1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Line 6 Linux USB driver
4 *
5 * Copyright (C) 2004-2010 Markus Grabner (line6@grabner-graz.at)
6 */
7
8 #include <linux/slab.h>
9 #include <sound/core.h>
10 #include <sound/pcm.h>
11 #include <sound/pcm_params.h>
12
13 #include "capture.h"
14 #include "driver.h"
15 #include "pcm.h"
16
17 /*
18 Find a free URB and submit it.
19 must be called in line6pcm->in.lock context
20 */
submit_audio_in_urb(struct snd_line6_pcm * line6pcm)21 static int submit_audio_in_urb(struct snd_line6_pcm *line6pcm)
22 {
23 int index;
24 int i, urb_size;
25 int ret;
26 struct urb *urb_in;
27
28 index = find_first_zero_bit(&line6pcm->in.active_urbs,
29 line6pcm->line6->iso_buffers);
30
31 if (index < 0 || index >= line6pcm->line6->iso_buffers) {
32 dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
33 return -EINVAL;
34 }
35
36 urb_in = line6pcm->in.urbs[index];
37 urb_size = 0;
38
39 for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
40 struct usb_iso_packet_descriptor *fin =
41 &urb_in->iso_frame_desc[i];
42 fin->offset = urb_size;
43 fin->length = line6pcm->max_packet_size_in;
44 urb_size += line6pcm->max_packet_size_in;
45 }
46
47 urb_in->transfer_buffer =
48 line6pcm->in.buffer +
49 index * LINE6_ISO_PACKETS * line6pcm->max_packet_size_in;
50 urb_in->transfer_buffer_length = urb_size;
51 urb_in->context = line6pcm;
52
53 ret = usb_submit_urb(urb_in, GFP_ATOMIC);
54
55 if (ret == 0)
56 set_bit(index, &line6pcm->in.active_urbs);
57 else
58 dev_err(line6pcm->line6->ifcdev,
59 "URB in #%d submission failed (%d)\n", index, ret);
60
61 return 0;
62 }
63
64 /*
65 Submit all currently available capture URBs.
66 must be called in line6pcm->in.lock context
67 */
line6_submit_audio_in_all_urbs(struct snd_line6_pcm * line6pcm)68 int line6_submit_audio_in_all_urbs(struct snd_line6_pcm *line6pcm)
69 {
70 int ret = 0, i;
71
72 for (i = 0; i < line6pcm->line6->iso_buffers; ++i) {
73 ret = submit_audio_in_urb(line6pcm);
74 if (ret < 0)
75 break;
76 }
77
78 return ret;
79 }
80
81 /*
82 Copy data into ALSA capture buffer.
83 */
line6_capture_copy(struct snd_line6_pcm * line6pcm,char * fbuf,int fsize)84 void line6_capture_copy(struct snd_line6_pcm *line6pcm, char *fbuf, int fsize)
85 {
86 struct snd_pcm_substream *substream =
87 get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
88 struct snd_pcm_runtime *runtime = substream->runtime;
89 const int bytes_per_frame =
90 line6pcm->properties->bytes_per_channel *
91 line6pcm->properties->capture_hw.channels_max;
92 int frames = fsize / bytes_per_frame;
93
94 if (runtime == NULL)
95 return;
96
97 if (line6pcm->in.pos_done + frames > runtime->buffer_size) {
98 /*
99 The transferred area goes over buffer boundary,
100 copy two separate chunks.
101 */
102 int len;
103
104 len = runtime->buffer_size - line6pcm->in.pos_done;
105
106 if (len > 0) {
107 memcpy(runtime->dma_area +
108 line6pcm->in.pos_done * bytes_per_frame, fbuf,
109 len * bytes_per_frame);
110 memcpy(runtime->dma_area, fbuf + len * bytes_per_frame,
111 (frames - len) * bytes_per_frame);
112 } else {
113 /* this is somewhat paranoid */
114 dev_err(line6pcm->line6->ifcdev,
115 "driver bug: len = %d\n", len);
116 }
117 } else {
118 /* copy single chunk */
119 memcpy(runtime->dma_area +
120 line6pcm->in.pos_done * bytes_per_frame, fbuf, fsize);
121 }
122
123 line6pcm->in.pos_done += frames;
124 if (line6pcm->in.pos_done >= runtime->buffer_size)
125 line6pcm->in.pos_done -= runtime->buffer_size;
126 }
127
line6_capture_check_period(struct snd_line6_pcm * line6pcm,int length)128 void line6_capture_check_period(struct snd_line6_pcm *line6pcm, int length)
129 {
130 struct snd_pcm_substream *substream =
131 get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
132
133 line6pcm->in.bytes += length;
134 if (line6pcm->in.bytes >= line6pcm->in.period) {
135 line6pcm->in.bytes %= line6pcm->in.period;
136 spin_unlock(&line6pcm->in.lock);
137 snd_pcm_period_elapsed(substream);
138 spin_lock(&line6pcm->in.lock);
139 }
140 }
141
142 /*
143 * Callback for completed capture URB.
144 */
audio_in_callback(struct urb * urb)145 static void audio_in_callback(struct urb *urb)
146 {
147 int i, index, length = 0, shutdown = 0;
148 unsigned long flags;
149
150 struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;
151
152 line6pcm->in.last_frame = urb->start_frame;
153
154 /* find index of URB */
155 for (index = 0; index < line6pcm->line6->iso_buffers; ++index)
156 if (urb == line6pcm->in.urbs[index])
157 break;
158
159 spin_lock_irqsave(&line6pcm->in.lock, flags);
160
161 for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
162 char *fbuf;
163 int fsize;
164 struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];
165
166 if (fin->status == -EXDEV) {
167 shutdown = 1;
168 break;
169 }
170
171 fbuf = urb->transfer_buffer + fin->offset;
172 fsize = fin->actual_length;
173
174 if (fsize > line6pcm->max_packet_size_in) {
175 dev_err(line6pcm->line6->ifcdev,
176 "driver and/or device bug: packet too large (%d > %d)\n",
177 fsize, line6pcm->max_packet_size_in);
178 }
179
180 length += fsize;
181
182 BUILD_BUG_ON_MSG(LINE6_ISO_PACKETS != 1,
183 "The following code assumes LINE6_ISO_PACKETS == 1");
184 /* TODO:
185 * Also, if iso_buffers != 2, the prev frame is almost random at
186 * playback side.
187 * This needs to be redesigned. It should be "stable", but we may
188 * experience sync problems on such high-speed configs.
189 */
190
191 line6pcm->prev_fbuf = fbuf;
192 line6pcm->prev_fsize = fsize /
193 (line6pcm->properties->bytes_per_channel *
194 line6pcm->properties->capture_hw.channels_max);
195
196 if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
197 test_bit(LINE6_STREAM_PCM, &line6pcm->in.running) &&
198 fsize > 0)
199 line6_capture_copy(line6pcm, fbuf, fsize);
200 }
201
202 clear_bit(index, &line6pcm->in.active_urbs);
203
204 if (test_and_clear_bit(index, &line6pcm->in.unlink_urbs))
205 shutdown = 1;
206
207 if (!shutdown) {
208 submit_audio_in_urb(line6pcm);
209
210 if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
211 test_bit(LINE6_STREAM_PCM, &line6pcm->in.running))
212 line6_capture_check_period(line6pcm, length);
213 }
214
215 spin_unlock_irqrestore(&line6pcm->in.lock, flags);
216 }
217
218 /* open capture callback */
snd_line6_capture_open(struct snd_pcm_substream * substream)219 static int snd_line6_capture_open(struct snd_pcm_substream *substream)
220 {
221 int err;
222 struct snd_pcm_runtime *runtime = substream->runtime;
223 struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
224
225 err = snd_pcm_hw_constraint_ratdens(runtime, 0,
226 SNDRV_PCM_HW_PARAM_RATE,
227 &line6pcm->properties->rates);
228 if (err < 0)
229 return err;
230
231 line6_pcm_acquire(line6pcm, LINE6_STREAM_CAPTURE_HELPER, false);
232
233 runtime->hw = line6pcm->properties->capture_hw;
234 return 0;
235 }
236
237 /* close capture callback */
snd_line6_capture_close(struct snd_pcm_substream * substream)238 static int snd_line6_capture_close(struct snd_pcm_substream *substream)
239 {
240 struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
241
242 line6_pcm_release(line6pcm, LINE6_STREAM_CAPTURE_HELPER);
243 return 0;
244 }
245
246 /* capture operators */
247 const struct snd_pcm_ops snd_line6_capture_ops = {
248 .open = snd_line6_capture_open,
249 .close = snd_line6_capture_close,
250 .hw_params = snd_line6_hw_params,
251 .hw_free = snd_line6_hw_free,
252 .prepare = snd_line6_prepare,
253 .trigger = snd_line6_trigger,
254 .pointer = snd_line6_pointer,
255 };
256
line6_create_audio_in_urbs(struct snd_line6_pcm * line6pcm)257 int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
258 {
259 struct usb_line6 *line6 = line6pcm->line6;
260 int i;
261
262 line6pcm->in.urbs = kcalloc(line6->iso_buffers, sizeof(struct urb *),
263 GFP_KERNEL);
264 if (line6pcm->in.urbs == NULL)
265 return -ENOMEM;
266
267 /* create audio URBs and fill in constant values: */
268 for (i = 0; i < line6->iso_buffers; ++i) {
269 struct urb *urb;
270
271 /* URB for audio in: */
272 urb = line6pcm->in.urbs[i] =
273 usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
274
275 if (urb == NULL)
276 return -ENOMEM;
277
278 urb->dev = line6->usbdev;
279 urb->pipe =
280 usb_rcvisocpipe(line6->usbdev,
281 line6->properties->ep_audio_r &
282 USB_ENDPOINT_NUMBER_MASK);
283 urb->transfer_flags = URB_ISO_ASAP;
284 urb->start_frame = -1;
285 urb->number_of_packets = LINE6_ISO_PACKETS;
286 urb->interval = LINE6_ISO_INTERVAL;
287 urb->error_count = 0;
288 urb->complete = audio_in_callback;
289 if (usb_urb_ep_type_check(urb))
290 return -EINVAL;
291 }
292
293 return 0;
294 }
295