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>
36 static struct uac_clock_source_descriptor *
37 snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
40 struct uac_clock_source_descriptor *cs = NULL;
42 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
44 cs, UAC2_CLOCK_SOURCE))) {
45 if (cs->bClockID == clock_id)
52 static struct uac_clock_selector_descriptor *
53 snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
56 struct uac_clock_selector_descriptor *cs = NULL;
58 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
60 cs, UAC2_CLOCK_SELECTOR))) {
61 if (cs->bClockID == clock_id)
68 static struct uac_clock_multiplier_descriptor *
69 snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
72 struct uac_clock_multiplier_descriptor *cs = NULL;
74 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
76 cs, UAC2_CLOCK_MULTIPLIER))) {
77 if (cs->bClockID == clock_id)
84 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
89 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
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),
102 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
107 ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
109 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
110 UAC2_CX_CLOCK_SELECTOR << 8,
111 snd_usb_ctrl_intf(chip) | (selector_id << 8),
116 if (ret != sizeof(pin)) {
118 "usb-audio:%d: setting selector (id %d) unexpected length %d\n",
119 chip->dev->devnum, selector_id, ret);
123 ret = uac_clock_selector_get_val(chip, selector_id);
129 "usb-audio:%d: setting selector (id %d) to %x failed (current: %d)\n",
130 chip->dev->devnum, selector_id, pin, ret);
137 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
141 struct usb_device *dev = chip->dev;
142 struct uac_clock_source_descriptor *cs_desc =
143 snd_usb_find_clock_source(chip->ctrl_intf, source_id);
148 /* If a clock source can't tell us whether it's valid, we assume it is */
149 if (!uac2_control_is_readable(cs_desc->bmControls,
150 UAC2_CS_CONTROL_CLOCK_VALID - 1))
153 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
154 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
155 UAC2_CS_CONTROL_CLOCK_VALID << 8,
156 snd_usb_ctrl_intf(chip) | (source_id << 8),
157 &data, sizeof(data));
160 snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
161 __func__, source_id);
168 static int __uac_clock_find_source(struct snd_usb_audio *chip,
169 int entity_id, unsigned long *visited,
172 struct uac_clock_source_descriptor *source;
173 struct uac_clock_selector_descriptor *selector;
174 struct uac_clock_multiplier_descriptor *multiplier;
178 if (test_and_set_bit(entity_id, visited)) {
179 snd_printk(KERN_WARNING
180 "%s(): recursive clock topology detected, id %d.\n",
181 __func__, entity_id);
185 /* first, see if the ID we're looking for is a clock source already */
186 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
188 entity_id = source->bClockID;
189 if (validate && !uac_clock_source_is_valid(chip, entity_id)) {
190 snd_printk(KERN_ERR "usb-audio:%d: clock source %d is not valid, cannot use\n",
191 chip->dev->devnum, entity_id);
197 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
201 /* the entity ID we are looking for is a selector.
202 * find out what it currently selects */
203 ret = uac_clock_selector_get_val(chip, selector->bClockID);
207 /* Selector values are one-based */
209 if (ret > selector->bNrInPins || ret < 1) {
211 "%s(): selector reported illegal value, id %d, ret %d\n",
212 __func__, selector->bClockID, ret);
218 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1],
220 if (!validate || ret > 0 || !chip->autoclock)
223 /* The current clock source is invalid, try others. */
224 for (i = 1; i <= selector->bNrInPins; i++) {
230 ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1],
235 err = uac_clock_selector_set_val(chip, entity_id, i);
240 "usb-audio:%d: found and selected valid clock source %d\n",
241 chip->dev->devnum, ret);
248 /* FIXME: multipliers only act as pass-thru element for now */
249 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
251 return __uac_clock_find_source(chip, multiplier->bCSourceID,
258 * For all kinds of sample rate settings and other device queries,
259 * the clock source (end-leaf) must be used. However, clock selectors,
260 * clock multipliers and sample rate converters may be specified as
261 * clock source input to terminal. This functions walks the clock path
262 * to its end and tries to find the source.
264 * The 'visited' bitfield is used internally to detect recursive loops.
266 * Returns the clock source UnitID (>=0) on success, or an error.
268 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id,
271 DECLARE_BITMAP(visited, 256);
272 memset(visited, 0, sizeof(visited));
273 return __uac_clock_find_source(chip, entity_id, visited, validate);
276 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
277 struct usb_host_interface *alts,
278 struct audioformat *fmt, int rate)
280 struct usb_device *dev = chip->dev;
282 unsigned char data[3];
285 ep = get_endpoint(alts, 0)->bEndpointAddress;
287 /* if endpoint doesn't have sampling rate control, bail out */
288 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
293 data[2] = rate >> 16;
294 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
295 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
296 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
297 data, sizeof(data))) < 0) {
298 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
299 dev->devnum, iface, fmt->altsetting, rate, ep);
303 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
304 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
305 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
306 data, sizeof(data))) < 0) {
307 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
308 dev->devnum, iface, fmt->altsetting, ep);
309 return 0; /* some devices don't support reading */
312 crate = data[0] | (data[1] << 8) | (data[2] << 16);
314 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
315 // runtime->rate = crate;
321 static int get_sample_rate_v2(struct snd_usb_audio *chip, int iface,
322 int altsetting, int clock)
324 struct usb_device *dev = chip->dev;
328 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
329 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
330 UAC2_CS_CONTROL_SAM_FREQ << 8,
331 snd_usb_ctrl_intf(chip) | (clock << 8),
332 &data, sizeof(data));
334 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2): err %d\n",
335 dev->devnum, iface, altsetting, err);
339 return le32_to_cpu(data);
342 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
343 struct usb_host_interface *alts,
344 struct audioformat *fmt, int rate)
346 struct usb_device *dev = chip->dev;
348 int err, cur_rate, prev_rate;
351 struct uac_clock_source_descriptor *cs_desc;
353 clock = snd_usb_clock_find_source(chip, fmt->clock, true);
357 prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
359 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
360 writeable = uac2_control_is_writeable(cs_desc->bmControls, UAC2_CS_CONTROL_SAM_FREQ - 1);
362 data = cpu_to_le32(rate);
363 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
364 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
365 UAC2_CS_CONTROL_SAM_FREQ << 8,
366 snd_usb_ctrl_intf(chip) | (clock << 8),
367 &data, sizeof(data));
369 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2): err %d\n",
370 dev->devnum, iface, fmt->altsetting, rate, err);
374 cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
376 cur_rate = prev_rate;
379 if (cur_rate != rate) {
381 snd_printk(KERN_WARNING
382 "%d:%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
383 dev->devnum, iface, fmt->altsetting, rate, cur_rate);
386 snd_printd(KERN_WARNING
387 "current rate %d is different from the runtime rate %d\n",
391 /* Some devices doesn't respond to sample rate changes while the
392 * interface is active. */
393 if (rate != prev_rate) {
394 usb_set_interface(dev, iface, 0);
395 usb_set_interface(dev, iface, fmt->altsetting);
401 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
402 struct usb_host_interface *alts,
403 struct audioformat *fmt, int rate)
405 struct usb_interface_descriptor *altsd = get_iface_desc(alts);
407 switch (altsd->bInterfaceProtocol) {
410 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
413 return set_sample_rate_v2(chip, iface, alts, fmt, rate);