summaryrefslogtreecommitdiffstats
path: root/sound/usb/clock.c
blob: 075195e8661a0f538343bc482db9e721b51dda18 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
/*
 *   Clock domain and sample rate management functions
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>
#include <linux/usb/audio-v2.h>

#include <sound/core.h>
#include <sound/info.h>
#include <sound/pcm.h>

#include "usbaudio.h"
#include "card.h"
#include "helper.h"
#include "clock.h"

static struct uac_clock_source_descriptor *
	snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
				  int clock_id)
{
	struct uac_clock_source_descriptor *cs = NULL;

	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
					     ctrl_iface->extralen,
					     cs, UAC2_CLOCK_SOURCE))) {
		if (cs->bClockID == clock_id)
			return cs;
	}

	return NULL;
}

static struct uac_clock_selector_descriptor *
	snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
				    int clock_id)
{
	struct uac_clock_selector_descriptor *cs = NULL;

	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
					     ctrl_iface->extralen,
					     cs, UAC2_CLOCK_SELECTOR))) {
		if (cs->bClockID == clock_id)
			return cs;
	}

	return NULL;
}

static struct uac_clock_multiplier_descriptor *
	snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
				      int clock_id)
{
	struct uac_clock_multiplier_descriptor *cs = NULL;

	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
					     ctrl_iface->extralen,
					     cs, UAC2_CLOCK_MULTIPLIER))) {
		if (cs->bClockID == clock_id)
			return cs;
	}

	return NULL;
}

static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
{
	unsigned char buf;
	int ret;

	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
			      UAC2_CS_CUR,
			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
			      UAC2_CX_CLOCK_SELECTOR << 8,
			      snd_usb_ctrl_intf(chip) | (selector_id << 8),
			      &buf, sizeof(buf), 1000);

	if (ret < 0)
		return ret;

	return buf;
}

static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
{
	int err;
	unsigned char data;
	struct usb_device *dev = chip->dev;
	struct uac_clock_source_descriptor *cs_desc =
		snd_usb_find_clock_source(chip->ctrl_intf, source_id);

	if (!cs_desc)
		return 0;

	/* If a clock source can't tell us whether it's valid, we assume it is */
	if (!uac2_control_is_readable(cs_desc->bmControls, UAC2_CS_CONTROL_CLOCK_VALID))
		return 1;

	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
			      UAC2_CS_CONTROL_CLOCK_VALID << 8,
			      snd_usb_ctrl_intf(chip) | (source_id << 8),
			      &data, sizeof(data), 1000);

	if (err < 0) {
		snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
			   __func__, source_id);
		return 0;
	}

	return !!data;
}

static int __uac_clock_find_source(struct snd_usb_audio *chip,
				   int entity_id, unsigned long *visited)
{
	struct uac_clock_source_descriptor *source;
	struct uac_clock_selector_descriptor *selector;
	struct uac_clock_multiplier_descriptor *multiplier;

	entity_id &= 0xff;

	if (test_and_set_bit(entity_id, visited)) {
		snd_printk(KERN_WARNING
			"%s(): recursive clock topology detected, id %d.\n",
			__func__, entity_id);
		return -EINVAL;
	}

	/* first, see if the ID we're looking for is a clock source already */
	source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
	if (source)
		return source->bClockID;

	selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
	if (selector) {
		int ret;

		/* the entity ID we are looking for is a selector.
		 * find out what it currently selects */
		ret = uac_clock_selector_get_val(chip, selector->bClockID);
		if (ret < 0)
			return ret;

		/* Selector values are one-based */

		if (ret > selector->bNrInPins || ret < 1) {
			printk(KERN_ERR
				"%s(): selector reported illegal value, id %d, ret %d\n",
				__func__, selector->bClockID, ret);

			return -EINVAL;
		}

		return __uac_clock_find_source(chip, selector->baCSourceID[ret-1],
					       visited);
	}

	/* FIXME: multipliers only act as pass-thru element for now */
	multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
	if (multiplier)
		return __uac_clock_find_source(chip, multiplier->bCSourceID,
						visited);

	return -EINVAL;
}

/*
 * For all kinds of sample rate settings and other device queries,
 * the clock source (end-leaf) must be used. However, clock selectors,
 * clock multipliers and sample rate converters may be specified as
 * clock source input to terminal. This functions walks the clock path
 * to its end and tries to find the source.
 *
 * The 'visited' bitfield is used internally to detect recursive loops.
 *
 * Returns the clock source UnitID (>=0) on success, or an error.
 */
int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id)
{
	DECLARE_BITMAP(visited, 256);
	memset(visited, 0, sizeof(visited));
	return __uac_clock_find_source(chip, entity_id, visited);
}

static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
			      struct usb_host_interface *alts,
			      struct audioformat *fmt, int rate)
{
	struct usb_device *dev = chip->dev;
	unsigned int ep;
	unsigned char data[3];
	int err, crate;

	ep = get_endpoint(alts, 0)->bEndpointAddress;

	/* if endpoint doesn't have sampling rate control, bail out */
	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
		return 0;

	data[0] = rate;
	data[1] = rate >> 8;
	data[2] = rate >> 16;
	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
				   data, sizeof(data), 1000)) < 0) {
		snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
			   dev->devnum, iface, fmt->altsetting, rate, ep);
		return err;
	}

	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
				   data, sizeof(data), 1000)) < 0) {
		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
			   dev->devnum, iface, fmt->altsetting, ep);
		return 0; /* some devices don't support reading */
	}

	crate = data[0] | (data[1] << 8) | (data[2] << 16);
	if (crate != rate) {
		snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
		// runtime->rate = crate;
	}

	return 0;
}

static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
			      struct usb_host_interface *alts,
			      struct audioformat *fmt, int rate)
{
	struct usb_device *dev = chip->dev;
	unsigned char data[4];
	int err, crate;
	int clock = snd_usb_clock_find_source(chip, fmt->clock);

	if (clock < 0)
		return clock;

	if (!uac_clock_source_is_valid(chip, clock)) {
		/* TODO: should we try to find valid clock setups by ourself? */
		snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
			   dev->devnum, iface, fmt->altsetting, clock);
		return -ENXIO;
	}

	data[0] = rate;
	data[1] = rate >> 8;
	data[2] = rate >> 16;
	data[3] = rate >> 24;
	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
				   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
				   UAC2_CS_CONTROL_SAM_FREQ << 8,
				   snd_usb_ctrl_intf(chip) | (clock << 8),
				   data, sizeof(data), 1000)) < 0) {
		snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
			   dev->devnum, iface, fmt->altsetting, rate);
		return err;
	}

	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
				   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
				   UAC2_CS_CONTROL_SAM_FREQ << 8,
				   snd_usb_ctrl_intf(chip) | (clock << 8),
				   data, sizeof(data), 1000)) < 0) {
		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
			   dev->devnum, iface, fmt->altsetting);
		return err;
	}

	crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
	if (crate != rate)
		snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);

	return 0;
}

int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
			     struct usb_host_interface *alts,
			     struct audioformat *fmt, int rate)
{
	struct usb_interface_descriptor *altsd = get_iface_desc(alts);

	switch (altsd->bInterfaceProtocol) {
	case UAC_VERSION_1:
	default:
		return set_sample_rate_v1(chip, iface, alts, fmt, rate);

	case UAC_VERSION_2:
		return set_sample_rate_v2(chip, iface, alts, fmt, rate);
	}
}

OpenPOWER on IntegriCloud