capture.c

  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*/
 21static 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*/
 68int 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*/
 84void 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
128void 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 */
145static void audio_in_callback(struct urb *urb)
146{
147	int i, index, length = 0, shutdown = 0;
148	struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;
149
150	line6pcm->in.last_frame = urb->start_frame;
151
152	/* find index of URB */
153	for (index = 0; index < line6pcm->line6->iso_buffers; ++index)
154		if (urb == line6pcm->in.urbs[index])
155			break;
156
157	guard(spinlock_irqsave)(&line6pcm->in.lock);
158
159	for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
160		char *fbuf;
161		int fsize;
162		struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];
163
164		if (fin->status == -EXDEV) {
165			shutdown = 1;
166			break;
167		}
168
169		fbuf = urb->transfer_buffer + fin->offset;
170		fsize = fin->actual_length;
171
172		if (fsize > line6pcm->max_packet_size_in) {
173			dev_err(line6pcm->line6->ifcdev,
174				"driver and/or device bug: packet too large (%d > %d)\n",
175				fsize, line6pcm->max_packet_size_in);
176		}
177
178		length += fsize;
179
180		BUILD_BUG_ON_MSG(LINE6_ISO_PACKETS != 1,
181			"The following code assumes LINE6_ISO_PACKETS == 1");
182		/* TODO:
183		 * Also, if iso_buffers != 2, the prev frame is almost random at
184		 * playback side.
185		 * This needs to be redesigned. It should be "stable", but we may
186		 * experience sync problems on such high-speed configs.
187		 */
188
189		line6pcm->prev_fbuf = fbuf;
190		line6pcm->prev_fsize = fsize /
191			(line6pcm->properties->bytes_per_channel *
192			line6pcm->properties->capture_hw.channels_max);
193
194		if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
195		    test_bit(LINE6_STREAM_PCM, &line6pcm->in.running) &&
196		    fsize > 0)
197			line6_capture_copy(line6pcm, fbuf, fsize);
198	}
199
200	clear_bit(index, &line6pcm->in.active_urbs);
201
202	if (test_and_clear_bit(index, &line6pcm->in.unlink_urbs))
203		shutdown = 1;
204
205	if (!shutdown) {
206		submit_audio_in_urb(line6pcm);
207
208		if (!test_bit(LINE6_STREAM_IMPULSE, &line6pcm->in.running) &&
209		    test_bit(LINE6_STREAM_PCM, &line6pcm->in.running))
210			line6_capture_check_period(line6pcm, length);
211	}
212}
213
214/* open capture callback */
215static int snd_line6_capture_open(struct snd_pcm_substream *substream)
216{
217	int err;
218	struct snd_pcm_runtime *runtime = substream->runtime;
219	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
220
221	err = snd_pcm_hw_constraint_ratdens(runtime, 0,
222					    SNDRV_PCM_HW_PARAM_RATE,
223					    &line6pcm->properties->rates);
224	if (err < 0)
225		return err;
226
227	line6_pcm_acquire(line6pcm, LINE6_STREAM_CAPTURE_HELPER, false);
228
229	runtime->hw = line6pcm->properties->capture_hw;
230	return 0;
231}
232
233/* close capture callback */
234static int snd_line6_capture_close(struct snd_pcm_substream *substream)
235{
236	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
237
238	line6_pcm_release(line6pcm, LINE6_STREAM_CAPTURE_HELPER);
239	return 0;
240}
241
242/* capture operators */
243const struct snd_pcm_ops snd_line6_capture_ops = {
244	.open = snd_line6_capture_open,
245	.close = snd_line6_capture_close,
246	.hw_params = snd_line6_hw_params,
247	.hw_free = snd_line6_hw_free,
248	.prepare = snd_line6_prepare,
249	.trigger = snd_line6_trigger,
250	.pointer = snd_line6_pointer,
251};
252
253int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
254{
255	struct usb_line6 *line6 = line6pcm->line6;
256	int i;
257
258	line6pcm->in.urbs = kcalloc(line6->iso_buffers, sizeof(struct urb *),
259				    GFP_KERNEL);
260	if (line6pcm->in.urbs == NULL)
261		return -ENOMEM;
262
263	/* create audio URBs and fill in constant values: */
264	for (i = 0; i < line6->iso_buffers; ++i) {
265		struct urb *urb;
266
267		/* URB for audio in: */
268		urb = line6pcm->in.urbs[i] =
269		    usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);
270
271		if (urb == NULL)
272			return -ENOMEM;
273
274		urb->dev = line6->usbdev;
275		urb->pipe =
276		    usb_rcvisocpipe(line6->usbdev,
277				    line6->properties->ep_audio_r &
278				    USB_ENDPOINT_NUMBER_MASK);
279		urb->transfer_flags = URB_ISO_ASAP;
280		urb->start_frame = -1;
281		urb->number_of_packets = LINE6_ISO_PACKETS;
282		urb->interval = LINE6_ISO_INTERVAL;
283		urb->error_count = 0;
284		urb->complete = audio_in_callback;
285		if (usb_urb_ep_type_check(urb))
286			return -EINVAL;
287	}
288
289	return 0;
290}