xref: /linux/sound/usb/clock.c (revision 36239c6704b71da7fb8e2a9429e159a84d0c5a3e)
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/list.h>
23 #include <linux/slab.h>
24 #include <linux/string.h>
25 #include <linux/usb.h>
26 #include <linux/moduleparam.h>
27 #include <linux/mutex.h>
28 #include <linux/usb/audio.h>
29 #include <linux/usb/audio-v2.h>
30 
31 #include <sound/core.h>
32 #include <sound/info.h>
33 #include <sound/pcm.h>
34 #include <sound/pcm_params.h>
35 #include <sound/initval.h>
36 
37 #include "usbaudio.h"
38 #include "card.h"
39 #include "midi.h"
40 #include "mixer.h"
41 #include "proc.h"
42 #include "quirks.h"
43 #include "endpoint.h"
44 #include "helper.h"
45 #include "debug.h"
46 #include "pcm.h"
47 #include "urb.h"
48 #include "format.h"
49 
50 static struct uac_clock_source_descriptor *
51 	snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
52 				  int clock_id)
53 {
54 	struct uac_clock_source_descriptor *cs = NULL;
55 
56 	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
57 					     ctrl_iface->extralen,
58 					     cs, UAC2_CLOCK_SOURCE))) {
59 		if (cs->bClockID == clock_id)
60 			return cs;
61 	}
62 
63 	return NULL;
64 }
65 
66 static struct uac_clock_selector_descriptor *
67 	snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
68 				    int clock_id)
69 {
70 	struct uac_clock_selector_descriptor *cs = NULL;
71 
72 	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
73 					     ctrl_iface->extralen,
74 					     cs, UAC2_CLOCK_SELECTOR))) {
75 		if (cs->bClockID == clock_id)
76 			return cs;
77 	}
78 
79 	return NULL;
80 }
81 
82 static struct uac_clock_multiplier_descriptor *
83 	snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
84 				      int clock_id)
85 {
86 	struct uac_clock_multiplier_descriptor *cs = NULL;
87 
88 	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
89 					     ctrl_iface->extralen,
90 					     cs, UAC2_CLOCK_MULTIPLIER))) {
91 		if (cs->bClockID == clock_id)
92 			return cs;
93 	}
94 
95 	return NULL;
96 }
97 
98 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
99 {
100 	unsigned char buf;
101 	int ret;
102 
103 	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
104 			      UAC2_CS_CUR,
105 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
106 			      UAC2_CX_CLOCK_SELECTOR << 8,
107 			      snd_usb_ctrl_intf(chip) | (selector_id << 8),
108 			      &buf, sizeof(buf), 1000);
109 
110 	if (ret < 0)
111 		return ret;
112 
113 	return buf;
114 }
115 
116 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
117 {
118 	int err;
119 	unsigned char data;
120 	struct usb_device *dev = chip->dev;
121 
122 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
123 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
124 			      UAC2_CS_CONTROL_CLOCK_VALID << 8,
125 			      snd_usb_ctrl_intf(chip) | (source_id << 8),
126 			      &data, sizeof(data), 1000);
127 
128 	if (err < 0) {
129 		snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
130 			   __func__, source_id);
131 		return err;
132 	}
133 
134 	return !!data;
135 }
136 
137 /* Try to find the clock source ID of a given clock entity */
138 
139 static int __uac_clock_find_source(struct snd_usb_audio *chip,
140 				   struct usb_host_interface *host_iface,
141 				   int entity_id, unsigned long *visited)
142 {
143 	struct uac_clock_source_descriptor *source;
144 	struct uac_clock_selector_descriptor *selector;
145 	struct uac_clock_multiplier_descriptor *multiplier;
146 
147 	entity_id &= 0xff;
148 
149 	if (test_and_set_bit(entity_id, visited)) {
150 		snd_printk(KERN_WARNING
151 			"%s(): recursive clock topology detected, id %d.\n",
152 			__func__, entity_id);
153 		return -EINVAL;
154 	}
155 
156 	/* first, see if the ID we're looking for is a clock source already */
157 	source = snd_usb_find_clock_source(host_iface, entity_id);
158 	if (source)
159 		return source->bClockID;
160 
161 	selector = snd_usb_find_clock_selector(host_iface, entity_id);
162 	if (selector) {
163 		int ret;
164 
165 		/* the entity ID we are looking for is a selector.
166 		 * find out what it currently selects */
167 		ret = uac_clock_selector_get_val(chip, selector->bClockID);
168 		if (ret < 0)
169 			return ret;
170 
171 		if (ret > selector->bNrInPins || ret < 1) {
172 			printk(KERN_ERR
173 				"%s(): selector reported illegal value, id %d, ret %d\n",
174 				__func__, selector->bClockID, ret);
175 
176 			return -EINVAL;
177 		}
178 
179 		return __uac_clock_find_source(chip, host_iface,
180 					       selector->baCSourceID[ret-1],
181 					       visited);
182 	}
183 
184 	/* FIXME: multipliers only act as pass-thru element for now */
185 	multiplier = snd_usb_find_clock_multiplier(host_iface, entity_id);
186 	if (multiplier)
187 		return __uac_clock_find_source(chip, host_iface,
188 					       multiplier->bCSourceID, visited);
189 
190 	return -EINVAL;
191 }
192 
193 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
194 			      struct usb_host_interface *host_iface,
195 			      int entity_id)
196 {
197 	DECLARE_BITMAP(visited, 256);
198 	memset(visited, 0, sizeof(visited));
199 	return __uac_clock_find_source(chip, host_iface, entity_id, visited);
200 }
201 
202 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
203 			      struct usb_host_interface *alts,
204 			      struct audioformat *fmt, int rate)
205 {
206 	struct usb_device *dev = chip->dev;
207 	unsigned int ep;
208 	unsigned char data[3];
209 	int err, crate;
210 
211 	ep = get_endpoint(alts, 0)->bEndpointAddress;
212 
213 	/* if endpoint doesn't have sampling rate control, bail out */
214 	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) {
215 		snd_printk(KERN_WARNING "%d:%d:%d: endpoint lacks sample rate attribute bit, cannot set.\n",
216 				   dev->devnum, iface, fmt->altsetting);
217 		return 0;
218 	}
219 
220 	data[0] = rate;
221 	data[1] = rate >> 8;
222 	data[2] = rate >> 16;
223 	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
224 				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
225 				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
226 				   data, sizeof(data), 1000)) < 0) {
227 		snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
228 			   dev->devnum, iface, fmt->altsetting, rate, ep);
229 		return err;
230 	}
231 
232 	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
233 				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
234 				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
235 				   data, sizeof(data), 1000)) < 0) {
236 		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
237 			   dev->devnum, iface, fmt->altsetting, ep);
238 		return 0; /* some devices don't support reading */
239 	}
240 
241 	crate = data[0] | (data[1] << 8) | (data[2] << 16);
242 	if (crate != rate) {
243 		snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
244 		// runtime->rate = crate;
245 	}
246 
247 	return 0;
248 }
249 
250 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
251 			      struct usb_host_interface *alts,
252 			      struct audioformat *fmt, int rate)
253 {
254 	struct usb_device *dev = chip->dev;
255 	unsigned char data[4];
256 	int err, crate;
257 	int clock = snd_usb_clock_find_source(chip, chip->ctrl_intf, fmt->clock);
258 
259 	if (clock < 0)
260 		return clock;
261 
262 	if (!uac_clock_source_is_valid(chip, clock)) {
263 		snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
264 			   dev->devnum, iface, fmt->altsetting, clock);
265 		return -ENXIO;
266 	}
267 
268 	data[0] = rate;
269 	data[1] = rate >> 8;
270 	data[2] = rate >> 16;
271 	data[3] = rate >> 24;
272 	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
273 				   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
274 				   UAC2_CS_CONTROL_SAM_FREQ << 8,
275 				   snd_usb_ctrl_intf(chip) | (clock << 8),
276 				   data, sizeof(data), 1000)) < 0) {
277 		snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
278 			   dev->devnum, iface, fmt->altsetting, rate);
279 		return err;
280 	}
281 
282 	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
283 				   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
284 				   UAC2_CS_CONTROL_SAM_FREQ << 8,
285 				   snd_usb_ctrl_intf(chip) | (clock << 8),
286 				   data, sizeof(data), 1000)) < 0) {
287 		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
288 			   dev->devnum, iface, fmt->altsetting);
289 		return err;
290 	}
291 
292 	crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
293 	if (crate != rate)
294 		snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
295 
296 	return 0;
297 }
298 
299 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
300 			     struct usb_host_interface *alts,
301 			     struct audioformat *fmt, int rate)
302 {
303 	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
304 
305 	switch (altsd->bInterfaceProtocol) {
306 	case UAC_VERSION_1:
307 		return set_sample_rate_v1(chip, iface, alts, fmt, rate);
308 
309 	case UAC_VERSION_2:
310 		return set_sample_rate_v2(chip, iface, alts, fmt, rate);
311 	}
312 
313 	return -EINVAL;
314 }
315 
316