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 #include "quirks.h" 36 37 static struct uac_clock_source_descriptor * 38 snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface, 39 int clock_id) 40 { 41 struct uac_clock_source_descriptor *cs = NULL; 42 43 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra, 44 ctrl_iface->extralen, 45 cs, UAC2_CLOCK_SOURCE))) { 46 if (cs->bClockID == clock_id) 47 return cs; 48 } 49 50 return NULL; 51 } 52 53 static struct uac_clock_selector_descriptor * 54 snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface, 55 int clock_id) 56 { 57 struct uac_clock_selector_descriptor *cs = NULL; 58 59 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra, 60 ctrl_iface->extralen, 61 cs, UAC2_CLOCK_SELECTOR))) { 62 if (cs->bClockID == clock_id) 63 return cs; 64 } 65 66 return NULL; 67 } 68 69 static struct uac_clock_multiplier_descriptor * 70 snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface, 71 int clock_id) 72 { 73 struct uac_clock_multiplier_descriptor *cs = NULL; 74 75 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra, 76 ctrl_iface->extralen, 77 cs, UAC2_CLOCK_MULTIPLIER))) { 78 if (cs->bClockID == clock_id) 79 return cs; 80 } 81 82 return NULL; 83 } 84 85 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id) 86 { 87 unsigned char buf; 88 int ret; 89 90 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), 91 UAC2_CS_CUR, 92 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN, 93 UAC2_CX_CLOCK_SELECTOR << 8, 94 snd_usb_ctrl_intf(chip) | (selector_id << 8), 95 &buf, sizeof(buf)); 96 97 if (ret < 0) 98 return ret; 99 100 return buf; 101 } 102 103 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id, 104 unsigned char pin) 105 { 106 int ret; 107 108 ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), 109 UAC2_CS_CUR, 110 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT, 111 UAC2_CX_CLOCK_SELECTOR << 8, 112 snd_usb_ctrl_intf(chip) | (selector_id << 8), 113 &pin, sizeof(pin)); 114 if (ret < 0) 115 return ret; 116 117 if (ret != sizeof(pin)) { 118 snd_printk(KERN_ERR 119 "usb-audio:%d: setting selector (id %d) unexpected length %d\n", 120 chip->dev->devnum, selector_id, ret); 121 return -EINVAL; 122 } 123 124 ret = uac_clock_selector_get_val(chip, selector_id); 125 if (ret < 0) 126 return ret; 127 128 if (ret != pin) { 129 snd_printk(KERN_ERR 130 "usb-audio:%d: setting selector (id %d) to %x failed (current: %d)\n", 131 chip->dev->devnum, selector_id, pin, ret); 132 return -EINVAL; 133 } 134 135 return ret; 136 } 137 138 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id) 139 { 140 int err; 141 unsigned char data; 142 struct usb_device *dev = chip->dev; 143 struct uac_clock_source_descriptor *cs_desc = 144 snd_usb_find_clock_source(chip->ctrl_intf, source_id); 145 146 if (!cs_desc) 147 return 0; 148 149 /* If a clock source can't tell us whether it's valid, we assume it is */ 150 if (!uac2_control_is_readable(cs_desc->bmControls, 151 UAC2_CS_CONTROL_CLOCK_VALID - 1)) 152 return 1; 153 154 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR, 155 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN, 156 UAC2_CS_CONTROL_CLOCK_VALID << 8, 157 snd_usb_ctrl_intf(chip) | (source_id << 8), 158 &data, sizeof(data)); 159 160 if (err < 0) { 161 snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n", 162 __func__, source_id); 163 return 0; 164 } 165 166 return !!data; 167 } 168 169 static int __uac_clock_find_source(struct snd_usb_audio *chip, 170 int entity_id, unsigned long *visited, 171 bool validate) 172 { 173 struct uac_clock_source_descriptor *source; 174 struct uac_clock_selector_descriptor *selector; 175 struct uac_clock_multiplier_descriptor *multiplier; 176 177 entity_id &= 0xff; 178 179 if (test_and_set_bit(entity_id, visited)) { 180 snd_printk(KERN_WARNING 181 "%s(): recursive clock topology detected, id %d.\n", 182 __func__, entity_id); 183 return -EINVAL; 184 } 185 186 /* first, see if the ID we're looking for is a clock source already */ 187 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id); 188 if (source) { 189 entity_id = source->bClockID; 190 if (validate && !uac_clock_source_is_valid(chip, entity_id)) { 191 snd_printk(KERN_ERR "usb-audio:%d: clock source %d is not valid, cannot use\n", 192 chip->dev->devnum, entity_id); 193 return -ENXIO; 194 } 195 return entity_id; 196 } 197 198 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id); 199 if (selector) { 200 int ret, i, cur; 201 202 /* the entity ID we are looking for is a selector. 203 * find out what it currently selects */ 204 ret = uac_clock_selector_get_val(chip, selector->bClockID); 205 if (ret < 0) 206 return ret; 207 208 /* Selector values are one-based */ 209 210 if (ret > selector->bNrInPins || ret < 1) { 211 snd_printk(KERN_ERR 212 "%s(): selector reported illegal value, id %d, ret %d\n", 213 __func__, selector->bClockID, ret); 214 215 return -EINVAL; 216 } 217 218 cur = ret; 219 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1], 220 visited, validate); 221 if (!validate || ret > 0 || !chip->autoclock) 222 return ret; 223 224 /* The current clock source is invalid, try others. */ 225 for (i = 1; i <= selector->bNrInPins; i++) { 226 int err; 227 228 if (i == cur) 229 continue; 230 231 ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1], 232 visited, true); 233 if (ret < 0) 234 continue; 235 236 err = uac_clock_selector_set_val(chip, entity_id, i); 237 if (err < 0) 238 continue; 239 240 snd_printk(KERN_INFO 241 "usb-audio:%d: found and selected valid clock source %d\n", 242 chip->dev->devnum, ret); 243 return ret; 244 } 245 246 return -ENXIO; 247 } 248 249 /* FIXME: multipliers only act as pass-thru element for now */ 250 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id); 251 if (multiplier) 252 return __uac_clock_find_source(chip, multiplier->bCSourceID, 253 visited, validate); 254 255 return -EINVAL; 256 } 257 258 /* 259 * For all kinds of sample rate settings and other device queries, 260 * the clock source (end-leaf) must be used. However, clock selectors, 261 * clock multipliers and sample rate converters may be specified as 262 * clock source input to terminal. This functions walks the clock path 263 * to its end and tries to find the source. 264 * 265 * The 'visited' bitfield is used internally to detect recursive loops. 266 * 267 * Returns the clock source UnitID (>=0) on success, or an error. 268 */ 269 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id, 270 bool validate) 271 { 272 DECLARE_BITMAP(visited, 256); 273 memset(visited, 0, sizeof(visited)); 274 return __uac_clock_find_source(chip, entity_id, visited, validate); 275 } 276 277 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface, 278 struct usb_host_interface *alts, 279 struct audioformat *fmt, int rate) 280 { 281 struct usb_device *dev = chip->dev; 282 unsigned int ep; 283 unsigned char data[3]; 284 int err, crate; 285 286 ep = get_endpoint(alts, 0)->bEndpointAddress; 287 288 /* if endpoint doesn't have sampling rate control, bail out */ 289 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) 290 return 0; 291 292 data[0] = rate; 293 data[1] = rate >> 8; 294 data[2] = rate >> 16; 295 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR, 296 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT, 297 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, 298 data, sizeof(data))) < 0) { 299 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n", 300 dev->devnum, iface, fmt->altsetting, rate, ep); 301 return err; 302 } 303 304 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR, 305 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN, 306 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, 307 data, sizeof(data))) < 0) { 308 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n", 309 dev->devnum, iface, fmt->altsetting, ep); 310 return 0; /* some devices don't support reading */ 311 } 312 313 crate = data[0] | (data[1] << 8) | (data[2] << 16); 314 if (crate != rate) { 315 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate); 316 // runtime->rate = crate; 317 } 318 319 return 0; 320 } 321 322 static int get_sample_rate_v2(struct snd_usb_audio *chip, int iface, 323 int altsetting, int clock) 324 { 325 struct usb_device *dev = chip->dev; 326 __le32 data; 327 int err; 328 329 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR, 330 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN, 331 UAC2_CS_CONTROL_SAM_FREQ << 8, 332 snd_usb_ctrl_intf(chip) | (clock << 8), 333 &data, sizeof(data)); 334 if (err < 0) { 335 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2): err %d\n", 336 dev->devnum, iface, altsetting, err); 337 return 0; 338 } 339 340 return le32_to_cpu(data); 341 } 342 343 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface, 344 struct usb_host_interface *alts, 345 struct audioformat *fmt, int rate) 346 { 347 struct usb_device *dev = chip->dev; 348 __le32 data; 349 int err, cur_rate, prev_rate; 350 int clock; 351 bool writeable; 352 struct uac_clock_source_descriptor *cs_desc; 353 354 clock = snd_usb_clock_find_source(chip, fmt->clock, true); 355 if (clock < 0) 356 return clock; 357 358 prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock); 359 if (prev_rate == rate) 360 return 0; 361 362 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock); 363 writeable = uac2_control_is_writeable(cs_desc->bmControls, UAC2_CS_CONTROL_SAM_FREQ - 1); 364 if (writeable) { 365 data = cpu_to_le32(rate); 366 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR, 367 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT, 368 UAC2_CS_CONTROL_SAM_FREQ << 8, 369 snd_usb_ctrl_intf(chip) | (clock << 8), 370 &data, sizeof(data)); 371 if (err < 0) { 372 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2): err %d\n", 373 dev->devnum, iface, fmt->altsetting, rate, err); 374 return err; 375 } 376 377 cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock); 378 } else { 379 cur_rate = prev_rate; 380 } 381 382 if (cur_rate != rate) { 383 if (!writeable) { 384 snd_printk(KERN_WARNING 385 "%d:%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n", 386 dev->devnum, iface, fmt->altsetting, rate, cur_rate); 387 return -ENXIO; 388 } 389 snd_printd(KERN_WARNING 390 "current rate %d is different from the runtime rate %d\n", 391 cur_rate, rate); 392 } 393 394 /* Some devices doesn't respond to sample rate changes while the 395 * interface is active. */ 396 if (rate != prev_rate) { 397 usb_set_interface(dev, iface, 0); 398 snd_usb_set_interface_quirk(dev); 399 usb_set_interface(dev, iface, fmt->altsetting); 400 snd_usb_set_interface_quirk(dev); 401 } 402 403 return 0; 404 } 405 406 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface, 407 struct usb_host_interface *alts, 408 struct audioformat *fmt, int rate) 409 { 410 switch (fmt->protocol) { 411 case UAC_VERSION_1: 412 default: 413 return set_sample_rate_v1(chip, iface, alts, fmt, rate); 414 415 case UAC_VERSION_2: 416 return set_sample_rate_v2(chip, iface, alts, fmt, rate); 417 } 418 } 419 420