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 bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
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);
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,
115 UAC2_CS_CONTROL_CLOCK_VALID - 1))
118 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
119 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
120 UAC2_CS_CONTROL_CLOCK_VALID << 8,
121 snd_usb_ctrl_intf(chip) | (source_id << 8),
122 &data, sizeof(data));
125 snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
126 __func__, source_id);
133 static int __uac_clock_find_source(struct snd_usb_audio *chip,
134 int entity_id, unsigned long *visited)
136 struct uac_clock_source_descriptor *source;
137 struct uac_clock_selector_descriptor *selector;
138 struct uac_clock_multiplier_descriptor *multiplier;
142 if (test_and_set_bit(entity_id, visited)) {
143 snd_printk(KERN_WARNING
144 "%s(): recursive clock topology detected, id %d.\n",
145 __func__, entity_id);
149 /* first, see if the ID we're looking for is a clock source already */
150 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
152 return source->bClockID;
154 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
158 /* the entity ID we are looking for is a selector.
159 * find out what it currently selects */
160 ret = uac_clock_selector_get_val(chip, selector->bClockID);
164 /* Selector values are one-based */
166 if (ret > selector->bNrInPins || ret < 1) {
168 "%s(): selector reported illegal value, id %d, ret %d\n",
169 __func__, selector->bClockID, ret);
174 return __uac_clock_find_source(chip, selector->baCSourceID[ret-1],
178 /* FIXME: multipliers only act as pass-thru element for now */
179 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
181 return __uac_clock_find_source(chip, multiplier->bCSourceID,
188 * For all kinds of sample rate settings and other device queries,
189 * the clock source (end-leaf) must be used. However, clock selectors,
190 * clock multipliers and sample rate converters may be specified as
191 * clock source input to terminal. This functions walks the clock path
192 * to its end and tries to find the source.
194 * The 'visited' bitfield is used internally to detect recursive loops.
196 * Returns the clock source UnitID (>=0) on success, or an error.
198 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id)
200 DECLARE_BITMAP(visited, 256);
201 memset(visited, 0, sizeof(visited));
202 return __uac_clock_find_source(chip, entity_id, visited);
205 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
206 struct usb_host_interface *alts,
207 struct audioformat *fmt, int rate)
209 struct usb_device *dev = chip->dev;
211 unsigned char data[3];
214 if (get_iface_desc(alts)->bNumEndpoints < 1)
216 ep = get_endpoint(alts, 0)->bEndpointAddress;
218 /* if endpoint doesn't have sampling rate control, bail out */
219 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
224 data[2] = rate >> 16;
225 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
226 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
227 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
228 data, sizeof(data))) < 0) {
229 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
230 dev->devnum, iface, fmt->altsetting, rate, ep);
234 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
235 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
236 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
237 data, sizeof(data))) < 0) {
238 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
239 dev->devnum, iface, fmt->altsetting, ep);
240 return 0; /* some devices don't support reading */
243 crate = data[0] | (data[1] << 8) | (data[2] << 16);
245 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
246 // runtime->rate = crate;
252 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
253 struct usb_host_interface *alts,
254 struct audioformat *fmt, int rate)
256 struct usb_device *dev = chip->dev;
257 unsigned char data[4];
259 int clock = snd_usb_clock_find_source(chip, fmt->clock);
264 if (!uac_clock_source_is_valid(chip, clock)) {
265 /* TODO: should we try to find valid clock setups by ourself? */
266 snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
267 dev->devnum, iface, fmt->altsetting, clock);
273 data[2] = rate >> 16;
274 data[3] = rate >> 24;
275 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
276 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
277 UAC2_CS_CONTROL_SAM_FREQ << 8,
278 snd_usb_ctrl_intf(chip) | (clock << 8),
279 data, sizeof(data))) < 0) {
280 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
281 dev->devnum, iface, fmt->altsetting, rate);
285 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
286 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
287 UAC2_CS_CONTROL_SAM_FREQ << 8,
288 snd_usb_ctrl_intf(chip) | (clock << 8),
289 data, sizeof(data))) < 0) {
290 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
291 dev->devnum, iface, fmt->altsetting);
295 crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
297 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
302 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
303 struct usb_host_interface *alts,
304 struct audioformat *fmt, int rate)
306 struct usb_interface_descriptor *altsd = get_iface_desc(alts);
308 switch (altsd->bInterfaceProtocol) {
311 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
314 return set_sample_rate_v2(chip, iface, alts, fmt, rate);