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),
94 &buf, sizeof(buf), 1000);
102 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
106 struct usb_device *dev = chip->dev;
108 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
109 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
110 UAC2_CS_CONTROL_CLOCK_VALID << 8,
111 snd_usb_ctrl_intf(chip) | (source_id << 8),
112 &data, sizeof(data), 1000);
115 snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
116 __func__, source_id);
123 /* Try to find the clock source ID of a given clock entity */
125 static int __uac_clock_find_source(struct snd_usb_audio *chip,
126 struct usb_host_interface *host_iface,
127 int entity_id, unsigned long *visited)
129 struct uac_clock_source_descriptor *source;
130 struct uac_clock_selector_descriptor *selector;
131 struct uac_clock_multiplier_descriptor *multiplier;
135 if (test_and_set_bit(entity_id, visited)) {
136 snd_printk(KERN_WARNING
137 "%s(): recursive clock topology detected, id %d.\n",
138 __func__, entity_id);
142 /* first, see if the ID we're looking for is a clock source already */
143 source = snd_usb_find_clock_source(host_iface, entity_id);
145 return source->bClockID;
147 selector = snd_usb_find_clock_selector(host_iface, entity_id);
151 /* the entity ID we are looking for is a selector.
152 * find out what it currently selects */
153 ret = uac_clock_selector_get_val(chip, selector->bClockID);
157 if (ret > selector->bNrInPins || ret < 1) {
159 "%s(): selector reported illegal value, id %d, ret %d\n",
160 __func__, selector->bClockID, ret);
165 return __uac_clock_find_source(chip, host_iface,
166 selector->baCSourceID[ret-1],
170 /* FIXME: multipliers only act as pass-thru element for now */
171 multiplier = snd_usb_find_clock_multiplier(host_iface, entity_id);
173 return __uac_clock_find_source(chip, host_iface,
174 multiplier->bCSourceID, visited);
179 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
180 struct usb_host_interface *host_iface,
183 DECLARE_BITMAP(visited, 256);
184 memset(visited, 0, sizeof(visited));
185 return __uac_clock_find_source(chip, host_iface, entity_id, visited);
188 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
189 struct usb_host_interface *alts,
190 struct audioformat *fmt, int rate)
192 struct usb_device *dev = chip->dev;
194 unsigned char data[3];
197 ep = get_endpoint(alts, 0)->bEndpointAddress;
199 /* if endpoint doesn't have sampling rate control, bail out */
200 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) {
201 snd_printk(KERN_WARNING "%d:%d:%d: endpoint lacks sample rate attribute bit, cannot set.\n",
202 dev->devnum, iface, fmt->altsetting);
208 data[2] = rate >> 16;
209 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
210 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
211 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
212 data, sizeof(data), 1000)) < 0) {
213 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
214 dev->devnum, iface, fmt->altsetting, rate, ep);
218 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
219 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
220 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
221 data, sizeof(data), 1000)) < 0) {
222 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
223 dev->devnum, iface, fmt->altsetting, ep);
224 return 0; /* some devices don't support reading */
227 crate = data[0] | (data[1] << 8) | (data[2] << 16);
229 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
230 // runtime->rate = crate;
236 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
237 struct usb_host_interface *alts,
238 struct audioformat *fmt, int rate)
240 struct usb_device *dev = chip->dev;
241 unsigned char data[4];
243 int clock = snd_usb_clock_find_source(chip, chip->ctrl_intf, fmt->clock);
248 if (!uac_clock_source_is_valid(chip, clock)) {
249 snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
250 dev->devnum, iface, fmt->altsetting, clock);
256 data[2] = rate >> 16;
257 data[3] = rate >> 24;
258 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
259 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
260 UAC2_CS_CONTROL_SAM_FREQ << 8,
261 snd_usb_ctrl_intf(chip) | (clock << 8),
262 data, sizeof(data), 1000)) < 0) {
263 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
264 dev->devnum, iface, fmt->altsetting, rate);
268 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
269 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
270 UAC2_CS_CONTROL_SAM_FREQ << 8,
271 snd_usb_ctrl_intf(chip) | (clock << 8),
272 data, sizeof(data), 1000)) < 0) {
273 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
274 dev->devnum, iface, fmt->altsetting);
278 crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
280 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
285 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
286 struct usb_host_interface *alts,
287 struct audioformat *fmt, int rate)
289 struct usb_interface_descriptor *altsd = get_iface_desc(alts);
291 switch (altsd->bInterfaceProtocol) {
293 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
296 return set_sample_rate_v2(chip, iface, alts, fmt, rate);