xref: /openbmc/linux/sound/usb/line6/capture.c (revision b9b77222)
1 /*
2  * Line 6 Linux USB driver
3  *
4  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License as
8  *	published by the Free Software Foundation, version 2.
9  *
10  */
11 
12 #include <linux/slab.h>
13 #include <sound/core.h>
14 #include <sound/pcm.h>
15 #include <sound/pcm_params.h>
16 
17 #include "capture.h"
18 #include "driver.h"
19 #include "pcm.h"
20 
21 /*
22 	Find a free URB and submit it.
23 	must be called in line6pcm->in.lock context
24 */
25 static int submit_audio_in_urb(struct snd_line6_pcm *line6pcm)
26 {
27 	int index;
28 	int i, urb_size;
29 	int ret;
30 	struct urb *urb_in;
31 
32 	index = find_first_zero_bit(&line6pcm->in.active_urbs,
33 				    line6pcm->line6->iso_buffers);
34 
35 	if (index < 0 || index >= line6pcm->line6->iso_buffers) {
36 		dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
37 		return -EINVAL;
38 	}
39 
40 	urb_in = line6pcm->in.urbs[index];
41 	urb_size = 0;
42 
43 	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
44 		struct usb_iso_packet_descriptor *fin =
45 		    &urb_in->iso_frame_desc[i];
46 		fin->offset = urb_size;
47 		fin->length = line6pcm->max_packet_size_in;
48 		urb_size += line6pcm->max_packet_size_in;
49 	}
50 
51 	urb_in->transfer_buffer =
52 	    line6pcm->in.buffer +
53 	    index * LINE6_ISO_PACKETS * line6pcm->max_packet_size_in;
54 	urb_in->transfer_buffer_length = urb_size;
55 	urb_in->context = line6pcm;
56 
57 	ret = usb_submit_urb(urb_in, GFP_ATOMIC);
58 
59 	if (ret == 0)
60 		set_bit(index, &line6pcm->in.active_urbs);
61 	else
62 		dev_err(line6pcm->line6->ifcdev,
63 			"URB in #%d submission failed (%d)\n", index, ret);
64 
65 	return 0;
66 }
67 
68 /*
69 	Submit all currently available capture URBs.
70 	must be called in line6pcm->in.lock context
71 */
72 int line6_submit_audio_in_all_urbs(struct snd_line6_pcm *line6pcm)
73 {
74 	int ret = 0, i;
75 
76 	for (i = 0; i < line6pcm->line6->iso_buffers; ++i) {
77 		ret = submit_audio_in_urb(line6pcm);
78 		if (ret < 0)
79 			break;
80 	}
81 
82 	return ret;
83 }
84 
85 /*
86 	Copy data into ALSA capture buffer.
87 */
88 void line6_capture_copy(struct snd_line6_pcm *line6pcm, char *fbuf, int fsize)
89 {
90 	struct snd_pcm_substream *substream =
91 	    get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
92 	struct snd_pcm_runtime *runtime = substream->runtime;
93 	const int bytes_per_frame =
94 		line6pcm->properties->bytes_per_channel *
95 		line6pcm->properties->capture_hw.channels_max;
96 	int frames = fsize / bytes_per_frame;
97 
98 	if (runtime == NULL)
99 		return;
100 
101 	if (line6pcm->in.pos_done + frames > runtime->buffer_size) {
102 		/*
103 		   The transferred area goes over buffer boundary,
104 		   copy two separate chunks.
105 		 */
106 		int len;
107 
108 		len = runtime->buffer_size - line6pcm->in.pos_done;
109 
110 		if (len > 0) {
111 			memcpy(runtime->dma_area +
112 			       line6pcm->in.pos_done * bytes_per_frame, fbuf,
113 			       len * bytes_per_frame);
114 			memcpy(runtime->dma_area, fbuf + len * bytes_per_frame,
115 			       (frames - len) * bytes_per_frame);
116 		} else {
117 			/* this is somewhat paranoid */
118 			dev_err(line6pcm->line6->ifcdev,
119 				"driver bug: len = %d\n", len);
120 		}
121 	} else {
122 		/* copy single chunk */
123 		memcpy(runtime->dma_area +
124 		       line6pcm->in.pos_done * bytes_per_frame, fbuf, fsize);
125 	}
126 
127 	line6pcm->in.pos_done += frames;
128 	if (line6pcm->in.pos_done >= runtime->buffer_size)
129 		line6pcm->in.pos_done -= runtime->buffer_size;
130 }
131 
132 void line6_capture_check_period(struct snd_line6_pcm *line6pcm, int length)
133 {
134 	struct snd_pcm_substream *substream =
135 	    get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
136 
137 	line6pcm->in.bytes += length;
138 	if (line6pcm->in.bytes >= line6pcm->in.period) {
139 		line6pcm->in.bytes %= line6pcm->in.period;
140 		spin_unlock(&line6pcm->in.lock);
141 		snd_pcm_period_elapsed(substream);
142 		spin_lock(&line6pcm->in.lock);
143 	}
144 }
145 
146 /*
147  * Callback for completed capture URB.
148  */
149 static void audio_in_callback(struct urb *urb)
150 {
151 	int i, index, length = 0, shutdown = 0;
152 	unsigned long flags;
153 
154 	struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;
155 
156 	line6pcm->in.last_frame = urb->start_frame;
157 
158 	/* find index of URB */
159 	for (index = 0; index < line6pcm->line6->iso_buffers; ++index)
160 		if (urb == line6pcm->in.urbs[index])
161 			break;
162 
163 	spin_lock_irqsave(&line6pcm->in.lock, flags);
164 
165 	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
166 		char *fbuf;
167 		int fsize;
168 		struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];
169 
170 		if (fin->status == -EXDEV) {
171 			shutdown = 1;
172 			break;
173 		}
174 
175 		fbuf = urb->transfer_buffer + fin->offset;
176 		fsize = fin->actual_length;
177 
178 		if (fsize > line6pcm->max_packet_size_in) {
179 			dev_err(line6pcm->line6->ifcdev,
180 				"driver and/or device bug: packet too large (%d > %d)\n",
181 				fsize, line6pcm->max_packet_size_in);
182 		}
183 
184 		length += fsize;
185 
186 		BUILD_BUG_ON_MSG(LINE6_ISO_PACKETS != 1,
187 			"The following code assumes LINE6_ISO_PACKETS == 1");
188 		/* TODO:
189 		 * Also, if iso_buffers != 2, the prev frame is almost random at
190 		 * playback side.
191 		 * This needs to be redesigned. It should be "stable", but we may
192 		 * experience sync problems on such high-speed configs.
193 		 */
194 
195 		line6pcm->prev_fbuf = fbuf;
196 		line6pcm->prev_fsize = fsize /
197 			(line6pcm->properties->bytes_per_channel *
198 			line6pcm->properties->capture_hw.channels_max);
199 
200 		if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
201 		    test_bit(LINE6_STREAM_PCM, &line6pcm->in.running) &&
202 		    fsize > 0)
203 			line6_capture_copy(line6pcm, fbuf, fsize);
204 	}
205 
206 	clear_bit(index, &line6pcm->in.active_urbs);
207 
208 	if (test_and_clear_bit(index, &line6pcm->in.unlink_urbs))
209 		shutdown = 1;
210 
211 	if (!shutdown) {
212 		submit_audio_in_urb(line6pcm);
213 
214 		if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
215 		    test_bit(LINE6_STREAM_PCM, &line6pcm->in.running))
216 			line6_capture_check_period(line6pcm, length);
217 	}
218 
219 	spin_unlock_irqrestore(&line6pcm->in.lock, flags);
220 }
221 
222 /* open capture callback */
223 static int snd_line6_capture_open(struct snd_pcm_substream *substream)
224 {
225 	int err;
226 	struct snd_pcm_runtime *runtime = substream->runtime;
227 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
228 
229 	err = snd_pcm_hw_constraint_ratdens(runtime, 0,
230 					    SNDRV_PCM_HW_PARAM_RATE,
231 					    &line6pcm->properties->rates);
232 	if (err < 0)
233 		return err;
234 
235 	line6_pcm_acquire(line6pcm, LINE6_STREAM_CAPTURE_HELPER, false);
236 
237 	runtime->hw = line6pcm->properties->capture_hw;
238 	return 0;
239 }
240 
241 /* close capture callback */
242 static int snd_line6_capture_close(struct snd_pcm_substream *substream)
243 {
244 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
245 
246 	line6_pcm_release(line6pcm, LINE6_STREAM_CAPTURE_HELPER);
247 	return 0;
248 }
249 
250 /* capture operators */
251 const struct snd_pcm_ops snd_line6_capture_ops = {
252 	.open = snd_line6_capture_open,
253 	.close = snd_line6_capture_close,
254 	.ioctl = snd_pcm_lib_ioctl,
255 	.hw_params = snd_line6_hw_params,
256 	.hw_free = snd_line6_hw_free,
257 	.prepare = snd_line6_prepare,
258 	.trigger = snd_line6_trigger,
259 	.pointer = snd_line6_pointer,
260 };
261 
262 int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
263 {
264 	struct usb_line6 *line6 = line6pcm->line6;
265 	int i;
266 
267 	line6pcm->in.urbs = kcalloc(line6->iso_buffers, sizeof(struct urb *),
268 				    GFP_KERNEL);
269 	if (line6pcm->in.urbs == NULL)
270 		return -ENOMEM;
271 
272 	/* create audio URBs and fill in constant values: */
273 	for (i = 0; i < line6->iso_buffers; ++i) {
274 		struct urb *urb;
275 
276 		/* URB for audio in: */
277 		urb = line6pcm->in.urbs[i] =
278 		    usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
279 
280 		if (urb == NULL)
281 			return -ENOMEM;
282 
283 		urb->dev = line6->usbdev;
284 		urb->pipe =
285 		    usb_rcvisocpipe(line6->usbdev,
286 				    line6->properties->ep_audio_r &
287 				    USB_ENDPOINT_NUMBER_MASK);
288 		urb->transfer_flags = URB_ISO_ASAP;
289 		urb->start_frame = -1;
290 		urb->number_of_packets = LINE6_ISO_PACKETS;
291 		urb->interval = LINE6_ISO_INTERVAL;
292 		urb->error_count = 0;
293 		urb->complete = audio_in_callback;
294 	}
295 
296 	return 0;
297 }
298