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 usb_audio_err(chip, 119 "setting selector (id %d) unexpected length %d\n", 120 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 usb_audio_err(chip, 130 "setting selector (id %d) to %x failed (current: %d)\n", 131 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 dev_warn(&dev->dev, 162 "%s(): cannot get clock validity for id %d\n", 163 __func__, source_id); 164 return 0; 165 } 166 167 return !!data; 168 } 169 170 static int __uac_clock_find_source(struct snd_usb_audio *chip, 171 int entity_id, unsigned long *visited, 172 bool validate) 173 { 174 struct uac_clock_source_descriptor *source; 175 struct uac_clock_selector_descriptor *selector; 176 struct uac_clock_multiplier_descriptor *multiplier; 177 178 entity_id &= 0xff; 179 180 if (test_and_set_bit(entity_id, visited)) { 181 usb_audio_warn(chip, 182 "%s(): recursive clock topology detected, id %d.\n", 183 __func__, entity_id); 184 return -EINVAL; 185 } 186 187 /* first, see if the ID we're looking for is a clock source already */ 188 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id); 189 if (source) { 190 entity_id = source->bClockID; 191 if (validate && !uac_clock_source_is_valid(chip, entity_id)) { 192 usb_audio_err(chip, 193 "clock source %d is not valid, cannot use\n", 194 entity_id); 195 return -ENXIO; 196 } 197 return entity_id; 198 } 199 200 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id); 201 if (selector) { 202 int ret, i, cur; 203 204 /* the entity ID we are looking for is a selector. 205 * find out what it currently selects */ 206 ret = uac_clock_selector_get_val(chip, selector->bClockID); 207 if (ret < 0) 208 return ret; 209 210 /* Selector values are one-based */ 211 212 if (ret > selector->bNrInPins || ret < 1) { 213 usb_audio_err(chip, 214 "%s(): selector reported illegal value, id %d, ret %d\n", 215 __func__, selector->bClockID, ret); 216 217 return -EINVAL; 218 } 219 220 cur = ret; 221 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1], 222 visited, validate); 223 if (!validate || ret > 0 || !chip->autoclock) 224 return ret; 225 226 /* The current clock source is invalid, try others. */ 227 for (i = 1; i <= selector->bNrInPins; i++) { 228 int err; 229 230 if (i == cur) 231 continue; 232 233 ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1], 234 visited, true); 235 if (ret < 0) 236 continue; 237 238 err = uac_clock_selector_set_val(chip, entity_id, i); 239 if (err < 0) 240 continue; 241 242 usb_audio_info(chip, 243 "found and selected valid clock source %d\n", 244 ret); 245 return ret; 246 } 247 248 return -ENXIO; 249 } 250 251 /* FIXME: multipliers only act as pass-thru element for now */ 252 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id); 253 if (multiplier) 254 return __uac_clock_find_source(chip, multiplier->bCSourceID, 255 visited, validate); 256 257 return -EINVAL; 258 } 259 260 /* 261 * For all kinds of sample rate settings and other device queries, 262 * the clock source (end-leaf) must be used. However, clock selectors, 263 * clock multipliers and sample rate converters may be specified as 264 * clock source input to terminal. This functions walks the clock path 265 * to its end and tries to find the source. 266 * 267 * The 'visited' bitfield is used internally to detect recursive loops. 268 * 269 * Returns the clock source UnitID (>=0) on success, or an error. 270 */ 271 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id, 272 bool validate) 273 { 274 DECLARE_BITMAP(visited, 256); 275 memset(visited, 0, sizeof(visited)); 276 return __uac_clock_find_source(chip, entity_id, visited, validate); 277 } 278 279 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface, 280 struct usb_host_interface *alts, 281 struct audioformat *fmt, int rate) 282 { 283 struct usb_device *dev = chip->dev; 284 unsigned int ep; 285 unsigned char data[3]; 286 int err, crate; 287 288 ep = get_endpoint(alts, 0)->bEndpointAddress; 289 290 /* if endpoint doesn't have sampling rate control, bail out */ 291 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) 292 return 0; 293 294 data[0] = rate; 295 data[1] = rate >> 8; 296 data[2] = rate >> 16; 297 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR, 298 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT, 299 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, 300 data, sizeof(data))) < 0) { 301 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n", 302 iface, fmt->altsetting, rate, ep); 303 return err; 304 } 305 306 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR, 307 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN, 308 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, 309 data, sizeof(data))) < 0) { 310 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n", 311 iface, fmt->altsetting, ep); 312 return 0; /* some devices don't support reading */ 313 } 314 315 crate = data[0] | (data[1] << 8) | (data[2] << 16); 316 if (crate != rate) { 317 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate); 318 // runtime->rate = crate; 319 } 320 321 return 0; 322 } 323 324 static int get_sample_rate_v2(struct snd_usb_audio *chip, int iface, 325 int altsetting, int clock) 326 { 327 struct usb_device *dev = chip->dev; 328 __le32 data; 329 int err; 330 331 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR, 332 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN, 333 UAC2_CS_CONTROL_SAM_FREQ << 8, 334 snd_usb_ctrl_intf(chip) | (clock << 8), 335 &data, sizeof(data)); 336 if (err < 0) { 337 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2): err %d\n", 338 iface, altsetting, err); 339 return 0; 340 } 341 342 return le32_to_cpu(data); 343 } 344 345 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface, 346 struct usb_host_interface *alts, 347 struct audioformat *fmt, int rate) 348 { 349 struct usb_device *dev = chip->dev; 350 __le32 data; 351 int err, cur_rate, prev_rate; 352 int clock; 353 bool writeable; 354 struct uac_clock_source_descriptor *cs_desc; 355 356 clock = snd_usb_clock_find_source(chip, fmt->clock, true); 357 if (clock < 0) 358 return clock; 359 360 prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock); 361 if (prev_rate == rate) 362 return 0; 363 364 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock); 365 writeable = uac2_control_is_writeable(cs_desc->bmControls, UAC2_CS_CONTROL_SAM_FREQ - 1); 366 if (writeable) { 367 data = cpu_to_le32(rate); 368 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR, 369 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT, 370 UAC2_CS_CONTROL_SAM_FREQ << 8, 371 snd_usb_ctrl_intf(chip) | (clock << 8), 372 &data, sizeof(data)); 373 if (err < 0) { 374 usb_audio_err(chip, 375 "%d:%d: cannot set freq %d (v2): err %d\n", 376 iface, fmt->altsetting, rate, err); 377 return err; 378 } 379 380 cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock); 381 } else { 382 cur_rate = prev_rate; 383 } 384 385 if (cur_rate != rate) { 386 if (!writeable) { 387 usb_audio_warn(chip, 388 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n", 389 iface, fmt->altsetting, rate, cur_rate); 390 return -ENXIO; 391 } 392 usb_audio_dbg(chip, 393 "current rate %d is different from the runtime rate %d\n", 394 cur_rate, rate); 395 } 396 397 /* Some devices doesn't respond to sample rate changes while the 398 * interface is active. */ 399 if (rate != prev_rate) { 400 usb_set_interface(dev, iface, 0); 401 snd_usb_set_interface_quirk(dev); 402 usb_set_interface(dev, iface, fmt->altsetting); 403 snd_usb_set_interface_quirk(dev); 404 } 405 406 return 0; 407 } 408 409 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface, 410 struct usb_host_interface *alts, 411 struct audioformat *fmt, int rate) 412 { 413 switch (fmt->protocol) { 414 case UAC_VERSION_1: 415 default: 416 return set_sample_rate_v1(chip, iface, alts, fmt, rate); 417 418 case UAC_VERSION_2: 419 return set_sample_rate_v2(chip, iface, alts, fmt, rate); 420 } 421 } 422 423