sound/usb/clock.c

   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