sound/core/vmaster.c

   1 /*
   2  * Virtual master and slave controls
   3  *
   4  *  Copyright (c) 2008 by Takashi Iwai <tiwai@suse.de>
   5  *
   6  *  This program is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU General Public License as
   8  *  published by the Free Software Foundation, version 2.
   9  *
  10  */
  11
  12 #include <linux/slab.h>
  13 #include <linux/export.h>
  14 #include <sound/core.h>
  15 #include <sound/control.h>
  16 #include <sound/tlv.h>
  17
  18 /*
  19  * a subset of information returned via ctl info callback
  20  */
  21 struct link_ctl_info {
  22         snd_ctl_elem_type_t type; /* value type */
  23         int count;              /* item count */
  24         int min_val, max_val;   /* min, max values */
  25 };
  26
  27 /*
  28  * link master - this contains a list of slave controls that are
  29  * identical types, i.e. info returns the same value type and value
  30  * ranges, but may have different number of counts.
  31  *
  32  * The master control is so far only mono volume/switch for simplicity.
  33  * The same value will be applied to all slaves.
  34  */
  35 struct link_master {
  36         struct list_head slaves;
  37         struct link_ctl_info info;
  38         int val;                /* the master value */
  39         unsigned int tlv[4];
  40         void (*hook)(void *private_data, int);
  41         void *hook_private_data;
  42 };
  43
  44 /*
  45  * link slave - this contains a slave control element
  46  *
  47  * It fakes the control callbacsk with additional attenuation by the
  48  * master control.  A slave may have either one or two channels.
  49  */
  50
  51 struct link_slave {
  52         struct list_head list;
  53         struct link_master *master;
  54         struct link_ctl_info info;
  55         int vals[2];            /* current values */
  56         unsigned int flags;
  57         struct snd_kcontrol *kctl; /* original kcontrol pointer */
  58         struct snd_kcontrol slave; /* the copy of original control entry */
  59 };
  60
  61 static int slave_update(struct link_slave *slave)
  62 {
  63         struct snd_ctl_elem_value *uctl;
  64         int err, ch;
  65
  66         uctl = kmalloc(sizeof(*uctl), GFP_KERNEL);
  67         if (!uctl)
  68                 return -ENOMEM;
  69         uctl->id = slave->slave.id;
  70         err = slave->slave.get(&slave->slave, uctl);
  71         if (err < 0)
  72                 goto error;
  73         for (ch = 0; ch < slave->info.count; ch++)
  74                 slave->vals[ch] = uctl->value.integer.value[ch];
  75  error:
  76         kfree(uctl);
  77         return err < 0 ? err : 0;
  78 }
  79
  80 /* get the slave ctl info and save the initial values */
  81 static int slave_init(struct link_slave *slave)
  82 {
  83         struct snd_ctl_elem_info *uinfo;
  84         int err;
  85
  86         if (slave->info.count) {
  87                 /* already initialized */
  88                 if (slave->flags & SND_CTL_SLAVE_NEED_UPDATE)
  89                         return slave_update(slave);
  90                 return 0;
  91         }
  92
  93         uinfo = kmalloc(sizeof(*uinfo), GFP_KERNEL);
  94         if (!uinfo)
  95                 return -ENOMEM;
  96         uinfo->id = slave->slave.id;
  97         err = slave->slave.info(&slave->slave, uinfo);
  98         if (err < 0) {
  99                 kfree(uinfo);
 100                 return err;
 101         }
 102         slave->info.type = uinfo->type;
 103         slave->info.count = uinfo->count;
 104         if (slave->info.count > 2  ||
 105             (slave->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER &&
 106              slave->info.type != SNDRV_CTL_ELEM_TYPE_BOOLEAN)) {
 107                 pr_err("ALSA: vmaster: invalid slave element\n");
 108                 kfree(uinfo);
 109                 return -EINVAL;
 110         }
 111         slave->info.min_val = uinfo->value.integer.min;
 112         slave->info.max_val = uinfo->value.integer.max;
 113         kfree(uinfo);
 114
 115         return slave_update(slave);
 116 }
 117
 118 /* initialize master volume */
 119 static int master_init(struct link_master *master)
 120 {
 121         struct link_slave *slave;
 122
 123         if (master->info.count)
 124                 return 0; /* already initialized */
 125
 126         list_for_each_entry(slave, &master->slaves, list) {
 127                 int err = slave_init(slave);
 128                 if (err < 0)
 129                         return err;
 130                 master->info = slave->info;
 131                 master->info.count = 1; /* always mono */
 132                 /* set full volume as default (= no attenuation) */
 133                 master->val = master->info.max_val;
 134                 if (master->hook)
 135                         master->hook(master->hook_private_data, master->val);
 136                 return 1;
 137         }
 138         return -ENOENT;
 139 }
 140
 141 static int slave_get_val(struct link_slave *slave,
 142                          struct snd_ctl_elem_value *ucontrol)
 143 {
 144         int err, ch;
 145
 146         err = slave_init(slave);
 147         if (err < 0)
 148                 return err;
 149         for (ch = 0; ch < slave->info.count; ch++)
 150                 ucontrol->value.integer.value[ch] = slave->vals[ch];
 151         return 0;
 152 }
 153
 154 static int slave_put_val(struct link_slave *slave,
 155                          struct snd_ctl_elem_value *ucontrol)
 156 {
 157         int err, ch, vol;
 158
 159         err = master_init(slave->master);
 160         if (err < 0)
 161                 return err;
 162
 163         switch (slave->info.type) {
 164         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 165                 for (ch = 0; ch < slave->info.count; ch++)
 166                         ucontrol->value.integer.value[ch] &=
 167                                 !!slave->master->val;
 168                 break;
 169         case SNDRV_CTL_ELEM_TYPE_INTEGER:
 170                 for (ch = 0; ch < slave->info.count; ch++) {
 171                         /* max master volume is supposed to be 0 dB */
 172                         vol = ucontrol->value.integer.value[ch];
 173                         vol += slave->master->val - slave->master->info.max_val;
 174                         if (vol < slave->info.min_val)
 175                                 vol = slave->info.min_val;
 176                         else if (vol > slave->info.max_val)
 177                                 vol = slave->info.max_val;
 178                         ucontrol->value.integer.value[ch] = vol;
 179                 }
 180                 break;
 181         }
 182         return slave->slave.put(&slave->slave, ucontrol);
 183 }
 184
 185 /*
 186  * ctl callbacks for slaves
 187  */
 188 static int slave_info(struct snd_kcontrol *kcontrol,
 189                       struct snd_ctl_elem_info *uinfo)
 190 {
 191         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 192         return slave->slave.info(&slave->slave, uinfo);
 193 }
 194
 195 static int slave_get(struct snd_kcontrol *kcontrol,
 196                      struct snd_ctl_elem_value *ucontrol)
 197 {
 198         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 199         return slave_get_val(slave, ucontrol);
 200 }
 201
 202 static int slave_put(struct snd_kcontrol *kcontrol,
 203                      struct snd_ctl_elem_value *ucontrol)
 204 {
 205         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 206         int err, ch, changed = 0;
 207
 208         err = slave_init(slave);
 209         if (err < 0)
 210                 return err;
 211         for (ch = 0; ch < slave->info.count; ch++) {
 212                 if (slave->vals[ch] != ucontrol->value.integer.value[ch]) {
 213                         changed = 1;
 214                         slave->vals[ch] = ucontrol->value.integer.value[ch];
 215                 }
 216         }
 217         if (!changed)
 218                 return 0;
 219         err = slave_put_val(slave, ucontrol);
 220         if (err < 0)
 221                 return err;
 222         return 1;
 223 }
 224
 225 static int slave_tlv_cmd(struct snd_kcontrol *kcontrol,
 226                          int op_flag, unsigned int size,
 227                          unsigned int __user *tlv)
 228 {
 229         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 230         /* FIXME: this assumes that the max volume is 0 dB */
 231         return slave->slave.tlv.c(&slave->slave, op_flag, size, tlv);
 232 }
 233
 234 static void slave_free(struct snd_kcontrol *kcontrol)
 235 {
 236         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 237         if (slave->slave.private_free)
 238                 slave->slave.private_free(&slave->slave);
 239         if (slave->master)
 240                 list_del(&slave->list);
 241         kfree(slave);
 242 }
 243
 244 /*
 245  * Add a slave control to the group with the given master control
 246  *
 247  * All slaves must be the same type (returning the same information
 248  * via info callback).  The function doesn't check it, so it's your
 249  * responsibility.
 250  *
 251  * Also, some additional limitations:
 252  * - at most two channels
 253  * - logarithmic volume control (dB level), no linear volume
 254  * - master can only attenuate the volume, no gain
 255  */
 256 int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
 257                        unsigned int flags)
 258 {
 259         struct link_master *master_link = snd_kcontrol_chip(master);
 260         struct link_slave *srec;
 261
 262         srec = kzalloc(sizeof(*srec) +
 263                        slave->count * sizeof(*slave->vd), GFP_KERNEL);
 264         if (!srec)
 265                 return -ENOMEM;
 266         srec->kctl = slave;
 267         srec->slave = *slave;
 268         memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd));
 269         srec->master = master_link;
 270         srec->flags = flags;
 271
 272         /* override callbacks */
 273         slave->info = slave_info;
 274         slave->get = slave_get;
 275         slave->put = slave_put;
 276         if (slave->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK)
 277                 slave->tlv.c = slave_tlv_cmd;
 278         slave->private_data = srec;
 279         slave->private_free = slave_free;
 280
 281         list_add_tail(&srec->list, &master_link->slaves);
 282         return 0;
 283 }
 284 EXPORT_SYMBOL(_snd_ctl_add_slave);
 285
 286 /*
 287  * ctl callbacks for master controls
 288  */
 289 static int master_info(struct snd_kcontrol *kcontrol,
 290                       struct snd_ctl_elem_info *uinfo)
 291 {
 292         struct link_master *master = snd_kcontrol_chip(kcontrol);
 293         int ret;
 294
 295         ret = master_init(master);
 296         if (ret < 0)
 297                 return ret;
 298         uinfo->type = master->info.type;
 299         uinfo->count = master->info.count;
 300         uinfo->value.integer.min = master->info.min_val;
 301         uinfo->value.integer.max = master->info.max_val;
 302         return 0;
 303 }
 304
 305 static int master_get(struct snd_kcontrol *kcontrol,
 306                       struct snd_ctl_elem_value *ucontrol)
 307 {
 308         struct link_master *master = snd_kcontrol_chip(kcontrol);
 309         int err = master_init(master);
 310         if (err < 0)
 311                 return err;
 312         ucontrol->value.integer.value[0] = master->val;
 313         return 0;
 314 }
 315
 316 static int sync_slaves(struct link_master *master, int old_val, int new_val)
 317 {
 318         struct link_slave *slave;
 319         struct snd_ctl_elem_value *uval;
 320
 321         uval = kmalloc(sizeof(*uval), GFP_KERNEL);
 322         if (!uval)
 323                 return -ENOMEM;
 324         list_for_each_entry(slave, &master->slaves, list) {
 325                 master->val = old_val;
 326                 uval->id = slave->slave.id;
 327                 slave_get_val(slave, uval);
 328                 master->val = new_val;
 329                 slave_put_val(slave, uval);
 330         }
 331         kfree(uval);
 332         return 0;
 333 }
 334
 335 static int master_put(struct snd_kcontrol *kcontrol,
 336                       struct snd_ctl_elem_value *ucontrol)
 337 {
 338         struct link_master *master = snd_kcontrol_chip(kcontrol);
 339         int err, new_val, old_val;
 340         bool first_init;
 341
 342         err = master_init(master);
 343         if (err < 0)
 344                 return err;
 345         first_init = err;
 346         old_val = master->val;
 347         new_val = ucontrol->value.integer.value[0];
 348         if (new_val == old_val)
 349                 return 0;
 350
 351         err = sync_slaves(master, old_val, new_val);
 352         if (err < 0)
 353                 return err;
 354         if (master->hook && !first_init)
 355                 master->hook(master->hook_private_data, master->val);
 356         return 1;
 357 }
 358
 359 static void master_free(struct snd_kcontrol *kcontrol)
 360 {
 361         struct link_master *master = snd_kcontrol_chip(kcontrol);
 362         struct link_slave *slave, *n;
 363
 364         /* free all slave links and retore the original slave kctls */
 365         list_for_each_entry_safe(slave, n, &master->slaves, list) {
 366                 struct snd_kcontrol *sctl = slave->kctl;
 367                 struct list_head olist = sctl->list;
 368                 memcpy(sctl, &slave->slave, sizeof(*sctl));
 369                 memcpy(sctl->vd, slave->slave.vd,
 370                        sctl->count * sizeof(*sctl->vd));
 371                 sctl->list = olist; /* keep the current linked-list */
 372                 kfree(slave);
 373         }
 374         kfree(master);
 375 }
 376
 377
 378 /**
 379  * snd_ctl_make_virtual_master - Create a virtual master control
 380  * @name: name string of the control element to create
 381  * @tlv: optional TLV int array for dB information
 382  *
 383  * Creates a virtual master control with the given name string.
 384  *
 385  * After creating a vmaster element, you can add the slave controls
 386  * via snd_ctl_add_slave() or snd_ctl_add_slave_uncached().
 387  *
 388  * The optional argument @tlv can be used to specify the TLV information
 389  * for dB scale of the master control.  It should be a single element
 390  * with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or
 391  * #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB.
 392  *
 393  * Return: The created control element, or %NULL for errors (ENOMEM).
 394  */
 395 struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
 396                                                  const unsigned int *tlv)
 397 {
 398         struct link_master *master;
 399         struct snd_kcontrol *kctl;
 400         struct snd_kcontrol_new knew;
 401
 402         memset(&knew, 0, sizeof(knew));
 403         knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
 404         knew.name = name;
 405         knew.info = master_info;
 406
 407         master = kzalloc(sizeof(*master), GFP_KERNEL);
 408         if (!master)
 409                 return NULL;
 410         INIT_LIST_HEAD(&master->slaves);
 411
 412         kctl = snd_ctl_new1(&knew, master);
 413         if (!kctl) {
 414                 kfree(master);
 415                 return NULL;
 416         }
 417         /* override some callbacks */
 418         kctl->info = master_info;
 419         kctl->get = master_get;
 420         kctl->put = master_put;
 421         kctl->private_free = master_free;
 422
 423         /* additional (constant) TLV read */
 424         if (tlv &&
 425             (tlv[0] == SNDRV_CTL_TLVT_DB_SCALE ||
 426              tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX ||
 427              tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX_MUTE)) {
 428                 kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
 429                 memcpy(master->tlv, tlv, sizeof(master->tlv));
 430                 kctl->tlv.p = master->tlv;
 431         }
 432
 433         return kctl;
 434 }
 435 EXPORT_SYMBOL(snd_ctl_make_virtual_master);
 436
 437 /**
 438  * snd_ctl_add_vmaster_hook - Add a hook to a vmaster control
 439  * @kcontrol: vmaster kctl element
 440  * @hook: the hook function
 441  * @private_data: the private_data pointer to be saved
 442  *
 443  * Adds the given hook to the vmaster control element so that it's called
 444  * at each time when the value is changed.
 445  *
 446  * Return: Zero.
 447  */
 448 int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol,
 449                              void (*hook)(void *private_data, int),
 450                              void *private_data)
 451 {
 452         struct link_master *master = snd_kcontrol_chip(kcontrol);
 453         master->hook = hook;
 454         master->hook_private_data = private_data;
 455         return 0;
 456 }
 457 EXPORT_SYMBOL_GPL(snd_ctl_add_vmaster_hook);
 458
 459 /**
 460  * snd_ctl_sync_vmaster - Sync the vmaster slaves and hook
 461  * @kcontrol: vmaster kctl element
 462  * @hook_only: sync only the hook
 463  *
 464  * Forcibly call the put callback of each slave and call the hook function
 465  * to synchronize with the current value of the given vmaster element.
 466  * NOP when NULL is passed to @kcontrol.
 467  */
 468 void snd_ctl_sync_vmaster(struct snd_kcontrol *kcontrol, bool hook_only)
 469 {
 470         struct link_master *master;
 471         bool first_init = false;
 472
 473         if (!kcontrol)
 474                 return;
 475         master = snd_kcontrol_chip(kcontrol);
 476         if (!hook_only) {
 477                 int err = master_init(master);
 478                 if (err < 0)
 479                         return;
 480                 first_init = err;
 481                 err = sync_slaves(master, master->val, master->val);
 482                 if (err < 0)
 483                         return;
 484         }
 485
 486         if (master->hook && !first_init)
 487                 master->hook(master->hook_private_data, master->val);
 488 }
 489 EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster);
 490
 491 /**
 492  * snd_ctl_apply_vmaster_slaves - Apply function to each vmaster slave
 493  * @kctl: vmaster kctl element
 494  * @func: function to apply
 495  * @arg: optional function argument
 496  *
 497  * Apply the function @func to each slave kctl of the given vmaster kctl.
 498  * Returns 0 if successful, or a negative error code.
 499  */
 500 int snd_ctl_apply_vmaster_slaves(struct snd_kcontrol *kctl,
 501                                  int (*func)(struct snd_kcontrol *vslave,
 502                                              struct snd_kcontrol *slave,
 503                                              void *arg),
 504                                  void *arg)
 505 {
 506         struct link_master *master;
 507         struct link_slave *slave;
 508         int err;
 509
 510         master = snd_kcontrol_chip(kctl);
 511         err = master_init(master);
 512         if (err < 0)
 513                 return err;
 514         list_for_each_entry(slave, &master->slaves, list) {
 515                 err = func(slave->kctl, &slave->slave, arg);
 516                 if (err < 0)
 517                         return err;
 518         }
 519
 520         return 0;
 521 }
 522 EXPORT_SYMBOL_GPL(snd_ctl_apply_vmaster_slaves);