linux/sound/usb/mixer_quirks.c

/*
 *   USB Audio Driver for ALSA
 *
 *   Quirks and vendor-specific extensions for mixer interfaces
 *
 *   Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
 *
 *   Many codes borrowed from audio.c by
 *	    Alan Cox (alan@lxorguk.ukuu.org.uk)
 *	    Thomas Sailer (sailer@ife.ee.ethz.ch)
 *
 *
 *   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 <linux/init.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>

#include <sound/core.h>
#include <sound/control.h>
#include <sound/hwdep.h>
#include <sound/info.h>

#include "usbaudio.h"
#include "mixer.h"
#include "mixer_quirks.h"
#include "helper.h"

extern struct snd_kcontrol_new *snd_usb_feature_unit_ctl;

/* private_free callback */
static void usb_mixer_elem_free(struct snd_kcontrol *kctl)
{
	kfree(kctl->private_data);
	kctl->private_data = NULL;
}

/* This function allows for the creation of standard UAC controls.
 * See the quirks for M-Audio FTUs or Ebox-44.
 * If you don't want to set a TLV callback pass NULL.
 *
 * Since there doesn't seem to be a devices that needs a multichannel
 * version, we keep it mono for simplicity.
 */
static int snd_create_std_mono_ctl(struct usb_mixer_interface *mixer,
				unsigned int unitid,
				unsigned int control,
				unsigned int cmask,
				int val_type,
				const char *name,
				snd_kcontrol_tlv_rw_t *tlv_callback)
{
	int err;
	struct usb_mixer_elem_info *cval;
	struct snd_kcontrol *kctl;

	cval = kzalloc(sizeof(*cval), GFP_KERNEL);
	if (!cval)
		return -ENOMEM;

	cval->id = unitid;
	cval->mixer = mixer;
	cval->val_type = val_type;
	cval->channels = 1;
	cval->control = control;
	cval->cmask = cmask;

	/* FIXME: Do we need this?
	 * The following values are for compatibility with
	 * Ebox-44 mixer.
	 * But the corresponding ebox-44 function says:
	 *    "Volume controls will override these values"
	 *
	 * These values don't have any effect at all for
	 * M-Audio FTUs.
	 * So I think, we can safely omit the range settings here.
	 */
	cval->min = 0;
	cval->max = 1;
	cval->res = 0;
	cval->dBmin = 0;
	cval->dBmax = 0;

	/* Create control */
	kctl = snd_ctl_new1(snd_usb_feature_unit_ctl, cval);
	if (!kctl) {
		kfree(cval);
		return -ENOMEM;
	}

	/* Set name */
	snprintf(kctl->id.name, sizeof(kctl->id.name), name);
	kctl->private_free = usb_mixer_elem_free;

	/* set TLV */
	if (tlv_callback) {
		kctl->tlv.c = tlv_callback;
		kctl->vd[0].access |=
			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
	}
	/* Add control to mixer */
	err = snd_usb_mixer_add_control(mixer, kctl);
	if (err < 0)
		return err;

	return 0;
}

/*
 * Sound Blaster remote control configuration
 *
 * format of remote control data:
 * Extigy:       xx 00
 * Audigy 2 NX:  06 80 xx 00 00 00
 * Live! 24-bit: 06 80 xx yy 22 83
 */
static const struct rc_config {
	u32 usb_id;
	u8  offset;
	u8  length;
	u8  packet_length;
	u8  min_packet_length; /* minimum accepted length of the URB result */
	u8  mute_mixer_id;
	u32 mute_code;
} rc_configs[] = {
	{ USB_ID(0x041e, 0x3000), 0, 1, 2, 1,  18, 0x0013 }, /* Extigy       */
	{ USB_ID(0x041e, 0x3020), 2, 1, 6, 6,  18, 0x0013 }, /* Audigy 2 NX  */
	{ USB_ID(0x041e, 0x3040), 2, 2, 6, 6,  2,  0x6e91 }, /* Live! 24-bit */
	{ USB_ID(0x041e, 0x3042), 0, 1, 1, 1,  1,  0x000d }, /* Usb X-Fi S51 */
	{ USB_ID(0x041e, 0x30df), 0, 1, 1, 1,  1,  0x000d }, /* Usb X-Fi S51 Pro */
	{ USB_ID(0x041e, 0x3048), 2, 2, 6, 6,  2,  0x6e91 }, /* Toshiba SB0500 */
};

static void snd_usb_soundblaster_remote_complete(struct urb *urb)
{
	struct usb_mixer_interface *mixer = urb->context;
	const struct rc_config *rc = mixer->rc_cfg;
	u32 code;

	if (urb->status < 0 || urb->actual_length < rc->min_packet_length)
		return;

	code = mixer->rc_buffer[rc->offset];
	if (rc->length == 2)
		code |= mixer->rc_buffer[rc->offset + 1] << 8;

	/* the Mute button actually changes the mixer control */
	if (code == rc->mute_code)
		snd_usb_mixer_notify_id(mixer, rc->mute_mixer_id);
	mixer->rc_code = code;
	wmb();
	wake_up(&mixer->rc_waitq);
}

static long snd_usb_sbrc_hwdep_read(struct snd_hwdep *hw, char __user *buf,
				     long count, loff_t *offset)
{
	struct usb_mixer_interface *mixer = hw->private_data;
	int err;
	u32 rc_code;

	if (count != 1 && count != 4)
		return -EINVAL;
	err = wait_event_interruptible(mixer->rc_waitq,
				       (rc_code = xchg(&mixer->rc_code, 0)) != 0);
	if (err == 0) {
		if (count == 1)
			err = put_user(rc_code, buf);
		else
			err = put_user(rc_code, (u32 __user *)buf);
	}
	return err < 0 ? err : count;
}

static unsigned int snd_usb_sbrc_hwdep_poll(struct snd_hwdep *hw, struct file *file,
					    poll_table *wait)
{
	struct usb_mixer_interface *mixer = hw->private_data;

	poll_wait(file, &mixer->rc_waitq, wait);
	return mixer->rc_code ? POLLIN | POLLRDNORM : 0;
}

static int snd_usb_soundblaster_remote_init(struct usb_mixer_interface *mixer)
{
	struct snd_hwdep *hwdep;
	int err, len, i;

	for (i = 0; i < ARRAY_SIZE(rc_configs); ++i)
		if (rc_configs[i].usb_id == mixer->chip->usb_id)
			break;
	if (i >= ARRAY_SIZE(rc_configs))
		return 0;
	mixer->rc_cfg = &rc_configs[i];

	len = mixer->rc_cfg->packet_length;

	init_waitqueue_head(&mixer->rc_waitq);
	err = snd_hwdep_new(mixer->chip->card, "SB remote control", 0, &hwdep);
	if (err < 0)
		return err;
	snprintf(hwdep->name, sizeof(hwdep->name),
		 "%s remote control", mixer->chip->card->shortname);
	hwdep->iface = SNDRV_HWDEP_IFACE_SB_RC;
	hwdep->private_data = mixer;
	hwdep->ops.read = snd_usb_sbrc_hwdep_read;
	hwdep->ops.poll = snd_usb_sbrc_hwdep_poll;
	hwdep->exclusive = 1;

	mixer->rc_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!mixer->rc_urb)
		return -ENOMEM;
	mixer->rc_setup_packet = kmalloc(sizeof(*mixer->rc_setup_packet), GFP_KERNEL);
	if (!mixer->rc_setup_packet) {
		usb_free_urb(mixer->rc_urb);
		mixer->rc_urb = NULL;
		return -ENOMEM;
	}
	mixer->rc_setup_packet->bRequestType =
		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
	mixer->rc_setup_packet->bRequest = UAC_GET_MEM;
	mixer->rc_setup_packet->wValue = cpu_to_le16(0);
	mixer->rc_setup_packet->wIndex = cpu_to_le16(0);
	mixer->rc_setup_packet->wLength = cpu_to_le16(len);
	usb_fill_control_urb(mixer->rc_urb, mixer->chip->dev,
			     usb_rcvctrlpipe(mixer->chip->dev, 0),
			     (u8*)mixer->rc_setup_packet, mixer->rc_buffer, len,
			     snd_usb_soundblaster_remote_complete, mixer);
	return 0;
}

#define snd_audigy2nx_led_info		snd_ctl_boolean_mono_info

static int snd_audigy2nx_led_get(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
{
	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
	int index = kcontrol->private_value;

	ucontrol->value.integer.value[0] = mixer->audigy2nx_leds[index];
	return 0;
}

static int snd_audigy2nx_led_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
{
	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
	int index = kcontrol->private_value;
	int value = ucontrol->value.integer.value[0];
	int err, changed;

	if (value > 1)
		return -EINVAL;
	changed = value != mixer->audigy2nx_leds[index];
	if (mixer->chip->usb_id == USB_ID(0x041e, 0x3042))
		err = snd_usb_ctl_msg(mixer->chip->dev,
			      usb_sndctrlpipe(mixer->chip->dev, 0), 0x24,
			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
			      !value, 0, NULL, 0);
	/* USB X-Fi S51 Pro */
	if (mixer->chip->usb_id == USB_ID(0x041e, 0x30df))
		err = snd_usb_ctl_msg(mixer->chip->dev,
			      usb_sndctrlpipe(mixer->chip->dev, 0), 0x24,
			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
			      !value, 0, NULL, 0);
	else
		err = snd_usb_ctl_msg(mixer->chip->dev,
			      usb_sndctrlpipe(mixer->chip->dev, 0), 0x24,
			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
			      value, index + 2, NULL, 0);
	if (err < 0)
		return err;
	mixer->audigy2nx_leds[index] = value;
	return changed;
}

static struct snd_kcontrol_new snd_audigy2nx_controls[] = {
	{
		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
		.name = "CMSS LED Switch",
		.info = snd_audigy2nx_led_info,
		.get = snd_audigy2nx_led_get,
		.put = snd_audigy2nx_led_put,
		.private_value = 0,
	},
	{
		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
		.name = "Power LED Switch",
		.info = snd_audigy2nx_led_info,
		.get = snd_audigy2nx_led_get,
		.put = snd_audigy2nx_led_put,
		.private_value = 1,
	},
	{
		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
		.name = "Dolby Digital LED Switch",
		.info = snd_audigy2nx_led_info,
		.get = snd_audigy2nx_led_get,
		.put = snd_audigy2nx_led_put,
		.private_value = 2,
	},
};

static int snd_audigy2nx_controls_create(struct usb_mixer_interface *mixer)
{
	int i, err;

	for (i = 0; i < ARRAY_SIZE(snd_audigy2nx_controls); ++i) {
		/* USB X-Fi S51 doesn't have a CMSS LED */
		if ((mixer->chip->usb_id == USB_ID(0x041e, 0x3042)) && i == 0)
			continue;
		/* USB X-Fi S51 Pro doesn't have one either */
		if ((mixer->chip->usb_id == USB_ID(0x041e, 0x30df)) && i == 0)
			continue;
		if (i > 1 && /* Live24ext has 2 LEDs only */
			(mixer->chip->usb_id == USB_ID(0x041e, 0x3040) ||
			 mixer->chip->usb_id == USB_ID(0x041e, 0x3042) ||
			 mixer->chip->usb_id == USB_ID(0x041e, 0x30df) ||
			 mixer->chip->usb_id == USB_ID(0x041e, 0x3048)))
			break; 
		err = snd_ctl_add(mixer->chip->card,
				  snd_ctl_new1(&snd_audigy2nx_controls[i], mixer));
		if (err < 0)
			return err;
	}
	mixer->audigy2nx_leds[1] = 1; /* Power LED is on by default */
	return 0;
}

static void snd_audigy2nx_proc_read(struct snd_info_entry *entry,
				    struct snd_info_buffer *buffer)
{
	static const struct sb_jack {
		int unitid;
		const char *name;
	}  jacks_audigy2nx[] = {
		{4,  "dig in "},
		{7,  "line in"},
		{19, "spk out"},
		{20, "hph out"},
		{-1, NULL}
	}, jacks_live24ext[] = {
		{4,  "line in"}, /* &1=Line, &2=Mic*/
		{3,  "hph out"}, /* headphones */
		{0,  "RC     "}, /* last command, 6 bytes see rc_config above */
		{-1, NULL}
	};
	const struct sb_jack *jacks;
	struct usb_mixer_interface *mixer = entry->private_data;
	int i, err;
	u8 buf[3];

	snd_iprintf(buffer, "%s jacks\n\n", mixer->chip->card->shortname);
	if (mixer->chip->usb_id == USB_ID(0x041e, 0x3020))
		jacks = jacks_audigy2nx;
	else if (mixer->chip->usb_id == USB_ID(0x041e, 0x3040) ||
		 mixer->chip->usb_id == USB_ID(0x041e, 0x3048))
		jacks = jacks_live24ext;
	else
		return;

	for (i = 0; jacks[i].name; ++i) {
		snd_iprintf(buffer, "%s: ", jacks[i].name);
		err = snd_usb_ctl_msg(mixer->chip->dev,
				      usb_rcvctrlpipe(mixer->chip->dev, 0),
				      UAC_GET_MEM, USB_DIR_IN | USB_TYPE_CLASS |
				      USB_RECIP_INTERFACE, 0,
				      jacks[i].unitid << 8, buf, 3);
		if (err == 3 && (buf[0] == 3 || buf[0] == 6))
			snd_iprintf(buffer, "%02x %02x\n", buf[1], buf[2]);
		else
			snd_iprintf(buffer, "?\n");
	}
}

static int snd_xonar_u1_switch_get(struct snd_kcontrol *kcontrol,
				   struct snd_ctl_elem_value *ucontrol)
{
	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);

	ucontrol->value.integer.value[0] = !!(mixer->xonar_u1_status & 0x02);
	return 0;
}

static int snd_xonar_u1_switch_put(struct snd_kcontrol *kcontrol,
				   struct snd_ctl_elem_value *ucontrol)
{
	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
	u8 old_status, new_status;
	int err, changed;

	old_status = mixer->xonar_u1_status;
	if (ucontrol->value.integer.value[0])
		new_status = old_status | 0x02;
	else
		new_status = old_status & ~0x02;
	changed = new_status != old_status;
	err = snd_usb_ctl_msg(mixer->chip->dev,
			      usb_sndctrlpipe(mixer->chip->dev, 0), 0x08,
			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
			      50, 0, &new_status, 1);
	if (err < 0)
		return err;
	mixer->xonar_u1_status = new_status;
	return changed;
}

static struct snd_kcontrol_new snd_xonar_u1_output_switch = {
	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
	.name = "Digital Playback Switch",
	.info = snd_ctl_boolean_mono_info,
	.get = snd_xonar_u1_switch_get,
	.put = snd_xonar_u1_switch_put,
};

static int snd_xonar_u1_controls_create(struct usb_mixer_interface *mixer)
{
	int err;

	err = snd_ctl_add(mixer->chip->card,
			  snd_ctl_new1(&snd_xonar_u1_output_switch, mixer));
	if (err < 0)
		return err;
	mixer->xonar_u1_status = 0x05;
	return 0;
}

/* Native Instruments device quirks */

#define _MAKE_NI_CONTROL(bRequest,wIndex) ((bRequest) << 16 | (wIndex))

static int snd_nativeinstruments_control_get(struct snd_kcontrol *kcontrol,
					     struct snd_ctl_elem_value *ucontrol)
{
	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
	struct usb_device *dev = mixer->chip->dev;
	u8 bRequest = (kcontrol->private_value >> 16) & 0xff;
	u16 wIndex = kcontrol->private_value & 0xffff;
	u8 tmp;

	int ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), bRequest,
				  USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
				  0, cpu_to_le16(wIndex),
				  &tmp, sizeof(tmp), 1000);

	if (ret < 0) {
		snd_printk(KERN_ERR
			   "unable to issue vendor read request (ret = %d)", ret);
		return ret;
	}

	ucontrol->value.integer.value[0] = tmp;

	return 0;
}

static int snd_nativeinstruments_control_put(struct snd_kcontrol *kcontrol,
					     struct snd_ctl_elem_value *ucontrol)
{
	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
	struct usb_device *dev = mixer->chip->dev;
	u8 bRequest = (kcontrol->private_value >> 16) & 0xff;
	u16 wIndex = kcontrol->private_value & 0xffff;
	u16 wValue = ucontrol->value.integer.value[0];

	int ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), bRequest,
				  USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
				  cpu_to_le16(wValue), cpu_to_le16(wIndex),
				  NULL, 0, 1000);

	if (ret < 0) {
		snd_printk(KERN_ERR
			   "unable to issue vendor write request (ret = %d)", ret);
		return ret;
	}

	return 0;
}

static struct snd_kcontrol_new snd_nativeinstruments_ta6_mixers[] = {
	{
		.name = "Direct Thru Channel A",
		.private_value = _MAKE_NI_CONTROL(0x01, 0x03),
	},
	{
		.name = "Direct Thru Channel B",
		.private_value = _MAKE_NI_CONTROL(0x01, 0x05),
	},
	{
		.name = "Phono Input Channel A",
		.private_value = _MAKE_NI_CONTROL(0x02, 0x03),
	},
	{
		.name = "Phono Input Channel B",
		.private_value = _MAKE_NI_CONTROL(0x02, 0x05),
	},
};

static struct snd_kcontrol_new snd_nativeinstruments_ta10_mixers[] = {
	{
		.name = "Direct Thru Channel A",
		.private_value = _MAKE_NI_CONTROL(0x01, 0x03),
	},
	{
		.name = "Direct Thru Channel B",
		.private_value = _MAKE_NI_CONTROL(0x01, 0x05),
	},
	{
		.name = "Direct Thru Channel C",
		.private_value = _MAKE_NI_CONTROL(0x01, 0x07),
	},
	{
		.name = "Direct Thru Channel D",
		.private_value = _MAKE_NI_CONTROL(0x01, 0x09),
	},
	{
		.name = "Phono Input Channel A",
		.private_value = _MAKE_NI_CONTROL(0x02, 0x03),
	},
	{
		.name = "Phono Input Channel B",
		.private_value = _MAKE_NI_CONTROL(0x02, 0x05),
	},
	{
		.name = "Phono Input Channel C",
		.private_value = _MAKE_NI_CONTROL(0x02, 0x07),
	},
	{
		.name = "Phono Input Channel D",
		.private_value = _MAKE_NI_CONTROL(0x02, 0x09),
	},
};

static int snd_nativeinstruments_create_mixer(struct usb_mixer_interface *mixer,
					      const struct snd_kcontrol_new *kc,
					      unsigned int count)
{
	int i, err = 0;
	struct snd_kcontrol_new template = {
		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
		.get = snd_nativeinstruments_control_get,
		.put = snd_nativeinstruments_control_put,
		.info = snd_ctl_boolean_mono_info,
	};

	for (i = 0; i < count; i++) {
		struct snd_kcontrol *c;

		template.name = kc[i].name;
		template.private_value = kc[i].private_value;

		c = snd_ctl_new1(&template, mixer);
		err = snd_ctl_add(mixer->chip->card, c);

		if (err < 0)
			break;
	}

	return err;
}

/* M-Audio FastTrack Ultra quirks */
/* FTU Effect switch */
struct snd_ftu_eff_switch_priv_val {
	struct usb_mixer_interface *mixer;
	int cached_value;
	int is_cached;
};

static int snd_ftu_eff_switch_info(struct snd_kcontrol *kcontrol,
					struct snd_ctl_elem_info *uinfo)
{
	static const char *texts[8] = {"Room 1",
				       "Room 2",
				       "Room 3",
				       "Hall 1",
				       "Hall 2",
				       "Plate",
				       "Delay",
				       "Echo"
	};

	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
	uinfo->count = 1;
	uinfo->value.enumerated.items = 8;
	if (uinfo->value.enumerated.item > 7)
		uinfo->value.enumerated.item = 7;
	strcpy(uinfo->value.enumerated.name,
		texts[uinfo->value.enumerated.item]);

	return 0;
}

static int snd_ftu_eff_switch_get(struct snd_kcontrol *kctl,
					struct snd_ctl_elem_value *ucontrol)
{
	struct snd_usb_audio *chip;
	struct usb_mixer_interface *mixer;
	struct snd_ftu_eff_switch_priv_val *pval;
	int err;
	unsigned char value[2];

	const int id = 6;
	const int validx = 1;
	const int val_len = 2;

	value[0] = 0x00;
	value[1] = 0x00;

	pval = (struct snd_ftu_eff_switch_priv_val *)
		kctl->private_value;

	if (pval->is_cached) {
		ucontrol->value.enumerated.item[0] = pval->cached_value;
		return 0;
	}

	mixer = (struct usb_mixer_interface *) pval->mixer;
	if (snd_BUG_ON(!mixer))
		return -EINVAL;

	chip = (struct snd_usb_audio *) mixer->chip;
	if (snd_BUG_ON(!chip))
		return -EINVAL;


	err = snd_usb_ctl_msg(chip->dev,
			usb_rcvctrlpipe(chip->dev, 0), UAC_GET_CUR,
			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
			validx << 8, snd_usb_ctrl_intf(chip) | (id << 8),
			value, val_len);
	if (err < 0)
		return err;

	ucontrol->value.enumerated.item[0] = value[0];
	pval->cached_value = value[0];
	pval->is_cached = 1;

	return 0;
}

static int snd_ftu_eff_switch_put(struct snd_kcontrol *kctl,
					struct snd_ctl_elem_value *ucontrol)
{
	struct snd_usb_audio *chip;
	struct snd_ftu_eff_switch_priv_val *pval;

	struct usb_mixer_interface *mixer;
	int changed, cur_val, err, new_val;
	unsigned char value[2];


	const int id = 6;
	const int validx = 1;
	const int val_len = 2;

	changed = 0;

	pval = (struct snd_ftu_eff_switch_priv_val *)
		kctl->private_value;
	cur_val = pval->cached_value;
	new_val = ucontrol->value.enumerated.item[0];

	mixer = (struct usb_mixer_interface *) pval->mixer;
	if (snd_BUG_ON(!mixer))
		return -EINVAL;

	chip = (struct snd_usb_audio *) mixer->chip;
	if (snd_BUG_ON(!chip))
		return -EINVAL;

	if (!pval->is_cached) {
		/* Read current value */
		err = snd_usb_ctl_msg(chip->dev,
				usb_rcvctrlpipe(chip->dev, 0), UAC_GET_CUR,
				USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
				validx << 8, snd_usb_ctrl_intf(chip) | (id << 8),
				value, val_len);
		if (err < 0)
			return err;

		cur_val = value[0];
		pval->cached_value = cur_val;
		pval->is_cached = 1;
	}
	/* update value if needed */
	if (cur_val != new_val) {
		value[0] = new_val;
		value[1] = 0;
		err = snd_usb_ctl_msg(chip->dev,
				usb_sndctrlpipe(chip->dev, 0), UAC_SET_CUR,
				USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
				validx << 8, snd_usb_ctrl_intf(chip) | (id << 8),
				value, val_len);
		if (err < 0)
			return err;

		pval->cached_value = new_val;
		pval->is_cached = 1;
		changed = 1;
	}

	return changed;
}

static int snd_ftu_create_effect_switch(struct usb_mixer_interface *mixer)
{
	static struct snd_kcontrol_new template = {
		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
		.name = "Effect Program Switch",
		.index = 0,
		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
		.info = snd_ftu_eff_switch_info,
		.get = snd_ftu_eff_switch_get,
		.put = snd_ftu_eff_switch_put
	};

	int err;
	struct snd_kcontrol *kctl;
	struct snd_ftu_eff_switch_priv_val *pval;

	pval = kzalloc(sizeof(*pval), GFP_KERNEL);
	if (!pval)
		return -ENOMEM;

	pval->cached_value = 0;
	pval->is_cached = 0;
	pval->mixer = mixer;

	template.private_value = (unsigned long) pval;
	kctl = snd_ctl_new1(&template, mixer->chip);
	if (!kctl) {
		kfree(pval);
		return -ENOMEM;
	}

	err = snd_ctl_add(mixer->chip->card, kctl);
	if (err < 0)
		return err;

	return 0;
}

/* Create volume controls for FTU devices*/
static int snd_ftu_create_volume_ctls(struct usb_mixer_interface *mixer)
{
	char name[64];
	unsigned int control, cmask;
	int in, out, err;

	const unsigned int id = 5;
	const int val_type = USB_MIXER_S16;

	for (out = 0; out < 8; out++) {
		control = out + 1;
		for (in = 0; in < 8; in++) {
			cmask = 1 << in;
			snprintf(name, sizeof(name),
				"AIn%d - Out%d Capture Volume",
				in  + 1, out + 1);
			err = snd_create_std_mono_ctl(mixer, id, control,
							cmask, val_type, name,
							&snd_usb_mixer_vol_tlv);
			if (err < 0)
				return err;
		}
		for (in = 8; in < 16; in++) {
			cmask = 1 << in;
			snprintf(name, sizeof(name),
				"DIn%d - Out%d Playback Volume",
				in - 7, out + 1);
			err = snd_create_std_mono_ctl(mixer, id, control,
							cmask, val_type, name,
							&snd_usb_mixer_vol_tlv);
			if (err < 0)
				return err;
		}
	}

	return 0;
}

/* This control needs a volume quirk, see mixer.c */
static int snd_ftu_create_effect_volume_ctl(struct usb_mixer_interface *mixer)
{
	static const char name[] = "Effect Volume";
	const unsigned int id = 6;
	const int val_type = USB_MIXER_U8;
	const unsigned int control = 2;
	const unsigned int cmask = 0;

	return snd_create_std_mono_ctl(mixer, id, control, cmask, val_type,
					name, snd_usb_mixer_vol_tlv);
}

/* This control needs a volume quirk, see mixer.c */
static int snd_ftu_create_effect_duration_ctl(struct usb_mixer_interface *mixer)
{
	static const char name[] = "Effect Duration";
	const unsigned int id = 6;
	const int val_type = USB_MIXER_S16;
	const unsigned int control = 3;
	const unsigned int cmask = 0;

	return snd_create_std_mono_ctl(mixer, id, control, cmask, val_type,
					name, snd_usb_mixer_vol_tlv);
}

/* This control needs a volume quirk, see mixer.c */
static int snd_ftu_create_effect_feedback_ctl(struct usb_mixer_interface *mixer)
{
	static const char name[] = "Effect Feedback Volume";
	const unsigned int id = 6;
	const int val_type = USB_MIXER_U8;
	const unsigned int control = 4;
	const unsigned int cmask = 0;

	return snd_create_std_mono_ctl(mixer, id, control, cmask, val_type,
					name, NULL);
}

static int snd_ftu_create_effect_return_ctls(struct usb_mixer_interface *mixer)
{
	unsigned int cmask;
	int err, ch;
	char name[48];

	const unsigned int id = 7;
	const int val_type = USB_MIXER_S16;
	const unsigned int control = 7;

	for (ch = 0; ch < 4; ++ch) {
		cmask = 1 << ch;
		snprintf(name, sizeof(name),
			"Effect Return %d Volume", ch + 1);
		err = snd_create_std_mono_ctl(mixer, id, control,
						cmask, val_type, name,
						snd_usb_mixer_vol_tlv);
		if (err < 0)
			return err;
	}

	return 0;
}

static int snd_ftu_create_effect_send_ctls(struct usb_mixer_interface *mixer)
{
	unsigned int  cmask;
	int err, ch;
	char name[48];

	const unsigned int id = 5;
	const int val_type = USB_MIXER_S16;
	const unsigned int control = 9;

	for (ch = 0; ch < 8; ++ch) {
		cmask = 1 << ch;
		snprintf(name, sizeof(name),
			"Effect Send AIn%d Volume", ch + 1);
		err = snd_create_std_mono_ctl(mixer, id, control, cmask,
						val_type, name,
						snd_usb_mixer_vol_tlv);
		if (err < 0)
			return err;
	}
	for (ch = 8; ch < 16; ++ch) {
		cmask = 1 << ch;
		snprintf(name, sizeof(name),
			"Effect Send DIn%d Volume", ch - 7);
		err = snd_create_std_mono_ctl(mixer, id, control, cmask,
						val_type, name,
						snd_usb_mixer_vol_tlv);
		if (err < 0)
			return err;
	}
	return 0;
}

static int snd_ftu_create_mixer(struct usb_mixer_interface *mixer)
{
	int err;

	err = snd_ftu_create_volume_ctls(mixer);
	if (err < 0)
		return err;

	err = snd_ftu_create_effect_switch(mixer);
	if (err < 0)
		return err;
	err = snd_ftu_create_effect_volume_ctl(mixer);
	if (err < 0)
		return err;

	err = snd_ftu_create_effect_duration_ctl(mixer);
	if (err < 0)
		return err;

	err = snd_ftu_create_effect_feedback_ctl(mixer);
	if (err < 0)
		return err;

	err = snd_ftu_create_effect_return_ctls(mixer);
	if (err < 0)
		return err;

	err = snd_ftu_create_effect_send_ctls(mixer);
	if (err < 0)
		return err;

	return 0;
}


/*
 * Create mixer for Electrix Ebox-44
 *
 * The mixer units from this device are corrupt, and even where they
 * are valid they presents mono controls as L and R channels of
 * stereo. So we create a good mixer in code.
 */

static int snd_ebox44_create_mixer(struct usb_mixer_interface *mixer)
{
	int err;

	err = snd_create_std_mono_ctl(mixer, 4, 1, 0x0, USB_MIXER_INV_BOOLEAN,
				"Headphone Playback Switch", NULL);
	if (err < 0)
		return err;
	err = snd_create_std_mono_ctl(mixer, 4, 2, 0x1, USB_MIXER_S16,
				"Headphone A Mix Playback Volume", NULL);
	if (err < 0)
		return err;
	err = snd_create_std_mono_ctl(mixer, 4, 2, 0x2, USB_MIXER_S16,
				"Headphone B Mix Playback Volume", NULL);
	if (err < 0)
		return err;

	err = snd_create_std_mono_ctl(mixer, 7, 1, 0x0, USB_MIXER_INV_BOOLEAN,
				"Output Playback Switch", NULL);
	if (err < 0)
		return err;
	err = snd_create_std_mono_ctl(mixer, 7, 2, 0x1, USB_MIXER_S16,
				"Output A Playback Volume", NULL);
	if (err < 0)
		return err;
	err = snd_create_std_mono_ctl(mixer, 7, 2, 0x2, USB_MIXER_S16,
				"Output B Playback Volume", NULL);
	if (err < 0)
		return err;

	err = snd_create_std_mono_ctl(mixer, 10, 1, 0x0, USB_MIXER_INV_BOOLEAN,
				"Input Capture Switch", NULL);
	if (err < 0)
		return err;
	err = snd_create_std_mono_ctl(mixer, 10, 2, 0x1, USB_MIXER_S16,
				"Input A Capture Volume", NULL);
	if (err < 0)
		return err;
	err = snd_create_std_mono_ctl(mixer, 10, 2, 0x2, USB_MIXER_S16,
				"Input B Capture Volume", NULL);
	if (err < 0)
		return err;

	return 0;
}

void snd_emuusb_set_samplerate(struct snd_usb_audio *chip,
			       unsigned char samplerate_id)
{
	struct usb_mixer_interface *mixer;
	struct usb_mixer_elem_info *cval;
	int unitid = 12; /* SamleRate ExtensionUnit ID */

	list_for_each_entry(mixer, &chip->mixer_list, list) {
		cval = mixer->id_elems[unitid];
		if (cval) {
			snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR,
						    cval->control << 8,
						    samplerate_id);
			snd_usb_mixer_notify_id(mixer, unitid);
		}
		break;
	}
}

int snd_usb_mixer_apply_create_quirk(struct usb_mixer_interface *mixer)
{
	int err = 0;
	struct snd_info_entry *entry;

	if ((err = snd_usb_soundblaster_remote_init(mixer)) < 0)
		return err;

	switch (mixer->chip->usb_id) {
	case USB_ID(0x041e, 0x3020):
	case USB_ID(0x041e, 0x3040):
	case USB_ID(0x041e, 0x3042):
	case USB_ID(0x041e, 0x30df):
	case USB_ID(0x041e, 0x3048):
		err = snd_audigy2nx_controls_create(mixer);
		if (err < 0)
			break;
		if (!snd_card_proc_new(mixer->chip->card, "audigy2nx", &entry))
			snd_info_set_text_ops(entry, mixer,
					      snd_audigy2nx_proc_read);
		break;

	case USB_ID(0x0763, 0x2080): /* M-Audio Fast Track Ultra */
	case USB_ID(0x0763, 0x2081): /* M-Audio Fast Track Ultra 8R */
		err = snd_ftu_create_mixer(mixer);
		break;

	case USB_ID(0x0b05, 0x1739):
	case USB_ID(0x0b05, 0x1743):
		err = snd_xonar_u1_controls_create(mixer);
		break;

	case USB_ID(0x17cc, 0x1011): /* Traktor Audio 6 */
		err = snd_nativeinstruments_create_mixer(mixer,
				snd_nativeinstruments_ta6_mixers,
				ARRAY_SIZE(snd_nativeinstruments_ta6_mixers));
		break;

	case USB_ID(0x17cc, 0x1021): /* Traktor Audio 10 */
		err = snd_nativeinstruments_create_mixer(mixer,
				snd_nativeinstruments_ta10_mixers,
				ARRAY_SIZE(snd_nativeinstruments_ta10_mixers));
		break;

	case USB_ID(0x200c, 0x1018): /* Electrix Ebox-44 */
		err = snd_ebox44_create_mixer(mixer);
		break;
	}

	return err;
}

void snd_usb_mixer_rc_memory_change(struct usb_mixer_interface *mixer,
				    int unitid)
{
	if (!mixer->rc_cfg)
		return;
	/* unit ids specific to Extigy/Audigy 2 NX: */
	switch (unitid) {
	case 0: /* remote control */
		mixer->rc_urb->dev = mixer->chip->dev;
		usb_submit_urb(mixer->rc_urb, GFP_ATOMIC);
		break;
	case 4: /* digital in jack */
	case 7: /* line in jacks */
	case 19: /* speaker out jacks */
	case 20: /* headphones out jack */
		break;
	/* live24ext: 4 = line-in jack */
	case 3:	/* hp-out jack (may actuate Mute) */
		if (mixer->chip->usb_id == USB_ID(0x041e, 0x3040) ||
		    mixer->chip->usb_id == USB_ID(0x041e, 0x3048))
			snd_usb_mixer_notify_id(mixer, mixer->rc_cfg->mute_mixer_id);
		break;
	default:
		snd_printd(KERN_DEBUG "memory change in unknown unit %d\n", unitid);
		break;
	}
}