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
  36 static struct uac_clock_source_descriptor *
  37         snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
  38                                   int clock_id)
  39 {
  40         struct uac_clock_source_descriptor *cs = NULL;
  41
  42         while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
  43                                              ctrl_iface->extralen,
  44                                              cs, UAC2_CLOCK_SOURCE))) {
  45                 if (cs->bClockID == clock_id)
  46                         return cs;
  47         }
  48
  49         return NULL;
  50 }
  51
  52 static struct uac_clock_selector_descriptor *
  53         snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
  54                                     int clock_id)
  55 {
  56         struct uac_clock_selector_descriptor *cs = NULL;
  57
  58         while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
  59                                              ctrl_iface->extralen,
  60                                              cs, UAC2_CLOCK_SELECTOR))) {
  61                 if (cs->bClockID == clock_id)
  62                         return cs;
  63         }
  64
  65         return NULL;
  66 }
  67
  68 static struct uac_clock_multiplier_descriptor *
  69         snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
  70                                       int clock_id)
  71 {
  72         struct uac_clock_multiplier_descriptor *cs = NULL;
  73
  74         while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
  75                                              ctrl_iface->extralen,
  76                                              cs, UAC2_CLOCK_MULTIPLIER))) {
  77                 if (cs->bClockID == clock_id)
  78                         return cs;
  79         }
  80
  81         return NULL;
  82 }
  83
  84 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
  85 {
  86         unsigned char buf;
  87         int ret;
  88
  89         ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
  90                               UAC2_CS_CUR,
  91                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
  92                               UAC2_CX_CLOCK_SELECTOR << 8,
  93                               snd_usb_ctrl_intf(chip) | (selector_id << 8),
  94                               &buf, sizeof(buf));
  95
  96         if (ret < 0)
  97                 return ret;
  98
  99         return buf;
 100 }
 101
 102 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
 103                                         unsigned char pin)
 104 {
 105         int ret;
 106
 107         ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
 108                               UAC2_CS_CUR,
 109                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
 110                               UAC2_CX_CLOCK_SELECTOR << 8,
 111                               snd_usb_ctrl_intf(chip) | (selector_id << 8),
 112                               &pin, sizeof(pin));
 113         if (ret < 0)
 114                 return ret;
 115
 116         if (ret != sizeof(pin)) {
 117                 snd_printk(KERN_ERR
 118                         "usb-audio:%d: setting selector (id %d) unexpected length %d\n",
 119                         chip->dev->devnum, selector_id, ret);
 120                 return -EINVAL;
 121         }
 122
 123         ret = uac_clock_selector_get_val(chip, selector_id);
 124         if (ret < 0)
 125                 return ret;
 126
 127         if (ret != pin) {
 128                 snd_printk(KERN_ERR
 129                         "usb-audio:%d: setting selector (id %d) to %x failed (current: %d)\n",
 130                         chip->dev->devnum, selector_id, pin, ret);
 131                 return -EINVAL;
 132         }
 133
 134         return ret;
 135 }
 136
 137 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
 138 {
 139         int err;
 140         unsigned char data;
 141         struct usb_device *dev = chip->dev;
 142         struct uac_clock_source_descriptor *cs_desc =
 143                 snd_usb_find_clock_source(chip->ctrl_intf, source_id);
 144
 145         if (!cs_desc)
 146                 return 0;
 147
 148         /* If a clock source can't tell us whether it's valid, we assume it is */
 149         if (!uac2_control_is_readable(cs_desc->bmControls,
 150                                       UAC2_CS_CONTROL_CLOCK_VALID - 1))
 151                 return 1;
 152
 153         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 154                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 155                               UAC2_CS_CONTROL_CLOCK_VALID << 8,
 156                               snd_usb_ctrl_intf(chip) | (source_id << 8),
 157                               &data, sizeof(data));
 158
 159         if (err < 0) {
 160                 snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
 161                            __func__, source_id);
 162                 return 0;
 163         }
 164
 165         return !!data;
 166 }
 167
 168 static int __uac_clock_find_source(struct snd_usb_audio *chip,
 169                                    int entity_id, unsigned long *visited,
 170                                    bool validate)
 171 {
 172         struct uac_clock_source_descriptor *source;
 173         struct uac_clock_selector_descriptor *selector;
 174         struct uac_clock_multiplier_descriptor *multiplier;
 175
 176         entity_id &= 0xff;
 177
 178         if (test_and_set_bit(entity_id, visited)) {
 179                 snd_printk(KERN_WARNING
 180                         "%s(): recursive clock topology detected, id %d.\n",
 181                         __func__, entity_id);
 182                 return -EINVAL;
 183         }
 184
 185         /* first, see if the ID we're looking for is a clock source already */
 186         source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
 187         if (source) {
 188                 entity_id = source->bClockID;
 189                 if (validate && !uac_clock_source_is_valid(chip, entity_id)) {
 190                         snd_printk(KERN_ERR "usb-audio:%d: clock source %d is not valid, cannot use\n",
 191                                    chip->dev->devnum, entity_id);
 192                         return -ENXIO;
 193                 }
 194                 return entity_id;
 195         }
 196
 197         selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
 198         if (selector) {
 199                 int ret, i, cur;
 200
 201                 /* the entity ID we are looking for is a selector.
 202                  * find out what it currently selects */
 203                 ret = uac_clock_selector_get_val(chip, selector->bClockID);
 204                 if (ret < 0)
 205                         return ret;
 206
 207                 /* Selector values are one-based */
 208
 209                 if (ret > selector->bNrInPins || ret < 1) {
 210                         snd_printk(KERN_ERR
 211                                 "%s(): selector reported illegal value, id %d, ret %d\n",
 212                                 __func__, selector->bClockID, ret);
 213
 214                         return -EINVAL;
 215                 }
 216
 217                 cur = ret;
 218                 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1],
 219                                                visited, validate);
 220                 if (!validate || ret > 0 || !chip->autoclock)
 221                         return ret;
 222
 223                 /* The current clock source is invalid, try others. */
 224                 for (i = 1; i <= selector->bNrInPins; i++) {
 225                         int err;
 226
 227                         if (i == cur)
 228                                 continue;
 229
 230                         ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1],
 231                                 visited, true);
 232                         if (ret < 0)
 233                                 continue;
 234
 235                         err = uac_clock_selector_set_val(chip, entity_id, i);
 236                         if (err < 0)
 237                                 continue;
 238
 239                         snd_printk(KERN_INFO
 240                                 "usb-audio:%d: found and selected valid clock source %d\n",
 241                                 chip->dev->devnum, ret);
 242                         return ret;
 243                 }
 244
 245                 return -ENXIO;
 246         }
 247
 248         /* FIXME: multipliers only act as pass-thru element for now */
 249         multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
 250         if (multiplier)
 251                 return __uac_clock_find_source(chip, multiplier->bCSourceID,
 252                                                 visited, validate);
 253
 254         return -EINVAL;
 255 }
 256
 257 /*
 258  * For all kinds of sample rate settings and other device queries,
 259  * the clock source (end-leaf) must be used. However, clock selectors,
 260  * clock multipliers and sample rate converters may be specified as
 261  * clock source input to terminal. This functions walks the clock path
 262  * to its end and tries to find the source.
 263  *
 264  * The 'visited' bitfield is used internally to detect recursive loops.
 265  *
 266  * Returns the clock source UnitID (>=0) on success, or an error.
 267  */
 268 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id,
 269                               bool validate)
 270 {
 271         DECLARE_BITMAP(visited, 256);
 272         memset(visited, 0, sizeof(visited));
 273         return __uac_clock_find_source(chip, entity_id, visited, validate);
 274 }
 275
 276 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
 277                               struct usb_host_interface *alts,
 278                               struct audioformat *fmt, int rate)
 279 {
 280         struct usb_device *dev = chip->dev;
 281         unsigned int ep;
 282         unsigned char data[3];
 283         int err, crate;
 284
 285         ep = get_endpoint(alts, 0)->bEndpointAddress;
 286
 287         /* if endpoint doesn't have sampling rate control, bail out */
 288         if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
 289                 return 0;
 290
 291         data[0] = rate;
 292         data[1] = rate >> 8;
 293         data[2] = rate >> 16;
 294         if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
 295                                    USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
 296                                    UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 297                                    data, sizeof(data))) < 0) {
 298                 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
 299                            dev->devnum, iface, fmt->altsetting, rate, ep);
 300                 return err;
 301         }
 302
 303         if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
 304                                    USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
 305                                    UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 306                                    data, sizeof(data))) < 0) {
 307                 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
 308                            dev->devnum, iface, fmt->altsetting, ep);
 309                 return 0; /* some devices don't support reading */
 310         }
 311
 312         crate = data[0] | (data[1] << 8) | (data[2] << 16);
 313         if (crate != rate) {
 314                 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
 315                 // runtime->rate = crate;
 316         }
 317
 318         return 0;
 319 }
 320
 321 static int get_sample_rate_v2(struct snd_usb_audio *chip, int iface,
 322                               int altsetting, int clock)
 323 {
 324         struct usb_device *dev = chip->dev;
 325         __le32 data;
 326         int err;
 327
 328         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 329                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 330                               UAC2_CS_CONTROL_SAM_FREQ << 8,
 331                               snd_usb_ctrl_intf(chip) | (clock << 8),
 332                               &data, sizeof(data));
 333         if (err < 0) {
 334                 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
 335                            dev->devnum, iface, altsetting);
 336                 return 0;
 337         }
 338
 339         return le32_to_cpu(data);
 340 }
 341
 342 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
 343                               struct usb_host_interface *alts,
 344                               struct audioformat *fmt, int rate)
 345 {
 346         struct usb_device *dev = chip->dev;
 347         __le32 data;
 348         int err, cur_rate, prev_rate;
 349         int clock;
 350
 351         clock = snd_usb_clock_find_source(chip, fmt->clock, true);
 352         if (clock < 0)
 353                 return clock;
 354
 355         prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
 356
 357         data = cpu_to_le32(rate);
 358         if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
 359                                    USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 360                                    UAC2_CS_CONTROL_SAM_FREQ << 8,
 361                                    snd_usb_ctrl_intf(chip) | (clock << 8),
 362                                    &data, sizeof(data))) < 0) {
 363                 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
 364                            dev->devnum, iface, fmt->altsetting, rate);
 365                 return err;
 366         }
 367
 368         cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
 369
 370         if (cur_rate != rate) {
 371                 snd_printd(KERN_WARNING
 372                            "current rate %d is different from the runtime rate %d\n",
 373                            cur_rate, rate);
 374         }
 375
 376         /* Some devices doesn't respond to sample rate changes while the
 377          * interface is active. */
 378         if (rate != prev_rate) {
 379                 usb_set_interface(dev, iface, 0);
 380                 usb_set_interface(dev, iface, fmt->altsetting);
 381         }
 382
 383         return 0;
 384 }
 385
 386 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
 387                              struct usb_host_interface *alts,
 388                              struct audioformat *fmt, int rate)
 389 {
 390         struct usb_interface_descriptor *altsd = get_iface_desc(alts);
 391
 392         switch (altsd->bInterfaceProtocol) {
 393         case UAC_VERSION_1:
 394         default:
 395                 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
 396
 397         case UAC_VERSION_2:
 398                 return set_sample_rate_v2(chip, iface, alts, fmt, rate);
 399         }
 400 }
 401