xref: /openbmc/linux/sound/usb/line6/capture.c (revision e15a5365)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Line 6 Linux USB driver
4  *
5  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.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 */
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 */
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 */
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 
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  */
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 */
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 */
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 
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