summaryrefslogtreecommitdiffstats
path: root/sound/usb/line6/capture.c
blob: 947d6168f24abe477e7ec9456e7c4fe293138707 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
/*
 * Line 6 Linux USB driver
 *
 * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License as
 *	published by the Free Software Foundation, version 2.
 *
 */

#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>

#include "capture.h"
#include "driver.h"
#include "pcm.h"

/*
	Find a free URB and submit it.
	must be called in line6pcm->in.lock context
*/
static int submit_audio_in_urb(struct snd_line6_pcm *line6pcm)
{
	int index;
	int i, urb_size;
	int ret;
	struct urb *urb_in;

	index = find_first_zero_bit(&line6pcm->in.active_urbs,
				    line6pcm->line6->iso_buffers);

	if (index < 0 || index >= line6pcm->line6->iso_buffers) {
		dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
		return -EINVAL;
	}

	urb_in = line6pcm->in.urbs[index];
	urb_size = 0;

	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
		struct usb_iso_packet_descriptor *fin =
		    &urb_in->iso_frame_desc[i];
		fin->offset = urb_size;
		fin->length = line6pcm->max_packet_size_in;
		urb_size += line6pcm->max_packet_size_in;
	}

	urb_in->transfer_buffer =
	    line6pcm->in.buffer +
	    index * LINE6_ISO_PACKETS * line6pcm->max_packet_size_in;
	urb_in->transfer_buffer_length = urb_size;
	urb_in->context = line6pcm;

	ret = usb_submit_urb(urb_in, GFP_ATOMIC);

	if (ret == 0)
		set_bit(index, &line6pcm->in.active_urbs);
	else
		dev_err(line6pcm->line6->ifcdev,
			"URB in #%d submission failed (%d)\n", index, ret);

	return 0;
}

/*
	Submit all currently available capture URBs.
	must be called in line6pcm->in.lock context
*/
int line6_submit_audio_in_all_urbs(struct snd_line6_pcm *line6pcm)
{
	int ret = 0, i;

	for (i = 0; i < line6pcm->line6->iso_buffers; ++i) {
		ret = submit_audio_in_urb(line6pcm);
		if (ret < 0)
			break;
	}

	return ret;
}

/*
	Copy data into ALSA capture buffer.
*/
void line6_capture_copy(struct snd_line6_pcm *line6pcm, char *fbuf, int fsize)
{
	struct snd_pcm_substream *substream =
	    get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
	struct snd_pcm_runtime *runtime = substream->runtime;
	const int bytes_per_frame =
		line6pcm->properties->bytes_per_channel *
		line6pcm->properties->capture_hw.channels_max;
	int frames = fsize / bytes_per_frame;

	if (runtime == NULL)
		return;

	if (line6pcm->in.pos_done + frames > runtime->buffer_size) {
		/*
		   The transferred area goes over buffer boundary,
		   copy two separate chunks.
		 */
		int len;

		len = runtime->buffer_size - line6pcm->in.pos_done;

		if (len > 0) {
			memcpy(runtime->dma_area +
			       line6pcm->in.pos_done * bytes_per_frame, fbuf,
			       len * bytes_per_frame);
			memcpy(runtime->dma_area, fbuf + len * bytes_per_frame,
			       (frames - len) * bytes_per_frame);
		} else {
			/* this is somewhat paranoid */
			dev_err(line6pcm->line6->ifcdev,
				"driver bug: len = %d\n", len);
		}
	} else {
		/* copy single chunk */
		memcpy(runtime->dma_area +
		       line6pcm->in.pos_done * bytes_per_frame, fbuf, fsize);
	}

	line6pcm->in.pos_done += frames;
	if (line6pcm->in.pos_done >= runtime->buffer_size)
		line6pcm->in.pos_done -= runtime->buffer_size;
}

void line6_capture_check_period(struct snd_line6_pcm *line6pcm, int length)
{
	struct snd_pcm_substream *substream =
	    get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);

	line6pcm->in.bytes += length;
	if (line6pcm->in.bytes >= line6pcm->in.period) {
		line6pcm->in.bytes %= line6pcm->in.period;
		spin_unlock(&line6pcm->in.lock);
		snd_pcm_period_elapsed(substream);
		spin_lock(&line6pcm->in.lock);
	}
}

/*
 * Callback for completed capture URB.
 */
static void audio_in_callback(struct urb *urb)
{
	int i, index, length = 0, shutdown = 0;
	unsigned long flags;

	struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;

	line6pcm->in.last_frame = urb->start_frame;

	/* find index of URB */
	for (index = 0; index < line6pcm->line6->iso_buffers; ++index)
		if (urb == line6pcm->in.urbs[index])
			break;

	spin_lock_irqsave(&line6pcm->in.lock, flags);

	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
		char *fbuf;
		int fsize;
		struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];

		if (fin->status == -EXDEV) {
			shutdown = 1;
			break;
		}

		fbuf = urb->transfer_buffer + fin->offset;
		fsize = fin->actual_length;

		if (fsize > line6pcm->max_packet_size_in) {
			dev_err(line6pcm->line6->ifcdev,
				"driver and/or device bug: packet too large (%d > %d)\n",
				fsize, line6pcm->max_packet_size_in);
		}

		length += fsize;

		BUILD_BUG_ON_MSG(LINE6_ISO_PACKETS != 1,
			"The following code assumes LINE6_ISO_PACKETS == 1");
		/* TODO:
		 * Also, if iso_buffers != 2, the prev frame is almost random at
		 * playback side.
		 * This needs to be redesigned. It should be "stable", but we may
		 * experience sync problems on such high-speed configs.
		 */

		line6pcm->prev_fbuf = fbuf;
		line6pcm->prev_fsize = fsize /
			(line6pcm->properties->bytes_per_channel *
			line6pcm->properties->capture_hw.channels_max);

		if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
		    test_bit(LINE6_STREAM_PCM, &line6pcm->in.running) &&
		    fsize > 0)
			line6_capture_copy(line6pcm, fbuf, fsize);
	}

	clear_bit(index, &line6pcm->in.active_urbs);

	if (test_and_clear_bit(index, &line6pcm->in.unlink_urbs))
		shutdown = 1;

	if (!shutdown) {
		submit_audio_in_urb(line6pcm);

		if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
		    test_bit(LINE6_STREAM_PCM, &line6pcm->in.running))
			line6_capture_check_period(line6pcm, length);
	}

	spin_unlock_irqrestore(&line6pcm->in.lock, flags);
}

/* open capture callback */
static int snd_line6_capture_open(struct snd_pcm_substream *substream)
{
	int err;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	err = snd_pcm_hw_constraint_ratdens(runtime, 0,
					    SNDRV_PCM_HW_PARAM_RATE,
					    &line6pcm->properties->rates);
	if (err < 0)
		return err;

	line6_pcm_acquire(line6pcm, LINE6_STREAM_CAPTURE_HELPER, false);

	runtime->hw = line6pcm->properties->capture_hw;
	return 0;
}

/* close capture callback */
static int snd_line6_capture_close(struct snd_pcm_substream *substream)
{
	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	line6_pcm_release(line6pcm, LINE6_STREAM_CAPTURE_HELPER);
	return 0;
}

/* capture operators */
const struct snd_pcm_ops snd_line6_capture_ops = {
	.open = snd_line6_capture_open,
	.close = snd_line6_capture_close,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = snd_line6_hw_params,
	.hw_free = snd_line6_hw_free,
	.prepare = snd_line6_prepare,
	.trigger = snd_line6_trigger,
	.pointer = snd_line6_pointer,
};

int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
{
	struct usb_line6 *line6 = line6pcm->line6;
	int i;

	line6pcm->in.urbs = kzalloc(
		sizeof(struct urb *) * line6->iso_buffers, GFP_KERNEL);
	if (line6pcm->in.urbs == NULL)
		return -ENOMEM;

	/* create audio URBs and fill in constant values: */
	for (i = 0; i < line6->iso_buffers; ++i) {
		struct urb *urb;

		/* URB for audio in: */
		urb = line6pcm->in.urbs[i] =
		    usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);

		if (urb == NULL)
			return -ENOMEM;

		urb->dev = line6->usbdev;
		urb->pipe =
		    usb_rcvisocpipe(line6->usbdev,
				    line6->properties->ep_audio_r &
				    USB_ENDPOINT_NUMBER_MASK);
		urb->transfer_flags = URB_ISO_ASAP;
		urb->start_frame = -1;
		urb->number_of_packets = LINE6_ISO_PACKETS;
		urb->interval = LINE6_ISO_INTERVAL;
		urb->error_count = 0;
		urb->complete = audio_in_callback;
	}

	return 0;
}