LXR linux/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
  37static 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
  53static 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
  69static 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
  85static 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
 103static 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
 138static 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
 170static 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 */
 271int 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
 279static 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
 331static 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
 352static 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
 416int 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
 430