[linux-2.6-block.git] / sound / core / vmaster.c

/*
 * Virtual master and slave controls
 *
 *  Copyright (c) 2008 by Takashi Iwai <tiwai@suse.de>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as
 *  published by the Free Software Foundation, version 2.
 *
 */

#include <linux/slab.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/tlv.h>

/*
 * a subset of information returned via ctl info callback
 */
struct link_ctl_info {
	snd_ctl_elem_type_t type; /* value type */
	int count;		/* item count */
	int min_val, max_val;	/* min, max values */
};

/*
 * link master - this contains a list of slave controls that are
 * identical types, i.e. info returns the same value type and value
 * ranges, but may have different number of counts.
 *
 * The master control is so far only mono volume/switch for simplicity.
 * The same value will be applied to all slaves.
 */
struct link_master {
	struct list_head slaves;
	struct link_ctl_info info;
	int val;		/* the master value */
	unsigned int tlv[4];
	void (*hook)(void *private_data, int);
	void *hook_private_data;
};

/*
 * link slave - this contains a slave control element
 *
 * It fakes the control callbacsk with additional attenuation by the
 * master control.  A slave may have either one or two channels.
 */

struct link_slave {
	struct list_head list;
	struct link_master *master;
	struct link_ctl_info info;
	int vals[2];		/* current values */
	unsigned int flags;
	struct snd_kcontrol *kctl; /* original kcontrol pointer */
	struct snd_kcontrol slave; /* the copy of original control entry */
};

static int slave_update(struct link_slave *slave)
{
	struct snd_ctl_elem_value *uctl;
	int err, ch;

	uctl = kmalloc(sizeof(*uctl), GFP_KERNEL);
	if (!uctl)
		return -ENOMEM;
	uctl->id = slave->slave.id;
	err = slave->slave.get(&slave->slave, uctl);
	for (ch = 0; ch < slave->info.count; ch++)
		slave->vals[ch] = uctl->value.integer.value[ch];
	kfree(uctl);
	return 0;
}

/* get the slave ctl info and save the initial values */
static int slave_init(struct link_slave *slave)
{
	struct snd_ctl_elem_info *uinfo;
	int err;

	if (slave->info.count) {
		/* already initialized */
		if (slave->flags & SND_CTL_SLAVE_NEED_UPDATE)
			return slave_update(slave);
		return 0;
	}

	uinfo = kmalloc(sizeof(*uinfo), GFP_KERNEL);
	if (!uinfo)
		return -ENOMEM;
	uinfo->id = slave->slave.id;
	err = slave->slave.info(&slave->slave, uinfo);
	if (err < 0) {
		kfree(uinfo);
		return err;
	}
	slave->info.type = uinfo->type;
	slave->info.count = uinfo->count;
	if (slave->info.count > 2  ||
	    (slave->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER &&
	     slave->info.type != SNDRV_CTL_ELEM_TYPE_BOOLEAN)) {
		pr_err("ALSA: vmaster: invalid slave element\n");
		kfree(uinfo);
		return -EINVAL;
	}
	slave->info.min_val = uinfo->value.integer.min;
	slave->info.max_val = uinfo->value.integer.max;
	kfree(uinfo);

	return slave_update(slave);
}

/* initialize master volume */
static int master_init(struct link_master *master)
{
	struct link_slave *slave;

	if (master->info.count)
		return 0; /* already initialized */

	list_for_each_entry(slave, &master->slaves, list) {
		int err = slave_init(slave);
		if (err < 0)
			return err;
		master->info = slave->info;
		master->info.count = 1; /* always mono */
		/* set full volume as default (= no attenuation) */
		master->val = master->info.max_val;
		if (master->hook)
			master->hook(master->hook_private_data, master->val);
		return 1;
	}
	return -ENOENT;
}

static int slave_get_val(struct link_slave *slave,
			 struct snd_ctl_elem_value *ucontrol)
{
	int err, ch;

	err = slave_init(slave);
	if (err < 0)
		return err;
	for (ch = 0; ch < slave->info.count; ch++)
		ucontrol->value.integer.value[ch] = slave->vals[ch];
	return 0;
}

static int slave_put_val(struct link_slave *slave,
			 struct snd_ctl_elem_value *ucontrol)
{
	int err, ch, vol;

	err = master_init(slave->master);
	if (err < 0)
		return err;

	switch (slave->info.type) {
	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
		for (ch = 0; ch < slave->info.count; ch++)
			ucontrol->value.integer.value[ch] &=
				!!slave->master->val;
		break;
	case SNDRV_CTL_ELEM_TYPE_INTEGER:
		for (ch = 0; ch < slave->info.count; ch++) {
			/* max master volume is supposed to be 0 dB */
			vol = ucontrol->value.integer.value[ch];
			vol += slave->master->val - slave->master->info.max_val;
			if (vol < slave->info.min_val)
				vol = slave->info.min_val;
			else if (vol > slave->info.max_val)
				vol = slave->info.max_val;
			ucontrol->value.integer.value[ch] = vol;
		}
		break;
	}
	return slave->slave.put(&slave->slave, ucontrol);
}

/*
 * ctl callbacks for slaves
 */
static int slave_info(struct snd_kcontrol *kcontrol,
		      struct snd_ctl_elem_info *uinfo)
{
	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
	return slave->slave.info(&slave->slave, uinfo);
}

static int slave_get(struct snd_kcontrol *kcontrol,
		     struct snd_ctl_elem_value *ucontrol)
{
	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
	return slave_get_val(slave, ucontrol);
}

static int slave_put(struct snd_kcontrol *kcontrol,
		     struct snd_ctl_elem_value *ucontrol)
{
	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
	int err, ch, changed = 0;

	err = slave_init(slave);
	if (err < 0)
		return err;
	for (ch = 0; ch < slave->info.count; ch++) {
		if (slave->vals[ch] != ucontrol->value.integer.value[ch]) {
			changed = 1;
			slave->vals[ch] = ucontrol->value.integer.value[ch];
		}
	}
	if (!changed)
		return 0;
	err = slave_put_val(slave, ucontrol);
	if (err < 0)
		return err;
	return 1;
}

static int slave_tlv_cmd(struct snd_kcontrol *kcontrol,
			 int op_flag, unsigned int size,
			 unsigned int __user *tlv)
{
	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
	/* FIXME: this assumes that the max volume is 0 dB */
	return slave->slave.tlv.c(&slave->slave, op_flag, size, tlv);
}

static void slave_free(struct snd_kcontrol *kcontrol)
{
	struct link_slave *slave = snd_kcontrol_chip(kcontrol);
	if (slave->slave.private_free)
		slave->slave.private_free(&slave->slave);
	if (slave->master)
		list_del(&slave->list);
	kfree(slave);
}

/*
 * Add a slave control to the group with the given master control
 *
 * All slaves must be the same type (returning the same information
 * via info callback).  The function doesn't check it, so it's your
 * responsibility.
 *
 * Also, some additional limitations:
 * - at most two channels
 * - logarithmic volume control (dB level), no linear volume
 * - master can only attenuate the volume, no gain
 */
int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave,
		       unsigned int flags)
{
	struct link_master *master_link = snd_kcontrol_chip(master);
	struct link_slave *srec;

	srec = kzalloc(sizeof(*srec) +
		       slave->count * sizeof(*slave->vd), GFP_KERNEL);
	if (!srec)
		return -ENOMEM;
	srec->kctl = slave;
	srec->slave = *slave;
	memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd));
	srec->master = master_link;
	srec->flags = flags;

	/* override callbacks */
	slave->info = slave_info;
	slave->get = slave_get;
	slave->put = slave_put;
	if (slave->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK)
		slave->tlv.c = slave_tlv_cmd;
	slave->private_data = srec;
	slave->private_free = slave_free;

	list_add_tail(&srec->list, &master_link->slaves);
	return 0;
}
EXPORT_SYMBOL(_snd_ctl_add_slave);

/*
 * ctl callbacks for master controls
 */
static int master_info(struct snd_kcontrol *kcontrol,
		      struct snd_ctl_elem_info *uinfo)
{
	struct link_master *master = snd_kcontrol_chip(kcontrol);
	int ret;

	ret = master_init(master);
	if (ret < 0)
		return ret;
	uinfo->type = master->info.type;
	uinfo->count = master->info.count;
	uinfo->value.integer.min = master->info.min_val;
	uinfo->value.integer.max = master->info.max_val;
	return 0;
}

static int master_get(struct snd_kcontrol *kcontrol,
		      struct snd_ctl_elem_value *ucontrol)
{
	struct link_master *master = snd_kcontrol_chip(kcontrol);
	int err = master_init(master);
	if (err < 0)
		return err;
	ucontrol->value.integer.value[0] = master->val;
	return 0;
}

static int sync_slaves(struct link_master *master, int old_val, int new_val)
{
	struct link_slave *slave;
	struct snd_ctl_elem_value *uval;

	uval = kmalloc(sizeof(*uval), GFP_KERNEL);
	if (!uval)
		return -ENOMEM;
	list_for_each_entry(slave, &master->slaves, list) {
		master->val = old_val;
		uval->id = slave->slave.id;
		slave_get_val(slave, uval);
		master->val = new_val;
		slave_put_val(slave, uval);
	}
	kfree(uval);
	return 0;
}

static int master_put(struct snd_kcontrol *kcontrol,
		      struct snd_ctl_elem_value *ucontrol)
{
	struct link_master *master = snd_kcontrol_chip(kcontrol);
	int err, new_val, old_val;
	bool first_init;

	err = master_init(master);
	if (err < 0)
		return err;
	first_init = err;
	old_val = master->val;
	new_val = ucontrol->value.integer.value[0];
	if (new_val == old_val)
		return 0;

	err = sync_slaves(master, old_val, new_val);
	if (err < 0)
		return err;
	if (master->hook && !first_init)
		master->hook(master->hook_private_data, master->val);
	return 1;
}

static void master_free(struct snd_kcontrol *kcontrol)
{
	struct link_master *master = snd_kcontrol_chip(kcontrol);
	struct link_slave *slave, *n;

	/* free all slave links and retore the original slave kctls */
	list_for_each_entry_safe(slave, n, &master->slaves, list) {
		struct snd_kcontrol *sctl = slave->kctl;
		struct list_head olist = sctl->list;
		memcpy(sctl, &slave->slave, sizeof(*sctl));
		memcpy(sctl->vd, slave->slave.vd,
		       sctl->count * sizeof(*sctl->vd));
		sctl->list = olist; /* keep the current linked-list */
		kfree(slave);
	}
	kfree(master);
}


/**
 * snd_ctl_make_virtual_master - Create a virtual master control
 * @name: name string of the control element to create
 * @tlv: optional TLV int array for dB information
 *
 * Creates a virtual master control with the given name string.
 *
 * After creating a vmaster element, you can add the slave controls
 * via snd_ctl_add_slave() or snd_ctl_add_slave_uncached().
 *
 * The optional argument @tlv can be used to specify the TLV information
 * for dB scale of the master control.  It should be a single element
 * with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or
 * #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB.
 *
 * Return: The created control element, or %NULL for errors (ENOMEM).
 */
struct snd_kcontrol *snd_ctl_make_virtual_master(char *name,
						 const unsigned int *tlv)
{
	struct link_master *master;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_new knew;

	memset(&knew, 0, sizeof(knew));
	knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
	knew.name = name;
	knew.info = master_info;

	master = kzalloc(sizeof(*master), GFP_KERNEL);
	if (!master)
		return NULL;
	INIT_LIST_HEAD(&master->slaves);

	kctl = snd_ctl_new1(&knew, master);
	if (!kctl) {
		kfree(master);
		return NULL;
	}
	/* override some callbacks */
	kctl->info = master_info;
	kctl->get = master_get;
	kctl->put = master_put;
	kctl->private_free = master_free;

	/* additional (constant) TLV read */
	if (tlv &&
	    (tlv[0] == SNDRV_CTL_TLVT_DB_SCALE ||
	     tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX ||
	     tlv[0] == SNDRV_CTL_TLVT_DB_MINMAX_MUTE)) {
		kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
		memcpy(master->tlv, tlv, sizeof(master->tlv));
		kctl->tlv.p = master->tlv;
	}

	return kctl;
}
EXPORT_SYMBOL(snd_ctl_make_virtual_master);

/**
 * snd_ctl_add_vmaster_hook - Add a hook to a vmaster control
 * @kcontrol: vmaster kctl element
 * @hook: the hook function
 * @private_data: the private_data pointer to be saved
 *
 * Adds the given hook to the vmaster control element so that it's called
 * at each time when the value is changed.
 *
 * Return: Zero.
 */
int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol,
			     void (*hook)(void *private_data, int),
			     void *private_data)
{
	struct link_master *master = snd_kcontrol_chip(kcontrol);
	master->hook = hook;
	master->hook_private_data = private_data;
	return 0;
}
EXPORT_SYMBOL_GPL(snd_ctl_add_vmaster_hook);

/**
 * snd_ctl_sync_vmaster - Sync the vmaster slaves and hook
 * @kcontrol: vmaster kctl element
 * @hook_only: sync only the hook
 *
 * Forcibly call the put callback of each slave and call the hook function
 * to synchronize with the current value of the given vmaster element.
 * NOP when NULL is passed to @kcontrol.
 */
void snd_ctl_sync_vmaster(struct snd_kcontrol *kcontrol, bool hook_only)
{
	struct link_master *master;
	bool first_init = false;

	if (!kcontrol)
		return;
	master = snd_kcontrol_chip(kcontrol);
	if (!hook_only) {
		int err = master_init(master);
		if (err < 0)
			return;
		first_init = err;
		err = sync_slaves(master, master->val, master->val);
		if (err < 0)
			return;
	}

	if (master->hook && !first_init)
		master->hook(master->hook_private_data, master->val);
}
EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster);
Commit	Line	Data
3b0a5f22 TI	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>
d81a6d71	13	#include <linux/export.h>
3b0a5f22 TI	14	#include <sound/core.h>
3b0a5f22 TI	15	#include <sound/control.h>
1c82ed1b	16	#include <sound/tlv.h>
3b0a5f22 TI	17
	18	/*
	19	* a subset of information returned via ctl info callback
	20	*/
	21	struct link_ctl_info {
fea952e5	22	snd_ctl_elem_type_t type; /* value type */
3b0a5f22 TI	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 */
1c82ed1b	39	unsigned int tlv[4];
2ad787e9 TI	40	void (hook)(void private_data, int);
2ad787e9 TI	41	void *hook_private_data;
3b0a5f22 TI	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 */
f5b1db63	56	unsigned int flags;
9e226b4b	57	struct snd_kcontrol kctl; / original kcontrol pointer */
3b0a5f22 TI	58	struct snd_kcontrol slave; /* the copy of original control entry */
	59	};
	60
f5b1db63 TI	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
3b0a5f22 TI	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;
f5b1db63	81	int err;
3b0a5f22	82
f5b1db63 TI	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	}
3b0a5f22 TI	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)) {
f2f9307a	104	pr_err("ALSA: vmaster: invalid slave element\n");
3b0a5f22 TI	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
f5b1db63	112	return slave_update(slave);
3b0a5f22 TI	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;
2ad787e9 TI	131	if (master->hook)
	132	master->hook(master->hook_private_data, master->val);
	133	return 1;
3b0a5f22 TI	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;
2069d483 TI	216	err = slave_put_val(slave, ucontrol);
	217	if (err < 0)
	218	return err;
	219	return 1;
3b0a5f22 TI	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
25985edc	245	* via info callback). The function doesn't check it, so it's your
3b0a5f22 TI	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	*/
f5b1db63 TI	253	int _snd_ctl_add_slave(struct snd_kcontrol master, struct snd_kcontrol slave,
f5b1db63 TI	254	unsigned int flags)
3b0a5f22 TI	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;
9e226b4b	263	srec->kctl = slave;
3b0a5f22 TI	264	srec->slave = *slave;
	265	memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd));
	266	srec->master = master_link;
f5b1db63	267	srec->flags = flags;
3b0a5f22 TI	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	}
f5b1db63	281	EXPORT_SYMBOL(_snd_ctl_add_slave);
e922b002	282
3b0a5f22 TI	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
1ca2f2ec	313	static int sync_slaves(struct link_master *master, int old_val, int new_val)
3b0a5f22	314	{
3b0a5f22 TI	315	struct link_slave *slave;
3b0a5f22 TI	316	struct snd_ctl_elem_value *uval;
3b0a5f22 TI	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);
1ca2f2ec	325	master->val = new_val;
3b0a5f22 TI	326	slave_put_val(slave, uval);
	327	}
	328	kfree(uval);
1ca2f2ec TI	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;
1ba65ae4	351	if (master->hook && !first_init)
2ad787e9	352	master->hook(master->hook_private_data, master->val);
3b0a5f22 TI	353	return 1;
	354	}
	355
	356	static void master_free(struct snd_kcontrol *kcontrol)
	357	{
	358	struct link_master *master = snd_kcontrol_chip(kcontrol);
9e226b4b TI	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	}
3b0a5f22 TI	371	kfree(master);
	372	}
	373
	374
79c7cdd5 TI	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	*
eb7c06e8	380	* Creates a virtual master control with the given name string.
79c7cdd5 TI	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
085f3065 TI	387	* with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or
085f3065 TI	388	* #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB.
eb7c06e8 YB	389	*
eb7c06e8 YB	390	* Return: The created control element, or %NULL for errors (ENOMEM).
3b0a5f22 TI	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 */
085f3065 TI	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)) {
3b0a5f22	425	kctl->vd[0].access \|= SNDRV_CTL_ELEM_ACCESS_TLV_READ;
1c82ed1b TI	426	memcpy(master->tlv, tlv, sizeof(master->tlv));
1c82ed1b TI	427	kctl->tlv.p = master->tlv;
3b0a5f22	428	}
1c82ed1b	429
3b0a5f22 TI	430	return kctl;
3b0a5f22 TI	431	}
e922b002	432	EXPORT_SYMBOL(snd_ctl_make_virtual_master);
2ad787e9 TI	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
f2ec52d4	438	* @private_data: the private_data pointer to be saved
2ad787e9 TI	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.
eb7c06e8 YB	442	*
eb7c06e8 YB	443	* Return: Zero.
2ad787e9 TI	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	/**
1ca2f2ec	457	* snd_ctl_sync_vmaster - Sync the vmaster slaves and hook
2ad787e9	458	* @kcontrol: vmaster kctl element
1ca2f2ec	459	* @hook_only: sync only the hook
2ad787e9	460	*
1ca2f2ec TI	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.
2ad787e9	464	*/
1ca2f2ec	465	void snd_ctl_sync_vmaster(struct snd_kcontrol *kcontrol, bool hook_only)
2ad787e9 TI	466	{
2ad787e9 TI	467	struct link_master *master;
1ca2f2ec TI	468	bool first_init = false;
1ca2f2ec TI	469
2ad787e9 TI	470	if (!kcontrol)
	471	return;
	472	master = snd_kcontrol_chip(kcontrol);
1ca2f2ec TI	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)
2ad787e9 TI	484	master->hook(master->hook_private_data, master->val);
2ad787e9 TI	485	}
1ca2f2ec	486	EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster);