/*
   *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   *  Universal routines for AK4531 codec
   *
   *
   *   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/delay.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/mutex.h>
  #include <linux/module.h>
  
  #include <sound/core.h>
  #include <sound/ak4531_codec.h>
  #include <sound/tlv.h>
  
  /*
  MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  MODULE_DESCRIPTION("Universal routines for AK4531 codec");
  MODULE_LICENSE("GPL");
  */
  
  #ifdef CONFIG_PROC_FS
  static void snd_ak4531_proc_init(struct snd_card *card, struct snd_ak4531 *ak4531);
  #else
  #define snd_ak4531_proc_init(card,ak)
  #endif
  
  /*
   *
   */
   
  #if 0
  
  static void snd_ak4531_dump(struct snd_ak4531 *ak4531)
  {
  	int idx;
  	
  	for (idx = 0; idx < 0x19; idx++)
  		printk(KERN_DEBUG "ak4531 0x%x: 0x%x
  ",
  		       idx, ak4531->regs[idx]);
  }
  
  #endif
  
  /*
   *
   */
  
  #define AK4531_SINGLE(xname, xindex, reg, shift, mask, invert) \
  { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
    .info = snd_ak4531_info_single, \
    .get = snd_ak4531_get_single, .put = snd_ak4531_put_single, \
    .private_value = reg | (shift << 16) | (mask << 24) | (invert << 22) }
  #define AK4531_SINGLE_TLV(xname, xindex, reg, shift, mask, invert, xtlv)    \
  { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
    .access = SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_READ, \
    .name = xname, .index = xindex, \
    .info = snd_ak4531_info_single, \
    .get = snd_ak4531_get_single, .put = snd_ak4531_put_single, \
    .private_value = reg | (shift << 16) | (mask << 24) | (invert << 22), \
    .tlv = { .p = (xtlv) } }
  
  static int snd_ak4531_info_single(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
  {
  	int mask = (kcontrol->private_value >> 24) & 0xff;
  
  	uinfo->type = mask == 1 ? SNDRV_CTL_ELEM_TYPE_BOOLEAN : SNDRV_CTL_ELEM_TYPE_INTEGER;
  	uinfo->count = 1;
  	uinfo->value.integer.min = 0;
  	uinfo->value.integer.max = mask;
  	return 0;
  }
   
  static int snd_ak4531_get_single(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
  {
  	struct snd_ak4531 *ak4531 = snd_kcontrol_chip(kcontrol);
  	int reg = kcontrol->private_value & 0xff;
  	int shift = (kcontrol->private_value >> 16) & 0x07;
  	int mask = (kcontrol->private_value >> 24) & 0xff;
  	int invert = (kcontrol->private_value >> 22) & 1;
  	int val;
  
  	mutex_lock(&ak4531->reg_mutex);
  	val = (ak4531->regs[reg] >> shift) & mask;
  	mutex_unlock(&ak4531->reg_mutex);
  	if (invert) {
  		val = mask - val;
  	}
  	ucontrol->value.integer.value[0] = val;
  	return 0;
  }
  
  static int snd_ak4531_put_single(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
  {
  	struct snd_ak4531 *ak4531 = snd_kcontrol_chip(kcontrol);
  	int reg = kcontrol->private_value & 0xff;
  	int shift = (kcontrol->private_value >> 16) & 0x07;
  	int mask = (kcontrol->private_value >> 24) & 0xff;
  	int invert = (kcontrol->private_value >> 22) & 1;
  	int change;
  	int val;
  
  	val = ucontrol->value.integer.value[0] & mask;
  	if (invert) {
  		val = mask - val;
  	}
  	val <<= shift;
  	mutex_lock(&ak4531->reg_mutex);
  	val = (ak4531->regs[reg] & ~(mask << shift)) | val;
  	change = val != ak4531->regs[reg];
  	ak4531->write(ak4531, reg, ak4531->regs[reg] = val);
  	mutex_unlock(&ak4531->reg_mutex);
  	return change;
  }
  
  #define AK4531_DOUBLE(xname, xindex, left_reg, right_reg, left_shift, right_shift, mask, invert) \
  { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
    .info = snd_ak4531_info_double, \
    .get = snd_ak4531_get_double, .put = snd_ak4531_put_double, \
    .private_value = left_reg | (right_reg << 8) | (left_shift << 16) | (right_shift << 19) | (mask << 24) | (invert << 22) }
  #define AK4531_DOUBLE_TLV(xname, xindex, left_reg, right_reg, left_shift, right_shift, mask, invert, xtlv) \
  { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
    .access = SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_READ, \
    .name = xname, .index = xindex, \
    .info = snd_ak4531_info_double, \
    .get = snd_ak4531_get_double, .put = snd_ak4531_put_double, \
    .private_value = left_reg | (right_reg << 8) | (left_shift << 16) | (right_shift << 19) | (mask << 24) | (invert << 22), \
    .tlv = { .p = (xtlv) } }
  
  static int snd_ak4531_info_double(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
  {
  	int mask = (kcontrol->private_value >> 24) & 0xff;
  
  	uinfo->type = mask == 1 ? SNDRV_CTL_ELEM_TYPE_BOOLEAN : SNDRV_CTL_ELEM_TYPE_INTEGER;
  	uinfo->count = 2;
  	uinfo->value.integer.min = 0;
  	uinfo->value.integer.max = mask;
  	return 0;
  }
   
  static int snd_ak4531_get_double(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
  {
  	struct snd_ak4531 *ak4531 = snd_kcontrol_chip(kcontrol);
  	int left_reg = kcontrol->private_value & 0xff;
  	int right_reg = (kcontrol->private_value >> 8) & 0xff;
  	int left_shift = (kcontrol->private_value >> 16) & 0x07;
  	int right_shift = (kcontrol->private_value >> 19) & 0x07;
  	int mask = (kcontrol->private_value >> 24) & 0xff;
  	int invert = (kcontrol->private_value >> 22) & 1;
  	int left, right;
  
  	mutex_lock(&ak4531->reg_mutex);
  	left = (ak4531->regs[left_reg] >> left_shift) & mask;
  	right = (ak4531->regs[right_reg] >> right_shift) & mask;
  	mutex_unlock(&ak4531->reg_mutex);
  	if (invert) {
  		left = mask - left;
  		right = mask - right;
  	}
  	ucontrol->value.integer.value[0] = left;
  	ucontrol->value.integer.value[1] = right;
  	return 0;
  }
  
  static int snd_ak4531_put_double(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
  {
  	struct snd_ak4531 *ak4531 = snd_kcontrol_chip(kcontrol);
  	int left_reg = kcontrol->private_value & 0xff;
  	int right_reg = (kcontrol->private_value >> 8) & 0xff;
  	int left_shift = (kcontrol->private_value >> 16) & 0x07;
  	int right_shift = (kcontrol->private_value >> 19) & 0x07;
  	int mask = (kcontrol->private_value >> 24) & 0xff;
  	int invert = (kcontrol->private_value >> 22) & 1;
  	int change;
  	int left, right;
  
  	left = ucontrol->value.integer.value[0] & mask;
  	right = ucontrol->value.integer.value[1] & mask;
  	if (invert) {
  		left = mask - left;
  		right = mask - right;
  	}
  	left <<= left_shift;
  	right <<= right_shift;
  	mutex_lock(&ak4531->reg_mutex);
  	if (left_reg == right_reg) {
  		left = (ak4531->regs[left_reg] & ~((mask << left_shift) | (mask << right_shift))) | left | right;
  		change = left != ak4531->regs[left_reg];
  		ak4531->write(ak4531, left_reg, ak4531->regs[left_reg] = left);
  	} else {
  		left = (ak4531->regs[left_reg] & ~(mask << left_shift)) | left;
  		right = (ak4531->regs[right_reg] & ~(mask << right_shift)) | right;
  		change = left != ak4531->regs[left_reg] || right != ak4531->regs[right_reg];
  		ak4531->write(ak4531, left_reg, ak4531->regs[left_reg] = left);
  		ak4531->write(ak4531, right_reg, ak4531->regs[right_reg] = right);
  	}
  	mutex_unlock(&ak4531->reg_mutex);
  	return change;
  }
  
  #define AK4531_INPUT_SW(xname, xindex, reg1, reg2, left_shift, right_shift) \
  { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, .index = xindex, \
    .info = snd_ak4531_info_input_sw, \
    .get = snd_ak4531_get_input_sw, .put = snd_ak4531_put_input_sw, \
    .private_value = reg1 | (reg2 << 8) | (left_shift << 16) | (right_shift << 24) }
  
  static int snd_ak4531_info_input_sw(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
  {
  	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
  	uinfo->count = 4;
  	uinfo->value.integer.min = 0;
  	uinfo->value.integer.max = 1;
  	return 0;
  }
   
  static int snd_ak4531_get_input_sw(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
  {
  	struct snd_ak4531 *ak4531 = snd_kcontrol_chip(kcontrol);
  	int reg1 = kcontrol->private_value & 0xff;
  	int reg2 = (kcontrol->private_value >> 8) & 0xff;
  	int left_shift = (kcontrol->private_value >> 16) & 0x0f;
  	int right_shift = (kcontrol->private_value >> 24) & 0x0f;
  
  	mutex_lock(&ak4531->reg_mutex);
  	ucontrol->value.integer.value[0] = (ak4531->regs[reg1] >> left_shift) & 1;
  	ucontrol->value.integer.value[1] = (ak4531->regs[reg2] >> left_shift) & 1;
  	ucontrol->value.integer.value[2] = (ak4531->regs[reg1] >> right_shift) & 1;
  	ucontrol->value.integer.value[3] = (ak4531->regs[reg2] >> right_shift) & 1;
  	mutex_unlock(&ak4531->reg_mutex);
  	return 0;
  }
  
  static int snd_ak4531_put_input_sw(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol)
  {
  	struct snd_ak4531 *ak4531 = snd_kcontrol_chip(kcontrol);
  	int reg1 = kcontrol->private_value & 0xff;
  	int reg2 = (kcontrol->private_value >> 8) & 0xff;
  	int left_shift = (kcontrol->private_value >> 16) & 0x0f;
  	int right_shift = (kcontrol->private_value >> 24) & 0x0f;
  	int change;
  	int val1, val2;
  
  	mutex_lock(&ak4531->reg_mutex);
  	val1 = ak4531->regs[reg1] & ~((1 << left_shift) | (1 << right_shift));
  	val2 = ak4531->regs[reg2] & ~((1 << left_shift) | (1 << right_shift));
  	val1 |= (ucontrol->value.integer.value[0] & 1) << left_shift;
  	val2 |= (ucontrol->value.integer.value[1] & 1) << left_shift;
  	val1 |= (ucontrol->value.integer.value[2] & 1) << right_shift;
  	val2 |= (ucontrol->value.integer.value[3] & 1) << right_shift;
  	change = val1 != ak4531->regs[reg1] || val2 != ak4531->regs[reg2];
  	ak4531->write(ak4531, reg1, ak4531->regs[reg1] = val1);
  	ak4531->write(ak4531, reg2, ak4531->regs[reg2] = val2);
  	mutex_unlock(&ak4531->reg_mutex);
  	return change;
  }
  
  static const DECLARE_TLV_DB_SCALE(db_scale_master, -6200, 200, 0);
  static const DECLARE_TLV_DB_SCALE(db_scale_mono, -2800, 400, 0);
  static const DECLARE_TLV_DB_SCALE(db_scale_input, -5000, 200, 0);
  
  static struct snd_kcontrol_new snd_ak4531_controls[] = {
  
  AK4531_DOUBLE_TLV("Master Playback Switch", 0,
  		  AK4531_LMASTER, AK4531_RMASTER, 7, 7, 1, 1,
  		  db_scale_master),
  AK4531_DOUBLE("Master Playback Volume", 0, AK4531_LMASTER, AK4531_RMASTER, 0, 0, 0x1f, 1),
  
  AK4531_SINGLE_TLV("Master Mono Playback Switch", 0, AK4531_MONO_OUT, 7, 1, 1,
  		  db_scale_mono),
  AK4531_SINGLE("Master Mono Playback Volume", 0, AK4531_MONO_OUT, 0, 0x07, 1),
  
  AK4531_DOUBLE("PCM Switch", 0, AK4531_LVOICE, AK4531_RVOICE, 7, 7, 1, 1),
  AK4531_DOUBLE_TLV("PCM Volume", 0, AK4531_LVOICE, AK4531_RVOICE, 0, 0, 0x1f, 1,
  		  db_scale_input),
  AK4531_DOUBLE("PCM Playback Switch", 0, AK4531_OUT_SW2, AK4531_OUT_SW2, 3, 2, 1, 0),
  AK4531_DOUBLE("PCM Capture Switch", 0, AK4531_LIN_SW2, AK4531_RIN_SW2, 2, 2, 1, 0),
  
  AK4531_DOUBLE("PCM Switch", 1, AK4531_LFM, AK4531_RFM, 7, 7, 1, 1),
  AK4531_DOUBLE_TLV("PCM Volume", 1, AK4531_LFM, AK4531_RFM, 0, 0, 0x1f, 1,
  		  db_scale_input),
  AK4531_DOUBLE("PCM Playback Switch", 1, AK4531_OUT_SW1, AK4531_OUT_SW1, 6, 5, 1, 0),
  AK4531_INPUT_SW("PCM Capture Route", 1, AK4531_LIN_SW1, AK4531_RIN_SW1, 6, 5),
  
  AK4531_DOUBLE("CD Switch", 0, AK4531_LCD, AK4531_RCD, 7, 7, 1, 1),
  AK4531_DOUBLE_TLV("CD Volume", 0, AK4531_LCD, AK4531_RCD, 0, 0, 0x1f, 1,
  		  db_scale_input),
  AK4531_DOUBLE("CD Playback Switch", 0, AK4531_OUT_SW1, AK4531_OUT_SW1, 2, 1, 1, 0),
  AK4531_INPUT_SW("CD Capture Route", 0, AK4531_LIN_SW1, AK4531_RIN_SW1, 2, 1),
  
  AK4531_DOUBLE("Line Switch", 0, AK4531_LLINE, AK4531_RLINE, 7, 7, 1, 1),
  AK4531_DOUBLE_TLV("Line Volume", 0, AK4531_LLINE, AK4531_RLINE, 0, 0, 0x1f, 1,
  		  db_scale_input),
  AK4531_DOUBLE("Line Playback Switch", 0, AK4531_OUT_SW1, AK4531_OUT_SW1, 4, 3, 1, 0),
  AK4531_INPUT_SW("Line Capture Route", 0, AK4531_LIN_SW1, AK4531_RIN_SW1, 4, 3),
  
  AK4531_DOUBLE("Aux Switch", 0, AK4531_LAUXA, AK4531_RAUXA, 7, 7, 1, 1),
  AK4531_DOUBLE_TLV("Aux Volume", 0, AK4531_LAUXA, AK4531_RAUXA, 0, 0, 0x1f, 1,
  		  db_scale_input),
  AK4531_DOUBLE("Aux Playback Switch", 0, AK4531_OUT_SW2, AK4531_OUT_SW2, 5, 4, 1, 0),
  AK4531_INPUT_SW("Aux Capture Route", 0, AK4531_LIN_SW2, AK4531_RIN_SW2, 4, 3),
  
  AK4531_SINGLE("Mono Switch", 0, AK4531_MONO1, 7, 1, 1),
  AK4531_SINGLE_TLV("Mono Volume", 0, AK4531_MONO1, 0, 0x1f, 1, db_scale_input),
  AK4531_SINGLE("Mono Playback Switch", 0, AK4531_OUT_SW2, 0, 1, 0),
  AK4531_DOUBLE("Mono Capture Switch", 0, AK4531_LIN_SW2, AK4531_RIN_SW2, 0, 0, 1, 0),
  
  AK4531_SINGLE("Mono Switch", 1, AK4531_MONO2, 7, 1, 1),
  AK4531_SINGLE_TLV("Mono Volume", 1, AK4531_MONO2, 0, 0x1f, 1, db_scale_input),
  AK4531_SINGLE("Mono Playback Switch", 1, AK4531_OUT_SW2, 1, 1, 0),
  AK4531_DOUBLE("Mono Capture Switch", 1, AK4531_LIN_SW2, AK4531_RIN_SW2, 1, 1, 1, 0),
  
  AK4531_SINGLE_TLV("Mic Volume", 0, AK4531_MIC, 0, 0x1f, 1, db_scale_input),
  AK4531_SINGLE("Mic Switch", 0, AK4531_MIC, 7, 1, 1),
  AK4531_SINGLE("Mic Playback Switch", 0, AK4531_OUT_SW1, 0, 1, 0),
  AK4531_DOUBLE("Mic Capture Switch", 0, AK4531_LIN_SW1, AK4531_RIN_SW1, 0, 0, 1, 0),
  
  AK4531_DOUBLE("Mic Bypass Capture Switch", 0, AK4531_LIN_SW2, AK4531_RIN_SW2, 7, 7, 1, 0),
  AK4531_DOUBLE("Mono1 Bypass Capture Switch", 0, AK4531_LIN_SW2, AK4531_RIN_SW2, 6, 6, 1, 0),
  AK4531_DOUBLE("Mono2 Bypass Capture Switch", 0, AK4531_LIN_SW2, AK4531_RIN_SW2, 5, 5, 1, 0),
  
  AK4531_SINGLE("AD Input Select", 0, AK4531_AD_IN, 0, 1, 0),
  AK4531_SINGLE("Mic Boost (+30dB)", 0, AK4531_MIC_GAIN, 0, 1, 0)
  };
  
  static int snd_ak4531_free(struct snd_ak4531 *ak4531)
  {
  	if (ak4531) {
  		if (ak4531->private_free)
  			ak4531->private_free(ak4531);
  		kfree(ak4531);
  	}
  	return 0;
  }
  
  static int snd_ak4531_dev_free(struct snd_device *device)
  {
  	struct snd_ak4531 *ak4531 = device->device_data;
  	return snd_ak4531_free(ak4531);
  }
  
  static u8 snd_ak4531_initial_map[0x19 + 1] = {
  	0x9f,		/* 00: Master Volume Lch */
  	0x9f,		/* 01: Master Volume Rch */
  	0x9f,		/* 02: Voice Volume Lch */
  	0x9f,		/* 03: Voice Volume Rch */
  	0x9f,		/* 04: FM Volume Lch */
  	0x9f,		/* 05: FM Volume Rch */
  	0x9f,		/* 06: CD Audio Volume Lch */
  	0x9f,		/* 07: CD Audio Volume Rch */
  	0x9f,		/* 08: Line Volume Lch */
  	0x9f,		/* 09: Line Volume Rch */
  	0x9f,		/* 0a: Aux Volume Lch */
  	0x9f,		/* 0b: Aux Volume Rch */
  	0x9f,		/* 0c: Mono1 Volume */
  	0x9f,		/* 0d: Mono2 Volume */
  	0x9f,		/* 0e: Mic Volume */
  	0x87,		/* 0f: Mono-out Volume */
  	0x00,		/* 10: Output Mixer SW1 */
  	0x00,		/* 11: Output Mixer SW2 */
  	0x00,		/* 12: Lch Input Mixer SW1 */
  	0x00,		/* 13: Rch Input Mixer SW1 */
  	0x00,		/* 14: Lch Input Mixer SW2 */
  	0x00,		/* 15: Rch Input Mixer SW2 */
  	0x00,		/* 16: Reset & Power Down */
  	0x00,		/* 17: Clock Select */
  	0x00,		/* 18: AD Input Select */
  	0x01		/* 19: Mic Amp Setup */
  };
  
  int snd_ak4531_mixer(struct snd_card *card,
  		     struct snd_ak4531 *_ak4531,
  		     struct snd_ak4531 **rak4531)
  {
  	unsigned int idx;
  	int err;
  	struct snd_ak4531 *ak4531;
  	static struct snd_device_ops ops = {
  		.dev_free =	snd_ak4531_dev_free,
  	};
  
  	if (snd_BUG_ON(!card || !_ak4531))
  		return -EINVAL;
  	if (rak4531)
  		*rak4531 = NULL;
  	ak4531 = kzalloc(sizeof(*ak4531), GFP_KERNEL);
  	if (ak4531 == NULL)
  		return -ENOMEM;
  	*ak4531 = *_ak4531;
  	mutex_init(&ak4531->reg_mutex);
  	if ((err = snd_component_add(card, "AK4531")) < 0) {
  		snd_ak4531_free(ak4531);
  		return err;
  	}
  	strcpy(card->mixername, "Asahi Kasei AK4531");
  	ak4531->write(ak4531, AK4531_RESET, 0x03);	/* no RST, PD */
  	udelay(100);
  	ak4531->write(ak4531, AK4531_CLOCK, 0x00);	/* CODEC ADC and CODEC DAC use {LR,B}CLK2 and run off LRCLK2 PLL */
  	for (idx = 0; idx <= 0x19; idx++) {
  		if (idx == AK4531_RESET || idx == AK4531_CLOCK)
  			continue;
  		ak4531->write(ak4531, idx, ak4531->regs[idx] = snd_ak4531_initial_map[idx]);	/* recording source is mixer */
  	}
  	for (idx = 0; idx < ARRAY_SIZE(snd_ak4531_controls); idx++) {
  		if ((err = snd_ctl_add(card, snd_ctl_new1(&snd_ak4531_controls[idx], ak4531))) < 0) {
  			snd_ak4531_free(ak4531);
  			return err;
  		}
  	}
  	snd_ak4531_proc_init(card, ak4531);
  	if ((err = snd_device_new(card, SNDRV_DEV_CODEC, ak4531, &ops)) < 0) {
  		snd_ak4531_free(ak4531);
  		return err;
  	}
  
  #if 0
  	snd_ak4531_dump(ak4531);
  #endif
  	if (rak4531)
  		*rak4531 = ak4531;
  	return 0;
  }
  
  /*
   * power management
   */
  #ifdef CONFIG_PM
  void snd_ak4531_suspend(struct snd_ak4531 *ak4531)
  {
  	/* mute */
  	ak4531->write(ak4531, AK4531_LMASTER, 0x9f);
  	ak4531->write(ak4531, AK4531_RMASTER, 0x9f);
  	/* powerdown */
  	ak4531->write(ak4531, AK4531_RESET, 0x01);
  }
  
  void snd_ak4531_resume(struct snd_ak4531 *ak4531)
  {
  	int idx;
  
  	/* initialize */
  	ak4531->write(ak4531, AK4531_RESET, 0x03);
  	udelay(100);
  	ak4531->write(ak4531, AK4531_CLOCK, 0x00);
  	/* restore mixer registers */
  	for (idx = 0; idx <= 0x19; idx++) {
  		if (idx == AK4531_RESET || idx == AK4531_CLOCK)
  			continue;
  		ak4531->write(ak4531, idx, ak4531->regs[idx]);
  	}
  }
  #endif
  
  #ifdef CONFIG_PROC_FS
  /*
   * /proc interface
   */
  
  static void snd_ak4531_proc_read(struct snd_info_entry *entry, 
  				 struct snd_info_buffer *buffer)
  {
  	struct snd_ak4531 *ak4531 = entry->private_data;
  
  	snd_iprintf(buffer, "Asahi Kasei AK4531
  
  ");
  	snd_iprintf(buffer, "Recording source   : %s
  "
  		    "MIC gain           : %s
  ",
  		    ak4531->regs[AK4531_AD_IN] & 1 ? "external" : "mixer",
  		    ak4531->regs[AK4531_MIC_GAIN] & 1 ? "+30dB" : "+0dB");
  }
  
  static void
  snd_ak4531_proc_init(struct snd_card *card, struct snd_ak4531 *ak4531)
  {
  	struct snd_info_entry *entry;
  
  	if (! snd_card_proc_new(card, "ak4531", &entry))
  		snd_info_set_text_ops(entry, ak4531, snd_ak4531_proc_read);
  }
  #endif