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521 lines
14 KiB
521 lines
14 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Virtual master and follower controls |
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* |
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* Copyright (c) 2008 by Takashi Iwai <[email protected]> |
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*/ |
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#include <linux/slab.h> |
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#include <linux/export.h> |
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#include <sound/core.h> |
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#include <sound/control.h> |
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#include <sound/tlv.h> |
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/* |
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* a subset of information returned via ctl info callback |
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*/ |
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struct link_ctl_info { |
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snd_ctl_elem_type_t type; /* value type */ |
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int count; /* item count */ |
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int min_val, max_val; /* min, max values */ |
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}; |
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/* |
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* link master - this contains a list of follower controls that are |
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* identical types, i.e. info returns the same value type and value |
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* ranges, but may have different number of counts. |
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* |
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* The master control is so far only mono volume/switch for simplicity. |
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* The same value will be applied to all followers. |
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*/ |
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struct link_master { |
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struct list_head followers; |
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struct link_ctl_info info; |
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int val; /* the master value */ |
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unsigned int tlv[4]; |
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void (*hook)(void *private_data, int); |
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void *hook_private_data; |
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}; |
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/* |
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* link follower - this contains a follower control element |
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* |
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* It fakes the control callbacks with additional attenuation by the |
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* master control. A follower may have either one or two channels. |
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*/ |
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struct link_follower { |
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struct list_head list; |
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struct link_master *master; |
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struct link_ctl_info info; |
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int vals[2]; /* current values */ |
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unsigned int flags; |
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struct snd_kcontrol *kctl; /* original kcontrol pointer */ |
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struct snd_kcontrol follower; /* the copy of original control entry */ |
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}; |
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static int follower_update(struct link_follower *follower) |
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{ |
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struct snd_ctl_elem_value *uctl; |
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int err, ch; |
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uctl = kzalloc(sizeof(*uctl), GFP_KERNEL); |
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if (!uctl) |
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return -ENOMEM; |
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uctl->id = follower->follower.id; |
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err = follower->follower.get(&follower->follower, uctl); |
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if (err < 0) |
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goto error; |
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for (ch = 0; ch < follower->info.count; ch++) |
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follower->vals[ch] = uctl->value.integer.value[ch]; |
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error: |
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kfree(uctl); |
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return err < 0 ? err : 0; |
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} |
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/* get the follower ctl info and save the initial values */ |
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static int follower_init(struct link_follower *follower) |
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{ |
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struct snd_ctl_elem_info *uinfo; |
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int err; |
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if (follower->info.count) { |
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/* already initialized */ |
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if (follower->flags & SND_CTL_FOLLOWER_NEED_UPDATE) |
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return follower_update(follower); |
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return 0; |
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} |
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uinfo = kmalloc(sizeof(*uinfo), GFP_KERNEL); |
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if (!uinfo) |
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return -ENOMEM; |
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uinfo->id = follower->follower.id; |
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err = follower->follower.info(&follower->follower, uinfo); |
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if (err < 0) { |
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kfree(uinfo); |
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return err; |
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} |
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follower->info.type = uinfo->type; |
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follower->info.count = uinfo->count; |
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if (follower->info.count > 2 || |
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(follower->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER && |
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follower->info.type != SNDRV_CTL_ELEM_TYPE_BOOLEAN)) { |
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pr_err("ALSA: vmaster: invalid follower element\n"); |
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kfree(uinfo); |
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return -EINVAL; |
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} |
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follower->info.min_val = uinfo->value.integer.min; |
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follower->info.max_val = uinfo->value.integer.max; |
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kfree(uinfo); |
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return follower_update(follower); |
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} |
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/* initialize master volume */ |
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static int master_init(struct link_master *master) |
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{ |
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struct link_follower *follower; |
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if (master->info.count) |
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return 0; /* already initialized */ |
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list_for_each_entry(follower, &master->followers, list) { |
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int err = follower_init(follower); |
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if (err < 0) |
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return err; |
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master->info = follower->info; |
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master->info.count = 1; /* always mono */ |
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/* set full volume as default (= no attenuation) */ |
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master->val = master->info.max_val; |
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if (master->hook) |
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master->hook(master->hook_private_data, master->val); |
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return 1; |
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} |
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return -ENOENT; |
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} |
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static int follower_get_val(struct link_follower *follower, |
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struct snd_ctl_elem_value *ucontrol) |
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{ |
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int err, ch; |
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err = follower_init(follower); |
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if (err < 0) |
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return err; |
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for (ch = 0; ch < follower->info.count; ch++) |
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ucontrol->value.integer.value[ch] = follower->vals[ch]; |
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return 0; |
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} |
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static int follower_put_val(struct link_follower *follower, |
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struct snd_ctl_elem_value *ucontrol) |
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{ |
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int err, ch, vol; |
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err = master_init(follower->master); |
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if (err < 0) |
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return err; |
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switch (follower->info.type) { |
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case SNDRV_CTL_ELEM_TYPE_BOOLEAN: |
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for (ch = 0; ch < follower->info.count; ch++) |
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ucontrol->value.integer.value[ch] &= |
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!!follower->master->val; |
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break; |
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case SNDRV_CTL_ELEM_TYPE_INTEGER: |
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for (ch = 0; ch < follower->info.count; ch++) { |
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/* max master volume is supposed to be 0 dB */ |
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vol = ucontrol->value.integer.value[ch]; |
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vol += follower->master->val - follower->master->info.max_val; |
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if (vol < follower->info.min_val) |
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vol = follower->info.min_val; |
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else if (vol > follower->info.max_val) |
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vol = follower->info.max_val; |
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ucontrol->value.integer.value[ch] = vol; |
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} |
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break; |
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} |
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return follower->follower.put(&follower->follower, ucontrol); |
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} |
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/* |
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* ctl callbacks for followers |
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*/ |
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static int follower_info(struct snd_kcontrol *kcontrol, |
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struct snd_ctl_elem_info *uinfo) |
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{ |
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struct link_follower *follower = snd_kcontrol_chip(kcontrol); |
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return follower->follower.info(&follower->follower, uinfo); |
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} |
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static int follower_get(struct snd_kcontrol *kcontrol, |
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struct snd_ctl_elem_value *ucontrol) |
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{ |
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struct link_follower *follower = snd_kcontrol_chip(kcontrol); |
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return follower_get_val(follower, ucontrol); |
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} |
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static int follower_put(struct snd_kcontrol *kcontrol, |
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struct snd_ctl_elem_value *ucontrol) |
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{ |
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struct link_follower *follower = snd_kcontrol_chip(kcontrol); |
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int err, ch, changed = 0; |
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err = follower_init(follower); |
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if (err < 0) |
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return err; |
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for (ch = 0; ch < follower->info.count; ch++) { |
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if (follower->vals[ch] != ucontrol->value.integer.value[ch]) { |
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changed = 1; |
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follower->vals[ch] = ucontrol->value.integer.value[ch]; |
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} |
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} |
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if (!changed) |
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return 0; |
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err = follower_put_val(follower, ucontrol); |
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if (err < 0) |
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return err; |
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return 1; |
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} |
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static int follower_tlv_cmd(struct snd_kcontrol *kcontrol, |
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int op_flag, unsigned int size, |
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unsigned int __user *tlv) |
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{ |
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struct link_follower *follower = snd_kcontrol_chip(kcontrol); |
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/* FIXME: this assumes that the max volume is 0 dB */ |
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return follower->follower.tlv.c(&follower->follower, op_flag, size, tlv); |
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} |
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static void follower_free(struct snd_kcontrol *kcontrol) |
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{ |
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struct link_follower *follower = snd_kcontrol_chip(kcontrol); |
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if (follower->follower.private_free) |
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follower->follower.private_free(&follower->follower); |
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if (follower->master) |
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list_del(&follower->list); |
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kfree(follower); |
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} |
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/* |
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* Add a follower control to the group with the given master control |
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* |
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* All followers must be the same type (returning the same information |
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* via info callback). The function doesn't check it, so it's your |
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* responsibility. |
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* |
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* Also, some additional limitations: |
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* - at most two channels |
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* - logarithmic volume control (dB level), no linear volume |
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* - master can only attenuate the volume, no gain |
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*/ |
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int _snd_ctl_add_follower(struct snd_kcontrol *master, |
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struct snd_kcontrol *follower, |
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unsigned int flags) |
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{ |
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struct link_master *master_link = snd_kcontrol_chip(master); |
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struct link_follower *srec; |
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srec = kzalloc(struct_size(srec, follower.vd, follower->count), |
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GFP_KERNEL); |
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if (!srec) |
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return -ENOMEM; |
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srec->kctl = follower; |
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srec->follower = *follower; |
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memcpy(srec->follower.vd, follower->vd, follower->count * sizeof(*follower->vd)); |
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srec->master = master_link; |
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srec->flags = flags; |
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/* override callbacks */ |
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follower->info = follower_info; |
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follower->get = follower_get; |
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follower->put = follower_put; |
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if (follower->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) |
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follower->tlv.c = follower_tlv_cmd; |
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follower->private_data = srec; |
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follower->private_free = follower_free; |
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list_add_tail(&srec->list, &master_link->followers); |
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return 0; |
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} |
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EXPORT_SYMBOL(_snd_ctl_add_follower); |
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/* |
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* ctl callbacks for master controls |
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*/ |
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static int master_info(struct snd_kcontrol *kcontrol, |
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struct snd_ctl_elem_info *uinfo) |
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{ |
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struct link_master *master = snd_kcontrol_chip(kcontrol); |
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int ret; |
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ret = master_init(master); |
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if (ret < 0) |
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return ret; |
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uinfo->type = master->info.type; |
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uinfo->count = master->info.count; |
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uinfo->value.integer.min = master->info.min_val; |
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uinfo->value.integer.max = master->info.max_val; |
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return 0; |
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} |
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static int master_get(struct snd_kcontrol *kcontrol, |
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struct snd_ctl_elem_value *ucontrol) |
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{ |
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struct link_master *master = snd_kcontrol_chip(kcontrol); |
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int err = master_init(master); |
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if (err < 0) |
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return err; |
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ucontrol->value.integer.value[0] = master->val; |
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return 0; |
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} |
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static int sync_followers(struct link_master *master, int old_val, int new_val) |
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{ |
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struct link_follower *follower; |
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struct snd_ctl_elem_value *uval; |
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uval = kmalloc(sizeof(*uval), GFP_KERNEL); |
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if (!uval) |
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return -ENOMEM; |
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list_for_each_entry(follower, &master->followers, list) { |
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master->val = old_val; |
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uval->id = follower->follower.id; |
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follower_get_val(follower, uval); |
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master->val = new_val; |
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follower_put_val(follower, uval); |
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} |
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kfree(uval); |
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return 0; |
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} |
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static int master_put(struct snd_kcontrol *kcontrol, |
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struct snd_ctl_elem_value *ucontrol) |
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{ |
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struct link_master *master = snd_kcontrol_chip(kcontrol); |
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int err, new_val, old_val; |
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bool first_init; |
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err = master_init(master); |
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if (err < 0) |
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return err; |
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first_init = err; |
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old_val = master->val; |
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new_val = ucontrol->value.integer.value[0]; |
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if (new_val == old_val) |
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return 0; |
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err = sync_followers(master, old_val, new_val); |
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if (err < 0) |
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return err; |
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if (master->hook && !first_init) |
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master->hook(master->hook_private_data, master->val); |
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return 1; |
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} |
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static void master_free(struct snd_kcontrol *kcontrol) |
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{ |
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struct link_master *master = snd_kcontrol_chip(kcontrol); |
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struct link_follower *follower, *n; |
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/* free all follower links and retore the original follower kctls */ |
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list_for_each_entry_safe(follower, n, &master->followers, list) { |
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struct snd_kcontrol *sctl = follower->kctl; |
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struct list_head olist = sctl->list; |
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memcpy(sctl, &follower->follower, sizeof(*sctl)); |
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memcpy(sctl->vd, follower->follower.vd, |
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sctl->count * sizeof(*sctl->vd)); |
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sctl->list = olist; /* keep the current linked-list */ |
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kfree(follower); |
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} |
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kfree(master); |
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} |
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/** |
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* snd_ctl_make_virtual_master - Create a virtual master control |
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* @name: name string of the control element to create |
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* @tlv: optional TLV int array for dB information |
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* |
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* Creates a virtual master control with the given name string. |
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* |
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* After creating a vmaster element, you can add the follower controls |
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* via snd_ctl_add_follower() or snd_ctl_add_follower_uncached(). |
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* |
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* The optional argument @tlv can be used to specify the TLV information |
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* for dB scale of the master control. It should be a single element |
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* with #SNDRV_CTL_TLVT_DB_SCALE, #SNDRV_CTL_TLV_DB_MINMAX or |
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* #SNDRV_CTL_TLVT_DB_MINMAX_MUTE type, and should be the max 0dB. |
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* |
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* Return: The created control element, or %NULL for errors (ENOMEM). |
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*/ |
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struct snd_kcontrol *snd_ctl_make_virtual_master(char *name, |
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const unsigned int *tlv) |
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{ |
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struct link_master *master; |
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struct snd_kcontrol *kctl; |
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struct snd_kcontrol_new knew; |
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memset(&knew, 0, sizeof(knew)); |
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knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER; |
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knew.name = name; |
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knew.info = master_info; |
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master = kzalloc(sizeof(*master), GFP_KERNEL); |
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if (!master) |
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return NULL; |
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INIT_LIST_HEAD(&master->followers); |
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kctl = snd_ctl_new1(&knew, master); |
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if (!kctl) { |
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kfree(master); |
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return NULL; |
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} |
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/* override some callbacks */ |
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kctl->info = master_info; |
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kctl->get = master_get; |
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kctl->put = master_put; |
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kctl->private_free = master_free; |
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/* additional (constant) TLV read */ |
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if (tlv) { |
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unsigned int type = tlv[SNDRV_CTL_TLVO_TYPE]; |
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if (type == SNDRV_CTL_TLVT_DB_SCALE || |
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type == SNDRV_CTL_TLVT_DB_MINMAX || |
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type == SNDRV_CTL_TLVT_DB_MINMAX_MUTE) { |
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kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ; |
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memcpy(master->tlv, tlv, sizeof(master->tlv)); |
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kctl->tlv.p = master->tlv; |
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} |
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} |
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return kctl; |
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} |
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EXPORT_SYMBOL(snd_ctl_make_virtual_master); |
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/** |
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* snd_ctl_add_vmaster_hook - Add a hook to a vmaster control |
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* @kcontrol: vmaster kctl element |
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* @hook: the hook function |
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* @private_data: the private_data pointer to be saved |
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* |
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* Adds the given hook to the vmaster control element so that it's called |
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* at each time when the value is changed. |
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* |
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* Return: Zero. |
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*/ |
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int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol, |
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void (*hook)(void *private_data, int), |
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void *private_data) |
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{ |
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struct link_master *master = snd_kcontrol_chip(kcontrol); |
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master->hook = hook; |
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master->hook_private_data = private_data; |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(snd_ctl_add_vmaster_hook); |
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/** |
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* snd_ctl_sync_vmaster - Sync the vmaster followers and hook |
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* @kcontrol: vmaster kctl element |
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* @hook_only: sync only the hook |
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* |
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* Forcibly call the put callback of each follower and call the hook function |
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* to synchronize with the current value of the given vmaster element. |
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* NOP when NULL is passed to @kcontrol. |
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*/ |
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void snd_ctl_sync_vmaster(struct snd_kcontrol *kcontrol, bool hook_only) |
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{ |
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struct link_master *master; |
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bool first_init = false; |
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if (!kcontrol) |
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return; |
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master = snd_kcontrol_chip(kcontrol); |
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if (!hook_only) { |
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int err = master_init(master); |
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if (err < 0) |
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return; |
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first_init = err; |
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err = sync_followers(master, master->val, master->val); |
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if (err < 0) |
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return; |
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} |
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if (master->hook && !first_init) |
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master->hook(master->hook_private_data, master->val); |
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} |
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EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster); |
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/** |
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* snd_ctl_apply_vmaster_followers - Apply function to each vmaster follower |
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* @kctl: vmaster kctl element |
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* @func: function to apply |
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* @arg: optional function argument |
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* |
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* Apply the function @func to each follower kctl of the given vmaster kctl. |
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* Returns 0 if successful, or a negative error code. |
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*/ |
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int snd_ctl_apply_vmaster_followers(struct snd_kcontrol *kctl, |
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int (*func)(struct snd_kcontrol *vfollower, |
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struct snd_kcontrol *follower, |
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void *arg), |
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void *arg) |
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{ |
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struct link_master *master; |
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struct link_follower *follower; |
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int err; |
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master = snd_kcontrol_chip(kctl); |
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err = master_init(master); |
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if (err < 0) |
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return err; |
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list_for_each_entry(follower, &master->followers, list) { |
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err = func(follower->kctl, &follower->follower, arg); |
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if (err < 0) |
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return err; |
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} |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(snd_ctl_apply_vmaster_followers);
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