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
36 static struct uac_clock_source_descriptor *
snd_usb_find_clock_source(struct usb_host_interface * ctrl_iface,int clock_id)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
52 static struct uac_clock_selector_descriptor *
snd_usb_find_clock_selector(struct usb_host_interface * ctrl_iface,int clock_id)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
68 static struct uac_clock_multiplier_descriptor *
snd_usb_find_clock_multiplier(struct usb_host_interface * ctrl_iface,int clock_id)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
uac_clock_selector_get_val(struct snd_usb_audio * chip,int selector_id)84 static 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
uac_clock_source_is_valid(struct snd_usb_audio * chip,int source_id)102 static 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
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);
113
114 if (err < 0) {
115 snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
116 __func__, source_id);
117 return err;
118 }
119
120 return !!data;
121 }
122
__uac_clock_find_source(struct snd_usb_audio * chip,int entity_id,unsigned long * visited)123 static int __uac_clock_find_source(struct snd_usb_audio *chip,
124 int entity_id, unsigned long *visited)
125 {
126 struct uac_clock_source_descriptor *source;
127 struct uac_clock_selector_descriptor *selector;
128 struct uac_clock_multiplier_descriptor *multiplier;
129
130 entity_id &= 0xff;
131
132 if (test_and_set_bit(entity_id, visited)) {
133 snd_printk(KERN_WARNING
134 "%s(): recursive clock topology detected, id %d.\n",
135 __func__, entity_id);
136 return -EINVAL;
137 }
138
139 /* first, see if the ID we're looking for is a clock source already */
140 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
141 if (source)
142 return source->bClockID;
143
144 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
145 if (selector) {
146 int ret;
147
148 /* the entity ID we are looking for is a selector.
149 * find out what it currently selects */
150 ret = uac_clock_selector_get_val(chip, selector->bClockID);
151 if (ret < 0)
152 return ret;
153
154 /* Selector values are one-based */
155
156 if (ret > selector->bNrInPins || ret < 1) {
157 printk(KERN_ERR
158 "%s(): selector reported illegal value, id %d, ret %d\n",
159 __func__, selector->bClockID, ret);
160
161 return -EINVAL;
162 }
163
164 return __uac_clock_find_source(chip, selector->baCSourceID[ret-1],
165 visited);
166 }
167
168 /* FIXME: multipliers only act as pass-thru element for now */
169 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
170 if (multiplier)
171 return __uac_clock_find_source(chip, multiplier->bCSourceID,
172 visited);
173
174 return -EINVAL;
175 }
176
177 /*
178 * For all kinds of sample rate settings and other device queries,
179 * the clock source (end-leaf) must be used. However, clock selectors,
180 * clock multipliers and sample rate converters may be specified as
181 * clock source input to terminal. This functions walks the clock path
182 * to its end and tries to find the source.
183 *
184 * The 'visited' bitfield is used internally to detect recursive loops.
185 *
186 * Returns the clock source UnitID (>=0) on success, or an error.
187 */
snd_usb_clock_find_source(struct snd_usb_audio * chip,int entity_id)188 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id)
189 {
190 DECLARE_BITMAP(visited, 256);
191 memset(visited, 0, sizeof(visited));
192 return __uac_clock_find_source(chip, entity_id, visited);
193 }
194
set_sample_rate_v1(struct snd_usb_audio * chip,int iface,struct usb_host_interface * alts,struct audioformat * fmt,int rate)195 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
196 struct usb_host_interface *alts,
197 struct audioformat *fmt, int rate)
198 {
199 struct usb_device *dev = chip->dev;
200 unsigned int ep;
201 unsigned char data[3];
202 int err, crate;
203
204 ep = get_endpoint(alts, 0)->bEndpointAddress;
205
206 /* if endpoint doesn't have sampling rate control, bail out */
207 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
208 return 0;
209
210 data[0] = rate;
211 data[1] = rate >> 8;
212 data[2] = rate >> 16;
213 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
214 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
215 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
216 data, sizeof(data), 1000)) < 0) {
217 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
218 dev->devnum, iface, fmt->altsetting, rate, ep);
219 return err;
220 }
221
222 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
223 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
224 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
225 data, sizeof(data), 1000)) < 0) {
226 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
227 dev->devnum, iface, fmt->altsetting, ep);
228 return 0; /* some devices don't support reading */
229 }
230
231 crate = data[0] | (data[1] << 8) | (data[2] << 16);
232 if (crate != rate) {
233 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
234 // runtime->rate = crate;
235 }
236
237 return 0;
238 }
239
set_sample_rate_v2(struct snd_usb_audio * chip,int iface,struct usb_host_interface * alts,struct audioformat * fmt,int rate)240 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
241 struct usb_host_interface *alts,
242 struct audioformat *fmt, int rate)
243 {
244 struct usb_device *dev = chip->dev;
245 unsigned char data[4];
246 int err, crate;
247 int clock = snd_usb_clock_find_source(chip, fmt->clock);
248
249 if (clock < 0)
250 return clock;
251
252 if (!uac_clock_source_is_valid(chip, clock)) {
253 /* TODO: should we try to find valid clock setups by ourself? */
254 snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
255 dev->devnum, iface, fmt->altsetting, clock);
256 return -ENXIO;
257 }
258
259 data[0] = rate;
260 data[1] = rate >> 8;
261 data[2] = rate >> 16;
262 data[3] = rate >> 24;
263 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
264 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
265 UAC2_CS_CONTROL_SAM_FREQ << 8,
266 snd_usb_ctrl_intf(chip) | (clock << 8),
267 data, sizeof(data), 1000)) < 0) {
268 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
269 dev->devnum, iface, fmt->altsetting, rate);
270 return err;
271 }
272
273 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
274 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
275 UAC2_CS_CONTROL_SAM_FREQ << 8,
276 snd_usb_ctrl_intf(chip) | (clock << 8),
277 data, sizeof(data), 1000)) < 0) {
278 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
279 dev->devnum, iface, fmt->altsetting);
280 return err;
281 }
282
283 crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
284 if (crate != rate)
285 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
286
287 return 0;
288 }
289
snd_usb_init_sample_rate(struct snd_usb_audio * chip,int iface,struct usb_host_interface * alts,struct audioformat * fmt,int rate)290 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
291 struct usb_host_interface *alts,
292 struct audioformat *fmt, int rate)
293 {
294 struct usb_interface_descriptor *altsd = get_iface_desc(alts);
295
296 switch (altsd->bInterfaceProtocol) {
297 case UAC_VERSION_1:
298 default:
299 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
300
301 case UAC_VERSION_2:
302 return set_sample_rate_v2(chip, iface, alts, fmt, rate);
303 }
304 }
305
306