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                 snd_printk(KERN_ERR "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         return slave_put_val(slave, ucontrol);
 217 }
 218
 219 static int slave_tlv_cmd(struct snd_kcontrol *kcontrol,
 220                          int op_flag, unsigned int size,
 221                          unsigned int __user *tlv)
 222 {
 223         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 224         /* FIXME: this assumes that the max volume is 0 dB */
 225         return slave->slave.tlv.c(&slave->slave, op_flag, size, tlv);
 226 }
 227
 228 static void slave_free(struct snd_kcontrol *kcontrol)
 229 {
 230         struct link_slave *slave = snd_kcontrol_chip(kcontrol);
 231         if (slave->slave.private_free)
 232                 slave->slave.private_free(&slave->slave);
 233         if (slave->master)
 234                 list_del(&slave->list);
 235         kfree(slave);
 236 }
 237
 238 /*
 239  * Add a slave control to the group with the given master control
 240  *
 241  * All slaves must be the same type (returning the same information
 242  * via info callback).  The function doesn't check it, so it's your
 243  * responsibility.
 244  *
 245  * Also, some additional limitations:
 246  * - at most two channels
 247  * - logarithmic volume control (dB level), no linear volume
 248  * - master can only attenuate the volume, no gain
 249  */
 250 int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
 251                        unsigned int flags)
 252 {
 253         struct link_master *master_link = snd_kcontrol_chip(master);
 254         struct link_slave *srec;
 255
 256         srec = kzalloc(sizeof(*srec) +
 257                        slave->count * sizeof(*slave->vd), GFP_KERNEL);
 258         if (!srec)
 259                 return -ENOMEM;
 260         srec->kctl = slave;
 261         srec->slave = *slave;
 262         memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd));
 263         srec->master = master_link;
 264         srec->flags = flags;
 265
 266         /* override callbacks */
 267         slave->info = slave_info;
 268         slave->get = slave_get;
 269         slave->put = slave_put;
 270         if (slave->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK)
 271                 slave->tlv.c = slave_tlv_cmd;
 272         slave->private_data = srec;
 273         slave->private_free = slave_free;
 274
 275         list_add_tail(&srec->list, &master_link->slaves);
 276         return 0;
 277 }
 278 EXPORT_SYMBOL(_snd_ctl_add_slave);
 279
 280 /*
 281  * ctl callbacks for master controls
 282  */
 283 static int master_info(struct snd_kcontrol *kcontrol,
 284                       struct snd_ctl_elem_info *uinfo)
 285 {
 286         struct link_master *master = snd_kcontrol_chip(kcontrol);
 287         int ret;
 288
 289         ret = master_init(master);
 290         if (ret < 0)
 291                 return ret;
 292         uinfo->type = master->info.type;
 293         uinfo->count = master->info.count;
 294         uinfo->value.integer.min = master->info.min_val;
 295         uinfo->value.integer.max = master->info.max_val;
 296         return 0;
 297 }
 298
 299 static int master_get(struct snd_kcontrol *kcontrol,
 300                       struct snd_ctl_elem_value *ucontrol)
 301 {
 302         struct link_master *master = snd_kcontrol_chip(kcontrol);
 303         int err = master_init(master);
 304         if (err < 0)
 305                 return err;
 306         ucontrol->value.integer.value[0] = master->val;
 307         return 0;
 308 }
 309
 310 static int master_put(struct snd_kcontrol *kcontrol,
 311                       struct snd_ctl_elem_value *ucontrol)
 312 {
 313         struct link_master *master = snd_kcontrol_chip(kcontrol);
 314         struct link_slave *slave;
 315         struct snd_ctl_elem_value *uval;
 316         int err, old_val;
 317
 318         err = master_init(master);
 319         if (err < 0)
 320                 return err;
 321         old_val = master->val;
 322         if (ucontrol->value.integer.value[0] == old_val)
 323                 return 0;
 324
 325         uval = kmalloc(sizeof(*uval), GFP_KERNEL);
 326         if (!uval)
 327                 return -ENOMEM;
 328         list_for_each_entry(slave, &master->slaves, list) {
 329                 master->val = old_val;
 330                 uval->id = slave->slave.id;
 331                 slave_get_val(slave, uval);
 332                 master->val = ucontrol->value.integer.value[0];
 333                 slave_put_val(slave, uval);
 334         }
 335         kfree(uval);
 336         if (master->hook && !err)
 337                 master->hook(master->hook_private_data, master->val);
 338         return 1;
 339 }
 340
 341 static void master_free(struct snd_kcontrol *kcontrol)
 342 {
 343         struct link_master *master = snd_kcontrol_chip(kcontrol);
 344         struct link_slave *slave, *n;
 345
 346         /* free all slave links and retore the original slave kctls */
 347         list_for_each_entry_safe(slave, n, &master->slaves, list) {
 348                 struct snd_kcontrol *sctl = slave->kctl;
 349                 struct list_head olist = sctl->list;
 350                 memcpy(sctl, &slave->slave, sizeof(*sctl));
 351                 memcpy(sctl->vd, slave->slave.vd,
 352                        sctl->count * sizeof(*sctl->vd));
 353                 sctl->list = olist; /* keep the current linked-list */
 354                 kfree(slave);
 355         }
 356         kfree(master);
 357 }
 358
 359
 360 /**
 361  * snd_ctl_make_virtual_master - Create a virtual master control
 362  * @name: name string of the control element to create
 363  * @tlv: optional TLV int array for dB information
 364  *
 365  * Creates a virtual matster control with the given name string.
 366  * Returns the created control element, or NULL for errors (ENOMEM).
 367  *
 368  * After creating a vmaster element, you can add the slave controls
 369  * via snd_ctl_add_slave() or snd_ctl_add_slave_uncached().
 370  *
 371  * The optional argument @tlv can be used to specify the TLV information
 372  * for dB scale of the master control.  It should be a single element
 373  * with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or
 374  * #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB.
 375  */
 376 struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
 377                                                  const unsigned int *tlv)
 378 {
 379         struct link_master *master;
 380         struct snd_kcontrol *kctl;
 381         struct snd_kcontrol_new knew;
 382
 383         memset(&knew, 0, sizeof(knew));
 384         knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
 385         knew.name = name;
 386         knew.info = master_info;
 387
 388         master = kzalloc(sizeof(*master), GFP_KERNEL);
 389         if (!master)
 390                 return NULL;
 391         INIT_LIST_HEAD(&master->slaves);
 392
 393         kctl = snd_ctl_new1(&knew, master);
 394         if (!kctl) {
 395                 kfree(master);
 396                 return NULL;
 397         }
 398         /* override some callbacks */
 399         kctl->info = master_info;
 400         kctl->get = master_get;
 401         kctl->put = master_put;
 402         kctl->private_free = master_free;
 403
 404         /* additional (constant) TLV read */
 405         if (tlv &&
 406             (tlv[0] == SNDRV_CTL_TLVT_DB_SCALE ||
 407              tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX ||
 408              tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX_MUTE)) {
 409                 kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
 410                 memcpy(master->tlv, tlv, sizeof(master->tlv));
 411                 kctl->tlv.p = master->tlv;
 412         }
 413
 414         return kctl;
 415 }
 416 EXPORT_SYMBOL(snd_ctl_make_virtual_master);
 417
 418 /**
 419  * snd_ctl_add_vmaster_hook - Add a hook to a vmaster control
 420  * @kcontrol: vmaster kctl element
 421  * @hook: the hook function
 422  * @private_data: the private_data pointer to be saved
 423  *
 424  * Adds the given hook to the vmaster control element so that it's called
 425  * at each time when the value is changed.
 426  */
 427 int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol,
 428                              void (*hook)(void *private_data, int),
 429                              void *private_data)
 430 {
 431         struct link_master *master = snd_kcontrol_chip(kcontrol);
 432         master->hook = hook;
 433         master->hook_private_data = private_data;
 434         return 0;
 435 }
 436 EXPORT_SYMBOL_GPL(snd_ctl_add_vmaster_hook);
 437
 438 /**
 439  * snd_ctl_sync_vmaster_hook - Sync the vmaster hook
 440  * @kcontrol: vmaster kctl element
 441  *
 442  * Call the hook function to synchronize with the current value of the given
 443  * vmaster element.  NOP when NULL is passed to @kcontrol or the hook doesn't
 444  * exist.
 445  */
 446 void snd_ctl_sync_vmaster_hook(struct snd_kcontrol *kcontrol)
 447 {
 448         struct link_master *master;
 449         if (!kcontrol)
 450                 return;
 451         master = snd_kcontrol_chip(kcontrol);
 452         if (master->hook)
 453                 master->hook(master->hook_private_data, master->val);
 454 }
 455 EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster_hook);