1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Linux driver for M2Tech hiFace compatible devices
4 *
5 * Copyright 2012-2013 (C) M2TECH S.r.l and Amarula Solutions B.V.
6 *
7 * Authors:  Michael Trimarchi <michael@amarulasolutions.com>
8 *           Antonio Ospite <ao2@amarulasolutions.com>
9 *
10 * The driver is based on the work done in TerraTec DMX 6Fire USB
11 */
12
13#include <linux/slab.h>
14#include <sound/pcm.h>
15
16#include "pcm.h"
17#include "chip.h"
18
19#define OUT_EP          0x2
20#define PCM_N_URBS      8
21#define PCM_PACKET_SIZE 4096
22#define PCM_BUFFER_SIZE (2 * PCM_N_URBS * PCM_PACKET_SIZE)
23
24struct pcm_urb {
25	struct hiface_chip *chip;
26
27	struct urb instance;
28	struct usb_anchor submitted;
29	u8 *buffer;
30};
31
32struct pcm_substream {
33	spinlock_t lock;
34	struct snd_pcm_substream *instance;
35
36	bool active;
37	snd_pcm_uframes_t dma_off;    /* current position in alsa dma_area */
38	snd_pcm_uframes_t period_off; /* current position in current period */
39};
40
41enum { /* pcm streaming states */
42	STREAM_DISABLED, /* no pcm streaming */
43	STREAM_STARTING, /* pcm streaming requested, waiting to become ready */
44	STREAM_RUNNING,  /* pcm streaming running */
45	STREAM_STOPPING
46};
47
48struct pcm_runtime {
49	struct hiface_chip *chip;
50	struct snd_pcm *instance;
51
52	struct pcm_substream playback;
53	bool panic; /* if set driver won't do anymore pcm on device */
54
55	struct pcm_urb out_urbs[PCM_N_URBS];
56
57	struct mutex stream_mutex;
58	u8 stream_state; /* one of STREAM_XXX */
59	u8 extra_freq;
60	wait_queue_head_t stream_wait_queue;
61	bool stream_wait_cond;
62};
63
64static const unsigned int rates[] = { 44100, 48000, 88200, 96000, 176400, 192000,
65				      352800, 384000 };
66static const struct snd_pcm_hw_constraint_list constraints_extra_rates = {
67	.count = ARRAY_SIZE(rates),
68	.list = rates,
69	.mask = 0,
70};
71
72static const struct snd_pcm_hardware pcm_hw = {
73	.info = SNDRV_PCM_INFO_MMAP |
74		SNDRV_PCM_INFO_INTERLEAVED |
75		SNDRV_PCM_INFO_BLOCK_TRANSFER |
76		SNDRV_PCM_INFO_PAUSE |
77		SNDRV_PCM_INFO_MMAP_VALID |
78		SNDRV_PCM_INFO_BATCH,
79
80	.formats = SNDRV_PCM_FMTBIT_S32_LE,
81
82	.rates = SNDRV_PCM_RATE_44100 |
83		SNDRV_PCM_RATE_48000 |
84		SNDRV_PCM_RATE_88200 |
85		SNDRV_PCM_RATE_96000 |
86		SNDRV_PCM_RATE_176400 |
87		SNDRV_PCM_RATE_192000,
88
89	.rate_min = 44100,
90	.rate_max = 192000, /* changes in hiface_pcm_open to support extra rates */
91	.channels_min = 2,
92	.channels_max = 2,
93	.buffer_bytes_max = PCM_BUFFER_SIZE,
94	.period_bytes_min = PCM_PACKET_SIZE,
95	.period_bytes_max = PCM_BUFFER_SIZE,
96	.periods_min = 2,
97	.periods_max = 1024
98};
99
100/* message values used to change the sample rate */
101#define HIFACE_SET_RATE_REQUEST 0xb0
102
103#define HIFACE_RATE_44100  0x43
104#define HIFACE_RATE_48000  0x4b
105#define HIFACE_RATE_88200  0x42
106#define HIFACE_RATE_96000  0x4a
107#define HIFACE_RATE_176400 0x40
108#define HIFACE_RATE_192000 0x48
109#define HIFACE_RATE_352800 0x58
110#define HIFACE_RATE_384000 0x68
111
112static int hiface_pcm_set_rate(struct pcm_runtime *rt, unsigned int rate)
113{
114	struct usb_device *device = rt->chip->dev;
115	u16 rate_value;
116	int ret;
117
118	/* We are already sure that the rate is supported here thanks to
119	 * ALSA constraints
120	 */
121	switch (rate) {
122	case 44100:
123		rate_value = HIFACE_RATE_44100;
124		break;
125	case 48000:
126		rate_value = HIFACE_RATE_48000;
127		break;
128	case 88200:
129		rate_value = HIFACE_RATE_88200;
130		break;
131	case 96000:
132		rate_value = HIFACE_RATE_96000;
133		break;
134	case 176400:
135		rate_value = HIFACE_RATE_176400;
136		break;
137	case 192000:
138		rate_value = HIFACE_RATE_192000;
139		break;
140	case 352800:
141		rate_value = HIFACE_RATE_352800;
142		break;
143	case 384000:
144		rate_value = HIFACE_RATE_384000;
145		break;
146	default:
147		dev_err(&device->dev, "Unsupported rate %d\n", rate);
148		return -EINVAL;
149	}
150
151	/*
152	 * USBIO: Vendor 0xb0(wValue=0x0043, wIndex=0x0000)
153	 * 43 b0 43 00 00 00 00 00
154	 * USBIO: Vendor 0xb0(wValue=0x004b, wIndex=0x0000)
155	 * 43 b0 4b 00 00 00 00 00
156	 * This control message doesn't have any ack from the
157	 * other side
158	 */
159	ret = usb_control_msg_send(device, 0,
160				   HIFACE_SET_RATE_REQUEST,
161				   USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
162				   rate_value, 0, NULL, 0, 100, GFP_KERNEL);
163	if (ret)
164		dev_err(&device->dev, "Error setting samplerate %d.\n", rate);
165
166	return ret;
167}
168
169static struct pcm_substream *hiface_pcm_get_substream(struct snd_pcm_substream
170						      *alsa_sub)
171{
172	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
173	struct device *device = &rt->chip->dev->dev;
174
175	if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
176		return &rt->playback;
177
178	dev_err(device, "Error getting pcm substream slot.\n");
179	return NULL;
180}
181
182/* call with stream_mutex locked */
183static void hiface_pcm_stream_stop(struct pcm_runtime *rt)
184{
185	int i, time;
186
187	if (rt->stream_state != STREAM_DISABLED) {
188		rt->stream_state = STREAM_STOPPING;
189
190		for (i = 0; i < PCM_N_URBS; i++) {
191			time = usb_wait_anchor_empty_timeout(
192					&rt->out_urbs[i].submitted, 100);
193			if (!time)
194				usb_kill_anchored_urbs(
195					&rt->out_urbs[i].submitted);
196			usb_kill_urb(&rt->out_urbs[i].instance);
197		}
198
199		rt->stream_state = STREAM_DISABLED;
200	}
201}
202
203/* call with stream_mutex locked */
204static int hiface_pcm_stream_start(struct pcm_runtime *rt)
205{
206	int ret = 0;
207	int i;
208
209	if (rt->stream_state == STREAM_DISABLED) {
210
211		/* reset panic state when starting a new stream */
212		rt->panic = false;
213
214		/* submit our out urbs zero init */
215		rt->stream_state = STREAM_STARTING;
216		for (i = 0; i < PCM_N_URBS; i++) {
217			memset(rt->out_urbs[i].buffer, 0, PCM_PACKET_SIZE);
218			usb_anchor_urb(&rt->out_urbs[i].instance,
219				       &rt->out_urbs[i].submitted);
220			ret = usb_submit_urb(&rt->out_urbs[i].instance,
221					     GFP_ATOMIC);
222			if (ret) {
223				hiface_pcm_stream_stop(rt);
224				return ret;
225			}
226		}
227
228		/* wait for first out urb to return (sent in urb handler) */
229		wait_event_timeout(rt->stream_wait_queue, rt->stream_wait_cond,
230				   HZ);
231		if (rt->stream_wait_cond) {
232			struct device *device = &rt->chip->dev->dev;
233			dev_dbg(device, "%s: Stream is running wakeup event\n",
234				 __func__);
235			rt->stream_state = STREAM_RUNNING;
236		} else {
237			hiface_pcm_stream_stop(rt);
238			return -EIO;
239		}
240	}
241	return ret;
242}
243
244/* The hardware wants word-swapped 32-bit values */
245static void memcpy_swahw32(u8 *dest, u8 *src, unsigned int n)
246{
247	unsigned int i;
248
249	for (i = 0; i < n / 4; i++)
250		((u32 *)dest)[i] = swahw32(((u32 *)src)[i]);
251}
252
253/* call with substream locked */
254/* returns true if a period elapsed */
255static bool hiface_pcm_playback(struct pcm_substream *sub, struct pcm_urb *urb)
256{
257	struct snd_pcm_runtime *alsa_rt = sub->instance->runtime;
258	struct device *device = &urb->chip->dev->dev;
259	u8 *source;
260	unsigned int pcm_buffer_size;
261
262	WARN_ON(alsa_rt->format != SNDRV_PCM_FORMAT_S32_LE);
263
264	pcm_buffer_size = snd_pcm_lib_buffer_bytes(sub->instance);
265
266	if (sub->dma_off + PCM_PACKET_SIZE <= pcm_buffer_size) {
267		dev_dbg(device, "%s: (1) buffer_size %#x dma_offset %#x\n", __func__,
268			 (unsigned int) pcm_buffer_size,
269			 (unsigned int) sub->dma_off);
270
271		source = alsa_rt->dma_area + sub->dma_off;
272		memcpy_swahw32(urb->buffer, source, PCM_PACKET_SIZE);
273	} else {
274		/* wrap around at end of ring buffer */
275		unsigned int len;
276
277		dev_dbg(device, "%s: (2) buffer_size %#x dma_offset %#x\n", __func__,
278			 (unsigned int) pcm_buffer_size,
279			 (unsigned int) sub->dma_off);
280
281		len = pcm_buffer_size - sub->dma_off;
282
283		source = alsa_rt->dma_area + sub->dma_off;
284		memcpy_swahw32(urb->buffer, source, len);
285
286		source = alsa_rt->dma_area;
287		memcpy_swahw32(urb->buffer + len, source,
288			       PCM_PACKET_SIZE - len);
289	}
290	sub->dma_off += PCM_PACKET_SIZE;
291	if (sub->dma_off >= pcm_buffer_size)
292		sub->dma_off -= pcm_buffer_size;
293
294	sub->period_off += PCM_PACKET_SIZE;
295	if (sub->period_off >= alsa_rt->period_size) {
296		sub->period_off %= alsa_rt->period_size;
297		return true;
298	}
299	return false;
300}
301
302static void hiface_pcm_out_urb_handler(struct urb *usb_urb)
303{
304	struct pcm_urb *out_urb = usb_urb->context;
305	struct pcm_runtime *rt = out_urb->chip->pcm;
306	struct pcm_substream *sub;
307	bool do_period_elapsed = false;
308	unsigned long flags;
309	int ret;
310
311	if (rt->panic || rt->stream_state == STREAM_STOPPING)
312		return;
313
314	if (unlikely(usb_urb->status == -ENOENT ||	/* unlinked */
315		     usb_urb->status == -ENODEV ||	/* device removed */
316		     usb_urb->status == -ECONNRESET ||	/* unlinked */
317		     usb_urb->status == -ESHUTDOWN)) {	/* device disabled */
318		goto out_fail;
319	}
320
321	if (rt->stream_state == STREAM_STARTING) {
322		rt->stream_wait_cond = true;
323		wake_up(&rt->stream_wait_queue);
324	}
325
326	/* now send our playback data (if a free out urb was found) */
327	sub = &rt->playback;
328	spin_lock_irqsave(&sub->lock, flags);
329	if (sub->active)
330		do_period_elapsed = hiface_pcm_playback(sub, out_urb);
331	else
332		memset(out_urb->buffer, 0, PCM_PACKET_SIZE);
333
334	spin_unlock_irqrestore(&sub->lock, flags);
335
336	if (do_period_elapsed)
337		snd_pcm_period_elapsed(sub->instance);
338
339	ret = usb_submit_urb(&out_urb->instance, GFP_ATOMIC);
340	if (ret < 0)
341		goto out_fail;
342
343	return;
344
345out_fail:
346	rt->panic = true;
347}
348
349static int hiface_pcm_open(struct snd_pcm_substream *alsa_sub)
350{
351	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
352	struct pcm_substream *sub = NULL;
353	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
354	int ret;
355
356	if (rt->panic)
357		return -EPIPE;
358
359	mutex_lock(&rt->stream_mutex);
360	alsa_rt->hw = pcm_hw;
361
362	if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
363		sub = &rt->playback;
364
365	if (!sub) {
366		struct device *device = &rt->chip->dev->dev;
367		mutex_unlock(&rt->stream_mutex);
368		dev_err(device, "Invalid stream type\n");
369		return -EINVAL;
370	}
371
372	if (rt->extra_freq) {
373		alsa_rt->hw.rates |= SNDRV_PCM_RATE_KNOT;
374		alsa_rt->hw.rate_max = 384000;
375
376		/* explicit constraints needed as we added SNDRV_PCM_RATE_KNOT */
377		ret = snd_pcm_hw_constraint_list(alsa_sub->runtime, 0,
378						 SNDRV_PCM_HW_PARAM_RATE,
379						 &constraints_extra_rates);
380		if (ret < 0) {
381			mutex_unlock(&rt->stream_mutex);
382			return ret;
383		}
384	}
385
386	sub->instance = alsa_sub;
387	sub->active = false;
388	mutex_unlock(&rt->stream_mutex);
389	return 0;
390}
391
392static int hiface_pcm_close(struct snd_pcm_substream *alsa_sub)
393{
394	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
395	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
396	unsigned long flags;
397
398	if (rt->panic)
399		return 0;
400
401	mutex_lock(&rt->stream_mutex);
402	if (sub) {
403		hiface_pcm_stream_stop(rt);
404
405		/* deactivate substream */
406		spin_lock_irqsave(&sub->lock, flags);
407		sub->instance = NULL;
408		sub->active = false;
409		spin_unlock_irqrestore(&sub->lock, flags);
410
411	}
412	mutex_unlock(&rt->stream_mutex);
413	return 0;
414}
415
416static int hiface_pcm_prepare(struct snd_pcm_substream *alsa_sub)
417{
418	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
419	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
420	struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
421	int ret;
422
423	if (rt->panic)
424		return -EPIPE;
425	if (!sub)
426		return -ENODEV;
427
428	mutex_lock(&rt->stream_mutex);
429
430	hiface_pcm_stream_stop(rt);
431
432	sub->dma_off = 0;
433	sub->period_off = 0;
434
435	if (rt->stream_state == STREAM_DISABLED) {
436
437		ret = hiface_pcm_set_rate(rt, alsa_rt->rate);
438		if (ret) {
439			mutex_unlock(&rt->stream_mutex);
440			return ret;
441		}
442		ret = hiface_pcm_stream_start(rt);
443		if (ret) {
444			mutex_unlock(&rt->stream_mutex);
445			return ret;
446		}
447	}
448	mutex_unlock(&rt->stream_mutex);
449	return 0;
450}
451
452static int hiface_pcm_trigger(struct snd_pcm_substream *alsa_sub, int cmd)
453{
454	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
455	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
456
457	if (rt->panic)
458		return -EPIPE;
459	if (!sub)
460		return -ENODEV;
461
462	switch (cmd) {
463	case SNDRV_PCM_TRIGGER_START:
464	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
465		spin_lock_irq(&sub->lock);
466		sub->active = true;
467		spin_unlock_irq(&sub->lock);
468		return 0;
469
470	case SNDRV_PCM_TRIGGER_STOP:
471	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
472		spin_lock_irq(&sub->lock);
473		sub->active = false;
474		spin_unlock_irq(&sub->lock);
475		return 0;
476
477	default:
478		return -EINVAL;
479	}
480}
481
482static snd_pcm_uframes_t hiface_pcm_pointer(struct snd_pcm_substream *alsa_sub)
483{
484	struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
485	struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
486	unsigned long flags;
487	snd_pcm_uframes_t dma_offset;
488
489	if (rt->panic || !sub)
490		return SNDRV_PCM_POS_XRUN;
491
492	spin_lock_irqsave(&sub->lock, flags);
493	dma_offset = sub->dma_off;
494	spin_unlock_irqrestore(&sub->lock, flags);
495	return bytes_to_frames(alsa_sub->runtime, dma_offset);
496}
497
498static const struct snd_pcm_ops pcm_ops = {
499	.open = hiface_pcm_open,
500	.close = hiface_pcm_close,
501	.prepare = hiface_pcm_prepare,
502	.trigger = hiface_pcm_trigger,
503	.pointer = hiface_pcm_pointer,
504};
505
506static int hiface_pcm_init_urb(struct pcm_urb *urb,
507			       struct hiface_chip *chip,
508			       unsigned int ep,
509			       void (*handler)(struct urb *))
510{
511	urb->chip = chip;
512	usb_init_urb(&urb->instance);
513
514	urb->buffer = kzalloc(PCM_PACKET_SIZE, GFP_KERNEL);
515	if (!urb->buffer)
516		return -ENOMEM;
517
518	usb_fill_bulk_urb(&urb->instance, chip->dev,
519			  usb_sndbulkpipe(chip->dev, ep), (void *)urb->buffer,
520			  PCM_PACKET_SIZE, handler, urb);
521	if (usb_urb_ep_type_check(&urb->instance))
522		return -EINVAL;
523	init_usb_anchor(&urb->submitted);
524
525	return 0;
526}
527
528void hiface_pcm_abort(struct hiface_chip *chip)
529{
530	struct pcm_runtime *rt = chip->pcm;
531
532	if (rt) {
533		rt->panic = true;
534
535		mutex_lock(&rt->stream_mutex);
536		hiface_pcm_stream_stop(rt);
537		mutex_unlock(&rt->stream_mutex);
538	}
539}
540
541static void hiface_pcm_destroy(struct hiface_chip *chip)
542{
543	struct pcm_runtime *rt = chip->pcm;
544	int i;
545
546	for (i = 0; i < PCM_N_URBS; i++)
547		kfree(rt->out_urbs[i].buffer);
548
549	kfree(chip->pcm);
550	chip->pcm = NULL;
551}
552
553static void hiface_pcm_free(struct snd_pcm *pcm)
554{
555	struct pcm_runtime *rt = pcm->private_data;
556
557	if (rt)
558		hiface_pcm_destroy(rt->chip);
559}
560
561int hiface_pcm_init(struct hiface_chip *chip, u8 extra_freq)
562{
563	int i;
564	int ret;
565	struct snd_pcm *pcm;
566	struct pcm_runtime *rt;
567
568	rt = kzalloc(sizeof(*rt), GFP_KERNEL);
569	if (!rt)
570		return -ENOMEM;
571
572	rt->chip = chip;
573	rt->stream_state = STREAM_DISABLED;
574	if (extra_freq)
575		rt->extra_freq = 1;
576
577	init_waitqueue_head(&rt->stream_wait_queue);
578	mutex_init(&rt->stream_mutex);
579	spin_lock_init(&rt->playback.lock);
580
581	for (i = 0; i < PCM_N_URBS; i++) {
582		ret = hiface_pcm_init_urb(&rt->out_urbs[i], chip, OUT_EP,
583				    hiface_pcm_out_urb_handler);
584		if (ret < 0)
585			goto error;
586	}
587
588	ret = snd_pcm_new(chip->card, "USB-SPDIF Audio", 0, 1, 0, &pcm);
589	if (ret < 0) {
590		dev_err(&chip->dev->dev, "Cannot create pcm instance\n");
591		goto error;
592	}
593
594	pcm->private_data = rt;
595	pcm->private_free = hiface_pcm_free;
596
597	strscpy(pcm->name, "USB-SPDIF Audio", sizeof(pcm->name));
598	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_ops);
599	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC,
600				       NULL, 0, 0);
601
602	rt->instance = pcm;
603
604	chip->pcm = rt;
605	return 0;
606
607error:
608	for (i = 0; i < PCM_N_URBS; i++)
609		kfree(rt->out_urbs[i].buffer);
610	kfree(rt);
611	return ret;
612}
613