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*/
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	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 */
219static 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 */
238static 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 */
247const 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
257int 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