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*/
25static 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*/
72int 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*/
88void 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
130void 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 */
147static 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 */
211static 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 */
228static int snd_line6_capture_close(struct snd_pcm_substream *substream)
229{
230	return 0;
231}
232
233/* capture operators */
234struct 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
245int 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