diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index cb7cdd3..033b6cb 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -3139,15 +3139,19 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
 	rt_mutex_init(&dev->i2c_bus_lock);
 
 	/* register i2c bus 0 */
-	retval = em28xx_i2c_register(dev, 0);
+	if (dev->board.is_em2800)
+		retval = em28xx_i2c_register(dev, 0, EM28XX_I2C_ALGO_EM2800);
+	else
+		retval = em28xx_i2c_register(dev, 0, EM28XX_I2C_ALGO_EM28XX);
 	if (retval < 0) {
 		em28xx_errdev("%s: em28xx_i2c_register bus 0 - error [%d]!\n",
 			__func__, retval);
 		goto unregister_dev;
 	}
 
+	/* register i2c bus 1 */
 	if (dev->def_i2c_bus) {
-		retval = em28xx_i2c_register(dev, 1);
+		retval = em28xx_i2c_register(dev, 1, EM28XX_I2C_ALGO_EM28XX);
 		if (retval < 0) {
 			em28xx_errdev("%s: em28xx_i2c_register bus 1 - error [%d]!\n",
 				__func__, retval);
diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c
index 704f283..4851cc2 100644
--- a/drivers/media/usb/em28xx/em28xx-i2c.c
+++ b/drivers/media/usb/em28xx/em28xx-i2c.c
@@ -5,6 +5,7 @@
 		      Markus Rechberger <mrechberger@gmail.com>
 		      Mauro Carvalho Chehab <mchehab@infradead.org>
 		      Sascha Sommer <saschasommer@freenet.de>
+   Copyright (C) 2013 Frank Schäfer <fschaefer.oss@googlemail.com>
 
    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
@@ -279,6 +280,183 @@ static int em28xx_i2c_check_for_device(struct em28xx *dev, u16 addr)
 }
 
 /*
+ * em25xx_bus_B_send_bytes
+ * write bytes to the i2c device
+ */
+static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
+				   u16 len)
+{
+	int ret;
+
+	if (len < 1 || len > 64)
+		return -EOPNOTSUPP;
+	/*
+	 * NOTE: limited by the USB ctrl message constraints
+	 * Zero length reads always succeed, even if no device is connected
+	 */
+
+	/* Set register and write value */
+	ret = dev->em28xx_write_regs_req(dev, 0x06, addr, buf, len);
+	if (ret != len) {
+		if (ret < 0) {
+			em28xx_warn("writing to i2c device at 0x%x failed (error=%i)\n",
+				    addr, ret);
+			return ret;
+		} else {
+			em28xx_warn("%i bytes write to i2c device at 0x%x requested, but %i bytes written\n",
+				    len, addr, ret);
+			return -EIO;
+		}
+	}
+	/* Check success */
+	ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
+	/*
+	 * NOTE: the only error we've seen so far is
+	 * 0x01 when the slave device is not present
+	 */
+	if (!ret)
+		return len;
+	else if (ret > 0)
+		return -ENODEV;
+
+	return ret;
+	/*
+	 * NOTE: With chip types (other chip IDs) which actually don't support
+	 * this operation, it seems to succeed ALWAYS ! (even if there is no
+	 * slave device or even no second i2c bus provided)
+	 */
+}
+
+/*
+ * em25xx_bus_B_recv_bytes
+ * read bytes from the i2c device
+ */
+static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
+				   u16 len)
+{
+	int ret;
+
+	if (len < 1 || len > 64)
+		return -EOPNOTSUPP;
+	/*
+	 * NOTE: limited by the USB ctrl message constraints
+	 * Zero length reads always succeed, even if no device is connected
+	 */
+
+	/* Read value */
+	ret = dev->em28xx_read_reg_req_len(dev, 0x06, addr, buf, len);
+	if (ret < 0) {
+		em28xx_warn("reading from i2c device at 0x%x failed (error=%i)\n",
+			    addr, ret);
+		return ret;
+	}
+	/*
+	 * NOTE: some devices with two i2c busses have the bad habit to return 0
+	 * bytes if we are on bus B AND there was no write attempt to the
+	 * specified slave address before AND no device is present at the
+	 * requested slave address.
+	 * Anyway, the next check will fail with -ENODEV in this case, so avoid
+	 * spamming the system log on device probing and do nothing here.
+	 */
+
+	/* Check success */
+	ret = dev->em28xx_read_reg_req(dev, 0x08, 0x0000);
+	/*
+	 * NOTE: the only error we've seen so far is
+	 * 0x01 when the slave device is not present
+	 */
+	if (!ret)
+		return len;
+	else if (ret > 0)
+		return -ENODEV;
+
+	return ret;
+	/*
+	 * NOTE: With chip types (other chip IDs) which actually don't support
+	 * this operation, it seems to succeed ALWAYS ! (even if there is no
+	 * slave device or even no second i2c bus provided)
+	 */
+}
+
+/*
+ * em25xx_bus_B_check_for_device()
+ * check if there is a i2c device at the supplied address
+ */
+static int em25xx_bus_B_check_for_device(struct em28xx *dev, u16 addr)
+{
+	u8 buf;
+	int ret;
+
+	ret = em25xx_bus_B_recv_bytes(dev, addr, &buf, 1);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+	/*
+	 * NOTE: With chips which do not support this operation,
+	 * it seems to succeed ALWAYS ! (even if no device connected)
+	 */
+}
+
+static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
+{
+	struct em28xx *dev = i2c_bus->dev;
+	int rc = -EOPNOTSUPP;
+
+	if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
+		rc = em28xx_i2c_check_for_device(dev, addr);
+	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
+		rc = em2800_i2c_check_for_device(dev, addr);
+	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
+		rc = em25xx_bus_B_check_for_device(dev, addr);
+	if (rc == -ENODEV) {
+		if (i2c_debug)
+			printk(" no device\n");
+	}
+	return rc;
+}
+
+static inline int i2c_recv_bytes(struct em28xx_i2c_bus *i2c_bus,
+				 struct i2c_msg msg)
+{
+	struct em28xx *dev = i2c_bus->dev;
+	u16 addr = msg.addr << 1;
+	int byte, rc = -EOPNOTSUPP;
+
+	if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
+		rc = em28xx_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
+	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
+		rc = em2800_i2c_recv_bytes(dev, addr, msg.buf, msg.len);
+	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
+		rc = em25xx_bus_B_recv_bytes(dev, addr, msg.buf, msg.len);
+	if (i2c_debug) {
+		for (byte = 0; byte < msg.len; byte++)
+			printk(" %02x", msg.buf[byte]);
+	}
+	return rc;
+}
+
+static inline int i2c_send_bytes(struct em28xx_i2c_bus *i2c_bus,
+				 struct i2c_msg msg, int stop)
+{
+	struct em28xx *dev = i2c_bus->dev;
+	u16 addr = msg.addr << 1;
+	int byte, rc = -EOPNOTSUPP;
+
+	if (i2c_debug) {
+		for (byte = 0; byte < msg.len; byte++)
+			printk(" %02x", msg.buf[byte]);
+	}
+	if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX)
+		rc = em28xx_i2c_send_bytes(dev, addr, msg.buf, msg.len, stop);
+	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)
+		rc = em2800_i2c_send_bytes(dev, addr, msg.buf, msg.len);
+	else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
+		rc = em25xx_bus_B_send_bytes(dev, addr, msg.buf, msg.len);
+	return rc;
+}
+
+/*
  * em28xx_i2c_xfer()
  * the main i2c transfer function
  */
@@ -288,7 +466,7 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
 	struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
 	struct em28xx *dev = i2c_bus->dev;
 	unsigned bus = i2c_bus->bus;
-	int addr, rc, i, byte;
+	int addr, rc, i;
 	u8 reg;
 
 	rc = rt_mutex_trylock(&dev->i2c_bus_lock);
@@ -296,7 +474,8 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
 		return rc;
 
 	/* Switch I2C bus if needed */
-	if (bus != dev->cur_i2c_bus) {
+	if (bus != dev->cur_i2c_bus &&
+	    i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) {
 		if (bus == 1)
 			reg = EM2874_I2C_SECONDARY_BUS_SELECT;
 		else
@@ -319,45 +498,17 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
 			       i == num - 1 ? "stop" : "nonstop",
 			       addr, msgs[i].len);
 		if (!msgs[i].len) { /* no len: check only for device presence */
-			if (dev->board.is_em2800)
-				rc = em2800_i2c_check_for_device(dev, addr);
-			else
-				rc = em28xx_i2c_check_for_device(dev, addr);
+			rc = i2c_check_for_device(i2c_bus, addr);
 			if (rc == -ENODEV) {
-				if (i2c_debug)
-					printk(" no device\n");
 				rt_mutex_unlock(&dev->i2c_bus_lock);
 				return rc;
 			}
 		} else if (msgs[i].flags & I2C_M_RD) {
 			/* read bytes */
-			if (dev->board.is_em2800)
-				rc = em2800_i2c_recv_bytes(dev, addr,
-							   msgs[i].buf,
-							   msgs[i].len);
-			else
-				rc = em28xx_i2c_recv_bytes(dev, addr,
-							   msgs[i].buf,
-							   msgs[i].len);
-			if (i2c_debug) {
-				for (byte = 0; byte < msgs[i].len; byte++)
-					printk(" %02x", msgs[i].buf[byte]);
-			}
+			rc = i2c_recv_bytes(i2c_bus, msgs[i]);
 		} else {
 			/* write bytes */
-			if (i2c_debug) {
-				for (byte = 0; byte < msgs[i].len; byte++)
-					printk(" %02x", msgs[i].buf[byte]);
-			}
-			if (dev->board.is_em2800)
-				rc = em2800_i2c_send_bytes(dev, addr,
-							   msgs[i].buf,
-							   msgs[i].len);
-			else
-				rc = em28xx_i2c_send_bytes(dev, addr,
-							   msgs[i].buf,
-							   msgs[i].len,
-							   i == num - 1);
+			rc = i2c_send_bytes(i2c_bus, msgs[i], i == num - 1);
 		}
 		if (rc < 0) {
 			if (i2c_debug)
@@ -633,12 +784,17 @@ error:
 static u32 functionality(struct i2c_adapter *i2c_adap)
 {
 	struct em28xx_i2c_bus *i2c_bus = i2c_adap->algo_data;
-	struct em28xx *dev = i2c_bus->dev;
 
-	u32 func_flags = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
-	if (dev->board.is_em2800)
-		func_flags &= ~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
-	return func_flags;
+	if ((i2c_bus->algo_type == EM28XX_I2C_ALGO_EM28XX) ||
+	    (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)) {
+		return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+	} else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM2800)  {
+		return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL) &
+			~I2C_FUNC_SMBUS_WRITE_BLOCK_DATA;
+	}
+
+	WARN(1, "Unknown i2c bus algorithm.\n");
+	return 0;
 }
 
 static struct i2c_algorithm em28xx_algo = {
@@ -712,7 +868,8 @@ void em28xx_do_i2c_scan(struct em28xx *dev, unsigned bus)
  * em28xx_i2c_register()
  * register i2c bus
  */
-int em28xx_i2c_register(struct em28xx *dev, unsigned bus)
+int em28xx_i2c_register(struct em28xx *dev, unsigned bus,
+			enum em28xx_i2c_algo_type algo_type)
 {
 	int retval;
 
@@ -727,6 +884,7 @@ int em28xx_i2c_register(struct em28xx *dev, unsigned bus)
 	strcpy(dev->i2c_adap[bus].name, dev->name);
 
 	dev->i2c_bus[bus].bus = bus;
+	dev->i2c_bus[bus].algo_type = algo_type;
 	dev->i2c_bus[bus].dev = dev;
 	dev->i2c_adap[bus].algo_data = &dev->i2c_bus[bus];
 	i2c_set_adapdata(&dev->i2c_adap[bus], &dev->v4l2_dev);
diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h
index 4c667fd..aeee896 100644
--- a/drivers/media/usb/em28xx/em28xx.h
+++ b/drivers/media/usb/em28xx/em28xx.h
@@ -461,10 +461,17 @@ struct em28xx_fh {
 	enum v4l2_buf_type           type;
 };
 
+enum em28xx_i2c_algo_type {
+	EM28XX_I2C_ALGO_EM28XX = 0,
+	EM28XX_I2C_ALGO_EM2800,
+	EM28XX_I2C_ALGO_EM25XX_BUS_B,
+};
+
 struct em28xx_i2c_bus {
 	struct em28xx *dev;
 
 	unsigned bus;
+	enum em28xx_i2c_algo_type algo_type;
 };
 
 
@@ -651,7 +658,8 @@ struct em28xx_ops {
 
 /* Provided by em28xx-i2c.c */
 void em28xx_do_i2c_scan(struct em28xx *dev, unsigned bus);
-int  em28xx_i2c_register(struct em28xx *dev, unsigned bus);
+int  em28xx_i2c_register(struct em28xx *dev, unsigned bus,
+			 enum em28xx_i2c_algo_type algo_type);
 int  em28xx_i2c_unregister(struct em28xx *dev, unsigned bus);
 
 /* Provided by em28xx-core.c */
