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                 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