diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
index 418d151eb30bef7112321f538bbcf5ead6f58554..20cd65035fc785f8e6f53e4a96dff23074f4583d 100644
--- a/drivers/base/regmap/Makefile
+++ b/drivers/base/regmap/Makefile
@@ -1,4 +1,4 @@
-obj-$(CONFIG_REGMAP) += regmap.o regcache.o regcache-indexed.o
+obj-$(CONFIG_REGMAP) += regmap.o regcache.o regcache-indexed.o regcache-rbtree.o
 obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o
 obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o
 obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 5bd5759efd5c4d005506d536e41792bf15e69738..7ef8afc77e7c4f35e60526f9c57b8f70b3d74759 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -119,4 +119,5 @@ int regcache_insert_reg(struct regmap *map, unsigned int reg,
 			unsigned int val);
 
 extern struct regcache_ops regcache_indexed_ops;
+extern struct regcache_ops regcache_rbtree_ops;
 #endif
diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
new file mode 100644
index 0000000000000000000000000000000000000000..4d7ba45117554364abd8513adbc4a3bd8966a296
--- /dev/null
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -0,0 +1,399 @@
+/*
+ * Register cache access API - rbtree caching support
+ *
+ * Copyright 2011 Wolfson Microelectronics plc
+ *
+ * Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+#include <linux/rbtree.h>
+
+#include "internal.h"
+
+static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
+				 unsigned int value);
+
+struct regcache_rbtree_node {
+	/* the actual rbtree node holding this block */
+	struct rb_node node;
+	/* base register handled by this block */
+	unsigned int base_reg;
+	/* number of bytes needed to represent the register index */
+	unsigned int word_size;
+	/* block of adjacent registers */
+	void *block;
+	/* number of registers available in the block */
+	unsigned int blklen;
+} __attribute__ ((packed));
+
+struct regcache_rbtree_ctx {
+	struct rb_root root;
+	struct regcache_rbtree_node *cached_rbnode;
+};
+
+static inline void regcache_rbtree_get_base_top_reg(
+	struct regcache_rbtree_node *rbnode,
+	unsigned int *base, unsigned int *top)
+{
+	*base = rbnode->base_reg;
+	*top = rbnode->base_reg + rbnode->blklen - 1;
+}
+
+static unsigned int regcache_rbtree_get_register(
+	struct regcache_rbtree_node *rbnode, unsigned int idx)
+{
+	unsigned int val;
+
+	switch (rbnode->word_size) {
+	case 1: {
+		u8 *p = rbnode->block;
+		val = p[idx];
+		return val;
+	}
+	case 2: {
+		u16 *p = rbnode->block;
+		val = p[idx];
+		return val;
+	}
+	default:
+		BUG();
+		break;
+	}
+	return -1;
+}
+
+static void regcache_rbtree_set_register(struct regcache_rbtree_node *rbnode,
+					 unsigned int idx, unsigned int val)
+{
+	switch (rbnode->word_size) {
+	case 1: {
+		u8 *p = rbnode->block;
+		p[idx] = val;
+		break;
+	}
+	case 2: {
+		u16 *p = rbnode->block;
+		p[idx] = val;
+		break;
+	}
+	default:
+		BUG();
+		break;
+	}
+}
+
+static struct regcache_rbtree_node *regcache_rbtree_lookup(
+	struct rb_root *root, unsigned int reg)
+{
+	struct rb_node *node;
+	struct regcache_rbtree_node *rbnode;
+	unsigned int base_reg, top_reg;
+
+	node = root->rb_node;
+	while (node) {
+		rbnode = container_of(node, struct regcache_rbtree_node, node);
+		regcache_rbtree_get_base_top_reg(rbnode, &base_reg, &top_reg);
+		if (reg >= base_reg && reg <= top_reg)
+			return rbnode;
+		else if (reg > top_reg)
+			node = node->rb_right;
+		else if (reg < base_reg)
+			node = node->rb_left;
+	}
+
+	return NULL;
+}
+
+static int regcache_rbtree_insert(struct rb_root *root,
+				  struct regcache_rbtree_node *rbnode)
+{
+	struct rb_node **new, *parent;
+	struct regcache_rbtree_node *rbnode_tmp;
+	unsigned int base_reg_tmp, top_reg_tmp;
+	unsigned int base_reg;
+
+	parent = NULL;
+	new = &root->rb_node;
+	while (*new) {
+		rbnode_tmp = container_of(*new, struct regcache_rbtree_node,
+					  node);
+		/* base and top registers of the current rbnode */
+		regcache_rbtree_get_base_top_reg(rbnode_tmp, &base_reg_tmp,
+						 &top_reg_tmp);
+		/* base register of the rbnode to be added */
+		base_reg = rbnode->base_reg;
+		parent = *new;
+		/* if this register has already been inserted, just return */
+		if (base_reg >= base_reg_tmp &&
+		    base_reg <= top_reg_tmp)
+			return 0;
+		else if (base_reg > top_reg_tmp)
+			new = &((*new)->rb_right);
+		else if (base_reg < base_reg_tmp)
+			new = &((*new)->rb_left);
+	}
+
+	/* insert the node into the rbtree */
+	rb_link_node(&rbnode->node, parent, new);
+	rb_insert_color(&rbnode->node, root);
+
+	return 1;
+}
+
+static int regcache_rbtree_init(struct regmap *map)
+{
+	struct regcache_rbtree_ctx *rbtree_ctx;
+	int i;
+	int ret;
+
+	map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
+	if (!map->cache)
+		return -ENOMEM;
+
+	rbtree_ctx = map->cache;
+	rbtree_ctx->root = RB_ROOT;
+	rbtree_ctx->cached_rbnode = NULL;
+
+	for (i = 0; i < map->num_reg_defaults; i++) {
+		ret = regcache_rbtree_write(map,
+					    map->reg_defaults[i].reg,
+					    map->reg_defaults[i].def);
+		if (ret)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	regcache_exit(map);
+	return ret;
+}
+
+static int regcache_rbtree_exit(struct regmap *map)
+{
+	struct rb_node *next;
+	struct regcache_rbtree_ctx *rbtree_ctx;
+	struct regcache_rbtree_node *rbtree_node;
+
+	/* if we've already been called then just return */
+	rbtree_ctx = map->cache;
+	if (!rbtree_ctx)
+		return 0;
+
+	/* free up the rbtree */
+	next = rb_first(&rbtree_ctx->root);
+	while (next) {
+		rbtree_node = rb_entry(next, struct regcache_rbtree_node, node);
+		next = rb_next(&rbtree_node->node);
+		rb_erase(&rbtree_node->node, &rbtree_ctx->root);
+		kfree(rbtree_node->block);
+		kfree(rbtree_node);
+	}
+
+	/* release the resources */
+	kfree(map->cache);
+	map->cache = NULL;
+
+	return 0;
+}
+
+static int regcache_rbtree_read(struct regmap *map,
+				unsigned int reg, unsigned int *value)
+{
+	struct regcache_rbtree_ctx *rbtree_ctx;
+	struct regcache_rbtree_node *rbnode;
+	unsigned int base_reg, top_reg;
+	unsigned int reg_tmp;
+
+	rbtree_ctx = map->cache;
+	/* look up the required register in the cached rbnode */
+	rbnode = rbtree_ctx->cached_rbnode;
+	if (rbnode) {
+		regcache_rbtree_get_base_top_reg(rbnode, &base_reg, &top_reg);
+		if (reg >= base_reg && reg <= top_reg) {
+			reg_tmp = reg - base_reg;
+			*value = regcache_rbtree_get_register(rbnode, reg_tmp);
+			return 0;
+		}
+	}
+	/* if we can't locate it in the cached rbnode we'll have
+	 * to traverse the rbtree looking for it.
+	 */
+	rbnode = regcache_rbtree_lookup(&rbtree_ctx->root, reg);
+	if (rbnode) {
+		reg_tmp = reg - rbnode->base_reg;
+		*value = regcache_rbtree_get_register(rbnode, reg_tmp);
+		rbtree_ctx->cached_rbnode = rbnode;
+	} else {
+		/* uninitialized registers default to 0 */
+		*value = 0;
+	}
+
+	return 0;
+}
+
+
+static int regcache_rbtree_insert_to_block(struct regcache_rbtree_node *rbnode,
+					   unsigned int pos, unsigned int reg,
+					   unsigned int value)
+{
+	u8 *blk;
+
+	blk = krealloc(rbnode->block,
+		       (rbnode->blklen + 1) * rbnode->word_size, GFP_KERNEL);
+	if (!blk)
+		return -ENOMEM;
+
+	/* insert the register value in the correct place in the rbnode block */
+	memmove(blk + (pos + 1) * rbnode->word_size,
+		blk + pos * rbnode->word_size,
+		(rbnode->blklen - pos) * rbnode->word_size);
+
+	/* update the rbnode block, its size and the base register */
+	rbnode->block = blk;
+	rbnode->blklen++;
+	if (!pos)
+		rbnode->base_reg = reg;
+
+	regcache_rbtree_set_register(rbnode, pos, value);
+	return 0;
+}
+
+static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
+				 unsigned int value)
+{
+	struct regcache_rbtree_ctx *rbtree_ctx;
+	struct regcache_rbtree_node *rbnode, *rbnode_tmp;
+	struct rb_node *node;
+	unsigned int val;
+	unsigned int reg_tmp;
+	unsigned int base_reg, top_reg;
+	unsigned int pos;
+	int i;
+	int ret;
+
+	rbtree_ctx = map->cache;
+	/* look up the required register in the cached rbnode */
+	rbnode = rbtree_ctx->cached_rbnode;
+	if (rbnode) {
+		regcache_rbtree_get_base_top_reg(rbnode, &base_reg, &top_reg);
+		if (reg >= base_reg && reg <= top_reg) {
+			reg_tmp = reg - base_reg;
+			val = regcache_rbtree_get_register(rbnode, reg_tmp);
+			if (val == value)
+				return 0;
+			regcache_rbtree_set_register(rbnode, reg_tmp, value);
+			return 0;
+		}
+	}
+	/* if we can't locate it in the cached rbnode we'll have
+	 * to traverse the rbtree looking for it.
+	 */
+	rbnode = regcache_rbtree_lookup(&rbtree_ctx->root, reg);
+	if (rbnode) {
+		reg_tmp = reg - rbnode->base_reg;
+		val = regcache_rbtree_get_register(rbnode, reg_tmp);
+		if (val == value)
+			return 0;
+		regcache_rbtree_set_register(rbnode, reg_tmp, value);
+		rbtree_ctx->cached_rbnode = rbnode;
+	} else {
+		/* bail out early, no need to create the rbnode yet */
+		if (!value)
+			return 0;
+		/* look for an adjacent register to the one we are about to add */
+		for (node = rb_first(&rbtree_ctx->root); node;
+		     node = rb_next(node)) {
+			rbnode_tmp = rb_entry(node, struct regcache_rbtree_node, node);
+			for (i = 0; i < rbnode_tmp->blklen; i++) {
+				reg_tmp = rbnode_tmp->base_reg + i;
+				if (abs(reg_tmp - reg) != 1)
+					continue;
+				/* decide where in the block to place our register */
+				if (reg_tmp + 1 == reg)
+					pos = i + 1;
+				else
+					pos = i;
+				ret = regcache_rbtree_insert_to_block(rbnode_tmp, pos,
+								      reg, value);
+				if (ret)
+					return ret;
+				rbtree_ctx->cached_rbnode = rbnode_tmp;
+				return 0;
+			}
+		}
+		/* we did not manage to find a place to insert it in an existing
+		 * block so create a new rbnode with a single register in its block.
+		 * This block will get populated further if any other adjacent
+		 * registers get modified in the future.
+		 */
+		rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL);
+		if (!rbnode)
+			return -ENOMEM;
+		rbnode->blklen = 1;
+		rbnode->base_reg = reg;
+		rbnode->word_size = map->cache_word_size;
+		rbnode->block = kmalloc(rbnode->blklen * rbnode->word_size,
+					GFP_KERNEL);
+		if (!rbnode->block) {
+			kfree(rbnode);
+			return -ENOMEM;
+		}
+		regcache_rbtree_set_register(rbnode, 0, value);
+		regcache_rbtree_insert(&rbtree_ctx->root, rbnode);
+		rbtree_ctx->cached_rbnode = rbnode;
+	}
+
+	return 0;
+}
+
+static int regcache_rbtree_sync(struct regmap *map)
+{
+	struct regcache_rbtree_ctx *rbtree_ctx;
+	struct rb_node *node;
+	struct regcache_rbtree_node *rbnode;
+	unsigned int regtmp;
+	unsigned int val, def;
+	int ret;
+	int i;
+
+	rbtree_ctx = map->cache;
+	for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
+		rbnode = rb_entry(node, struct regcache_rbtree_node, node);
+		for (i = 0; i < rbnode->blklen; i++) {
+			regtmp = rbnode->base_reg + i;
+			val = regcache_rbtree_get_register(rbnode, i);
+			ret = regcache_lookup_reg(map, i);
+			if (ret < 0)
+				def = 0;
+			else
+				def = map->reg_defaults[ret].def;
+			if (val == def)
+				continue;
+			map->cache_bypass = 1;
+			ret = regmap_write(map, regtmp, val);
+			map->cache_bypass = 0;
+			if (ret)
+				return ret;
+			dev_dbg(map->dev, "Synced register %#x, value %#x\n",
+				regtmp, val);
+		}
+	}
+
+	return 0;
+}
+
+struct regcache_ops regcache_rbtree_ops = {
+	.type = REGCACHE_RBTREE,
+	.name = "rbtree",
+	.init = regcache_rbtree_init,
+	.exit = regcache_rbtree_exit,
+	.read = regcache_rbtree_read,
+	.write = regcache_rbtree_write,
+	.sync = regcache_rbtree_sync
+};
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 22b73ec12fd526803a979c8fd22a0daf994dae60..b870a668b77174f6a84e0935fce8d74e8e514ef4 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -17,6 +17,7 @@
 
 static const struct regcache_ops *cache_types[] = {
 	&regcache_indexed_ops,
+	&regcache_rbtree_ops,
 };
 
 static int regcache_hw_init(struct regmap *map)
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index ae6d3a4cee978c4c47a31eff6a5bfdbf60d8b313..63c4a5e126e9d643f980fd30f85b81f0286a4ff8 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -24,6 +24,7 @@ struct spi_device;
 enum regcache_type {
 	REGCACHE_NONE,
 	REGCACHE_INDEXED,
+	REGCACHE_RBTREE,
 };
 
 /**