xref: /linux/sound/usb/line6/capture.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 =
33 	    find_first_zero_bit(&line6pcm->in.active_urbs, LINE6_ISO_BUFFERS);
34 
35 	if (index < 0 || index >= 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;
48 		urb_size += line6pcm->max_packet_size;
49 	}
50 
51 	urb_in->transfer_buffer =
52 	    line6pcm->in.buffer +
53 	    index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;
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 < 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 = line6pcm->properties->bytes_per_frame;
94 	int frames = fsize / bytes_per_frame;
95 
96 	if (runtime == NULL)
97 		return;
98 
99 	if (line6pcm->in.pos_done + frames > runtime->buffer_size) {
100 		/*
101 		   The transferred area goes over buffer boundary,
102 		   copy two separate chunks.
103 		 */
104 		int len;
105 
106 		len = runtime->buffer_size - line6pcm->in.pos_done;
107 
108 		if (len > 0) {
109 			memcpy(runtime->dma_area +
110 			       line6pcm->in.pos_done * bytes_per_frame, fbuf,
111 			       len * bytes_per_frame);
112 			memcpy(runtime->dma_area, fbuf + len * bytes_per_frame,
113 			       (frames - len) * bytes_per_frame);
114 		} else {
115 			/* this is somewhat paranoid */
116 			dev_err(line6pcm->line6->ifcdev,
117 				"driver bug: len = %d\n", len);
118 		}
119 	} else {
120 		/* copy single chunk */
121 		memcpy(runtime->dma_area +
122 		       line6pcm->in.pos_done * bytes_per_frame, fbuf, fsize);
123 	}
124 
125 	line6pcm->in.pos_done += frames;
126 	if (line6pcm->in.pos_done >= runtime->buffer_size)
127 		line6pcm->in.pos_done -= runtime->buffer_size;
128 }
129 
130 void line6_capture_check_period(struct snd_line6_pcm *line6pcm, int length)
131 {
132 	struct snd_pcm_substream *substream =
133 	    get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
134 
135 	line6pcm->in.bytes += length;
136 	if (line6pcm->in.bytes >= line6pcm->in.period) {
137 		line6pcm->in.bytes %= line6pcm->in.period;
138 		spin_unlock(&line6pcm->in.lock);
139 		snd_pcm_period_elapsed(substream);
140 		spin_lock(&line6pcm->in.lock);
141 	}
142 }
143 
144 /*
145  * Callback for completed capture URB.
146  */
147 static void audio_in_callback(struct urb *urb)
148 {
149 	int i, index, length = 0, shutdown = 0;
150 	unsigned long flags;
151 
152 	struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;
153 
154 	line6pcm->in.last_frame = urb->start_frame;
155 
156 	/* find index of URB */
157 	for (index = 0; index < LINE6_ISO_BUFFERS; ++index)
158 		if (urb == line6pcm->in.urbs[index])
159 			break;
160 
161 	spin_lock_irqsave(&line6pcm->in.lock, flags);
162 
163 	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
164 		char *fbuf;
165 		int fsize;
166 		struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];
167 
168 		if (fin->status == -EXDEV) {
169 			shutdown = 1;
170 			break;
171 		}
172 
173 		fbuf = urb->transfer_buffer + fin->offset;
174 		fsize = fin->actual_length;
175 
176 		if (fsize > line6pcm->max_packet_size) {
177 			dev_err(line6pcm->line6->ifcdev,
178 				"driver and/or device bug: packet too large (%d > %d)\n",
179 				fsize, line6pcm->max_packet_size);
180 		}
181 
182 		length += fsize;
183 
184 		/* the following assumes LINE6_ISO_PACKETS == 1: */
185 		line6pcm->prev_fbuf = fbuf;
186 		line6pcm->prev_fsize = fsize;
187 
188 		if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
189 		    test_bit(LINE6_STREAM_PCM, &line6pcm->in.running) &&
190 		    fsize > 0)
191 			line6_capture_copy(line6pcm, fbuf, fsize);
192 	}
193 
194 	clear_bit(index, &line6pcm->in.active_urbs);
195 
196 	if (test_and_clear_bit(index, &line6pcm->in.unlink_urbs))
197 		shutdown = 1;
198 
199 	if (!shutdown) {
200 		submit_audio_in_urb(line6pcm);
201 
202 		if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
203 		    test_bit(LINE6_STREAM_PCM, &line6pcm->in.running))
204 			line6_capture_check_period(line6pcm, length);
205 	}
206 
207 	spin_unlock_irqrestore(&line6pcm->in.lock, flags);
208 }
209 
210 /* open capture callback */
211 static int snd_line6_capture_open(struct snd_pcm_substream *substream)
212 {
213 	int err;
214 	struct snd_pcm_runtime *runtime = substream->runtime;
215 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
216 
217 	err = snd_pcm_hw_constraint_ratdens(runtime, 0,
218 					    SNDRV_PCM_HW_PARAM_RATE,
219 					    &line6pcm->properties->rates);
220 	if (err < 0)
221 		return err;
222 
223 	runtime->hw = line6pcm->properties->capture_hw;
224 	return 0;
225 }
226 
227 /* close capture callback */
228 static int snd_line6_capture_close(struct snd_pcm_substream *substream)
229 {
230 	return 0;
231 }
232 
233 /* capture operators */
234 struct snd_pcm_ops snd_line6_capture_ops = {
235 	.open = snd_line6_capture_open,
236 	.close = snd_line6_capture_close,
237 	.ioctl = snd_pcm_lib_ioctl,
238 	.hw_params = snd_line6_hw_params,
239 	.hw_free = snd_line6_hw_free,
240 	.prepare = snd_line6_prepare,
241 	.trigger = snd_line6_trigger,
242 	.pointer = snd_line6_pointer,
243 };
244 
245 int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
246 {
247 	struct usb_line6 *line6 = line6pcm->line6;
248 	int i;
249 
250 	/* create audio URBs and fill in constant values: */
251 	for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
252 		struct urb *urb;
253 
254 		/* URB for audio in: */
255 		urb = line6pcm->in.urbs[i] =
256 		    usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
257 
258 		if (urb == NULL)
259 			return -ENOMEM;
260 
261 		urb->dev = line6->usbdev;
262 		urb->pipe =
263 		    usb_rcvisocpipe(line6->usbdev,
264 				    line6->properties->ep_audio_r &
265 				    USB_ENDPOINT_NUMBER_MASK);
266 		urb->transfer_flags = URB_ISO_ASAP;
267 		urb->start_frame = -1;
268 		urb->number_of_packets = LINE6_ISO_PACKETS;
269 		urb->interval = LINE6_ISO_INTERVAL;
270 		urb->error_count = 0;
271 		urb->complete = audio_in_callback;
272 	}
273 
274 	return 0;
275 }
276