2 * Clock domain and sample rate management functions
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.
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.
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
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>
27 #include <sound/core.h>
28 #include <sound/info.h>
29 #include <sound/pcm.h>
37 static struct uac_clock_source_descriptor *
38 snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
41 struct uac_clock_source_descriptor *cs = NULL;
43 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
45 cs, UAC2_CLOCK_SOURCE))) {
46 if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id)
53 static struct uac_clock_selector_descriptor *
54 snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
57 struct uac_clock_selector_descriptor *cs = NULL;
59 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
61 cs, UAC2_CLOCK_SELECTOR))) {
62 if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id) {
63 if (cs->bLength < 5 + cs->bNrInPins)
72 static struct uac_clock_multiplier_descriptor *
73 snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
76 struct uac_clock_multiplier_descriptor *cs = NULL;
78 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
80 cs, UAC2_CLOCK_MULTIPLIER))) {
81 if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id)
88 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
93 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
95 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
96 UAC2_CX_CLOCK_SELECTOR << 8,
97 snd_usb_ctrl_intf(chip) | (selector_id << 8),
106 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
111 ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
113 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
114 UAC2_CX_CLOCK_SELECTOR << 8,
115 snd_usb_ctrl_intf(chip) | (selector_id << 8),
120 if (ret != sizeof(pin)) {
122 "setting selector (id %d) unexpected length %d\n",
127 ret = uac_clock_selector_get_val(chip, selector_id);
133 "setting selector (id %d) to %x failed (current: %d)\n",
134 selector_id, pin, ret);
141 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
145 struct usb_device *dev = chip->dev;
146 struct uac_clock_source_descriptor *cs_desc =
147 snd_usb_find_clock_source(chip->ctrl_intf, source_id);
152 /* If a clock source can't tell us whether it's valid, we assume it is */
153 if (!uac2_control_is_readable(cs_desc->bmControls,
154 UAC2_CS_CONTROL_CLOCK_VALID - 1))
157 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
158 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
159 UAC2_CS_CONTROL_CLOCK_VALID << 8,
160 snd_usb_ctrl_intf(chip) | (source_id << 8),
161 &data, sizeof(data));
165 "%s(): cannot get clock validity for id %d\n",
166 __func__, source_id);
173 static int __uac_clock_find_source(struct snd_usb_audio *chip,
174 int entity_id, unsigned long *visited,
177 struct uac_clock_source_descriptor *source;
178 struct uac_clock_selector_descriptor *selector;
179 struct uac_clock_multiplier_descriptor *multiplier;
183 if (test_and_set_bit(entity_id, visited)) {
185 "%s(): recursive clock topology detected, id %d.\n",
186 __func__, entity_id);
190 /* first, see if the ID we're looking for is a clock source already */
191 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
193 entity_id = source->bClockID;
194 if (validate && !uac_clock_source_is_valid(chip, entity_id)) {
196 "clock source %d is not valid, cannot use\n",
203 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
207 /* the entity ID we are looking for is a selector.
208 * find out what it currently selects */
209 ret = uac_clock_selector_get_val(chip, selector->bClockID);
213 /* Selector values are one-based */
215 if (ret > selector->bNrInPins || ret < 1) {
217 "%s(): selector reported illegal value, id %d, ret %d\n",
218 __func__, selector->bClockID, ret);
224 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1],
226 if (!validate || ret > 0 || !chip->autoclock)
229 /* The current clock source is invalid, try others. */
230 for (i = 1; i <= selector->bNrInPins; i++) {
236 ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1],
241 err = uac_clock_selector_set_val(chip, entity_id, i);
246 "found and selected valid clock source %d\n",
254 /* FIXME: multipliers only act as pass-thru element for now */
255 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
257 return __uac_clock_find_source(chip, multiplier->bCSourceID,
264 * For all kinds of sample rate settings and other device queries,
265 * the clock source (end-leaf) must be used. However, clock selectors,
266 * clock multipliers and sample rate converters may be specified as
267 * clock source input to terminal. This functions walks the clock path
268 * to its end and tries to find the source.
270 * The 'visited' bitfield is used internally to detect recursive loops.
272 * Returns the clock source UnitID (>=0) on success, or an error.
274 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id,
277 DECLARE_BITMAP(visited, 256);
278 memset(visited, 0, sizeof(visited));
279 return __uac_clock_find_source(chip, entity_id, visited, validate);
282 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
283 struct usb_host_interface *alts,
284 struct audioformat *fmt, int rate)
286 struct usb_device *dev = chip->dev;
288 unsigned char data[3];
291 if (get_iface_desc(alts)->bNumEndpoints < 1)
293 ep = get_endpoint(alts, 0)->bEndpointAddress;
295 /* if endpoint doesn't have sampling rate control, bail out */
296 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
301 data[2] = rate >> 16;
302 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
303 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
304 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
305 data, sizeof(data))) < 0) {
306 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
307 iface, fmt->altsetting, rate, ep);
311 /* Don't check the sample rate for devices which we know don't
313 if (snd_usb_get_sample_rate_quirk(chip))
316 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
317 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
318 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
319 data, sizeof(data))) < 0) {
320 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
321 iface, fmt->altsetting, ep);
322 return 0; /* some devices don't support reading */
325 crate = data[0] | (data[1] << 8) | (data[2] << 16);
327 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
328 // runtime->rate = crate;
334 static int get_sample_rate_v2(struct snd_usb_audio *chip, int iface,
335 int altsetting, int clock)
337 struct usb_device *dev = chip->dev;
341 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
342 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
343 UAC2_CS_CONTROL_SAM_FREQ << 8,
344 snd_usb_ctrl_intf(chip) | (clock << 8),
345 &data, sizeof(data));
347 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2): err %d\n",
348 iface, altsetting, err);
352 return le32_to_cpu(data);
355 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
356 struct usb_host_interface *alts,
357 struct audioformat *fmt, int rate)
359 struct usb_device *dev = chip->dev;
361 int err, cur_rate, prev_rate;
364 struct uac_clock_source_descriptor *cs_desc;
366 clock = snd_usb_clock_find_source(chip, fmt->clock, true);
370 prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
371 if (prev_rate == rate)
374 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
375 writeable = uac2_control_is_writeable(cs_desc->bmControls, UAC2_CS_CONTROL_SAM_FREQ - 1);
377 data = cpu_to_le32(rate);
378 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
379 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
380 UAC2_CS_CONTROL_SAM_FREQ << 8,
381 snd_usb_ctrl_intf(chip) | (clock << 8),
382 &data, sizeof(data));
385 "%d:%d: cannot set freq %d (v2): err %d\n",
386 iface, fmt->altsetting, rate, err);
390 cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
392 cur_rate = prev_rate;
395 if (cur_rate != rate) {
398 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
399 iface, fmt->altsetting, rate, cur_rate);
403 "current rate %d is different from the runtime rate %d\n",
407 /* Some devices doesn't respond to sample rate changes while the
408 * interface is active. */
409 if (rate != prev_rate) {
410 usb_set_interface(dev, iface, 0);
411 snd_usb_set_interface_quirk(dev);
412 usb_set_interface(dev, iface, fmt->altsetting);
413 snd_usb_set_interface_quirk(dev);
419 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
420 struct usb_host_interface *alts,
421 struct audioformat *fmt, int rate)
423 switch (fmt->protocol) {
426 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
429 return set_sample_rate_v2(chip, iface, alts, fmt, rate);