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         for (ch = 0; ch < slave->info.count; ch++)
  72                 slave->vals[ch] = uctl->value.integer.value[ch];
  73         kfree(uctl);
  74         return 0;
  75 }
  76
  77 /* get the slave ctl info and save the initial values */
  78 static int slave_init(struct link_slave *slave)
  79 {
  80         struct snd_ctl_elem_info *uinfo;
  81         int err;
  82
  83         if (slave->info.count) {
  84                 /* already initialized */
  85                 if (slave->flags & SND_CTL_SLAVE_NEED_UPDATE)
  86                         return slave_update(slave);
  87                 return 0;
  88         }
  89
  90         uinfo = kmalloc(sizeof(*uinfo), GFP_KERNEL);
  91         if (!uinfo)
  92                 return -ENOMEM;
  93         uinfo->id = slave->slave.id;
  94         err = slave->slave.info(&slave->slave, uinfo);
  95         if (err < 0) {
  96                 kfree(uinfo);
  97                 return err;
  98         }
  99         slave->info.type = uinfo->type;
 100         slave->info.count = uinfo->count;
 101         if (slave->info.count > 2  ||
 102             (slave->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER &&
 103              slave->info.type != SNDRV_CTL_ELEM_TYPE_BOOLEAN)) {
 104                 pr_err("ALSA: vmaster: invalid slave element\n");
 105                 kfree(uinfo);
 106                 return -EINVAL;
 107         }
 108         slave->info.min_val = uinfo->value.integer.min;
 109         slave->info.max_val = uinfo->value.integer.max;
 110         kfree(uinfo);
 111
 112         return slave_update(slave);
 113 }
 114
 115 /* initialize master volume */
 116 static int master_init(struct link_master *master)
 117 {
 118         struct link_slave *slave;
 119
 120         if (master->info.count)
 121                 return 0; /* already initialized */
 122
 123         list_for_each_entry(slave, &master->slaves, list) {
 124                 int err = slave_init(slave);
 125                 if (err < 0)
 126                         return err;
 127                 master->info = slave->info;
 128                 master->info.count = 1; /* always mono */
 129                 /* set full volume as default (= no attenuation) */
 130                 master->val = master->info.max_val;
 131                 if (master->hook)
 132                         master->hook(master->hook_private_data, master->val);
 133                 return 1;
 134         }
 135         return -ENOENT;
 136 }
 137
 138 static int slave_get_val(struct link_slave *slave,
 139                          struct snd_ctl_elem_value *ucontrol)
 140 {
 141         int err, ch;
 142
 143         err = slave_init(slave);
 144         if (err < 0)
 145                 return err;
 146         for (ch = 0; ch < slave->info.count; ch++)
 147                 ucontrol->value.integer.value[ch] = slave->vals[ch];
 148         return 0;
 149 }
 150
 151 static int slave_put_val(struct link_slave *slave,
 152                          struct snd_ctl_elem_value *ucontrol)
 153 {
 154         int err, ch, vol;
 155
 156         err = master_init(slave->master);
 157         if (err < 0)
 158                 return err;
 159
 160         switch (slave->info.type) {
 161         case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
 162                 for (ch = 0; ch < slave->info.count; ch++)
 163                         ucontrol->value.integer.value[ch] &=
 164                                 !!slave->master->val;
 165                 break;
 166         case SNDRV_CTL_ELEM_TYPE_INTEGER:
 167                 for (ch = 0; ch < slave->info.count; ch++) {
 168                         /* max master volume is supposed to be 0 dB */
 169                         vol = ucontrol->value.integer.value[ch];
 170                         vol += slave->master->val - slave->master->info.max_val;
 171                         if (vol < slave->info.min_val)
 172                                 vol = slave->info.min_val;
 173                         else if (vol > slave->info.max_val)
 174                                 vol = slave->info.max_val;
 175                         ucontrol->value.integer.value[ch] = vol;
 176                 }
 177                 break;
 178         }
 179         return slave->slave.put(&slave->slave, ucontrol);
 180 }
 181
 182 /*
 183  * ctl callbacks for slaves
 184  */
 185 static int slave_info(struct snd_kcontrol *kcontrol,
 186                       struct snd_ctl_elem_info *uinfo)
 187 {
 188         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 189         return slave->slave.info(&slave->slave, uinfo);
 190 }
 191
 192 static int slave_get(struct snd_kcontrol *kcontrol,
 193                      struct snd_ctl_elem_value *ucontrol)
 194 {
 195         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 196         return slave_get_val(slave, ucontrol);
 197 }
 198
 199 static int slave_put(struct snd_kcontrol *kcontrol,
 200                      struct snd_ctl_elem_value *ucontrol)
 201 {
 202         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 203         int err, ch, changed = 0;
 204
 205         err = slave_init(slave);
 206         if (err < 0)
 207                 return err;
 208         for (ch = 0; ch < slave->info.count; ch++) {
 209                 if (slave->vals[ch] != ucontrol->value.integer.value[ch]) {
 210                         changed = 1;
 211                         slave->vals[ch] = ucontrol->value.integer.value[ch];
 212                 }
 213         }
 214         if (!changed)
 215                 return 0;
 216         err = slave_put_val(slave, ucontrol);
 217         if (err < 0)
 218                 return err;
 219         return 1;
 220 }
 221
 222 static int slave_tlv_cmd(struct snd_kcontrol *kcontrol,
 223                          int op_flag, unsigned int size,
 224                          unsigned int __user *tlv)
 225 {
 226         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 227         /* FIXME: this assumes that the max volume is 0 dB */
 228         return slave->slave.tlv.c(&slave->slave, op_flag, size, tlv);
 229 }
 230
 231 static void slave_free(struct snd_kcontrol *kcontrol)
 232 {
 233         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 234         if (slave->slave.private_free)
 235                 slave->slave.private_free(&slave->slave);
 236         if (slave->master)
 237                 list_del(&slave->list);
 238         kfree(slave);
 239 }
 240
 241 /*
 242  * Add a slave control to the group with the given master control
 243  *
 244  * All slaves must be the same type (returning the same information
 245  * via info callback).  The function doesn't check it, so it's your
 246  * responsibility.
 247  *
 248  * Also, some additional limitations:
 249  * - at most two channels
 250  * - logarithmic volume control (dB level), no linear volume
 251  * - master can only attenuate the volume, no gain
 252  */
 253 int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
 254                        unsigned int flags)
 255 {
 256         struct link_master *master_link = snd_kcontrol_chip(master);
 257         struct link_slave *srec;
 258
 259         srec = kzalloc(sizeof(*srec) +
 260                        slave->count * sizeof(*slave->vd), GFP_KERNEL);
 261         if (!srec)
 262                 return -ENOMEM;
 263         srec->kctl = slave;
 264         srec->slave = *slave;
 265         memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd));
 266         srec->master = master_link;
 267         srec->flags = flags;
 268
 269         /* override callbacks */
 270         slave->info = slave_info;
 271         slave->get = slave_get;
 272         slave->put = slave_put;
 273         if (slave->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK)
 274                 slave->tlv.c = slave_tlv_cmd;
 275         slave->private_data = srec;
 276         slave->private_free = slave_free;
 277
 278         list_add_tail(&srec->list, &master_link->slaves);
 279         return 0;
 280 }
 281 EXPORT_SYMBOL(_snd_ctl_add_slave);
 282
 283 /*
 284  * ctl callbacks for master controls
 285  */
 286 static int master_info(struct snd_kcontrol *kcontrol,
 287                       struct snd_ctl_elem_info *uinfo)
 288 {
 289         struct link_master *master = snd_kcontrol_chip(kcontrol);
 290         int ret;
 291
 292         ret = master_init(master);
 293         if (ret < 0)
 294                 return ret;
 295         uinfo->type = master->info.type;
 296         uinfo->count = master->info.count;
 297         uinfo->value.integer.min = master->info.min_val;
 298         uinfo->value.integer.max = master->info.max_val;
 299         return 0;
 300 }
 301
 302 static int master_get(struct snd_kcontrol *kcontrol,
 303                       struct snd_ctl_elem_value *ucontrol)
 304 {
 305         struct link_master *master = snd_kcontrol_chip(kcontrol);
 306         int err = master_init(master);
 307         if (err < 0)
 308                 return err;
 309         ucontrol->value.integer.value[0] = master->val;
 310         return 0;
 311 }
 312
 313 static int sync_slaves(struct link_master *master, int old_val, int new_val)
 314 {
 315         struct link_slave *slave;
 316         struct snd_ctl_elem_value *uval;
 317
 318         uval = kmalloc(sizeof(*uval), GFP_KERNEL);
 319         if (!uval)
 320                 return -ENOMEM;
 321         list_for_each_entry(slave, &master->slaves, list) {
 322                 master->val = old_val;
 323                 uval->id = slave->slave.id;
 324                 slave_get_val(slave, uval);
 325                 master->val = new_val;
 326                 slave_put_val(slave, uval);
 327         }
 328         kfree(uval);
 329         return 0;
 330 }
 331
 332 static int master_put(struct snd_kcontrol *kcontrol,
 333                       struct snd_ctl_elem_value *ucontrol)
 334 {
 335         struct link_master *master = snd_kcontrol_chip(kcontrol);
 336         int err, new_val, old_val;
 337         bool first_init;
 338
 339         err = master_init(master);
 340         if (err < 0)
 341                 return err;
 342         first_init = err;
 343         old_val = master->val;
 344         new_val = ucontrol->value.integer.value[0];
 345         if (new_val == old_val)
 346                 return 0;
 347
 348         err = sync_slaves(master, old_val, new_val);
 349         if (err < 0)
 350                 return err;
 351         if (master->hook && !first_init)
 352                 master->hook(master->hook_private_data, master->val);
 353         return 1;
 354 }
 355
 356 static void master_free(struct snd_kcontrol *kcontrol)
 357 {
 358         struct link_master *master = snd_kcontrol_chip(kcontrol);
 359         struct link_slave *slave, *n;
 360
 361         /* free all slave links and retore the original slave kctls */
 362         list_for_each_entry_safe(slave, n, &master->slaves, list) {
 363                 struct snd_kcontrol *sctl = slave->kctl;
 364                 struct list_head olist = sctl->list;
 365                 memcpy(sctl, &slave->slave, sizeof(*sctl));
 366                 memcpy(sctl->vd, slave->slave.vd,
 367                        sctl->count * sizeof(*sctl->vd));
 368                 sctl->list = olist; /* keep the current linked-list */
 369                 kfree(slave);
 370         }
 371         kfree(master);
 372 }
 373
 374
 375 /**
 376  * snd_ctl_make_virtual_master - Create a virtual master control
 377  * @name: name string of the control element to create
 378  * @tlv: optional TLV int array for dB information
 379  *
 380  * Creates a virtual master control with the given name string.
 381  *
 382  * After creating a vmaster element, you can add the slave controls
 383  * via snd_ctl_add_slave() or snd_ctl_add_slave_uncached().
 384  *
 385  * The optional argument @tlv can be used to specify the TLV information
 386  * for dB scale of the master control.  It should be a single element
 387  * with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or
 388  * #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB.
 389  *
 390  * Return: The created control element, or %NULL for errors (ENOMEM).
 391  */
 392 struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
 393                                                  const unsigned int *tlv)
 394 {
 395         struct link_master *master;
 396         struct snd_kcontrol *kctl;
 397         struct snd_kcontrol_new knew;
 398
 399         memset(&knew, 0, sizeof(knew));
 400         knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
 401         knew.name = name;
 402         knew.info = master_info;
 403
 404         master = kzalloc(sizeof(*master), GFP_KERNEL);
 405         if (!master)
 406                 return NULL;
 407         INIT_LIST_HEAD(&master->slaves);
 408
 409         kctl = snd_ctl_new1(&knew, master);
 410         if (!kctl) {
 411                 kfree(master);
 412                 return NULL;
 413         }
 414         /* override some callbacks */
 415         kctl->info = master_info;
 416         kctl->get = master_get;
 417         kctl->put = master_put;
 418         kctl->private_free = master_free;
 419
 420         /* additional (constant) TLV read */
 421         if (tlv &&
 422             (tlv[0] == SNDRV_CTL_TLVT_DB_SCALE ||
 423              tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX ||
 424              tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX_MUTE)) {
 425                 kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
 426                 memcpy(master->tlv, tlv, sizeof(master->tlv));
 427                 kctl->tlv.p = master->tlv;
 428         }
 429
 430         return kctl;
 431 }
 432 EXPORT_SYMBOL(snd_ctl_make_virtual_master);
 433
 434 /**
 435  * snd_ctl_add_vmaster_hook - Add a hook to a vmaster control
 436  * @kcontrol: vmaster kctl element
 437  * @hook: the hook function
 438  * @private_data: the private_data pointer to be saved
 439  *
 440  * Adds the given hook to the vmaster control element so that it's called
 441  * at each time when the value is changed.
 442  *
 443  * Return: Zero.
 444  */
 445 int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol,
 446                              void (*hook)(void *private_data, int),
 447                              void *private_data)
 448 {
 449         struct link_master *master = snd_kcontrol_chip(kcontrol);
 450         master->hook = hook;
 451         master->hook_private_data = private_data;
 452         return 0;
 453 }
 454 EXPORT_SYMBOL_GPL(snd_ctl_add_vmaster_hook);
 455
 456 /**
 457  * snd_ctl_sync_vmaster - Sync the vmaster slaves and hook
 458  * @kcontrol: vmaster kctl element
 459  * @hook_only: sync only the hook
 460  *
 461  * Forcibly call the put callback of each slave and call the hook function
 462  * to synchronize with the current value of the given vmaster element.
 463  * NOP when NULL is passed to @kcontrol.
 464  */
 465 void snd_ctl_sync_vmaster(struct snd_kcontrol *kcontrol, bool hook_only)
 466 {
 467         struct link_master *master;
 468         bool first_init = false;
 469
 470         if (!kcontrol)
 471                 return;
 472         master = snd_kcontrol_chip(kcontrol);
 473         if (!hook_only) {
 474                 int err = master_init(master);
 475                 if (err < 0)
 476                         return;
 477                 first_init = err;
 478                 err = sync_slaves(master, master->val, master->val);
 479                 if (err < 0)
 480                         return;
 481         }
 482
 483         if (master->hook && !first_init)
 484                 master->hook(master->hook_private_data, master->val);
 485 }
 486 EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster);