDRV_PCM_TRIGGER_RESUME:
544 		if (pi->dbdma_ring.running) {
545 			result = -EALREADY;
546 			goto out_unlock;
547 		}
548 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
549 			if (cii->codec->start)
550 				cii->codec->start(cii, pi->substream);
551 		pi->dbdma_ring.running = 1;
552 
553 		if (pi->dbdma_ring.stopping) {
554 			/* Clear the S0 bit, then see if we stopped yet */
555 			out_le32(&pi->dbdma->control, 1 << 16);
556 			if (in_le32(&pi->dbdma->status) & ACTIVE) {
557 				/* possible race here? */
558 				udelay(10);
559 				if (in_le32(&pi->dbdma->status) & ACTIVE) {
560 					pi->dbdma_ring.stopping = 0;
561 					goto out_unlock; /* keep running */
562 				}
563 			}
564 		}
565 
566 		/* make sure RUN, PAUSE and S0 bits are cleared */
567 		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
568 
569 		/* set branch condition select register */
570 		out_le32(&pi->dbdma->br_sel, (1 << 16) | 1);
571 
572 		/* write dma command buffer address to the dbdma chip */
573 		out_le32(&pi->dbdma->cmdptr, pi->dbdma_ring.bus_cmd_start);
574 
575 		/* initialize the frame count and current period */
576 		pi->current_period = 0;
577 		pi->frame_count = in_le32(&i2sdev->intfregs->frame_count);
578 
579 		/* set the DMA controller running */
580 		out_le32(&pi->dbdma->control, (RUN << 16) | RUN);
581 
582 		/* off you go! */
583 		break;
584 
585 	case SNDRV_PCM_TRIGGER_STOP:
586 	case SNDRV_PCM_TRIGGER_SUSPEND:
587 		if (!pi->dbdma_ring.running) {
588 			result = -EALREADY;
589 			goto out_unlock;
590 		}
591 		pi->dbdma_ring.running = 0;
592 
593 		/* Set the S0 bit to make the DMA branch to the stop cmd */
594 		out_le32(&pi->dbdma->control, (1 << 16) | 1);
595 		pi->dbdma_ring.stopping = 1;
596 
597 		list_for_each_entry(cii, &i2sdev->sound.codec_list, list)
598 			if (cii->codec->stop)
599 				cii->codec->stop(cii, pi->substream);
600 		break;
601 	default:
602 		result = -EINVAL;
603 		goto out_unlock;
604 	}
605 
606  out_unlock:
607 	spin_unlock_irqrestore(&i2sdev->low_lock, flags);
608 	return result;
609 }
610 
611 static snd_pcm_uframes_t i2sbus_pcm_pointer(struct i2sbus_dev *i2sdev, int in)
612 {
613 	struct pcm_info *pi;
614 	u32 fc;
615 
616 	get_pcm_info(i2sdev, in, &pi, NULL);
617 
618 	fc = in_le32(&i2sdev->intfregs->frame_count);
619 	fc = fc - pi->frame_count;
620 
621 	if (fc >= pi->substream->runtime->buffer_size)
622 		fc %= pi->substream->runtime->buffer_size;
623 	return fc;
624 }
625 
626 static inline void handle_interrupt(struct i2sbus_dev *i2sdev, int in)
627 {
628 	struct pcm_info *pi;
629 	u32 fc, nframes;
630 	u32 status;
631 	int timeout, i;
632 	int dma_stopped = 0;
633 	struct snd_pcm_runtime *runtime;
634 
635 	spin_lock(&i2sdev->low_lock);
636 	get_pcm_info(i2sdev, in, &pi, NULL);
637 	if (!pi->dbdma_ring.running && !pi->dbdma_ring.stopping)
638 		goto out_unlock;
639 
640 	i = pi->current_period;
641 	runtime = pi->substream->runtime;
642 	while (pi->dbdma_ring.cmds[i].xfer_status) {
643 		if (le16_to_cpu(pi->dbdma_ring.cmds[i].xfer_status) & BT)
644 			/*
645 			 * BT is the branch taken bit.  If it took a branch
646 			 * it is because we set the S0 bit to make it
647 			 * branch to the stop command.
648 			 */
649 			dma_stopped = 1;
650 		pi->dbdma_ring.cmds[i].xfer_status = 0;
651 
652 		if (++i >= runtime->periods) {
653 			i = 0;
654 			pi->frame_count += runtime->buffer_size;
655 		}
656 		pi->current_period = i;
657 
658 		/*
659 		 * Check the frame count.  The DMA tends to get a bit
660 		 * ahead of the frame counter, which confuses the core.
661 		 */
662 		fc = in_le32(&i2sdev->intfregs->frame_count);
663 		nframes = i * runtime->period_size;
664 		if (fc < pi->frame_count + nframes)
665 			pi->frame_count = fc - nframes;
666 	}
667 
668 	if (dma_stopped) {
669 		timeout = 1000;
670 		for (;;) {
671 			status = in_le32(&pi->dbdma->status);
672 			if (!(status & ACTIVE) && (!in || (status & 0x80)))
673 				break;
674 			if (--timeout <= 0) {
675 				printk(KERN_ERR "i2sbus: timed out "
676 				       "waiting for DMA to stop!\n");
677 				break;
678 			}
679 			udelay(1);
680 		}
681 
682 		/* Turn off DMA controller, clear S0 bit */
683 		out_le32(&pi->dbdma->control, (RUN | PAUSE | 1) << 16);
684 
685 		pi->dbdma_ring.stopping = 0;
686 		if (pi->stop_completion)
687 			complete(pi->stop_completion);
688 	}
689 
690 	if (!pi->dbdma_ring.running)
691 		goto out_unlock;
692 	spin_unlock(&i2sdev->low_lock);
693 	/* may call _trigger again, hence needs to be unlocked */
694 	snd_pcm_period_elapsed(pi->substream);
695 	return;
696 
697  out_unlock:
698 	spin_unlock(&i2sdev->low_lock);
699 }
700 
701 irqreturn_t i2sbus_tx_intr(int irq, void *devid)
702 {
703 	handle_interrupt((struct i2sbus_dev *)devid, 0);
704 	return IRQ_HANDLED;
705 }
706 
707 irqreturn_t i2sbus_rx_intr(int irq, void *devid)
708 {
709 	handle_interrupt((struct i2sbus_dev *)devid, 1);
710 	return IRQ_HANDLED;
711 }
712 
713 static int i2sbus_playback_open(struct snd_pcm_substream *substream)
714 {
715 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
716 
717 	if (!i2sdev)
718 		return -EINVAL;
719 	i2sdev->out.substream = substream;
720 	return i2sbus_pcm_open(i2sdev, 0);
721 }
722 
723 static int i2sbus_playback_close(struct snd_pcm_substream *substream)
724 {
725 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
726 	int err;
727 
728 	if (!i2sdev)
729 		return -EINVAL;
730 	if (i2sdev->out.substream != substream)
731 		return -EINVAL;
732 	err = i2sbus_pcm_close(i2sdev, 0);
733 	if (!err)
734 		i2sdev->out.substream = NULL;
735 	return err;
736 }
737 
738 static int i2sbus_playback_prepare(struct snd_pcm_substream *substream)
739 {
740 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
741 
742 	if (!i2sdev)
743 		return -EINVAL;
744 	if (i2sdev->out.substream != substream)
745 		return -EINVAL;
746 	return i2sbus_pcm_prepare(i2sdev, 0);
747 }
748 
749 static int i2sbus_playback_trigger(struct snd_pcm_substream *substream, int cmd)
750 {
751 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
752 
753 	if (!i2sdev)
754 		return -EINVAL;
755 	if (i2sdev->out.substream != substream)
756 		return -EINVAL;
757 	return i2sbus_pcm_trigger(i2sdev, 0, cmd);
758 }
759 
760 static snd_pcm_uframes_t i2sbus_playback_pointer(struct snd_pcm_substream
761 						 *substream)
762 {
763 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
764 
765 	if (!i2sdev)
766 		return -EINVAL;
767 	if (i2sdev->out.substream != substream)
768 		return 0;
769 	return i2sbus_pcm_pointer(i2sdev, 0);
770 }
771 
772 static const struct snd_pcm_ops i2sbus_playback_ops = {
773 	.open =		i2sbus_playback_open,
774 	.close =	i2sbus_playback_close,
775 	.hw_free =	i2sbus_playback_hw_free,
776 	.prepare =	i2sbus_playback_prepare,
777 	.trigger =	i2sbus_playback_trigger,
778 	.pointer =	i2sbus_playback_pointer,
779 };
780 
781 static int i2sbus_record_open(struct snd_pcm_substream *substream)
782 {
783 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
784 
785 	if (!i2sdev)
786 		return -EINVAL;
787 	i2sdev->in.substream = substream;
788 	return i2sbus_pcm_open(i2sdev, 1);
789 }
790 
791 static int i2sbus_record_close(struct snd_pcm_substream *substream)
792 {
793 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
794 	int err;
795 
796 	if (!i2sdev)
797 		return -EINVAL;
798 	if (i2sdev->in.substream != substream)
799 		return -EINVAL;
800 	err = i2sbus_pcm_close(i2sdev, 1);
801 	if (!err)
802 		i2sdev->in.substream = NULL;
803 	return err;
804 }
805 
806 static int i2sbus_record_prepare(struct snd_pcm_substream *substream)
807 {
808 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
809 
810 	if (!i2sdev)
811 		return -EINVAL;
812 	if (i2sdev->in.substream != substream)
813 		return -EINVAL;
814 	return i2sbus_pcm_prepare(i2sdev, 1);
815 }
816 
817 static int i2sbus_record_trigger(struct snd_pcm_substream *substream, int cmd)
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_trigger(i2sdev, 1, cmd);
826 }
827 
828 static snd_pcm_uframes_t i2sbus_record_pointer(struct snd_pcm_substream
829 					       *substream)
830 {
831 	struct i2sbus_dev *i2sdev = snd_pcm_substream_chip(substream);
832 
833 	if (!i2sdev)
834 		return -EINVAL;
835 	if (i2sdev->in.substream != substream)
836 		return 0;
837 	return i2sbus_pcm_pointer(i2sdev, 1);
838 }
839 
840 static const struct snd_pcm_ops i2sbus_record_ops = {
841 	.open =		i2sbus_record_open,
842 	.close =	i2sbus_record_close,
843 	.hw_free =	i2sbus_record_hw_free,
844 	.prepare =	i2sbus_record_prepare,
845 	.trigger =	i2sbus_record_trigger,
846 	.pointer =	i2sbus_record_pointer,
847 };
848 
849 static void i2sbus_private_free(struct snd_pcm *pcm)
850 {
851 	struct i2sbus_dev *i2sdev = snd_pcm_chip(pcm);
852 	struct codec_info_item *p, *tmp;
853 
854 	i2sdev->sound.pcm = NULL;
855 	i2sdev->out.created = 0;
856 	i2sdev->in.created = 0;
857 	list_for_each_entry_safe(p, tmp, &i2sdev->sound.codec_list, list) {
858 		printk(KERN_ERR "i2sbus: a codec didn't unregister!\n");
859 		list_del(&p->list);
860 		module_put(p->codec->owner);
861 		kfree(p);
862 	}
863 	soundbus_dev_put(&i2sdev->sound);
864 	module_put(THIS_MODULE);
865 }
866 
867 int
868 i2sbus_attach_codec(struct soundbus_dev *dev, struct snd_card *card,
869 		    struct codec_info *ci, void *data)
870 {
871 	int err, in = 0, out = 0;
872 	struct transfer_info *tmp;
873 	struct i2sbus_dev *i2sdev = soundbus_dev_to_i2sbus_dev(dev);
874 	struct codec_info_item *cii;
875 
876 	if (!dev->pcmname || dev->pcmid == -1) {
877 		printk(KERN_ERR "i2sbus: pcm name and id must be set!\n");
878 		return -EINVAL;
879 	}
880 
881 	list_for_each_entry(cii, &dev->codec_list, list) {
882 		if (cii->codec_data == data)
883 			return -EALREADY;
884 	}
885 
886 	if (!ci->transfers || !ci->transfers->formats
887 	    || !ci->transfers->rates || !ci->usable)
888 		return -EINVAL;
889 
890 	/* we currently code the i2s transfer on the clock, and support only
891 	 * 32 and 64 */
892 	if (ci->bus_factor != 32 && ci->bus_factor != 64)
893 		return -EINVAL;
894 
895 	/* If you want to fix this, you need to keep track of what transport infos
896 	 * are to be used, which codecs they belong to, and then fix all the
897 	 * sysclock/busclock stuff above to depend on which is usable */
898 	list_for_each_entry(cii, &dev->codec_list, list) {
899 		if (cii->codec->sysclock_factor != ci->sysclock_factor) {
900 			printk(KERN_DEBUG
901 			       "cannot yet handle multiple different sysclocks!\n");
902 			return -EINVAL;
903 		}
904 		if (cii->codec->bus_factor != ci->bus_factor) {
905 			printk(KERN_DEBUG
906 			       "cannot yet handle multiple different bus clocks!\n");
907 			return -EINVAL;
908 		}
909 	}
910 
911 	tmp = ci->transfers;
912 	while (tmp->formats && tmp->rates) {
913 		if (tmp->transfer_in)
914 			in = 1;
915 		else
916 			out = 1;
917 		tmp++;
918 	}
919 
920 	cii = kzalloc(sizeof(struct codec_info_item), GFP_KERNEL);
921 	if (!cii)
922 		return -ENOMEM;
923 
924 	/* use the private data to point to the codec info */
925 	cii->sdev = soundbus_dev_get(dev);
926 	cii->codec = ci;
927 	cii->codec_data = data;
928 
929 	if (!cii->sdev) {
930 		printk(KERN_DEBUG
931 		       "i2sbus: failed to get soundbus dev reference\n");
932 		err = -ENODEV;
933 		goto out_free_cii;
934 	}
935 
936 	if (!try_module_get(THIS_MODULE)) {
937 		printk(KERN_DEBUG "i2sbus: failed to get module reference!\n");
938 		err = -EBUSY;
939 		goto out_put_sdev;
940 	}
941 
942 	if (!try_module_get(ci->owner)) {
943 		printk(KERN_DEBUG
944 		       "i2sbus: failed to get module reference to codec owner!\n");
945 		err = -EBUSY;
946 		goto out_put_this_module;
947 	}
948 
949 	if (!dev->pcm) {
950 		err = snd_pcm_new(card, dev->pcmname, dev->pcmid, 0, 0,
951 				  &dev->pcm);
952 		if (err) {
953 			printk(KERN_DEBUG "i2sbus: failed to create pcm\n");
954 			goto out_put_ci_module;
955 		}
956 	}
957 
958 	/* ALSA yet again sucks.
959 	 * If it is ever fixed, remove this line. See below. */
960 	out = in = 1;
961 
962 	if (!i2sdev->out.created && out) {
963 		if (dev->pcm->card != card) {
964 			/* eh? */
965 			printk(KERN_ERR
966 			       "Can't attach same bus to different cards!\n");
967 			err = -EINVAL;
968 			goto out_put_ci_module;
969 		}
970 		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK, 1);
971 		if (err)
972 			goto out_put_ci_module;
973 		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK,
974 				&i2sbus_playback_ops);
975 		dev->pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].dev->parent =
976 			&dev->ofdev.dev;
977 		i2sdev->out.created = 1;
978 	}
979 
980 	if (!i2sdev->in.created && in) {
981 		if (dev->pcm->card != card) {
982 			printk(KERN_ERR
983 			       "Can't attach same bus to different cards!\n");
984 			err = -EINVAL;
985 			goto out_put_ci_module;
986 		}
987 		err = snd_pcm_new_stream(dev->pcm, SNDRV_PCM_STREAM_CAPTURE, 1);
988 		if (err)
989 			goto out_put_ci_module;
990 		snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_CAPTURE,
991 				&i2sbus_record_ops);
992 		dev->pcm->streams[SNDRV_PCM_STREAM_CAPTURE].dev->parent =
993 			&dev->ofdev.dev;
994 		i2sdev->in.created = 1;
995 	}
996 
997 	/* so we have to register the pcm after adding any substream
998 	 * to it because alsa doesn't create the devices for the
999 	 * substreams when we add them later.
1000 	 * Therefore, force in and out on both busses (above) and
1001 	 * register the pcm now instead of just after creating it.
1002 	 */
1003 	err = snd_device_register(card, dev->pcm);
1004 	if (err) {
1005 		printk(KERN_ERR "i2sbus: error registering new pcm\n");
1006 		goto out_put_ci_module;
1007 	}
1008 	/* no errors any more, so let's add this to our list */
1009 	list_add(&cii->list, &dev->codec_list);
1010 
1011 	dev->pcm->private_data = i2sdev;
1012 	dev->pcm->private_free = i2sbus_private_free;
1013 
1014 	/* well, we really should support scatter/gather DMA */
1015 	snd_pcm_set_managed_buffer_all(
1016 		dev->pcm, SNDRV_DMA_TYPE_DEV,
1017 		&macio_get_pci_dev(i2sdev->macio)->dev,
1018 		64 * 1024, 64 * 1024);
1019 
1020 	return 0;
1021  out_put_ci_module:
1022 	module_put(ci->owner);
1023  out_put_this_module:
1024 	module_put(THIS_MODULE);
1025  out_put_sdev:
1026 	soundbus_dev_put(dev);
1027  out_free_cii:
1028 	kfree(cii);
1029 	return err;
1030 }
1031 
1032 void i2sbus_detach_codec(struct soundbus_dev *dev, void *data)
1033 {
1034 	struct codec_info_item *cii = NULL, *i;
1035 
1036 	list_for_each_entry(i, &dev->codec_list, list) {
1037 		if (i->codec_data == data) {
1038 			cii = i;
1039 			break;
1040 		}
1041 	}
1042 	if (cii) {
1043 		list_del(&cii->list);
1044 		module_put(cii->codec->owner);
1045 		kfree(cii);
1046 	}
1047 	/* no more codecs, but still a pcm? */
1048 	if (list_empty(&dev->codec_list) && dev->pcm) {
1049 		/* the actual cleanup is done by the callback above! */
1050 		snd_device_free(dev->pcm->card, dev->pcm);
1051 	}
1052 }
1053