diff --git a/include/sound/pt2258.h b/include/sound/pt2258.h
new file mode 100644
index 0000000..160f812
--- /dev/null
+++ b/include/sound/pt2258.h
@@ -0,0 +1,37 @@
+/*
+ *   ALSA Driver for the PT2258 volume controller.
+ *
+ *	Copyright (c) 2006  Jochen Voss <voss@seehuhn.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
+ *
+ */      
+
+#ifndef __SOUND_PT2258_H
+#define __SOUND_PT2258_H
+
+struct snd_pt2258 {
+	struct snd_card *card;
+	struct snd_i2c_bus *i2c_bus;
+	struct snd_i2c_device *i2c_dev;
+
+	unsigned char volume[6];
+	int mute;
+};
+
+extern int snd_pt2258_reset(struct snd_pt2258 *pt);
+extern int snd_pt2258_build_controls(struct snd_pt2258 *pt);
+
+#endif /* __SOUND_PT2258_H */
diff --git a/sound/i2c/Makefile b/sound/i2c/Makefile
index 816a2e7..45902d4 100644
--- a/sound/i2c/Makefile
+++ b/sound/i2c/Makefile
@@ -16,3 +16,4 @@
 # Toplevel Module Dependency
 obj-$(CONFIG_SND_INTERWAVE_STB) += snd-tea6330t.o snd-i2c.o
 obj-$(CONFIG_SND_ICE1712) += snd-cs8427.o snd-i2c.o
+obj-$(CONFIG_SND_ICE1724) += snd-i2c.o
diff --git a/sound/i2c/other/Makefile b/sound/i2c/other/Makefile
index 2fe023ef..77a8a7c 100644
--- a/sound/i2c/other/Makefile
+++ b/sound/i2c/other/Makefile
@@ -6,11 +6,11 @@
 snd-ak4114-objs := ak4114.o
 snd-ak4117-objs := ak4117.o
 snd-ak4xxx-adda-objs := ak4xxx-adda.o
+snd-pt2258-objs := pt2258.o
 snd-tea575x-tuner-objs := tea575x-tuner.o
 
 # Module Dependency
 obj-$(CONFIG_SND_PDAUDIOCF) += snd-ak4117.o
 obj-$(CONFIG_SND_ICE1712) += snd-ak4xxx-adda.o
-obj-$(CONFIG_SND_ICE1724) += snd-ak4xxx-adda.o
-obj-$(CONFIG_SND_ICE1724) += snd-ak4114.o
+obj-$(CONFIG_SND_ICE1724) += snd-ak4114.o snd-ak4xxx-adda.o snd-pt2258.o
 obj-$(CONFIG_SND_FM801_TEA575X) += snd-tea575x-tuner.o
diff --git a/sound/i2c/other/pt2258.c b/sound/i2c/other/pt2258.c
new file mode 100644
index 0000000..50df1df
--- /dev/null
+++ b/sound/i2c/other/pt2258.c
@@ -0,0 +1,233 @@
+/*
+ *   ALSA Driver for the PT2258 volume controller.
+ *
+ *	Copyright (c) 2006  Jochen Voss <voss@seehuhn.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 <sound/core.h>
+#include <sound/control.h>
+#include <sound/tlv.h>
+#include <sound/i2c.h>
+#include <sound/pt2258.h>
+
+MODULE_AUTHOR("Jochen Voss <voss@seehuhn.de>");
+MODULE_DESCRIPTION("PT2258 volume controller (Princeton Technology Corp.)");
+MODULE_LICENSE("GPL");
+
+#define PT2258_CMD_RESET 0xc0
+#define PT2258_CMD_UNMUTE 0xf8
+#define PT2258_CMD_MUTE 0xf9
+
+static const unsigned char pt2258_channel_code[12] = {
+	0x80, 0x90,		/* channel 1: -10dB, -1dB */
+	0x40, 0x50,		/* channel 2: -10dB, -1dB */
+	0x00, 0x10,		/* channel 3: -10dB, -1dB */
+	0x20, 0x30,		/* channel 4: -10dB, -1dB */
+	0x60, 0x70,		/* channel 5: -10dB, -1dB */
+	0xa0, 0xb0		/* channel 6: -10dB, -1dB */
+};
+
+int snd_pt2258_reset(struct snd_pt2258 *pt)
+{
+	unsigned char bytes[2];
+	int i;
+
+	/* reset chip */
+	bytes[0] = PT2258_CMD_RESET;
+	snd_i2c_lock(pt->i2c_bus);
+	if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 1) != 1)
+		goto __error;
+	snd_i2c_unlock(pt->i2c_bus);
+
+	/* mute all channels */
+	pt->mute = 1;
+	bytes[0] = PT2258_CMD_MUTE;
+	snd_i2c_lock(pt->i2c_bus);
+	if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 1) != 1)
+		goto __error;
+	snd_i2c_unlock(pt->i2c_bus);
+
+	/* set all channels to 0dB */
+	for (i = 0; i < 6; ++i)
+		pt->volume[i] = 0;
+	bytes[0] = 0xd0;
+	bytes[1] = 0xe0;
+	snd_i2c_lock(pt->i2c_bus);
+	if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 2) != 2)
+		goto __error;
+	snd_i2c_unlock(pt->i2c_bus);
+
+	return 0;
+
+      __error:
+	snd_i2c_unlock(pt->i2c_bus);
+	snd_printk(KERN_ERR "PT2258 reset failed\n");
+	return -EIO;
+}
+
+static int pt2258_stereo_volume_info(struct snd_kcontrol *kcontrol,
+				     struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 2;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 79;
+	return 0;
+}
+
+static int pt2258_stereo_volume_get(struct snd_kcontrol *kcontrol,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_pt2258 *pt = kcontrol->private_data;
+	int base = kcontrol->private_value;
+
+	/* chip does not support register reads */
+	ucontrol->value.integer.value[0] = 79 - pt->volume[base];
+	ucontrol->value.integer.value[1] = 79 - pt->volume[base + 1];
+	return 0;
+}
+
+static int pt2258_stereo_volume_put(struct snd_kcontrol *kcontrol,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_pt2258 *pt = kcontrol->private_data;
+	int base = kcontrol->private_value;
+	unsigned char bytes[2];
+	int val0, val1;
+
+	val0 = 79 - ucontrol->value.integer.value[0];
+	val1 = 79 - ucontrol->value.integer.value[1];
+	if (val0 == pt->volume[base] && val1 == pt->volume[base + 1])
+		return 0;
+
+	pt->volume[base] = val0;
+	bytes[0] = pt2258_channel_code[2 * base] | (val0 / 10);
+	bytes[1] = pt2258_channel_code[2 * base + 1] | (val0 % 10);
+	snd_i2c_lock(pt->i2c_bus);
+	if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 2) != 2)
+		goto __error;
+	snd_i2c_unlock(pt->i2c_bus);
+
+	pt->volume[base + 1] = val1;
+	bytes[0] = pt2258_channel_code[2 * base + 2] | (val1 / 10);
+	bytes[1] = pt2258_channel_code[2 * base + 3] | (val1 % 10);
+	snd_i2c_lock(pt->i2c_bus);
+	if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 2) != 2)
+		goto __error;
+	snd_i2c_unlock(pt->i2c_bus);
+
+	return 1;
+
+      __error:
+	snd_i2c_unlock(pt->i2c_bus);
+	snd_printk(KERN_ERR "PT2258 access failed\n");
+	return -EIO;
+}
+
+static int pt2258_switch_info(struct snd_kcontrol *kcontrol,
+			      struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+	uinfo->count = 1;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 1;
+	return 0;
+}
+
+static int pt2258_switch_get(struct snd_kcontrol *kcontrol,
+			     struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_pt2258 *pt = kcontrol->private_data;
+
+	ucontrol->value.integer.value[0] = !pt->mute;
+	return 0;
+}
+
+static int pt2258_switch_put(struct snd_kcontrol *kcontrol,
+			     struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_pt2258 *pt = kcontrol->private_data;
+	unsigned char bytes[2];
+	int val;
+
+	val = !ucontrol->value.integer.value[0];
+	if (pt->mute == val)
+		return 0;
+
+	pt->mute = val;
+	bytes[0] = val ? PT2258_CMD_MUTE : PT2258_CMD_UNMUTE;
+	snd_i2c_lock(pt->i2c_bus);
+	if (snd_i2c_sendbytes(pt->i2c_dev, bytes, 1) != 1)
+		goto __error;
+	snd_i2c_unlock(pt->i2c_bus);
+
+	return 1;
+
+      __error:
+	snd_i2c_unlock(pt->i2c_bus);
+	snd_printk(KERN_ERR "PT2258 access failed 2\n");
+	return -EIO;
+}
+
+static DECLARE_TLV_DB_SCALE(pt2258_db_scale, -7900, 100, 0);
+
+int snd_pt2258_build_controls(struct snd_pt2258 *pt)
+{
+	struct snd_kcontrol_new knew;
+	char *names[3] = {
+		"Mic Loopback Playback Volume",
+		"Line Loopback Playback Volume",
+		"CD Loopback Playback Volume"
+	};
+	int i, err;
+
+	for (i = 0; i < 3; ++i) {
+		memset(&knew, 0, sizeof(knew));
+		knew.name = names[i];
+		knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+		knew.count = 1;
+		knew.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		    SNDRV_CTL_ELEM_ACCESS_TLV_READ;
+		knew.private_value = 2 * i;
+		knew.info = pt2258_stereo_volume_info;
+		knew.get = pt2258_stereo_volume_get;
+		knew.put = pt2258_stereo_volume_put;
+		knew.tlv.p = pt2258_db_scale;
+
+		err = snd_ctl_add(pt->card, snd_ctl_new1(&knew, pt));
+		if (err < 0)
+			return err;
+	}
+
+	memset(&knew, 0, sizeof(knew));
+	knew.name = "Loopback Switch";
+	knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+	knew.info = pt2258_switch_info;
+	knew.get = pt2258_switch_get;
+	knew.put = pt2258_switch_put;
+	knew.access = 0;
+	err = snd_ctl_add(pt->card, snd_ctl_new1(&knew, pt));
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+EXPORT_SYMBOL(snd_pt2258_reset);
+EXPORT_SYMBOL(snd_pt2258_build_controls);
diff --git a/sound/pci/ice1712/ice1712.h b/sound/pci/ice1712/ice1712.h
index ce27eac..064542b 100644
--- a/sound/pci/ice1712/ice1712.h
+++ b/sound/pci/ice1712/ice1712.h
@@ -28,6 +28,7 @@
 #include <sound/i2c.h>
 #include <sound/ak4xxx-adda.h>
 #include <sound/ak4114.h>
+#include <sound/pt2258.h>
 #include <sound/pcm.h>
 #include <sound/mpu401.h>
 
@@ -381,6 +382,11 @@
 			unsigned short master[2];
 			unsigned short vol[8];
 		} phase28;
+		/* a non-standard I2C device for revo51 */
+		struct revo51_spec {
+			struct snd_i2c_device *dev;
+			struct snd_pt2258 *pt2258;
+		} revo51;
 		/* Hoontech-specific setting */
 		struct hoontech_spec {
 			unsigned char boxbits[4];
@@ -462,6 +468,14 @@
 	snd_ice1712_gpio_write(ice, mask & bits);
 }
 
+static inline int snd_ice1712_gpio_read_bits(struct snd_ice1712 *ice,
+					      unsigned int mask)
+{
+	ice->gpio.direction &= ~mask;
+	snd_ice1712_gpio_set_dir(ice, ice->gpio.direction);
+	return  (snd_ice1712_gpio_read(ice) & mask);
+}
+
 int snd_ice1712_spdif_build_controls(struct snd_ice1712 *ice);
 
 int snd_ice1712_akm4xxx_init(struct snd_akm4xxx *ak, const struct snd_akm4xxx *template,
diff --git a/sound/pci/ice1712/revo.c b/sound/pci/ice1712/revo.c
index d556de5..233e9a5 100644
--- a/sound/pci/ice1712/revo.c
+++ b/sound/pci/ice1712/revo.c
@@ -84,6 +84,102 @@
 }
 
 /*
+ * I2C access to the PT2258 volume controller on GPIO 6/7 (Revolution 5.1)
+ */
+
+static void revo_i2c_start(struct snd_i2c_bus *bus)
+{
+	struct snd_ice1712 *ice = bus->private_data;
+	snd_ice1712_save_gpio_status(ice);
+}
+
+static void revo_i2c_stop(struct snd_i2c_bus *bus)
+{
+	struct snd_ice1712 *ice = bus->private_data;
+	snd_ice1712_restore_gpio_status(ice);
+}
+
+static void revo_i2c_direction(struct snd_i2c_bus *bus, int clock, int data)
+{
+	struct snd_ice1712 *ice = bus->private_data;
+	unsigned int mask, val;
+
+	val = 0;
+	if (clock)
+		val |= VT1724_REVO_I2C_CLOCK;	/* write SCL */
+	if (data)
+		val |= VT1724_REVO_I2C_DATA;	/* write SDA */
+	mask = VT1724_REVO_I2C_CLOCK | VT1724_REVO_I2C_DATA;
+	ice->gpio.direction &= ~mask;
+	ice->gpio.direction |= val;
+	snd_ice1712_gpio_set_dir(ice, ice->gpio.direction);
+	snd_ice1712_gpio_set_mask(ice, ~mask);
+}
+
+static void revo_i2c_setlines(struct snd_i2c_bus *bus, int clk, int data)
+{
+	struct snd_ice1712 *ice = bus->private_data;
+	unsigned int val = 0;
+
+	if (clk)
+		val |= VT1724_REVO_I2C_CLOCK;
+	if (data)
+		val |= VT1724_REVO_I2C_DATA;
+	snd_ice1712_gpio_write_bits(ice,
+				    VT1724_REVO_I2C_DATA |
+				    VT1724_REVO_I2C_CLOCK, val);
+	udelay(5);
+}
+
+static int revo_i2c_getdata(struct snd_i2c_bus *bus, int ack)
+{
+	struct snd_ice1712 *ice = bus->private_data;
+	int bit;
+
+	if (ack)
+		udelay(5);
+	bit = snd_ice1712_gpio_read_bits(ice, VT1724_REVO_I2C_DATA) ? 1 : 0;
+	return bit;
+}
+
+static struct snd_i2c_bit_ops revo51_bit_ops = {
+	.start = revo_i2c_start,
+	.stop = revo_i2c_stop,
+	.direction = revo_i2c_direction,
+	.setlines = revo_i2c_setlines,
+	.getdata = revo_i2c_getdata,
+};
+
+static int revo51_i2c_init(struct snd_ice1712 *ice,
+			   struct snd_pt2258 *pt)
+{
+	int err;
+
+	/* create the I2C bus */
+	err = snd_i2c_bus_create(ice->card, "ICE1724 GPIO6", NULL, &ice->i2c);
+	if (err < 0)
+		return err;
+
+	ice->i2c->private_data = ice;
+	ice->i2c->hw_ops.bit = &revo51_bit_ops;
+
+	/* create the I2C device */
+	err = snd_i2c_device_create(ice->i2c, "PT2258", 0x40,
+				    &ice->spec.revo51.dev);
+	if (err < 0)
+		return err;
+
+	pt->card = ice->card;
+	pt->i2c_bus = ice->i2c;
+	pt->i2c_dev = ice->spec.revo51.dev;
+	ice->spec.revo51.pt2258 = pt;
+
+	snd_pt2258_reset(pt);
+
+	return 0;
+}
+
+/*
  * initialize the chips on M-Audio Revolution cards
  */
 
@@ -180,9 +276,9 @@
 	.cif = 0,
 	.data_mask = VT1724_REVO_CDOUT,
 	.clk_mask = VT1724_REVO_CCLK,
-	.cs_mask = VT1724_REVO_CS0 | VT1724_REVO_CS1 | VT1724_REVO_CS2,
-	.cs_addr = VT1724_REVO_CS1 | VT1724_REVO_CS2,
-	.cs_none = VT1724_REVO_CS0 | VT1724_REVO_CS1 | VT1724_REVO_CS2,
+	.cs_mask = VT1724_REVO_CS0 | VT1724_REVO_CS1,
+	.cs_addr = VT1724_REVO_CS1,
+	.cs_none = VT1724_REVO_CS0 | VT1724_REVO_CS1,
 	.add_flags = VT1724_REVO_CCLK, /* high at init */
 	.mask_flags = 0,
 };
@@ -198,13 +294,15 @@
 	.cif = 0,
 	.data_mask = VT1724_REVO_CDOUT,
 	.clk_mask = VT1724_REVO_CCLK,
-	.cs_mask = VT1724_REVO_CS0 | VT1724_REVO_CS1 | VT1724_REVO_CS2,
-	.cs_addr = VT1724_REVO_CS0 | VT1724_REVO_CS2,
-	.cs_none = VT1724_REVO_CS0 | VT1724_REVO_CS1 | VT1724_REVO_CS2,
+	.cs_mask = VT1724_REVO_CS0 | VT1724_REVO_CS1,
+	.cs_addr = VT1724_REVO_CS0,
+	.cs_none = VT1724_REVO_CS0 | VT1724_REVO_CS1,
 	.add_flags = VT1724_REVO_CCLK, /* high at init */
 	.mask_flags = 0,
 };
 
+static struct snd_pt2258 ptc_revo51_volume;
+
 static int __devinit revo_init(struct snd_ice1712 *ice)
 {
 	struct snd_akm4xxx *ak;
@@ -243,14 +341,20 @@
 		break;
 	case VT1724_SUBDEVICE_REVOLUTION51:
 		ice->akm_codecs = 2;
-		if ((err = snd_ice1712_akm4xxx_init(ak, &akm_revo51, &akm_revo51_priv, ice)) < 0)
+		err = snd_ice1712_akm4xxx_init(ak, &akm_revo51,
+					       &akm_revo51_priv, ice);
+		if (err < 0)
 			return err;
-		err = snd_ice1712_akm4xxx_init(ak + 1, &akm_revo51_adc,
+		err = snd_ice1712_akm4xxx_init(ak+1, &akm_revo51_adc,
 					       &akm_revo51_adc_priv, ice);
 		if (err < 0)
 			return err;
-		/* unmute all codecs - needed! */
-		snd_ice1712_gpio_write_bits(ice, VT1724_REVO_MUTE, VT1724_REVO_MUTE);
+		err = revo51_i2c_init(ice, &ptc_revo51_volume);
+		if (err < 0)
+			return err;
+		/* unmute all codecs */
+		snd_ice1712_gpio_write_bits(ice, VT1724_REVO_MUTE,
+					    VT1724_REVO_MUTE);
 		break;
 	}
 
@@ -264,10 +368,18 @@
 
 	switch (ice->eeprom.subvendor) {
 	case VT1724_SUBDEVICE_REVOLUTION71:
+		err = snd_ice1712_akm4xxx_build_controls(ice);
+		if (err < 0)
+			return err;
+		break;
 	case VT1724_SUBDEVICE_REVOLUTION51:
 		err = snd_ice1712_akm4xxx_build_controls(ice);
 		if (err < 0)
 			return err;
+		err = snd_pt2258_build_controls(ice->spec.revo51.pt2258);
+		if (err < 0)
+			return err;
+		break;
 	}
 	return 0;
 }
diff --git a/sound/pci/ice1712/revo.h b/sound/pci/ice1712/revo.h
index efbb86e..c70adaf 100644
--- a/sound/pci/ice1712/revo.h
+++ b/sound/pci/ice1712/revo.h
@@ -42,9 +42,11 @@
 #define VT1724_REVO_CCLK	0x02
 #define VT1724_REVO_CDIN	0x04	/* not used */
 #define VT1724_REVO_CDOUT	0x08
-#define VT1724_REVO_CS0		0x10	/* AK5365 chipselect for Rev. 5.1 */
+#define VT1724_REVO_CS0		0x10	/* AK5365 chipselect for (revo51) */
 #define VT1724_REVO_CS1		0x20	/* front AKM4381 chipselect */
-#define VT1724_REVO_CS2		0x40	/* surround AKM4355 chipselect */
+#define VT1724_REVO_CS2		0x40	/* surround AKM4355 CS (revo71) */
+#define VT1724_REVO_I2C_DATA    0x40    /* I2C: PT 2258 SDA (on revo51) */
+#define VT1724_REVO_I2C_CLOCK   0x80    /* I2C: PT 2258 SCL (on revo51) */
 #define VT1724_REVO_MUTE	(1<<22)	/* 0 = all mute, 1 = normal operation */
 
 #endif /* __SOUND_REVO_H */