xref: /openbmc/linux/sound/usb/line6/playback.c (revision a06c488d)
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 #include "playback.h"
21 
22 /*
23 	Software stereo volume control.
24 */
25 static void change_volume(struct urb *urb_out, int volume[],
26 			  int bytes_per_frame)
27 {
28 	int chn = 0;
29 
30 	if (volume[0] == 256 && volume[1] == 256)
31 		return;		/* maximum volume - no change */
32 
33 	if (bytes_per_frame == 4) {
34 		__le16 *p, *buf_end;
35 
36 		p = (__le16 *)urb_out->transfer_buffer;
37 		buf_end = p + urb_out->transfer_buffer_length / sizeof(*p);
38 
39 		for (; p < buf_end; ++p) {
40 			short pv = le16_to_cpu(*p);
41 			int val = (pv * volume[chn & 1]) >> 8;
42 			pv = clamp(val, -0x8000, 0x7fff);
43 			*p = cpu_to_le16(pv);
44 			++chn;
45 		}
46 	} else if (bytes_per_frame == 6) {
47 		unsigned char *p, *buf_end;
48 
49 		p = (unsigned char *)urb_out->transfer_buffer;
50 		buf_end = p + urb_out->transfer_buffer_length;
51 
52 		for (; p < buf_end; p += 3) {
53 			int val;
54 
55 			val = p[0] + (p[1] << 8) + ((signed char)p[2] << 16);
56 			val = (val * volume[chn & 1]) >> 8;
57 			val = clamp(val, -0x800000, 0x7fffff);
58 			p[0] = val;
59 			p[1] = val >> 8;
60 			p[2] = val >> 16;
61 			++chn;
62 		}
63 	}
64 }
65 
66 /*
67 	Create signal for impulse response test.
68 */
69 static void create_impulse_test_signal(struct snd_line6_pcm *line6pcm,
70 				       struct urb *urb_out, int bytes_per_frame)
71 {
72 	int frames = urb_out->transfer_buffer_length / bytes_per_frame;
73 
74 	if (bytes_per_frame == 4) {
75 		int i;
76 		short *pi = (short *)line6pcm->prev_fbuf;
77 		short *po = (short *)urb_out->transfer_buffer;
78 
79 		for (i = 0; i < frames; ++i) {
80 			po[0] = pi[0];
81 			po[1] = 0;
82 			pi += 2;
83 			po += 2;
84 		}
85 	} else if (bytes_per_frame == 6) {
86 		int i, j;
87 		unsigned char *pi = line6pcm->prev_fbuf;
88 		unsigned char *po = urb_out->transfer_buffer;
89 
90 		for (i = 0; i < frames; ++i) {
91 			for (j = 0; j < bytes_per_frame / 2; ++j)
92 				po[j] = pi[j];
93 
94 			for (; j < bytes_per_frame; ++j)
95 				po[j] = 0;
96 
97 			pi += bytes_per_frame;
98 			po += bytes_per_frame;
99 		}
100 	}
101 	if (--line6pcm->impulse_count <= 0) {
102 		((unsigned char *)(urb_out->transfer_buffer))[bytes_per_frame -
103 							      1] =
104 		    line6pcm->impulse_volume;
105 		line6pcm->impulse_count = line6pcm->impulse_period;
106 	}
107 }
108 
109 /*
110 	Add signal to buffer for software monitoring.
111 */
112 static void add_monitor_signal(struct urb *urb_out, unsigned char *signal,
113 			       int volume, int bytes_per_frame)
114 {
115 	if (volume == 0)
116 		return;		/* zero volume - no change */
117 
118 	if (bytes_per_frame == 4) {
119 		__le16 *pi, *po, *buf_end;
120 
121 		pi = (__le16 *)signal;
122 		po = (__le16 *)urb_out->transfer_buffer;
123 		buf_end = po + urb_out->transfer_buffer_length / sizeof(*po);
124 
125 		for (; po < buf_end; ++pi, ++po) {
126 			short pov = le16_to_cpu(*po);
127 			short piv = le16_to_cpu(*pi);
128 			int val = pov + ((piv * volume) >> 8);
129 			pov = clamp(val, -0x8000, 0x7fff);
130 			*po = cpu_to_le16(pov);
131 		}
132 	}
133 
134 	/*
135 	   We don't need to handle devices with 6 bytes per frame here
136 	   since they all support hardware monitoring.
137 	 */
138 }
139 
140 /*
141 	Find a free URB, prepare audio data, and submit URB.
142 	must be called in line6pcm->out.lock context
143 */
144 static int submit_audio_out_urb(struct snd_line6_pcm *line6pcm)
145 {
146 	int index;
147 	int i, urb_size, urb_frames;
148 	int ret;
149 	const int bytes_per_frame = line6pcm->properties->bytes_per_frame;
150 	const int frame_increment =
151 		line6pcm->properties->rates.rats[0].num_min;
152 	const int frame_factor =
153 		line6pcm->properties->rates.rats[0].den *
154 		(USB_INTERVALS_PER_SECOND / LINE6_ISO_INTERVAL);
155 	struct urb *urb_out;
156 
157 	index =
158 	    find_first_zero_bit(&line6pcm->out.active_urbs, LINE6_ISO_BUFFERS);
159 
160 	if (index < 0 || index >= LINE6_ISO_BUFFERS) {
161 		dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
162 		return -EINVAL;
163 	}
164 
165 	urb_out = line6pcm->out.urbs[index];
166 	urb_size = 0;
167 
168 	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
169 		/* compute frame size for given sampling rate */
170 		int fsize = 0;
171 		struct usb_iso_packet_descriptor *fout =
172 		    &urb_out->iso_frame_desc[i];
173 
174 		fsize = line6pcm->prev_fsize;
175 		if (fsize == 0) {
176 			int n;
177 
178 			line6pcm->out.count += frame_increment;
179 			n = line6pcm->out.count / frame_factor;
180 			line6pcm->out.count -= n * frame_factor;
181 			fsize = n * bytes_per_frame;
182 		}
183 
184 		fout->offset = urb_size;
185 		fout->length = fsize;
186 		urb_size += fsize;
187 	}
188 
189 	if (urb_size == 0) {
190 		/* can't determine URB size */
191 		dev_err(line6pcm->line6->ifcdev, "driver bug: urb_size = 0\n");
192 		return -EINVAL;
193 	}
194 
195 	urb_frames = urb_size / bytes_per_frame;
196 	urb_out->transfer_buffer =
197 	    line6pcm->out.buffer +
198 	    index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;
199 	urb_out->transfer_buffer_length = urb_size;
200 	urb_out->context = line6pcm;
201 
202 	if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running) &&
203 	    !test_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags)) {
204 		struct snd_pcm_runtime *runtime =
205 		    get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK)->runtime;
206 
207 		if (line6pcm->out.pos + urb_frames > runtime->buffer_size) {
208 			/*
209 			   The transferred area goes over buffer boundary,
210 			   copy the data to the temp buffer.
211 			 */
212 			int len;
213 
214 			len = runtime->buffer_size - line6pcm->out.pos;
215 
216 			if (len > 0) {
217 				memcpy(urb_out->transfer_buffer,
218 				       runtime->dma_area +
219 				       line6pcm->out.pos * bytes_per_frame,
220 				       len * bytes_per_frame);
221 				memcpy(urb_out->transfer_buffer +
222 				       len * bytes_per_frame, runtime->dma_area,
223 				       (urb_frames - len) * bytes_per_frame);
224 			} else
225 				dev_err(line6pcm->line6->ifcdev, "driver bug: len = %d\n",
226 					len);
227 		} else {
228 			memcpy(urb_out->transfer_buffer,
229 			       runtime->dma_area +
230 			       line6pcm->out.pos * bytes_per_frame,
231 			       urb_out->transfer_buffer_length);
232 		}
233 
234 		line6pcm->out.pos += urb_frames;
235 		if (line6pcm->out.pos >= runtime->buffer_size)
236 			line6pcm->out.pos -= runtime->buffer_size;
237 
238 		change_volume(urb_out, line6pcm->volume_playback,
239 			      bytes_per_frame);
240 	} else {
241 		memset(urb_out->transfer_buffer, 0,
242 		       urb_out->transfer_buffer_length);
243 	}
244 
245 	spin_lock_nested(&line6pcm->in.lock, SINGLE_DEPTH_NESTING);
246 	if (line6pcm->prev_fbuf) {
247 		if (test_bit(LINE6_STREAM_IMPULSE, &line6pcm->out.running)) {
248 			create_impulse_test_signal(line6pcm, urb_out,
249 						   bytes_per_frame);
250 			if (test_bit(LINE6_STREAM_PCM, &line6pcm->in.running)) {
251 				line6_capture_copy(line6pcm,
252 						   urb_out->transfer_buffer,
253 						   urb_out->
254 						   transfer_buffer_length);
255 				line6_capture_check_period(line6pcm,
256 					urb_out->transfer_buffer_length);
257 			}
258 		} else {
259 			if (!(line6pcm->line6->properties->capabilities & LINE6_CAP_HWMON)
260 			    && line6pcm->out.running && line6pcm->in.running)
261 				add_monitor_signal(urb_out, line6pcm->prev_fbuf,
262 						   line6pcm->volume_monitor,
263 						   bytes_per_frame);
264 		}
265 		line6pcm->prev_fbuf = NULL;
266 		line6pcm->prev_fsize = 0;
267 	}
268 	spin_unlock(&line6pcm->in.lock);
269 
270 	ret = usb_submit_urb(urb_out, GFP_ATOMIC);
271 
272 	if (ret == 0)
273 		set_bit(index, &line6pcm->out.active_urbs);
274 	else
275 		dev_err(line6pcm->line6->ifcdev,
276 			"URB out #%d submission failed (%d)\n", index, ret);
277 
278 	return 0;
279 }
280 
281 /*
282 	Submit all currently available playback URBs.
283 	must be called in line6pcm->out.lock context
284  */
285 int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm)
286 {
287 	int ret = 0, i;
288 
289 	for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
290 		ret = submit_audio_out_urb(line6pcm);
291 		if (ret < 0)
292 			break;
293 	}
294 
295 	return ret;
296 }
297 
298 /*
299 	Callback for completed playback URB.
300 */
301 static void audio_out_callback(struct urb *urb)
302 {
303 	int i, index, length = 0, shutdown = 0;
304 	unsigned long flags;
305 	struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;
306 	struct snd_pcm_substream *substream =
307 	    get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK);
308 
309 #if USE_CLEAR_BUFFER_WORKAROUND
310 	memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
311 #endif
312 
313 	line6pcm->out.last_frame = urb->start_frame;
314 
315 	/* find index of URB */
316 	for (index = 0; index < LINE6_ISO_BUFFERS; index++)
317 		if (urb == line6pcm->out.urbs[index])
318 			break;
319 
320 	if (index >= LINE6_ISO_BUFFERS)
321 		return;		/* URB has been unlinked asynchronously */
322 
323 	for (i = 0; i < LINE6_ISO_PACKETS; i++)
324 		length += urb->iso_frame_desc[i].length;
325 
326 	spin_lock_irqsave(&line6pcm->out.lock, flags);
327 
328 	if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running)) {
329 		struct snd_pcm_runtime *runtime = substream->runtime;
330 
331 		line6pcm->out.pos_done +=
332 		    length / line6pcm->properties->bytes_per_frame;
333 
334 		if (line6pcm->out.pos_done >= runtime->buffer_size)
335 			line6pcm->out.pos_done -= runtime->buffer_size;
336 	}
337 
338 	clear_bit(index, &line6pcm->out.active_urbs);
339 
340 	for (i = 0; i < LINE6_ISO_PACKETS; i++)
341 		if (urb->iso_frame_desc[i].status == -EXDEV) {
342 			shutdown = 1;
343 			break;
344 		}
345 
346 	if (test_and_clear_bit(index, &line6pcm->out.unlink_urbs))
347 		shutdown = 1;
348 
349 	if (!shutdown) {
350 		submit_audio_out_urb(line6pcm);
351 
352 		if (test_bit(LINE6_STREAM_PCM, &line6pcm->out.running)) {
353 			line6pcm->out.bytes += length;
354 			if (line6pcm->out.bytes >= line6pcm->out.period) {
355 				line6pcm->out.bytes %= line6pcm->out.period;
356 				spin_unlock(&line6pcm->out.lock);
357 				snd_pcm_period_elapsed(substream);
358 				spin_lock(&line6pcm->out.lock);
359 			}
360 		}
361 	}
362 	spin_unlock_irqrestore(&line6pcm->out.lock, flags);
363 }
364 
365 /* open playback callback */
366 static int snd_line6_playback_open(struct snd_pcm_substream *substream)
367 {
368 	int err;
369 	struct snd_pcm_runtime *runtime = substream->runtime;
370 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
371 
372 	err = snd_pcm_hw_constraint_ratdens(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
373 					    &line6pcm->properties->rates);
374 	if (err < 0)
375 		return err;
376 
377 	runtime->hw = line6pcm->properties->playback_hw;
378 	return 0;
379 }
380 
381 /* close playback callback */
382 static int snd_line6_playback_close(struct snd_pcm_substream *substream)
383 {
384 	return 0;
385 }
386 
387 /* playback operators */
388 struct snd_pcm_ops snd_line6_playback_ops = {
389 	.open = snd_line6_playback_open,
390 	.close = snd_line6_playback_close,
391 	.ioctl = snd_pcm_lib_ioctl,
392 	.hw_params = snd_line6_hw_params,
393 	.hw_free = snd_line6_hw_free,
394 	.prepare = snd_line6_prepare,
395 	.trigger = snd_line6_trigger,
396 	.pointer = snd_line6_pointer,
397 };
398 
399 int line6_create_audio_out_urbs(struct snd_line6_pcm *line6pcm)
400 {
401 	struct usb_line6 *line6 = line6pcm->line6;
402 	int i;
403 
404 	/* create audio URBs and fill in constant values: */
405 	for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
406 		struct urb *urb;
407 
408 		/* URB for audio out: */
409 		urb = line6pcm->out.urbs[i] =
410 		    usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
411 
412 		if (urb == NULL)
413 			return -ENOMEM;
414 
415 		urb->dev = line6->usbdev;
416 		urb->pipe =
417 		    usb_sndisocpipe(line6->usbdev,
418 				    line6->properties->ep_audio_w &
419 				    USB_ENDPOINT_NUMBER_MASK);
420 		urb->transfer_flags = URB_ISO_ASAP;
421 		urb->start_frame = -1;
422 		urb->number_of_packets = LINE6_ISO_PACKETS;
423 		urb->interval = LINE6_ISO_INTERVAL;
424 		urb->error_count = 0;
425 		urb->complete = audio_out_callback;
426 	}
427 
428 	return 0;
429 }
430