1/*
2 * Linux driver for M2Tech hiFace compatible devices
3 *
4 * Copyright 2012-2013 (C) M2TECH S.r.l and Amarula Solutions B.V.
5 *
6 * Authors:  Michael Trimarchi <michael@amarulasolutions.com>
7 *           Antonio Ospite <ao2@amarulasolutions.com>
8 *
9 * The driver is based on the work done in TerraTec DMX 6Fire USB
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 */
16
17#include <linux/slab.h>
18#include <sound/pcm.h>
19
20#include "pcm.h"
21#include "chip.h"
22
23#define OUT_EP          0x2
24#define PCM_N_URBS      8
25#define PCM_PACKET_SIZE 4096
26#define PCM_BUFFER_SIZE (2 * PCM_N_URBS * PCM_PACKET_SIZE)
27
28struct pcm_urb {
29	struct hiface_chip *chip;
30
31	struct urb instance;
32	struct usb_anchor submitted;
33	u8 *buffer;
34};
35
36struct pcm_substream {
37	spinlock_t lock;
38	struct snd_pcm_substream *instance;
39
40	bool active;
41	snd_pcm_uframes_t dma_off;    /* current position in alsa dma_area */
42	snd_pcm_uframes_t period_off; /* current position in current period */
43};
44
45enum { /* pcm streaming states */
46	STREAM_DISABLED, /* no pcm streaming */
47	STREAM_STARTING, /* pcm streaming requested, waiting to become ready */
48	STREAM_RUNNING,  /* pcm streaming running */
49	STREAM_STOPPING
50};
51
52struct pcm_runtime {
53	struct hiface_chip *chip;
54	struct snd_pcm *instance;
55
56	struct pcm_substream playback;
57	bool panic; /* if set driver won't do anymore pcm on device */
58
59	struct pcm_urb out_urbs[PCM_N_URBS];
60
61	struct mutex stream_mutex;
62	u8 stream_state; /* one of STREAM_XXX */
63	u8 extra_freq;
64	wait_queue_head_t stream_wait_queue;
65	bool stream_wait_cond;
66};
67
68static const unsigned int rates[] = { 44100, 48000, 88200, 96000, 176400, 192000,
69				      352800, 384000 };
70static const struct snd_pcm_hw_constraint_list constraints_extra_rates = {
71	.count = ARRAY_SIZE(rates),
72	.list = rates,
73	.mask = 0,
74};
75
76static const struct snd_pcm_hardware pcm_hw = {
77	.info = SNDRV_PCM_INFO_MMAP |
78		SNDRV_PCM_INFO_INTERLEAVED |
79		SNDRV_PCM_INFO_BLOCK_TRANSFER |
80		SNDRV_PCM_INFO_PAUSE |
81		SNDRV_PCM_INFO_MMAP_VALID |
82		SNDRV_PCM_INFO_BATCH,
83
84	.formats = SNDRV_PCM_FMTBIT_S32_LE,
85
86	.rates = SNDRV_PCM_RATE_44100 |
87		SNDRV_PCM_RATE_48000 |
88		SNDRV_PCM_RATE_88200 |
89		SNDRV_PCM_RATE_96000 |
90		SNDRV_PCM_RATE_176400 |
91		SNDRV_PCM_RATE_192000,
92
93	.rate_min = 44100,
94	.rate_max = 192000, /* changes in hiface_pcm_open to support extra rates */
95	.channels_min = 2,
96	.channels_max = 2,
97	.buffer_bytes_max = PCM_BUFFER_SIZE,
98	.period_bytes_min = PCM_PACKET_SIZE,
99	.period_bytes_max = PCM_BUFFER_SIZE,
100	.periods_min = 2,
101	.periods_max = 1024
102};
103
104/* message values used to change the sample rate */
105#define HIFACE_SET_RATE_REQUEST 0xb0
106
107#define HIFACE_RATE_44100  0x43
108#define HIFACE_RATE_48000  0x4b
109#define HIFACE_RATE_88200  0x42
110#define HIFACE_RATE_96000  0x4a
111#define HIFACE_RATE_176400 0x40
112#define HIFACE_RATE_192000 0x48
113#define HIFACE_RATE_352800 0x58
114#define HIFACE_RATE_384000 0x68
115
116static int hiface_pcm_set_rate(struct pcm_runtime *rt, unsigned int rate)
117{
118	struct usb_device *device = rt->chip->dev;
119	u16 rate_value;
120	int ret;
121
122	/* We are already sure that the rate is supported here thanks to
123	 * ALSA constraints
124	 */
125	switch (rate) {
126	case 44100:
127		rate_value = HIFACE_RATE_44100;
128		break;
129	case 48000:
130		rate_value = HIFACE_RATE_48000;
131		break;
132	case 88200:
133		rate_value = HIFACE_RATE_88200;
134		break;
135	case 96000:
136		rate_value = HIFACE_RATE_96000;
137		break;
138	case 176400:
139		rate_value = HIFACE_RATE_176400;
140		break;
141	case 192000:
142		rate_value = HIFACE_RATE_192000;
143		break;
144	case 352800:
145		rate_value = HIFACE_RATE_352800;
146		break;
147	case 384000:
148		rate_value = HIFACE_RATE_384000;
149		break;
150	default:
151		dev_err(&device->dev, "Unsupported rate %d\n", rate);
152		return -EINVAL;
153	}
154
155	/*
156	 * USBIO: Vendor 0xb0(wValue=0x0043, wIndex=0x0000)
157	 * 43 b0 43 00 00 00 00 00
158	 * USBIO: Vendor 0xb0(wValue=0x004b, wIndex=0x0000)
159	 * 43 b0 4b 00 00 00 00 00
160	 * This control message doesn't have any ack from the
161	 * other side
162	 */
163	ret = usb_control_msg(device, usb_sndctrlpipe(device, 0),
164			      HIFACE_SET_RATE_REQUEST,
165			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
166			      rate_value, 0, NULL, 0, 100);
167	if (ret < 0) {
168		dev_err(&device->dev, "Error setting samplerate %d.\n", rate);
169		return ret;
170	}
171
172	return 0;
173}
174
175static struct pcm_substream *hiface_pcm_get_substream(struct snd_pcm_substream
176						      *alsa_sub)
177{
178	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
179	struct device *device = &rt->chip->dev->dev;
180
181	if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
182		return &rt->playback;
183
184	dev_err(device, "Error getting pcm substream slot.\n");
185	return NULL;
186}
187
188/* call with stream_mutex locked */
189static void hiface_pcm_stream_stop(struct pcm_runtime *rt)
190{
191	int i, time;
192
193	if (rt->stream_state != STREAM_DISABLED) {
194		rt->stream_state = STREAM_STOPPING;
195
196		for (i = 0; i < PCM_N_URBS; i++) {
197			time = usb_wait_anchor_empty_timeout(
198					&rt->out_urbs[i].submitted, 100);
199			if (!time)
200				usb_kill_anchored_urbs(
201					&rt->out_urbs[i].submitted);
202			usb_kill_urb(&rt->out_urbs[i].instance);
203		}
204
205		rt->stream_state = STREAM_DISABLED;
206	}
207}
208
209/* call with stream_mutex locked */
210static int hiface_pcm_stream_start(struct pcm_runtime *rt)
211{
212	int ret = 0;
213	int i;
214
215	if (rt->stream_state == STREAM_DISABLED) {
216
217		/* reset panic state when starting a new stream */
218		rt->panic = false;
219
220		/* submit our out urbs zero init */
221		rt->stream_state = STREAM_STARTING;
222		for (i = 0; i < PCM_N_URBS; i++) {
223			memset(rt->out_urbs[i].buffer, 0, PCM_PACKET_SIZE);
224			usb_anchor_urb(&rt->out_urbs[i].instance,
225				       &rt->out_urbs[i].submitted);
226			ret = usb_submit_urb(&rt->out_urbs[i].instance,
227					     GFP_ATOMIC);
228			if (ret) {
229				hiface_pcm_stream_stop(rt);
230				return ret;
231			}
232		}
233
234		/* wait for first out urb to return (sent in in urb handler) */
235		wait_event_timeout(rt->stream_wait_queue, rt->stream_wait_cond,
236				   HZ);
237		if (rt->stream_wait_cond) {
238			struct device *device = &rt->chip->dev->dev;
239			dev_dbg(device, "%s: Stream is running wakeup event\n",
240				 __func__);
241			rt->stream_state = STREAM_RUNNING;
242		} else {
243			hiface_pcm_stream_stop(rt);
244			return -EIO;
245		}
246	}
247	return ret;
248}
249
250/* The hardware wants word-swapped 32-bit values */
251static void memcpy_swahw32(u8 *dest, u8 *src, unsigned int n)
252{
253	unsigned int i;
254
255	for (i = 0; i < n / 4; i++)
256		((u32 *)dest)[i] = swahw32(((u32 *)src)[i]);
257}
258
259/* call with substream locked */
260/* returns true if a period elapsed */
261static bool hiface_pcm_playback(struct pcm_substream *sub, struct pcm_urb *urb)
262{
263	struct snd_pcm_runtime *alsa_rt = sub->instance->runtime;
264	struct device *device = &urb->chip->dev->dev;
265	u8 *source;
266	unsigned int pcm_buffer_size;
267
268	WARN_ON(alsa_rt->format != SNDRV_PCM_FORMAT_S32_LE);
269
270	pcm_buffer_size = snd_pcm_lib_buffer_bytes(sub->instance);
271
272	if (sub->dma_off + PCM_PACKET_SIZE <= pcm_buffer_size) {
273		dev_dbg(device, "%s: (1) buffer_size %#x dma_offset %#x\n", __func__,
274			 (unsigned int) pcm_buffer_size,
275			 (unsigned int) sub->dma_off);
276
277		source = alsa_rt->dma_area + sub->dma_off;
278		memcpy_swahw32(urb->buffer, source, PCM_PACKET_SIZE);
279	} else {
280		/* wrap around at end of ring buffer */
281		unsigned int len;
282
283		dev_dbg(device, "%s: (2) buffer_size %#x dma_offset %#x\n", __func__,
284			 (unsigned int) pcm_buffer_size,
285			 (unsigned int) sub->dma_off);
286
287		len = pcm_buffer_size - sub->dma_off;
288
289		source = alsa_rt->dma_area + sub->dma_off;
290		memcpy_swahw32(urb->buffer, source, len);
291
292		source = alsa_rt->dma_area;
293		memcpy_swahw32(urb->buffer + len, source,
294			       PCM_PACKET_SIZE - len);
295	}
296	sub->dma_off += PCM_PACKET_SIZE;
297	if (sub->dma_off >= pcm_buffer_size)
298		sub->dma_off -= pcm_buffer_size;
299
300	sub->period_off += PCM_PACKET_SIZE;
301	if (sub->period_off >= alsa_rt->period_size) {
302		sub->period_off %= alsa_rt->period_size;
303		return true;
304	}
305	return false;
306}
307
308static void hiface_pcm_out_urb_handler(struct urb *usb_urb)
309{
310	struct pcm_urb *out_urb = usb_urb->context;
311	struct pcm_runtime *rt = out_urb->chip->pcm;
312	struct pcm_substream *sub;
313	bool do_period_elapsed = false;
314	unsigned long flags;
315	int ret;
316
317	if (rt->panic || rt->stream_state == STREAM_STOPPING)
318		return;
319
320	if (unlikely(usb_urb->status == -ENOENT ||	/* unlinked */
321		     usb_urb->status == -ENODEV ||	/* device removed */
322		     usb_urb->status == -ECONNRESET ||	/* unlinked */
323		     usb_urb->status == -ESHUTDOWN)) {	/* device disabled */
324		goto out_fail;
325	}
326
327	if (rt->stream_state == STREAM_STARTING) {
328		rt->stream_wait_cond = true;
329		wake_up(&rt->stream_wait_queue);
330	}
331
332	/* now send our playback data (if a free out urb was found) */
333	sub = &rt->playback;
334	spin_lock_irqsave(&sub->lock, flags);
335	if (sub->active)
336		do_period_elapsed = hiface_pcm_playback(sub, out_urb);
337	else
338		memset(out_urb->buffer, 0, PCM_PACKET_SIZE);
339
340	spin_unlock_irqrestore(&sub->lock, flags);
341
342	if (do_period_elapsed)
343		snd_pcm_period_elapsed(sub->instance);
344
345	ret = usb_submit_urb(&out_urb->instance, GFP_ATOMIC);
346	if (ret < 0)
347		goto out_fail;
348
349	return;
350
351out_fail:
352	rt->panic = true;
353}
354
355static int hiface_pcm_open(struct snd_pcm_substream *alsa_sub)
356{
357	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
358	struct pcm_substream *sub = NULL;
359	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
360	int ret;
361
362	if (rt->panic)
363		return -EPIPE;
364
365	mutex_lock(&rt->stream_mutex);
366	alsa_rt->hw = pcm_hw;
367
368	if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
369		sub = &rt->playback;
370
371	if (!sub) {
372		struct device *device = &rt->chip->dev->dev;
373		mutex_unlock(&rt->stream_mutex);
374		dev_err(device, "Invalid stream type\n");
375		return -EINVAL;
376	}
377
378	if (rt->extra_freq) {
379		alsa_rt->hw.rates |= SNDRV_PCM_RATE_KNOT;
380		alsa_rt->hw.rate_max = 384000;
381
382		/* explicit constraints needed as we added SNDRV_PCM_RATE_KNOT */
383		ret = snd_pcm_hw_constraint_list(alsa_sub->runtime, 0,
384						 SNDRV_PCM_HW_PARAM_RATE,
385						 &constraints_extra_rates);
386		if (ret < 0) {
387			mutex_unlock(&rt->stream_mutex);
388			return ret;
389		}
390	}
391
392	sub->instance = alsa_sub;
393	sub->active = false;
394	mutex_unlock(&rt->stream_mutex);
395	return 0;
396}
397
398static int hiface_pcm_close(struct snd_pcm_substream *alsa_sub)
399{
400	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
401	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
402	unsigned long flags;
403
404	if (rt->panic)
405		return 0;
406
407	mutex_lock(&rt->stream_mutex);
408	if (sub) {
409		hiface_pcm_stream_stop(rt);
410
411		/* deactivate substream */
412		spin_lock_irqsave(&sub->lock, flags);
413		sub->instance = NULL;
414		sub->active = false;
415		spin_unlock_irqrestore(&sub->lock, flags);
416
417	}
418	mutex_unlock(&rt->stream_mutex);
419	return 0;
420}
421
422static int hiface_pcm_hw_params(struct snd_pcm_substream *alsa_sub,
423				struct snd_pcm_hw_params *hw_params)
424{
425	return snd_pcm_lib_alloc_vmalloc_buffer(alsa_sub,
426						params_buffer_bytes(hw_params));
427}
428
429static int hiface_pcm_hw_free(struct snd_pcm_substream *alsa_sub)
430{
431	return snd_pcm_lib_free_vmalloc_buffer(alsa_sub);
432}
433
434static int hiface_pcm_prepare(struct snd_pcm_substream *alsa_sub)
435{
436	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
437	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
438	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
439	int ret;
440
441	if (rt->panic)
442		return -EPIPE;
443	if (!sub)
444		return -ENODEV;
445
446	mutex_lock(&rt->stream_mutex);
447
448	sub->dma_off = 0;
449	sub->period_off = 0;
450
451	if (rt->stream_state == STREAM_DISABLED) {
452
453		ret = hiface_pcm_set_rate(rt, alsa_rt->rate);
454		if (ret) {
455			mutex_unlock(&rt->stream_mutex);
456			return ret;
457		}
458		ret = hiface_pcm_stream_start(rt);
459		if (ret) {
460			mutex_unlock(&rt->stream_mutex);
461			return ret;
462		}
463	}
464	mutex_unlock(&rt->stream_mutex);
465	return 0;
466}
467
468static int hiface_pcm_trigger(struct snd_pcm_substream *alsa_sub, int cmd)
469{
470	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
471	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
472
473	if (rt->panic)
474		return -EPIPE;
475	if (!sub)
476		return -ENODEV;
477
478	switch (cmd) {
479	case SNDRV_PCM_TRIGGER_START:
480	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
481		spin_lock_irq(&sub->lock);
482		sub->active = true;
483		spin_unlock_irq(&sub->lock);
484		return 0;
485
486	case SNDRV_PCM_TRIGGER_STOP:
487	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
488		spin_lock_irq(&sub->lock);
489		sub->active = false;
490		spin_unlock_irq(&sub->lock);
491		return 0;
492
493	default:
494		return -EINVAL;
495	}
496}
497
498static snd_pcm_uframes_t hiface_pcm_pointer(struct snd_pcm_substream *alsa_sub)
499{
500	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
501	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
502	unsigned long flags;
503	snd_pcm_uframes_t dma_offset;
504
505	if (rt->panic || !sub)
506		return SNDRV_PCM_POS_XRUN;
507
508	spin_lock_irqsave(&sub->lock, flags);
509	dma_offset = sub->dma_off;
510	spin_unlock_irqrestore(&sub->lock, flags);
511	return bytes_to_frames(alsa_sub->runtime, dma_offset);
512}
513
514static struct snd_pcm_ops pcm_ops = {
515	.open = hiface_pcm_open,
516	.close = hiface_pcm_close,
517	.ioctl = snd_pcm_lib_ioctl,
518	.hw_params = hiface_pcm_hw_params,
519	.hw_free = hiface_pcm_hw_free,
520	.prepare = hiface_pcm_prepare,
521	.trigger = hiface_pcm_trigger,
522	.pointer = hiface_pcm_pointer,
523	.page = snd_pcm_lib_get_vmalloc_page,
524	.mmap = snd_pcm_lib_mmap_vmalloc,
525};
526
527static int hiface_pcm_init_urb(struct pcm_urb *urb,
528			       struct hiface_chip *chip,
529			       unsigned int ep,
530			       void (*handler)(struct urb *))
531{
532	urb->chip = chip;
533	usb_init_urb(&urb->instance);
534
535	urb->buffer = kzalloc(PCM_PACKET_SIZE, GFP_KERNEL);
536	if (!urb->buffer)
537		return -ENOMEM;
538
539	usb_fill_bulk_urb(&urb->instance, chip->dev,
540			  usb_sndbulkpipe(chip->dev, ep), (void *)urb->buffer,
541			  PCM_PACKET_SIZE, handler, urb);
542	init_usb_anchor(&urb->submitted);
543
544	return 0;
545}
546
547void hiface_pcm_abort(struct hiface_chip *chip)
548{
549	struct pcm_runtime *rt = chip->pcm;
550
551	if (rt) {
552		rt->panic = true;
553
554		mutex_lock(&rt->stream_mutex);
555		hiface_pcm_stream_stop(rt);
556		mutex_unlock(&rt->stream_mutex);
557	}
558}
559
560static void hiface_pcm_destroy(struct hiface_chip *chip)
561{
562	struct pcm_runtime *rt = chip->pcm;
563	int i;
564
565	for (i = 0; i < PCM_N_URBS; i++)
566		kfree(rt->out_urbs[i].buffer);
567
568	kfree(chip->pcm);
569	chip->pcm = NULL;
570}
571
572static void hiface_pcm_free(struct snd_pcm *pcm)
573{
574	struct pcm_runtime *rt = pcm->private_data;
575
576	if (rt)
577		hiface_pcm_destroy(rt->chip);
578}
579
580int hiface_pcm_init(struct hiface_chip *chip, u8 extra_freq)
581{
582	int i;
583	int ret;
584	struct snd_pcm *pcm;
585	struct pcm_runtime *rt;
586
587	rt = kzalloc(sizeof(*rt), GFP_KERNEL);
588	if (!rt)
589		return -ENOMEM;
590
591	rt->chip = chip;
592	rt->stream_state = STREAM_DISABLED;
593	if (extra_freq)
594		rt->extra_freq = 1;
595
596	init_waitqueue_head(&rt->stream_wait_queue);
597	mutex_init(&rt->stream_mutex);
598	spin_lock_init(&rt->playback.lock);
599
600	for (i = 0; i < PCM_N_URBS; i++)
601		hiface_pcm_init_urb(&rt->out_urbs[i], chip, OUT_EP,
602				    hiface_pcm_out_urb_handler);
603
604	ret = snd_pcm_new(chip->card, "USB-SPDIF Audio", 0, 1, 0, &pcm);
605	if (ret < 0) {
606		kfree(rt);
607		dev_err(&chip->dev->dev, "Cannot create pcm instance\n");
608		return ret;
609	}
610
611	pcm->private_data = rt;
612	pcm->private_free = hiface_pcm_free;
613
614	strlcpy(pcm->name, "USB-SPDIF Audio", sizeof(pcm->name));
615	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_ops);
616
617	rt->instance = pcm;
618
619	chip->pcm = rt;
620	return 0;
621}
622