mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Takashi Iwai](/assets/img/avatar_default.png)
Add a new helper to add multiple vmaster followers in a shot. The same function was open-coded in various places, and this helper replaces them. Link: https://lore.kernel.org/r/20230721071643.3631-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
550 lines
15 KiB
C
550 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Virtual master and follower controls
|
|
*
|
|
* Copyright (c) 2008 by Takashi Iwai <tiwai@suse.de>
|
|
*/
|
|
|
|
#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 follower 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 followers.
|
|
*/
|
|
struct link_master {
|
|
struct list_head followers;
|
|
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 follower - this contains a follower control element
|
|
*
|
|
* It fakes the control callbacks with additional attenuation by the
|
|
* master control. A follower may have either one or two channels.
|
|
*/
|
|
|
|
struct link_follower {
|
|
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 follower; /* the copy of original control entry */
|
|
};
|
|
|
|
static int follower_update(struct link_follower *follower)
|
|
{
|
|
struct snd_ctl_elem_value *uctl;
|
|
int err, ch;
|
|
|
|
uctl = kzalloc(sizeof(*uctl), GFP_KERNEL);
|
|
if (!uctl)
|
|
return -ENOMEM;
|
|
uctl->id = follower->follower.id;
|
|
err = follower->follower.get(&follower->follower, uctl);
|
|
if (err < 0)
|
|
goto error;
|
|
for (ch = 0; ch < follower->info.count; ch++)
|
|
follower->vals[ch] = uctl->value.integer.value[ch];
|
|
error:
|
|
kfree(uctl);
|
|
return err < 0 ? err : 0;
|
|
}
|
|
|
|
/* get the follower ctl info and save the initial values */
|
|
static int follower_init(struct link_follower *follower)
|
|
{
|
|
struct snd_ctl_elem_info *uinfo;
|
|
int err;
|
|
|
|
if (follower->info.count) {
|
|
/* already initialized */
|
|
if (follower->flags & SND_CTL_FOLLOWER_NEED_UPDATE)
|
|
return follower_update(follower);
|
|
return 0;
|
|
}
|
|
|
|
uinfo = kmalloc(sizeof(*uinfo), GFP_KERNEL);
|
|
if (!uinfo)
|
|
return -ENOMEM;
|
|
uinfo->id = follower->follower.id;
|
|
err = follower->follower.info(&follower->follower, uinfo);
|
|
if (err < 0) {
|
|
kfree(uinfo);
|
|
return err;
|
|
}
|
|
follower->info.type = uinfo->type;
|
|
follower->info.count = uinfo->count;
|
|
if (follower->info.count > 2 ||
|
|
(follower->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER &&
|
|
follower->info.type != SNDRV_CTL_ELEM_TYPE_BOOLEAN)) {
|
|
pr_err("ALSA: vmaster: invalid follower element\n");
|
|
kfree(uinfo);
|
|
return -EINVAL;
|
|
}
|
|
follower->info.min_val = uinfo->value.integer.min;
|
|
follower->info.max_val = uinfo->value.integer.max;
|
|
kfree(uinfo);
|
|
|
|
return follower_update(follower);
|
|
}
|
|
|
|
/* initialize master volume */
|
|
static int master_init(struct link_master *master)
|
|
{
|
|
struct link_follower *follower;
|
|
|
|
if (master->info.count)
|
|
return 0; /* already initialized */
|
|
|
|
list_for_each_entry(follower, &master->followers, list) {
|
|
int err = follower_init(follower);
|
|
if (err < 0)
|
|
return err;
|
|
master->info = follower->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 follower_get_val(struct link_follower *follower,
|
|
struct snd_ctl_elem_value *ucontrol)
|
|
{
|
|
int err, ch;
|
|
|
|
err = follower_init(follower);
|
|
if (err < 0)
|
|
return err;
|
|
for (ch = 0; ch < follower->info.count; ch++)
|
|
ucontrol->value.integer.value[ch] = follower->vals[ch];
|
|
return 0;
|
|
}
|
|
|
|
static int follower_put_val(struct link_follower *follower,
|
|
struct snd_ctl_elem_value *ucontrol)
|
|
{
|
|
int err, ch, vol;
|
|
|
|
err = master_init(follower->master);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
switch (follower->info.type) {
|
|
case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
|
|
for (ch = 0; ch < follower->info.count; ch++)
|
|
ucontrol->value.integer.value[ch] &=
|
|
!!follower->master->val;
|
|
break;
|
|
case SNDRV_CTL_ELEM_TYPE_INTEGER:
|
|
for (ch = 0; ch < follower->info.count; ch++) {
|
|
/* max master volume is supposed to be 0 dB */
|
|
vol = ucontrol->value.integer.value[ch];
|
|
vol += follower->master->val - follower->master->info.max_val;
|
|
if (vol < follower->info.min_val)
|
|
vol = follower->info.min_val;
|
|
else if (vol > follower->info.max_val)
|
|
vol = follower->info.max_val;
|
|
ucontrol->value.integer.value[ch] = vol;
|
|
}
|
|
break;
|
|
}
|
|
return follower->follower.put(&follower->follower, ucontrol);
|
|
}
|
|
|
|
/*
|
|
* ctl callbacks for followers
|
|
*/
|
|
static int follower_info(struct snd_kcontrol *kcontrol,
|
|
struct snd_ctl_elem_info *uinfo)
|
|
{
|
|
struct link_follower *follower = snd_kcontrol_chip(kcontrol);
|
|
return follower->follower.info(&follower->follower, uinfo);
|
|
}
|
|
|
|
static int follower_get(struct snd_kcontrol *kcontrol,
|
|
struct snd_ctl_elem_value *ucontrol)
|
|
{
|
|
struct link_follower *follower = snd_kcontrol_chip(kcontrol);
|
|
return follower_get_val(follower, ucontrol);
|
|
}
|
|
|
|
static int follower_put(struct snd_kcontrol *kcontrol,
|
|
struct snd_ctl_elem_value *ucontrol)
|
|
{
|
|
struct link_follower *follower = snd_kcontrol_chip(kcontrol);
|
|
int err, ch, changed = 0;
|
|
|
|
err = follower_init(follower);
|
|
if (err < 0)
|
|
return err;
|
|
for (ch = 0; ch < follower->info.count; ch++) {
|
|
if (follower->vals[ch] != ucontrol->value.integer.value[ch]) {
|
|
changed = 1;
|
|
follower->vals[ch] = ucontrol->value.integer.value[ch];
|
|
}
|
|
}
|
|
if (!changed)
|
|
return 0;
|
|
err = follower_put_val(follower, ucontrol);
|
|
if (err < 0)
|
|
return err;
|
|
return 1;
|
|
}
|
|
|
|
static int follower_tlv_cmd(struct snd_kcontrol *kcontrol,
|
|
int op_flag, unsigned int size,
|
|
unsigned int __user *tlv)
|
|
{
|
|
struct link_follower *follower = snd_kcontrol_chip(kcontrol);
|
|
/* FIXME: this assumes that the max volume is 0 dB */
|
|
return follower->follower.tlv.c(&follower->follower, op_flag, size, tlv);
|
|
}
|
|
|
|
static void follower_free(struct snd_kcontrol *kcontrol)
|
|
{
|
|
struct link_follower *follower = snd_kcontrol_chip(kcontrol);
|
|
if (follower->follower.private_free)
|
|
follower->follower.private_free(&follower->follower);
|
|
if (follower->master)
|
|
list_del(&follower->list);
|
|
kfree(follower);
|
|
}
|
|
|
|
/*
|
|
* Add a follower control to the group with the given master control
|
|
*
|
|
* All followers 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_follower(struct snd_kcontrol *master,
|
|
struct snd_kcontrol *follower,
|
|
unsigned int flags)
|
|
{
|
|
struct link_master *master_link = snd_kcontrol_chip(master);
|
|
struct link_follower *srec;
|
|
|
|
srec = kzalloc(struct_size(srec, follower.vd, follower->count),
|
|
GFP_KERNEL);
|
|
if (!srec)
|
|
return -ENOMEM;
|
|
srec->kctl = follower;
|
|
srec->follower = *follower;
|
|
memcpy(srec->follower.vd, follower->vd, follower->count * sizeof(*follower->vd));
|
|
srec->master = master_link;
|
|
srec->flags = flags;
|
|
|
|
/* override callbacks */
|
|
follower->info = follower_info;
|
|
follower->get = follower_get;
|
|
follower->put = follower_put;
|
|
if (follower->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK)
|
|
follower->tlv.c = follower_tlv_cmd;
|
|
follower->private_data = srec;
|
|
follower->private_free = follower_free;
|
|
|
|
list_add_tail(&srec->list, &master_link->followers);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(_snd_ctl_add_follower);
|
|
|
|
/**
|
|
* snd_ctl_add_followers - add multiple followers to vmaster
|
|
* @card: card instance
|
|
* @master: the target vmaster kcontrol object
|
|
* @list: NULL-terminated list of name strings of followers to be added
|
|
*
|
|
* Adds the multiple follower kcontrols with the given names.
|
|
* Returns 0 for success or a negative error code.
|
|
*/
|
|
int snd_ctl_add_followers(struct snd_card *card, struct snd_kcontrol *master,
|
|
const char * const *list)
|
|
{
|
|
struct snd_kcontrol *follower;
|
|
int err;
|
|
|
|
for (; *list; list++) {
|
|
follower = snd_ctl_find_id_mixer(card, *list);
|
|
if (follower) {
|
|
err = snd_ctl_add_follower(master, follower);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(snd_ctl_add_followers);
|
|
|
|
/*
|
|
* 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_followers(struct link_master *master, int old_val, int new_val)
|
|
{
|
|
struct link_follower *follower;
|
|
struct snd_ctl_elem_value *uval;
|
|
|
|
uval = kmalloc(sizeof(*uval), GFP_KERNEL);
|
|
if (!uval)
|
|
return -ENOMEM;
|
|
list_for_each_entry(follower, &master->followers, list) {
|
|
master->val = old_val;
|
|
uval->id = follower->follower.id;
|
|
follower_get_val(follower, uval);
|
|
master->val = new_val;
|
|
follower_put_val(follower, 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_followers(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_follower *follower, *n;
|
|
|
|
/* free all follower links and retore the original follower kctls */
|
|
list_for_each_entry_safe(follower, n, &master->followers, list) {
|
|
struct snd_kcontrol *sctl = follower->kctl;
|
|
struct list_head olist = sctl->list;
|
|
memcpy(sctl, &follower->follower, sizeof(*sctl));
|
|
memcpy(sctl->vd, follower->follower.vd,
|
|
sctl->count * sizeof(*sctl->vd));
|
|
sctl->list = olist; /* keep the current linked-list */
|
|
kfree(follower);
|
|
}
|
|
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 follower controls
|
|
* via snd_ctl_add_follower() or snd_ctl_add_follower_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->followers);
|
|
|
|
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) {
|
|
unsigned int type = tlv[SNDRV_CTL_TLVO_TYPE];
|
|
if (type == SNDRV_CTL_TLVT_DB_SCALE ||
|
|
type == SNDRV_CTL_TLVT_DB_MINMAX ||
|
|
type == 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 followers and hook
|
|
* @kcontrol: vmaster kctl element
|
|
* @hook_only: sync only the hook
|
|
*
|
|
* Forcibly call the put callback of each follower 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_followers(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);
|
|
|
|
/**
|
|
* snd_ctl_apply_vmaster_followers - Apply function to each vmaster follower
|
|
* @kctl: vmaster kctl element
|
|
* @func: function to apply
|
|
* @arg: optional function argument
|
|
*
|
|
* Apply the function @func to each follower kctl of the given vmaster kctl.
|
|
*
|
|
* Return: 0 if successful, or a negative error code
|
|
*/
|
|
int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl,
|
|
int (*func)(struct snd_kcontrol *vfollower,
|
|
struct snd_kcontrol *follower,
|
|
void *arg),
|
|
void *arg)
|
|
{
|
|
struct link_master *master;
|
|
struct link_follower *follower;
|
|
int err;
|
|
|
|
master = snd_kcontrol_chip(kctl);
|
|
err = master_init(master);
|
|
if (err < 0)
|
|
return err;
|
|
list_for_each_entry(follower, &master->followers, list) {
|
|
err = func(follower->kctl, &follower->follower, arg);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(snd_ctl_apply_vmaster_followers);
|