kernel/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->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         if (get_iface_desc(alts)->bNumEndpoints < 1)
 289                 return -EINVAL;
 290         ep = get_endpoint(alts, 0)->bEndpointAddress;
 291
 292         /* if endpoint doesn't have sampling rate control, bail out */
 293         if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
 294                 return 0;
 295
 296         data[0] = rate;
 297         data[1] = rate >> 8;
 298         data[2] = rate >> 16;
 299         if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
 300                                    USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
 301                                    UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 302                                    data, sizeof(data))) < 0) {
 303                 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
 304                         iface, fmt->altsetting, rate, ep);
 305                 return err;
 306         }
 307
 308         /* Don't check the sample rate for devices which we know don't
 309          * support reading */
 310         if (snd_usb_get_sample_rate_quirk(chip))
 311                 return 0;
 312
 313         if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
 314                                    USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
 315                                    UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 316                                    data, sizeof(data))) < 0) {
 317                 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
 318                         iface, fmt->altsetting, ep);
 319                 return 0; /* some devices don't support reading */
 320         }
 321
 322         crate = data[0] | (data[1] << 8) | (data[2] << 16);
 323         if (crate != rate) {
 324                 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
 325                 // runtime->rate = crate;
 326         }
 327
 328         return 0;
 329 }
 330
 331 static int get_sample_rate_v2(struct snd_usb_audio *chip, int iface,
 332                               int altsetting, int clock)
 333 {
 334         struct usb_device *dev = chip->dev;
 335         __le32 data;
 336         int err;
 337
 338         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 339                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 340                               UAC2_CS_CONTROL_SAM_FREQ << 8,
 341                               snd_usb_ctrl_intf(chip) | (clock << 8),
 342                               &data, sizeof(data));
 343         if (err < 0) {
 344                 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2): err %d\n",
 345                          iface, altsetting, err);
 346                 return 0;
 347         }
 348
 349         return le32_to_cpu(data);
 350 }
 351
 352 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
 353                               struct usb_host_interface *alts,
 354                               struct audioformat *fmt, int rate)
 355 {
 356         struct usb_device *dev = chip->dev;
 357         __le32 data;
 358         int err, cur_rate, prev_rate;
 359         int clock;
 360         bool writeable;
 361         struct uac_clock_source_descriptor *cs_desc;
 362
 363         clock = snd_usb_clock_find_source(chip, fmt->clock, true);
 364         if (clock < 0)
 365                 return clock;
 366
 367         prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
 368         if (prev_rate == rate)
 369                 return 0;
 370
 371         cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
 372         writeable = uac2_control_is_writeable(cs_desc->bmControls, UAC2_CS_CONTROL_SAM_FREQ - 1);
 373         if (writeable) {
 374                 data = cpu_to_le32(rate);
 375                 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
 376                                       USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 377                                       UAC2_CS_CONTROL_SAM_FREQ << 8,
 378                                       snd_usb_ctrl_intf(chip) | (clock << 8),
 379                                       &data, sizeof(data));
 380                 if (err < 0) {
 381                         usb_audio_err(chip,
 382                                 "%d:%d: cannot set freq %d (v2): err %d\n",
 383                                 iface, fmt->altsetting, rate, err);
 384                         return err;
 385                 }
 386
 387                 cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
 388         } else {
 389                 cur_rate = prev_rate;
 390         }
 391
 392         if (cur_rate != rate) {
 393                 if (!writeable) {
 394                         usb_audio_warn(chip,
 395                                  "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
 396                                  iface, fmt->altsetting, rate, cur_rate);
 397                         return -ENXIO;
 398                 }
 399                 usb_audio_dbg(chip,
 400                         "current rate %d is different from the runtime rate %d\n",
 401                         cur_rate, rate);
 402         }
 403
 404         /* Some devices doesn't respond to sample rate changes while the
 405          * interface is active. */
 406         if (rate != prev_rate) {
 407                 usb_set_interface(dev, iface, 0);
 408                 snd_usb_set_interface_quirk(dev);
 409                 usb_set_interface(dev, iface, fmt->altsetting);
 410                 snd_usb_set_interface_quirk(dev);
 411         }
 412
 413         return 0;
 414 }
 415
 416 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
 417                              struct usb_host_interface *alts,
 418                              struct audioformat *fmt, int rate)
 419 {
 420         switch (fmt->protocol) {
 421         case UAC_VERSION_1:
 422         default:
 423                 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
 424
 425         case UAC_VERSION_2:
 426                 return set_sample_rate_v2(chip, iface, alts, fmt, rate);
 427         }
 428 }
 429