This patch adds the virtual master control to sound core.
Takashi
diff -r 1207d46e60b3 core/Kconfig --- a/core/Kconfig Mon Dec 03 15:15:59 2007 +0100 +++ b/core/Kconfig Mon Dec 03 15:46:17 2007 +0100 @@ -15,6 +15,9 @@ config SND_RAWMIDI config SND_RAWMIDI tristate depends on SND + +config SND_VMASTER + bool
config SND_SEQUENCER tristate "Sequencer support" diff -r 1207d46e60b3 core/Makefile --- a/core/Makefile Mon Dec 03 15:15:59 2007 +0100 +++ b/core/Makefile Mon Dec 03 15:46:17 2007 +0100 @@ -6,6 +6,7 @@ snd-y := sound.o init.o memory.o inf snd-y := sound.o init.o memory.o info.o control.o misc.o device.o snd-$(CONFIG_ISA_DMA_API) += isadma.o snd-$(CONFIG_SND_OSSEMUL) += sound_oss.o info_oss.o +snd-$(CONFIG_SND_VMASTER) += vmaster.o
snd-pcm-objs := pcm.o pcm_native.o pcm_lib.o pcm_timer.o pcm_misc.o \ pcm_memory.o diff -r 1207d46e60b3 core/vmaster.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/core/vmaster.c Mon Dec 03 15:46:17 2007 +0100 @@ -0,0 +1,379 @@ +/* + * Virtual master and slave controls + * + * Copyright (c) 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; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <sound/driver.h> +#include <linux/slab.h> +#include <sound/core.h> +#include <sound/control.h> + +/* + * a subset of information returned via ctl info callback + */ +struct link_ctl_info { + int 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 */ +}; + +/* + * 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 */ + struct snd_kcontrol slave; /* the copy of original control entry */ +}; + +/* get the slave ctl info and save the initial values */ +static int slave_init(struct link_slave *slave) +{ + struct snd_ctl_elem_info *uinfo; + struct snd_ctl_elem_value *uctl; + int err, ch; + + if (slave->info.count) + return 0; /* already initialized */ + + 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)) { + snd_printk(KERN_ERR "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); + + 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; +} + +/* 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; + return 0; + } + 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; + return slave_put_val(slave, ucontrol); +} + +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 fucntion 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) +{ + 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->slave = *slave; + memcpy(srec->slave.vd, slave->vd, slave->count * sizeof(*slave->vd)); + srec->master = master_link; + + /* 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 master_put(struct snd_kcontrol *kcontrol, + struct snd_ctl_elem_value *ucontrol) +{ + struct link_master *master = snd_kcontrol_chip(kcontrol); + struct link_slave *slave; + struct snd_ctl_elem_value *uval; + int err, old_val; + + err = master_init(master); + if (err < 0) + return err; + old_val = master->val; + if (ucontrol->value.integer.value[0] == old_val) + return 0; + + 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 = ucontrol->value.integer.value[0]; + slave_put_val(slave, uval); + } + kfree(uval); + return 1; +} + +static void master_free(struct snd_kcontrol *kcontrol) +{ + struct link_master *master = snd_kcontrol_chip(kcontrol); + struct link_slave *slave; + + list_for_each_entry(slave, &master->slaves, list) + slave->master = NULL; + kfree(master); +} + + +/* + * Create a virtual master control with the given name + */ +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) { + /* FIXME: this assumes that the max volume is 0 dB */ + kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ; + kctl->tlv.p = tlv; + } + return kctl; +} + +EXPORT_SYMBOL(snd_ctl_make_virtual_master); diff -r 1207d46e60b3 include/control.h --- a/include/control.h Mon Dec 03 15:15:59 2007 +0100 +++ b/include/control.h Mon Dec 03 15:46:17 2007 +0100 @@ -169,4 +169,12 @@ int snd_ctl_boolean_stereo_info(struct s int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo);
+/* + * virtual master control + */ +struct snd_kcontrol *snd_ctl_make_virtual_master(char *name, + const unsigned int *tlv); +int snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave); + + #endif /* __SOUND_CONTROL_H */