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->bLength >= sizeof(*cs) && 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->bLength >= sizeof(*cs) && cs->bClockID == clock_id) { 63 if (cs->bLength < 5 + cs->bNrInPins) 64 return NULL; 65 return cs; 66 } 67 } 68 69 return NULL; 70 } 71 72 static struct uac_clock_multiplier_descriptor * 73 snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface, 74 int clock_id) 75 { 76 struct uac_clock_multiplier_descriptor *cs = NULL; 77 78 while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra, 79 ctrl_iface->extralen, 80 cs, UAC2_CLOCK_MULTIPLIER))) { 81 if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id) 82 return cs; 83 } 84 85 return NULL; 86 } 87 88 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id) 89 { 90 unsigned char buf; 91 int ret; 92 93 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), 94 UAC2_CS_CUR, 95 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN, 96 UAC2_CX_CLOCK_SELECTOR << 8, 97 snd_usb_ctrl_intf(chip) | (selector_id << 8), 98 &buf, sizeof(buf)); 99 100 if (ret < 0) 101 return ret; 102 103 return buf; 104 } 105 106 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id, 107 unsigned char pin) 108 { 109 int ret; 110 111 ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), 112 UAC2_CS_CUR, 113 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT, 114 UAC2_CX_CLOCK_SELECTOR << 8, 115 snd_usb_ctrl_intf(chip) | (selector_id << 8), 116 &pin, sizeof(pin)); 117 if (ret < 0) 118 return ret; 119 120 if (ret != sizeof(pin)) { 121 usb_audio_err(chip, 122 "setting selector (id %d) unexpected length %d\n", 123 selector_id, ret); 124 return -EINVAL; 125 } 126 127 ret = uac_clock_selector_get_val(chip, selector_id); 128 if (ret < 0) 129 return ret; 130 131 if (ret != pin) { 132 usb_audio_err(chip, 133 "setting selector (id %d) to %x failed (current: %d)\n", 134 selector_id, pin, ret); 135 return -EINVAL; 136 } 137 138 return ret; 139 } 140 141 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id) 142 { 143 int err; 144 unsigned char data; 145 struct usb_device *dev = chip->dev; 146 struct uac_clock_source_descriptor *cs_desc = 147 snd_usb_find_clock_source(chip->ctrl_intf, source_id); 148 149 if (!cs_desc) 150 return 0; 151 152 /* If a clock source can't tell us whether it's valid, we assume it is */ 153 if (!uac2_control_is_readable(cs_desc->bmControls, 154 UAC2_CS_CONTROL_CLOCK_VALID - 1)) 155 return 1; 156 157 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR, 158 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN, 159 UAC2_CS_CONTROL_CLOCK_VALID << 8, 160 snd_usb_ctrl_intf(chip) | (source_id << 8), 161 &data, sizeof(data)); 162 163 if (err < 0) { 164 dev_warn(&dev->dev, 165 "%s(): cannot get clock validity for id %d\n", 166 __func__, source_id); 167 return 0; 168 } 169 170 return !!data; 171 } 172 173 static int __uac_clock_find_source(struct snd_usb_audio *chip, 174 int entity_id, unsigned long *visited, 175 bool validate) 176 { 177 struct uac_clock_source_descriptor *source; 178 struct uac_clock_selector_descriptor *selector; 179 struct uac_clock_multiplier_descriptor *multiplier; 180 181 entity_id &= 0xff; 182 183 if (test_and_set_bit(entity_id, visited)) { 184 usb_audio_warn(chip, 185 "%s(): recursive clock topology detected, id %d.\n", 186 __func__, entity_id); 187 return -EINVAL; 188 } 189 190 /* first, see if the ID we're looking for is a clock source already */ 191 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id); 192 if (source) { 193 entity_id = source->bClockID; 194 if (validate && !uac_clock_source_is_valid(chip, entity_id)) { 195 usb_audio_err(chip, 196 "clock source %d is not valid, cannot use\n", 197 entity_id); 198 return -ENXIO; 199 } 200 return entity_id; 201 } 202 203 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id); 204 if (selector) { 205 int ret, i, cur; 206 207 /* the entity ID we are looking for is a selector. 208 * find out what it currently selects */ 209 ret = uac_clock_selector_get_val(chip, selector->bClockID); 210 if (ret < 0) 211 return ret; 212 213 /* Selector values are one-based */ 214 215 if (ret > selector->bNrInPins || ret < 1) { 216 usb_audio_err(chip, 217 "%s(): selector reported illegal value, id %d, ret %d\n", 218 __func__, selector->bClockID, ret); 219 220 return -EINVAL; 221 } 222 223 cur = ret; 224 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1], 225 visited, validate); 226 if (!validate || ret > 0 || !chip->autoclock) 227 return ret; 228 229 /* The current clock source is invalid, try others. */ 230 for (i = 1; i <= selector->bNrInPins; i++) { 231 int err; 232 233 if (i == cur) 234 continue; 235 236 ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1], 237 visited, true); 238 if (ret < 0) 239 continue; 240 241 err = uac_clock_selector_set_val(chip, entity_id, i); 242 if (err < 0) 243 continue; 244 245 usb_audio_info(chip, 246 "found and selected valid clock source %d\n", 247 ret); 248 return ret; 249 } 250 251 return -ENXIO; 252 } 253 254 /* FIXME: multipliers only act as pass-thru element for now */ 255 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id); 256 if (multiplier) 257 return __uac_clock_find_source(chip, multiplier->bCSourceID, 258 visited, validate); 259 260 return -EINVAL; 261 } 262 263 /* 264 * For all kinds of sample rate settings and other device queries, 265 * the clock source (end-leaf) must be used. However, clock selectors, 266 * clock multipliers and sample rate converters may be specified as 267 * clock source input to terminal. This functions walks the clock path 268 * to its end and tries to find the source. 269 * 270 * The 'visited' bitfield is used internally to detect recursive loops. 271 * 272 * Returns the clock source UnitID (>=0) on success, or an error. 273 */ 274 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id, 275 bool validate) 276 { 277 DECLARE_BITMAP(visited, 256); 278 memset(visited, 0, sizeof(visited)); 279 return __uac_clock_find_source(chip, entity_id, visited, validate); 280 } 281 282 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface, 283 struct usb_host_interface *alts, 284 struct audioformat *fmt, int rate) 285 { 286 struct usb_device *dev = chip->dev; 287 unsigned int ep; 288 unsigned char data[3]; 289 int err, crate; 290 291 if (get_iface_desc(alts)->bNumEndpoints < 1) 292 return -EINVAL; 293 ep = get_endpoint(alts, 0)->bEndpointAddress; 294 295 /* if endpoint doesn't have sampling rate control, bail out */ 296 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) 297 return 0; 298 299 data[0] = rate; 300 data[1] = rate >> 8; 301 data[2] = rate >> 16; 302 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR, 303 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT, 304 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, 305 data, sizeof(data))) < 0) { 306 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n", 307 iface, fmt->altsetting, rate, ep); 308 return err; 309 } 310 311 /* Don't check the sample rate for devices which we know don't 312 * support reading */ 313 if (snd_usb_get_sample_rate_quirk(chip)) 314 return 0; 315 /* the firmware is likely buggy, don't repeat to fail too many times */ 316 if (chip->sample_rate_read_error > 2) 317 return 0; 318 319 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR, 320 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN, 321 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, 322 data, sizeof(data))) < 0) { 323 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n", 324 iface, fmt->altsetting, ep); 325 chip->sample_rate_read_error++; 326 return 0; /* some devices don't support reading */ 327 } 328 329 crate = data[0] | (data[1] << 8) | (data[2] << 16); 330 if (crate != rate) { 331 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate); 332 // runtime->rate = crate; 333 } 334 335 return 0; 336 } 337 338 static int get_sample_rate_v2(struct snd_usb_audio *chip, int iface, 339 int altsetting, int clock) 340 { 341 struct usb_device *dev = chip->dev; 342 __le32 data; 343 int err; 344 345 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR, 346 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN, 347 UAC2_CS_CONTROL_SAM_FREQ << 8, 348 snd_usb_ctrl_intf(chip) | (clock << 8), 349 &data, sizeof(data)); 350 if (err < 0) { 351 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2): err %d\n", 352 iface, altsetting, err); 353 return 0; 354 } 355 356 return le32_to_cpu(data); 357 } 358 359 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface, 360 struct usb_host_interface *alts, 361 struct audioformat *fmt, int rate) 362 { 363 struct usb_device *dev = chip->dev; 364 __le32 data; 365 int err, cur_rate, prev_rate; 366 int clock; 367 bool writeable; 368 struct uac_clock_source_descriptor *cs_desc; 369 370 clock = snd_usb_clock_find_source(chip, fmt->clock, true); 371 if (clock < 0) 372 return clock; 373 374 prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock); 375 if (prev_rate == rate) 376 return 0; 377 378 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock); 379 writeable = uac2_control_is_writeable(cs_desc->bmControls, UAC2_CS_CONTROL_SAM_FREQ - 1); 380 if (writeable) { 381 data = cpu_to_le32(rate); 382 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR, 383 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT, 384 UAC2_CS_CONTROL_SAM_FREQ << 8, 385 snd_usb_ctrl_intf(chip) | (clock << 8), 386 &data, sizeof(data)); 387 if (err < 0) { 388 usb_audio_err(chip, 389 "%d:%d: cannot set freq %d (v2): err %d\n", 390 iface, fmt->altsetting, rate, err); 391 return err; 392 } 393 394 cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock); 395 } else { 396 cur_rate = prev_rate; 397 } 398 399 if (cur_rate != rate) { 400 if (!writeable) { 401 usb_audio_warn(chip, 402 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n", 403 iface, fmt->altsetting, rate, cur_rate); 404 return -ENXIO; 405 } 406 usb_audio_dbg(chip, 407 "current rate %d is different from the runtime rate %d\n", 408 cur_rate, rate); 409 } 410 411 /* Some devices doesn't respond to sample rate changes while the 412 * interface is active. */ 413 if (rate != prev_rate) { 414 usb_set_interface(dev, iface, 0); 415 snd_usb_set_interface_quirk(dev); 416 usb_set_interface(dev, iface, fmt->altsetting); 417 snd_usb_set_interface_quirk(dev); 418 } 419 420 return 0; 421 } 422 423 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface, 424 struct usb_host_interface *alts, 425 struct audioformat *fmt, int rate) 426 { 427 switch (fmt->protocol) { 428 case UAC_VERSION_1: 429 default: 430 return set_sample_rate_v1(chip, iface, alts, fmt, rate); 431 432 case UAC_VERSION_2: 433 return set_sample_rate_v2(chip, iface, alts, fmt, rate); 434 } 435 } 436 437