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1/*
2 * Clock domain and sample rate management functions
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 */
19
20#include <linux/bitops.h>
21#include <linux/init.h>
22#include <linux/string.h>
23#include <linux/usb.h>
24#include <linux/usb/audio.h>
25#include <linux/usb/audio-v2.h>
26
27#include <sound/core.h>
28#include <sound/info.h>
29#include <sound/pcm.h>
30
31#include "usbaudio.h"
32#include "card.h"
33#include "helper.h"
34#include "clock.h"
35
36static struct uac_clock_source_descriptor *
37 snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
38 int clock_id)
39{
40 struct uac_clock_source_descriptor *cs = NULL;
41
42 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
43 ctrl_iface->extralen,
44 cs, UAC2_CLOCK_SOURCE))) {
45 if (cs->bClockID == clock_id)
46 return cs;
47 }
48
49 return NULL;
50}
51
52static struct uac_clock_selector_descriptor *
53 snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
54 int clock_id)
55{
56 struct uac_clock_selector_descriptor *cs = NULL;
57
58 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
59 ctrl_iface->extralen,
60 cs, UAC2_CLOCK_SELECTOR))) {
61 if (cs->bClockID == clock_id)
62 return cs;
63 }
64
65 return NULL;
66}
67
68static struct uac_clock_multiplier_descriptor *
69 snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
70 int clock_id)
71{
72 struct uac_clock_multiplier_descriptor *cs = NULL;
73
74 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
75 ctrl_iface->extralen,
76 cs, UAC2_CLOCK_MULTIPLIER))) {
77 if (cs->bClockID == clock_id)
78 return cs;
79 }
80
81 return NULL;
82}
83
84static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
85{
86 unsigned char buf;
87 int ret;
88
89 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
90 UAC2_CS_CUR,
91 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
92 UAC2_CX_CLOCK_SELECTOR << 8,
93 snd_usb_ctrl_intf(chip) | (selector_id << 8),
94 &buf, sizeof(buf), 1000);
95
96 if (ret < 0)
97 return ret;
98
99 return buf;
100}
101
102static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
103{
104 int err;
105 unsigned char data;
106 struct usb_device *dev = chip->dev;
107 struct uac_clock_source_descriptor *cs_desc =
108 snd_usb_find_clock_source(chip->ctrl_intf, source_id);
109
110 if (!cs_desc)
111 return 0;
112
113 /* If a clock source can't tell us whether it's valid, we assume it is */
114 if (!uac2_control_is_readable(cs_desc->bmControls, UAC2_CS_CONTROL_CLOCK_VALID))
115 return 1;
116
117 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
118 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
119 UAC2_CS_CONTROL_CLOCK_VALID << 8,
120 snd_usb_ctrl_intf(chip) | (source_id << 8),
121 &data, sizeof(data), 1000);
122
123 if (err < 0) {
124 snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
125 __func__, source_id);
126 return 0;
127 }
128
129 return !!data;
130}
131
132static int __uac_clock_find_source(struct snd_usb_audio *chip,
133 int entity_id, unsigned long *visited)
134{
135 struct uac_clock_source_descriptor *source;
136 struct uac_clock_selector_descriptor *selector;
137 struct uac_clock_multiplier_descriptor *multiplier;
138
139 entity_id &= 0xff;
140
141 if (test_and_set_bit(entity_id, visited)) {
142 snd_printk(KERN_WARNING
143 "%s(): recursive clock topology detected, id %d.\n",
144 __func__, entity_id);
145 return -EINVAL;
146 }
147
148 /* first, see if the ID we're looking for is a clock source already */
149 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
150 if (source)
151 return source->bClockID;
152
153 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
154 if (selector) {
155 int ret;
156
157 /* the entity ID we are looking for is a selector.
158 * find out what it currently selects */
159 ret = uac_clock_selector_get_val(chip, selector->bClockID);
160 if (ret < 0)
161 return ret;
162
163 /* Selector values are one-based */
164
165 if (ret > selector->bNrInPins || ret < 1) {
166 printk(KERN_ERR
167 "%s(): selector reported illegal value, id %d, ret %d\n",
168 __func__, selector->bClockID, ret);
169
170 return -EINVAL;
171 }
172
173 return __uac_clock_find_source(chip, selector->baCSourceID[ret-1],
174 visited);
175 }
176
177 /* FIXME: multipliers only act as pass-thru element for now */
178 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
179 if (multiplier)
180 return __uac_clock_find_source(chip, multiplier->bCSourceID,
181 visited);
182
183 return -EINVAL;
184}
185
186/*
187 * For all kinds of sample rate settings and other device queries,
188 * the clock source (end-leaf) must be used. However, clock selectors,
189 * clock multipliers and sample rate converters may be specified as
190 * clock source input to terminal. This functions walks the clock path
191 * to its end and tries to find the source.
192 *
193 * The 'visited' bitfield is used internally to detect recursive loops.
194 *
195 * Returns the clock source UnitID (>=0) on success, or an error.
196 */
197int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id)
198{
199 DECLARE_BITMAP(visited, 256);
200 memset(visited, 0, sizeof(visited));
201 return __uac_clock_find_source(chip, entity_id, visited);
202}
203
204static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
205 struct usb_host_interface *alts,
206 struct audioformat *fmt, int rate)
207{
208 struct usb_device *dev = chip->dev;
209 unsigned int ep;
210 unsigned char data[3];
211 int err, crate;
212
213 ep = get_endpoint(alts, 0)->bEndpointAddress;
214
215 /* if endpoint doesn't have sampling rate control, bail out */
216 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
217 return 0;
218
219 data[0] = rate;
220 data[1] = rate >> 8;
221 data[2] = rate >> 16;
222 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
223 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
224 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
225 data, sizeof(data), 1000)) < 0) {
226 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
227 dev->devnum, iface, fmt->altsetting, rate, ep);
228 return err;
229 }
230
231 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
232 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
233 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
234 data, sizeof(data), 1000)) < 0) {
235 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
236 dev->devnum, iface, fmt->altsetting, ep);
237 return 0; /* some devices don't support reading */
238 }
239
240 crate = data[0] | (data[1] << 8) | (data[2] << 16);
241 if (crate != rate) {
242 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
243 // runtime->rate = crate;
244 }
245
246 return 0;
247}
248
249static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
250 struct usb_host_interface *alts,
251 struct audioformat *fmt, int rate)
252{
253 struct usb_device *dev = chip->dev;
254 unsigned char data[4];
255 int err, crate;
256 int clock = snd_usb_clock_find_source(chip, fmt->clock);
257
258 if (clock < 0)
259 return clock;
260
261 if (!uac_clock_source_is_valid(chip, clock)) {
262 /* TODO: should we try to find valid clock setups by ourself? */
263 snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
264 dev->devnum, iface, fmt->altsetting, clock);
265 return -ENXIO;
266 }
267
268 data[0] = rate;
269 data[1] = rate >> 8;
270 data[2] = rate >> 16;
271 data[3] = rate >> 24;
272 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
273 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
274 UAC2_CS_CONTROL_SAM_FREQ << 8,
275 snd_usb_ctrl_intf(chip) | (clock << 8),
276 data, sizeof(data), 1000)) < 0) {
277 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
278 dev->devnum, iface, fmt->altsetting, rate);
279 return err;
280 }
281
282 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
283 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
284 UAC2_CS_CONTROL_SAM_FREQ << 8,
285 snd_usb_ctrl_intf(chip) | (clock << 8),
286 data, sizeof(data), 1000)) < 0) {
287 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
288 dev->devnum, iface, fmt->altsetting);
289 return err;
290 }
291
292 crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
293 if (crate != rate)
294 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
295
296 return 0;
297}
298
299int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
300 struct usb_host_interface *alts,
301 struct audioformat *fmt, int rate)
302{
303 struct usb_interface_descriptor *altsd = get_iface_desc(alts);
304
305 switch (altsd->bInterfaceProtocol) {
306 case UAC_VERSION_1:
307 default:
308 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
309
310 case UAC_VERSION_2:
311 return set_sample_rate_v2(chip, iface, alts, fmt, rate);
312 }
313}
314
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Clock domain and sample rate management functions
4 */
5
6#include <linux/bitops.h>
7#include <linux/init.h>
8#include <linux/string.h>
9#include <linux/usb.h>
10#include <linux/usb/audio.h>
11#include <linux/usb/audio-v2.h>
12#include <linux/usb/audio-v3.h>
13
14#include <sound/core.h>
15#include <sound/info.h>
16#include <sound/pcm.h>
17
18#include "usbaudio.h"
19#include "card.h"
20#include "helper.h"
21#include "clock.h"
22#include "quirks.h"
23
24static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
25 bool (*validator)(void *, int), u8 type)
26{
27 void *cs = NULL;
28
29 while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
30 cs, type))) {
31 if (validator(cs, id))
32 return cs;
33 }
34
35 return NULL;
36}
37
38static bool validate_clock_source_v2(void *p, int id)
39{
40 struct uac_clock_source_descriptor *cs = p;
41 return cs->bClockID == id;
42}
43
44static bool validate_clock_source_v3(void *p, int id)
45{
46 struct uac3_clock_source_descriptor *cs = p;
47 return cs->bClockID == id;
48}
49
50static bool validate_clock_selector_v2(void *p, int id)
51{
52 struct uac_clock_selector_descriptor *cs = p;
53 return cs->bClockID == id;
54}
55
56static bool validate_clock_selector_v3(void *p, int id)
57{
58 struct uac3_clock_selector_descriptor *cs = p;
59 return cs->bClockID == id;
60}
61
62static bool validate_clock_multiplier_v2(void *p, int id)
63{
64 struct uac_clock_multiplier_descriptor *cs = p;
65 return cs->bClockID == id;
66}
67
68static bool validate_clock_multiplier_v3(void *p, int id)
69{
70 struct uac3_clock_multiplier_descriptor *cs = p;
71 return cs->bClockID == id;
72}
73
74#define DEFINE_FIND_HELPER(name, obj, validator, type) \
75static obj *name(struct usb_host_interface *iface, int id) \
76{ \
77 return find_uac_clock_desc(iface, id, validator, type); \
78}
79
80DEFINE_FIND_HELPER(snd_usb_find_clock_source,
81 struct uac_clock_source_descriptor,
82 validate_clock_source_v2, UAC2_CLOCK_SOURCE);
83DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
84 struct uac3_clock_source_descriptor,
85 validate_clock_source_v3, UAC3_CLOCK_SOURCE);
86
87DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
88 struct uac_clock_selector_descriptor,
89 validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
90DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
91 struct uac3_clock_selector_descriptor,
92 validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
93
94DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
95 struct uac_clock_multiplier_descriptor,
96 validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
97DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
98 struct uac3_clock_multiplier_descriptor,
99 validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
100
101static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
102{
103 unsigned char buf;
104 int ret;
105
106 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
107 UAC2_CS_CUR,
108 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
109 UAC2_CX_CLOCK_SELECTOR << 8,
110 snd_usb_ctrl_intf(chip) | (selector_id << 8),
111 &buf, sizeof(buf));
112
113 if (ret < 0)
114 return ret;
115
116 return buf;
117}
118
119static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
120 unsigned char pin)
121{
122 int ret;
123
124 ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
125 UAC2_CS_CUR,
126 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
127 UAC2_CX_CLOCK_SELECTOR << 8,
128 snd_usb_ctrl_intf(chip) | (selector_id << 8),
129 &pin, sizeof(pin));
130 if (ret < 0)
131 return ret;
132
133 if (ret != sizeof(pin)) {
134 usb_audio_err(chip,
135 "setting selector (id %d) unexpected length %d\n",
136 selector_id, ret);
137 return -EINVAL;
138 }
139
140 ret = uac_clock_selector_get_val(chip, selector_id);
141 if (ret < 0)
142 return ret;
143
144 if (ret != pin) {
145 usb_audio_err(chip,
146 "setting selector (id %d) to %x failed (current: %d)\n",
147 selector_id, pin, ret);
148 return -EINVAL;
149 }
150
151 return ret;
152}
153
154static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
155 int protocol,
156 int source_id)
157{
158 int err;
159 unsigned char data;
160 struct usb_device *dev = chip->dev;
161 u32 bmControls;
162
163 if (protocol == UAC_VERSION_3) {
164 struct uac3_clock_source_descriptor *cs_desc =
165 snd_usb_find_clock_source_v3(chip->ctrl_intf, source_id);
166
167 if (!cs_desc)
168 return 0;
169 bmControls = le32_to_cpu(cs_desc->bmControls);
170 } else { /* UAC_VERSION_1/2 */
171 struct uac_clock_source_descriptor *cs_desc =
172 snd_usb_find_clock_source(chip->ctrl_intf, source_id);
173
174 if (!cs_desc)
175 return 0;
176 bmControls = cs_desc->bmControls;
177 }
178
179 /* If a clock source can't tell us whether it's valid, we assume it is */
180 if (!uac_v2v3_control_is_readable(bmControls,
181 UAC2_CS_CONTROL_CLOCK_VALID))
182 return 1;
183
184 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
185 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
186 UAC2_CS_CONTROL_CLOCK_VALID << 8,
187 snd_usb_ctrl_intf(chip) | (source_id << 8),
188 &data, sizeof(data));
189
190 if (err < 0) {
191 dev_warn(&dev->dev,
192 "%s(): cannot get clock validity for id %d\n",
193 __func__, source_id);
194 return 0;
195 }
196
197 return !!data;
198}
199
200static int __uac_clock_find_source(struct snd_usb_audio *chip, int entity_id,
201 unsigned long *visited, bool validate)
202{
203 struct uac_clock_source_descriptor *source;
204 struct uac_clock_selector_descriptor *selector;
205 struct uac_clock_multiplier_descriptor *multiplier;
206
207 entity_id &= 0xff;
208
209 if (test_and_set_bit(entity_id, visited)) {
210 usb_audio_warn(chip,
211 "%s(): recursive clock topology detected, id %d.\n",
212 __func__, entity_id);
213 return -EINVAL;
214 }
215
216 /* first, see if the ID we're looking for is a clock source already */
217 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
218 if (source) {
219 entity_id = source->bClockID;
220 if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_2,
221 entity_id)) {
222 usb_audio_err(chip,
223 "clock source %d is not valid, cannot use\n",
224 entity_id);
225 return -ENXIO;
226 }
227 return entity_id;
228 }
229
230 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
231 if (selector) {
232 int ret, i, cur;
233
234 /* the entity ID we are looking for is a selector.
235 * find out what it currently selects */
236 ret = uac_clock_selector_get_val(chip, selector->bClockID);
237 if (ret < 0)
238 return ret;
239
240 /* Selector values are one-based */
241
242 if (ret > selector->bNrInPins || ret < 1) {
243 usb_audio_err(chip,
244 "%s(): selector reported illegal value, id %d, ret %d\n",
245 __func__, selector->bClockID, ret);
246
247 return -EINVAL;
248 }
249
250 cur = ret;
251 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1],
252 visited, validate);
253 if (!validate || ret > 0 || !chip->autoclock)
254 return ret;
255
256 /* The current clock source is invalid, try others. */
257 for (i = 1; i <= selector->bNrInPins; i++) {
258 int err;
259
260 if (i == cur)
261 continue;
262
263 ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1],
264 visited, true);
265 if (ret < 0)
266 continue;
267
268 err = uac_clock_selector_set_val(chip, entity_id, i);
269 if (err < 0)
270 continue;
271
272 usb_audio_info(chip,
273 "found and selected valid clock source %d\n",
274 ret);
275 return ret;
276 }
277
278 return -ENXIO;
279 }
280
281 /* FIXME: multipliers only act as pass-thru element for now */
282 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
283 if (multiplier)
284 return __uac_clock_find_source(chip, multiplier->bCSourceID,
285 visited, validate);
286
287 return -EINVAL;
288}
289
290static int __uac3_clock_find_source(struct snd_usb_audio *chip, int entity_id,
291 unsigned long *visited, bool validate)
292{
293 struct uac3_clock_source_descriptor *source;
294 struct uac3_clock_selector_descriptor *selector;
295 struct uac3_clock_multiplier_descriptor *multiplier;
296
297 entity_id &= 0xff;
298
299 if (test_and_set_bit(entity_id, visited)) {
300 usb_audio_warn(chip,
301 "%s(): recursive clock topology detected, id %d.\n",
302 __func__, entity_id);
303 return -EINVAL;
304 }
305
306 /* first, see if the ID we're looking for is a clock source already */
307 source = snd_usb_find_clock_source_v3(chip->ctrl_intf, entity_id);
308 if (source) {
309 entity_id = source->bClockID;
310 if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_3,
311 entity_id)) {
312 usb_audio_err(chip,
313 "clock source %d is not valid, cannot use\n",
314 entity_id);
315 return -ENXIO;
316 }
317 return entity_id;
318 }
319
320 selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id);
321 if (selector) {
322 int ret, i, cur;
323
324 /* the entity ID we are looking for is a selector.
325 * find out what it currently selects */
326 ret = uac_clock_selector_get_val(chip, selector->bClockID);
327 if (ret < 0)
328 return ret;
329
330 /* Selector values are one-based */
331
332 if (ret > selector->bNrInPins || ret < 1) {
333 usb_audio_err(chip,
334 "%s(): selector reported illegal value, id %d, ret %d\n",
335 __func__, selector->bClockID, ret);
336
337 return -EINVAL;
338 }
339
340 cur = ret;
341 ret = __uac3_clock_find_source(chip, selector->baCSourceID[ret - 1],
342 visited, validate);
343 if (!validate || ret > 0 || !chip->autoclock)
344 return ret;
345
346 /* The current clock source is invalid, try others. */
347 for (i = 1; i <= selector->bNrInPins; i++) {
348 int err;
349
350 if (i == cur)
351 continue;
352
353 ret = __uac3_clock_find_source(chip, selector->baCSourceID[i - 1],
354 visited, true);
355 if (ret < 0)
356 continue;
357
358 err = uac_clock_selector_set_val(chip, entity_id, i);
359 if (err < 0)
360 continue;
361
362 usb_audio_info(chip,
363 "found and selected valid clock source %d\n",
364 ret);
365 return ret;
366 }
367
368 return -ENXIO;
369 }
370
371 /* FIXME: multipliers only act as pass-thru element for now */
372 multiplier = snd_usb_find_clock_multiplier_v3(chip->ctrl_intf,
373 entity_id);
374 if (multiplier)
375 return __uac3_clock_find_source(chip, multiplier->bCSourceID,
376 visited, validate);
377
378 return -EINVAL;
379}
380
381/*
382 * For all kinds of sample rate settings and other device queries,
383 * the clock source (end-leaf) must be used. However, clock selectors,
384 * clock multipliers and sample rate converters may be specified as
385 * clock source input to terminal. This functions walks the clock path
386 * to its end and tries to find the source.
387 *
388 * The 'visited' bitfield is used internally to detect recursive loops.
389 *
390 * Returns the clock source UnitID (>=0) on success, or an error.
391 */
392int snd_usb_clock_find_source(struct snd_usb_audio *chip, int protocol,
393 int entity_id, bool validate)
394{
395 DECLARE_BITMAP(visited, 256);
396 memset(visited, 0, sizeof(visited));
397
398 switch (protocol) {
399 case UAC_VERSION_2:
400 return __uac_clock_find_source(chip, entity_id, visited,
401 validate);
402 case UAC_VERSION_3:
403 return __uac3_clock_find_source(chip, entity_id, visited,
404 validate);
405 default:
406 return -EINVAL;
407 }
408}
409
410static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
411 struct usb_host_interface *alts,
412 struct audioformat *fmt, int rate)
413{
414 struct usb_device *dev = chip->dev;
415 unsigned int ep;
416 unsigned char data[3];
417 int err, crate;
418
419 if (get_iface_desc(alts)->bNumEndpoints < 1)
420 return -EINVAL;
421 ep = get_endpoint(alts, 0)->bEndpointAddress;
422
423 /* if endpoint doesn't have sampling rate control, bail out */
424 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
425 return 0;
426
427 data[0] = rate;
428 data[1] = rate >> 8;
429 data[2] = rate >> 16;
430 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
431 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
432 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
433 data, sizeof(data));
434 if (err < 0) {
435 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
436 iface, fmt->altsetting, rate, ep);
437 return err;
438 }
439
440 /* Don't check the sample rate for devices which we know don't
441 * support reading */
442 if (snd_usb_get_sample_rate_quirk(chip))
443 return 0;
444 /* the firmware is likely buggy, don't repeat to fail too many times */
445 if (chip->sample_rate_read_error > 2)
446 return 0;
447
448 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
449 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
450 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
451 data, sizeof(data));
452 if (err < 0) {
453 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
454 iface, fmt->altsetting, ep);
455 chip->sample_rate_read_error++;
456 return 0; /* some devices don't support reading */
457 }
458
459 crate = data[0] | (data[1] << 8) | (data[2] << 16);
460 if (crate != rate) {
461 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
462 // runtime->rate = crate;
463 }
464
465 return 0;
466}
467
468static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
469 int altsetting, int clock)
470{
471 struct usb_device *dev = chip->dev;
472 __le32 data;
473 int err;
474
475 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
476 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
477 UAC2_CS_CONTROL_SAM_FREQ << 8,
478 snd_usb_ctrl_intf(chip) | (clock << 8),
479 &data, sizeof(data));
480 if (err < 0) {
481 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
482 iface, altsetting, err);
483 return 0;
484 }
485
486 return le32_to_cpu(data);
487}
488
489static int set_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
490 struct usb_host_interface *alts,
491 struct audioformat *fmt, int rate)
492{
493 struct usb_device *dev = chip->dev;
494 __le32 data;
495 int err, cur_rate, prev_rate;
496 int clock;
497 bool writeable;
498 u32 bmControls;
499
500 /* First, try to find a valid clock. This may trigger
501 * automatic clock selection if the current clock is not
502 * valid.
503 */
504 clock = snd_usb_clock_find_source(chip, fmt->protocol,
505 fmt->clock, true);
506 if (clock < 0) {
507 /* We did not find a valid clock, but that might be
508 * because the current sample rate does not match an
509 * external clock source. Try again without validation
510 * and we will do another validation after setting the
511 * rate.
512 */
513 clock = snd_usb_clock_find_source(chip, fmt->protocol,
514 fmt->clock, false);
515 if (clock < 0)
516 return clock;
517 }
518
519 prev_rate = get_sample_rate_v2v3(chip, iface, fmt->altsetting, clock);
520 if (prev_rate == rate)
521 goto validation;
522
523 if (fmt->protocol == UAC_VERSION_3) {
524 struct uac3_clock_source_descriptor *cs_desc;
525
526 cs_desc = snd_usb_find_clock_source_v3(chip->ctrl_intf, clock);
527 bmControls = le32_to_cpu(cs_desc->bmControls);
528 } else {
529 struct uac_clock_source_descriptor *cs_desc;
530
531 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
532 bmControls = cs_desc->bmControls;
533 }
534
535 writeable = uac_v2v3_control_is_writeable(bmControls,
536 UAC2_CS_CONTROL_SAM_FREQ);
537 if (writeable) {
538 data = cpu_to_le32(rate);
539 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
540 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
541 UAC2_CS_CONTROL_SAM_FREQ << 8,
542 snd_usb_ctrl_intf(chip) | (clock << 8),
543 &data, sizeof(data));
544 if (err < 0) {
545 usb_audio_err(chip,
546 "%d:%d: cannot set freq %d (v2/v3): err %d\n",
547 iface, fmt->altsetting, rate, err);
548 return err;
549 }
550
551 cur_rate = get_sample_rate_v2v3(chip, iface,
552 fmt->altsetting, clock);
553 } else {
554 cur_rate = prev_rate;
555 }
556
557 if (cur_rate != rate) {
558 if (!writeable) {
559 usb_audio_warn(chip,
560 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
561 iface, fmt->altsetting, rate, cur_rate);
562 return -ENXIO;
563 }
564 usb_audio_dbg(chip,
565 "current rate %d is different from the runtime rate %d\n",
566 cur_rate, rate);
567 }
568
569 /* Some devices doesn't respond to sample rate changes while the
570 * interface is active. */
571 if (rate != prev_rate) {
572 usb_set_interface(dev, iface, 0);
573 snd_usb_set_interface_quirk(dev);
574 usb_set_interface(dev, iface, fmt->altsetting);
575 snd_usb_set_interface_quirk(dev);
576 }
577
578validation:
579 /* validate clock after rate change */
580 if (!uac_clock_source_is_valid(chip, fmt->protocol, clock))
581 return -ENXIO;
582 return 0;
583}
584
585int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
586 struct usb_host_interface *alts,
587 struct audioformat *fmt, int rate)
588{
589 switch (fmt->protocol) {
590 case UAC_VERSION_1:
591 default:
592 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
593
594 case UAC_VERSION_3:
595 if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
596 if (rate != UAC3_BADD_SAMPLING_RATE)
597 return -ENXIO;
598 else
599 return 0;
600 }
601 /* fall through */
602 case UAC_VERSION_2:
603 return set_sample_rate_v2v3(chip, iface, alts, fmt, rate);
604 }
605}
606