1 files changed, 455 insertions, 0 deletions
diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c
new file mode 100644
index 00000000..85758613
--- /dev/null
+++ b/sound/core/vmaster.c
@@ -0,0 +1,455 @@
+/*
+ * 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)) {
+		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);
+
+	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;
+	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 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 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);
+	if (master->hook && !err)
+		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 matster control with the given name string.
+ * Returns the created control element, or NULL for errors (ENOMEM).
+ *
+ * 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.
+ */
+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.
+ */
+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_hook - Sync the vmaster hook
+ * @kcontrol: vmaster kctl element
+ *
+ * Call the hook function to synchronize with the current value of the given
+ * vmaster element.  NOP when NULL is passed to @kcontrol or the hook doesn't
+ * exist.
+ */
+void snd_ctl_sync_vmaster_hook(struct snd_kcontrol *kcontrol)
+{
+	struct link_master *master;
+	if (!kcontrol)
+		return;
+	master = snd_kcontrol_chip(kcontrol);
+	if (master->hook)
+		master->hook(master->hook_private_data, master->val);
+}
+EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster_hook);