Merge branch 'for-linus' of git://opensource.wolfsonmicro.com/regmap

* 'for-linus' of git://opensource.wolfsonmicro.com/regmap: (62 commits)
  mfd: Enable rbtree cache for wm831x devices
  regmap: Support some block operations on cached devices
  regmap: Allow caches for devices with no defaults
  regmap: Ensure rbtree syncs registers set to zero properly
  regmap: Allow rbtree to cache zero default values
  regmap: Warn on raw I/O as well as bulk reads that bypass cache
  regmap: Return a sensible error code if we fail to read the cache
  regmap: Use bsearch() to search the register defaults
  regmap: Fix doc comment
  regmap: Optimize the lookup path to use binary search
  regmap: Ensure we scream if we enable cache bypass/only at the same time
  regmap: Implement regcache_cache_bypass helper function
  regmap: Save/restore the bypass state upon syncing
  regmap: Lock the sync path, ensure we use the lockless _regmap_write()
  regmap: Fix apostrophe usage
  regmap: Make _regmap_write() global
  regmap: Fix lock used for regcache_cache_only()
  regmap: Grab the lock in regcache_cache_only()
  regmap: Modify map->cache_bypass directly
  regmap: Fix regcache_sync generic implementation
  ...

drivers/base/regmap/Kconfig

@@ -4,6 +4,8 @@
 
 config REGMAP
 	default y if (REGMAP_I2C || REGMAP_SPI)
+	select LZO_COMPRESS
+	select LZO_DECOMPRESS
 	bool
 
 config REGMAP_I2C

drivers/base/regmap/Makefile

-obj-$(CONFIG_REGMAP) += regmap.o
+obj-$(CONFIG_REGMAP) += regmap.o regcache.o regcache-indexed.o regcache-rbtree.o regcache-lzo.o
+obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o
 obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o
 obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o

drivers/base/regmap/internal.h

+/*
+ * Register map access API internal header
+ *
+ * Copyright 2011 Wolfson Microelectronics plc
+ *
+ * Author: Mark Brown <broonie@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.
+ */
+
+#ifndef _REGMAP_INTERNAL_H
+#define _REGMAP_INTERNAL_H
+
+#include <linux/regmap.h>
+#include <linux/fs.h>
+
+struct regmap;
+struct regcache_ops;
+
+struct regmap_format {
+	size_t buf_size;
+	size_t reg_bytes;
+	size_t val_bytes;
+	void (*format_write)(struct regmap *map,
+			     unsigned int reg, unsigned int val);
+	void (*format_reg)(void *buf, unsigned int reg);
+	void (*format_val)(void *buf, unsigned int val);
+	unsigned int (*parse_val)(void *buf);
+};
+
+struct regmap {
+	struct mutex lock;
+
+	struct device *dev; /* Device we do I/O on */
+	void *work_buf;     /* Scratch buffer used to format I/O */
+	struct regmap_format format;  /* Buffer format */
+	const struct regmap_bus *bus;
+
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debugfs;
+#endif
+
+	unsigned int max_register;
+	bool (*writeable_reg)(struct device *dev, unsigned int reg);
+	bool (*readable_reg)(struct device *dev, unsigned int reg);
+	bool (*volatile_reg)(struct device *dev, unsigned int reg);
+	bool (*precious_reg)(struct device *dev, unsigned int reg);
+
+	u8 read_flag_mask;
+	u8 write_flag_mask;
+
+	/* regcache specific members */
+	const struct regcache_ops *cache_ops;
+	enum regcache_type cache_type;
+
+	/* number of bytes in reg_defaults_raw */
+	unsigned int cache_size_raw;
+	/* number of bytes per word in reg_defaults_raw */
+	unsigned int cache_word_size;
+	/* number of entries in reg_defaults */
+	unsigned int num_reg_defaults;
+	/* number of entries in reg_defaults_raw */
+	unsigned int num_reg_defaults_raw;
+
+	/* if set, only the cache is modified not the HW */
+	unsigned int cache_only:1;
+	/* if set, only the HW is modified not the cache */
+	unsigned int cache_bypass:1;
+	/* if set, remember to free reg_defaults_raw */
+	unsigned int cache_free:1;
+
+	struct reg_default *reg_defaults;
+	const void *reg_defaults_raw;
+	void *cache;
+};
+
+struct regcache_ops {
+	const char *name;
+	enum regcache_type type;
+	int (*init)(struct regmap *map);
+	int (*exit)(struct regmap *map);
+	int (*read)(struct regmap *map, unsigned int reg, unsigned int *value);
+	int (*write)(struct regmap *map, unsigned int reg, unsigned int value);
+	int (*sync)(struct regmap *map);
+};
+
+bool regmap_writeable(struct regmap *map, unsigned int reg);
+bool regmap_readable(struct regmap *map, unsigned int reg);
+bool regmap_volatile(struct regmap *map, unsigned int reg);
+bool regmap_precious(struct regmap *map, unsigned int reg);
+
+int _regmap_write(struct regmap *map, unsigned int reg,
+		  unsigned int val);
+
+#ifdef CONFIG_DEBUG_FS
+extern void regmap_debugfs_initcall(void);
+extern void regmap_debugfs_init(struct regmap *map);
+extern void regmap_debugfs_exit(struct regmap *map);
+#else
+static inline void regmap_debugfs_initcall(void) { }
+static inline void regmap_debugfs_init(struct regmap *map) { }
+static inline void regmap_debugfs_exit(struct regmap *map) { }
+#endif
+
+/* regcache core declarations */
+int regcache_init(struct regmap *map);
+void regcache_exit(struct regmap *map);
+int regcache_read(struct regmap *map,
+		       unsigned int reg, unsigned int *value);
+int regcache_write(struct regmap *map,
+			unsigned int reg, unsigned int value);
+int regcache_sync(struct regmap *map);
+
+unsigned int regcache_get_val(const void *base, unsigned int idx,
+			      unsigned int word_size);
+bool regcache_set_val(void *base, unsigned int idx,
+		      unsigned int val, unsigned int word_size);
+int regcache_lookup_reg(struct regmap *map, unsigned int reg);
+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;
+extern struct regcache_ops regcache_lzo_ops;
+
+#endif

drivers/base/regmap/regcache-indexed.c

+/*
+ * Register cache access API - indexed 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 "internal.h"
+
+static int regcache_indexed_read(struct regmap *map, unsigned int reg,
+				 unsigned int *value)
+{
+	int ret;
+
+	ret = regcache_lookup_reg(map, reg);
+	if (ret >= 0)
+		*value = map->reg_defaults[ret].def;
+
+	return ret;
+}
+
+static int regcache_indexed_write(struct regmap *map, unsigned int reg,
+				  unsigned int value)
+{
+	int ret;
+
+	ret = regcache_lookup_reg(map, reg);
+	if (ret < 0)
+		return regcache_insert_reg(map, reg, value);
+	map->reg_defaults[ret].def = value;
+	return 0;
+}
+
+static int regcache_indexed_sync(struct regmap *map)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < map->num_reg_defaults; i++) {
+		ret = _regmap_write(map, map->reg_defaults[i].reg,
+				    map->reg_defaults[i].def);
+		if (ret < 0)
+			return ret;
+		dev_dbg(map->dev, "Synced register %#x, value %#x\n",
+			map->reg_defaults[i].reg,
+			map->reg_defaults[i].def);
+	}
+	return 0;
+}
+
+struct regcache_ops regcache_indexed_ops = {
+	.type = REGCACHE_INDEXED,
+	.name = "indexed",
+	.read = regcache_indexed_read,
+	.write = regcache_indexed_write,
+	.sync = regcache_indexed_sync
+};

drivers/base/regmap/regcache-lzo.c

+/*
+ * Register cache access API - LZO 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/lzo.h>
+
+#include "internal.h"
+
+struct regcache_lzo_ctx {
+	void *wmem;
+	void *dst;
+	const void *src;
+	size_t src_len;
+	size_t dst_len;
+	size_t decompressed_size;
+	unsigned long *sync_bmp;
+	int sync_bmp_nbits;
+};
+
+#define LZO_BLOCK_NUM 8
+static int regcache_lzo_block_count(void)
+{
+	return LZO_BLOCK_NUM;
+}
+
+static int regcache_lzo_prepare(struct regcache_lzo_ctx *lzo_ctx)
+{
+	lzo_ctx->wmem = kmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
+	if (!lzo_ctx->wmem)
+		return -ENOMEM;
+	return 0;
+}
+
+static int regcache_lzo_compress(struct regcache_lzo_ctx *lzo_ctx)
+{
+	size_t compress_size;
+	int ret;
+
+	ret = lzo1x_1_compress(lzo_ctx->src, lzo_ctx->src_len,
+			       lzo_ctx->dst, &compress_size, lzo_ctx->wmem);
+	if (ret != LZO_E_OK || compress_size > lzo_ctx->dst_len)
+		return -EINVAL;
+	lzo_ctx->dst_len = compress_size;
+	return 0;
+}
+
+static int regcache_lzo_decompress(struct regcache_lzo_ctx *lzo_ctx)
+{
+	size_t dst_len;
+	int ret;
+
+	dst_len = lzo_ctx->dst_len;
+	ret = lzo1x_decompress_safe(lzo_ctx->src, lzo_ctx->src_len,
+				    lzo_ctx->dst, &dst_len);
+	if (ret != LZO_E_OK || dst_len != lzo_ctx->dst_len)
+		return -EINVAL;
+	return 0;
+}
+
+static int regcache_lzo_compress_cache_block(struct regmap *map,
+		struct regcache_lzo_ctx *lzo_ctx)
+{
+	int ret;
+
+	lzo_ctx->dst_len = lzo1x_worst_compress(PAGE_SIZE);
+	lzo_ctx->dst = kmalloc(lzo_ctx->dst_len, GFP_KERNEL);
+	if (!lzo_ctx->dst) {
+		lzo_ctx->dst_len = 0;
+		return -ENOMEM;
+	}
+
+	ret = regcache_lzo_compress(lzo_ctx);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+static int regcache_lzo_decompress_cache_block(struct regmap *map,
+		struct regcache_lzo_ctx *lzo_ctx)
+{
+	int ret;
+
+	lzo_ctx->dst_len = lzo_ctx->decompressed_size;
+	lzo_ctx->dst = kmalloc(lzo_ctx->dst_len, GFP_KERNEL);
+	if (!lzo_ctx->dst) {
+		lzo_ctx->dst_len = 0;
+		return -ENOMEM;
+	}
+
+	ret = regcache_lzo_decompress(lzo_ctx);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+static inline int regcache_lzo_get_blkindex(struct regmap *map,
+					    unsigned int reg)
+{
+	return (reg * map->cache_word_size) /
+		DIV_ROUND_UP(map->cache_size_raw, regcache_lzo_block_count());
+}
+
+static inline int regcache_lzo_get_blkpos(struct regmap *map,
+					  unsigned int reg)
+{
+	return reg % (DIV_ROUND_UP(map->cache_size_raw, regcache_lzo_block_count()) /
+		      map->cache_word_size);
+}
+
+static inline int regcache_lzo_get_blksize(struct regmap *map)
+{
+	return DIV_ROUND_UP(map->cache_size_raw, regcache_lzo_block_count());
+}
+
+static int regcache_lzo_init(struct regmap *map)
+{
+	struct regcache_lzo_ctx **lzo_blocks;
+	size_t bmp_size;
+	int ret, i, blksize, blkcount;
+	const char *p, *end;
+	unsigned long *sync_bmp;
+
+	ret = 0;
+
+	blkcount = regcache_lzo_block_count();
+	map->cache = kzalloc(blkcount * sizeof *lzo_blocks,
+			     GFP_KERNEL);
+	if (!map->cache)
+		return -ENOMEM;
+	lzo_blocks = map->cache;
+
+	/*
+	 * allocate a bitmap to be used when syncing the cache with
+	 * the hardware.  Each time a register is modified, the corresponding
+	 * bit is set in the bitmap, so we know that we have to sync
+	 * that register.
+	 */
+	bmp_size = map->num_reg_defaults_raw;
+	sync_bmp = kmalloc(BITS_TO_LONGS(bmp_size) * sizeof(long),
+			   GFP_KERNEL);
+	if (!sync_bmp) {
+		ret = -ENOMEM;
+		goto err;
+	}
+	bitmap_zero(sync_bmp, bmp_size);
+
+	/* allocate the lzo blocks and initialize them */
+	for (i = 0; i < blkcount; i++) {
+		lzo_blocks[i] = kzalloc(sizeof **lzo_blocks,
+					GFP_KERNEL);
+		if (!lzo_blocks[i]) {
+			kfree(sync_bmp);
+			ret = -ENOMEM;
+			goto err;
+		}
+		lzo_blocks[i]->sync_bmp = sync_bmp;
+		lzo_blocks[i]->sync_bmp_nbits = bmp_size;
+		/* alloc the working space for the compressed block */
+		ret = regcache_lzo_prepare(lzo_blocks[i]);
+		if (ret < 0)
+			goto err;
+	}
+
+	blksize = regcache_lzo_get_blksize(map);
+	p = map->reg_defaults_raw;
+	end = map->reg_defaults_raw + map->cache_size_raw;
+	/* compress the register map and fill the lzo blocks */
+	for (i = 0; i < blkcount; i++, p += blksize) {
+		lzo_blocks[i]->src = p;
+		if (p + blksize > end)
+			lzo_blocks[i]->src_len = end - p;
+		else
+			lzo_blocks[i]->src_len = blksize;
+		ret = regcache_lzo_compress_cache_block(map,
+						       lzo_blocks[i]);
+		if (ret < 0)
+			goto err;
+		lzo_blocks[i]->decompressed_size =
+			lzo_blocks[i]->src_len;
+	}
+
+	return 0;
+err:
+	regcache_exit(map);
+	return ret;
+}
+
+static int regcache_lzo_exit(struct regmap *map)
+{
+	struct regcache_lzo_ctx **lzo_blocks;
+	int i, blkcount;
+
+	lzo_blocks = map->cache;
+	if (!lzo_blocks)
+		return 0;
+
+	blkcount = regcache_lzo_block_count();
+	/*
+	 * the pointer to the bitmap used for syncing the cache
+	 * is shared amongst all lzo_blocks.  Ensure it is freed
+	 * only once.
+	 */
+	if (lzo_blocks[0])
+		kfree(lzo_blocks[0]->sync_bmp);
+	for (i = 0; i < blkcount; i++) {
+		if (lzo_blocks[i]) {
+			kfree(lzo_blocks[i]->wmem);
+			kfree(lzo_blocks[i]->dst);
+		}
+		/* each lzo_block is a pointer returned by kmalloc or NULL */
+		kfree(lzo_blocks[i]);
+	}
+	kfree(lzo_blocks);
+	map->cache = NULL;
+	return 0;
+}
+
+static int regcache_lzo_read(struct regmap *map,
+			     unsigned int reg, unsigned int *value)
+{
+	struct regcache_lzo_ctx *lzo_block, **lzo_blocks;
+	int ret, blkindex, blkpos;
+	size_t blksize, tmp_dst_len;
+	void *tmp_dst;
+
+	/* index of the compressed lzo block */
+	blkindex = regcache_lzo_get_blkindex(map, reg);
+	/* register index within the decompressed block */
+	blkpos = regcache_lzo_get_blkpos(map, reg);
+	/* size of the compressed block */
+	blksize = regcache_lzo_get_blksize(map);
+	lzo_blocks = map->cache;
+	lzo_block = lzo_blocks[blkindex];
+
+	/* save the pointer and length of the compressed block */
+	tmp_dst = lzo_block->dst;
+	tmp_dst_len = lzo_block->dst_len;
+
+	/* prepare the source to be the compressed block */
+	lzo_block->src = lzo_block->dst;
+	lzo_block->src_len = lzo_block->dst_len;
+
+	/* decompress the block */
+	ret = regcache_lzo_decompress_cache_block(map, lzo_block);
+	if (ret >= 0)
+		/* fetch the value from the cache */
+		*value = regcache_get_val(lzo_block->dst, blkpos,
+					  map->cache_word_size);
+
+	kfree(lzo_block->dst);
+	/* restore the pointer and length of the compressed block */
+	lzo_block->dst = tmp_dst;
+	lzo_block->dst_len = tmp_dst_len;
+
+	return ret;
+}
+
+static int regcache_lzo_write(struct regmap *map,
+			      unsigned int reg, unsigned int value)
+{
+	struct regcache_lzo_ctx *lzo_block, **lzo_blocks;
+	int ret, blkindex, blkpos;
+	size_t blksize, tmp_dst_len;
+	void *tmp_dst;
+
+	/* index of the compressed lzo block */
+	blkindex = regcache_lzo_get_blkindex(map, reg);
+	/* register index within the decompressed block */
+	blkpos = regcache_lzo_get_blkpos(map, reg);
+	/* size of the compressed block */
+	blksize = regcache_lzo_get_blksize(map);
+	lzo_blocks = map->cache;
+	lzo_block = lzo_blocks[blkindex];
+
+	/* save the pointer and length of the compressed block */
+	tmp_dst = lzo_block->dst;
+	tmp_dst_len = lzo_block->dst_len;
+
+	/* prepare the source to be the compressed block */
+	lzo_block->src = lzo_block->dst;
+	lzo_block->src_len = lzo_block->dst_len;
+
+	/* decompress the block */
+	ret = regcache_lzo_decompress_cache_block(map, lzo_block);
+	if (ret < 0) {
+		kfree(lzo_block->dst);
+		goto out;
+	}
+
+	/* write the new value to the cache */
+	if (regcache_set_val(lzo_block->dst, blkpos, value,
+			     map->cache_word_size)) {
+		kfree(lzo_block->dst);
+		goto out;
+	}
+
+	/* prepare the source to be the decompressed block */
+	lzo_block->src = lzo_block->dst;
+	lzo_block->src_len = lzo_block->dst_len;
+
+	/* compress the block */
+	ret = regcache_lzo_compress_cache_block(map, lzo_block);
+	if (ret < 0) {
+		kfree(lzo_block->dst);
+		kfree(lzo_block->src);
+		goto out;
+	}
+
+	/* set the bit so we know we have to sync this register */
+	set_bit(reg, lzo_block->sync_bmp);
+	kfree(tmp_dst);
+	kfree(lzo_block->src);
+	return 0;
+out:
+	lzo_block->dst = tmp_dst;
+	lzo_block->dst_len = tmp_dst_len;
+	return ret;
+}
+
+static int regcache_lzo_sync(struct regmap *map)
+{
+	struct regcache_lzo_ctx **lzo_blocks;
+	unsigned int val;
+	int i;
+	int ret;
+
+	lzo_blocks = map->cache;
+	for_each_set_bit(i, lzo_blocks[0]->sync_bmp, lzo_blocks[0]->sync_bmp_nbits) {
+		ret = regcache_read(map, i, &val);
+		if (ret)
+			return ret;
+		map->cache_bypass = 1;
+		ret = _regmap_write(map, i, val);
+		map->cache_bypass = 0;
+		if (ret)
+			return ret;
+		dev_dbg(map->dev, "Synced register %#x, value %#x\n",
+			i, val);
+	}
+
+	return 0;
+}
+
+struct regcache_ops regcache_lzo_ops = {
+	.type = REGCACHE_LZO,
+	.name = "lzo",
+	.init = regcache_lzo_init,
+	.exit = regcache_lzo_exit,
+	.read = regcache_lzo_read,
+	.write = regcache_lzo_write,
+	.sync = regcache_lzo_sync
+};

drivers/base/regmap/regcache-rbtree.c

+/*
+ * 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;
+	/* 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 word_size)
+{
+	return regcache_get_val(rbnode->block, idx, word_size);
+}
+
+static void regcache_rbtree_set_register(struct regcache_rbtree_node *rbnode,
+					 unsigned int idx, unsigned int val,
+					 unsigned int word_size)
+{
+	regcache_set_val(rbnode->block, idx, val, word_size);
+}
+
+static struct regcache_rbtree_node *regcache_rbtree_lookup(struct regmap *map,
+	unsigned int reg)
+{
+	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
+	struct rb_node *node;
+	struct regcache_rbtree_node *rbnode;
+	unsigned int base_reg, top_reg;
+
+	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)
+			return rbnode;
+	}
+
+	node = rbtree_ctx->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) {
+			rbtree_ctx->cached_rbnode = rbnode;
+			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_node *rbnode;
+	unsigned int reg_tmp;
+
+	rbnode = regcache_rbtree_lookup(map, reg);
+	if (rbnode) {
+		reg_tmp = reg - rbnode->base_reg;
+		*value = regcache_rbtree_get_register(rbnode, reg_tmp,
+						      map->cache_word_size);
+	} else {
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+
+static int regcache_rbtree_insert_to_block(struct regcache_rbtree_node *rbnode,
+					   unsigned int pos, unsigned int reg,
+					   unsigned int value, unsigned int word_size)
+{
+	u8 *blk;
+
+	blk = krealloc(rbnode->block,
+		       (rbnode->blklen + 1) * word_size, GFP_KERNEL);
+	if (!blk)
+		return -ENOMEM;
+
+	/* insert the register value in the correct place in the rbnode block */
+	memmove(blk + (pos + 1) * word_size,
+		blk + pos * word_size,
+		(rbnode->blklen - pos) * 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, word_size);
+	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 pos;
+	int i;
+	int ret;
+
+	rbtree_ctx = map->cache;
+	/* if we can't locate it in the cached rbnode we'll have
+	 * to traverse the rbtree looking for it.
+	 */
+	rbnode = regcache_rbtree_lookup(map, reg);
+	if (rbnode) {
+		reg_tmp = reg - rbnode->base_reg;
+		val = regcache_rbtree_get_register(rbnode, reg_tmp,
+						   map->cache_word_size);
+		if (val == value)
+			return 0;
+		regcache_rbtree_set_register(rbnode, reg_tmp, value,
+					     map->cache_word_size);
+	} else {
+		/* 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,
+								      map->cache_word_size);
+				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->block = kmalloc(rbnode->blklen * map->cache_word_size,
+					GFP_KERNEL);
+		if (!rbnode->block) {
+			kfree(rbnode);
+			return -ENOMEM;
+		}
+		regcache_rbtree_set_register(rbnode, 0, value, map->cache_word_size);
+		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;
+	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,
+							   map->cache_word_size);
+
+			/* Is this the hardware default?  If so skip. */
+			ret = regcache_lookup_reg(map, i);
+			if (ret > 0 && val == map->reg_defaults[ret].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
+};

drivers/base/regmap/regcache.c

+/*
+ * Register cache access API
+ *
+ * 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 <trace/events/regmap.h>
+#include <linux/bsearch.h>
+#include <linux/sort.h>
+
+#include "internal.h"
+
+static const struct regcache_ops *cache_types[] = {
+	&regcache_indexed_ops,
+	&regcache_rbtree_ops,
+	&regcache_lzo_ops,
+};
+
+static int regcache_hw_init(struct regmap *map)
+{
+	int i, j;
+	int ret;
+	int count;
+	unsigned int val;
+	void *tmp_buf;
+
+	if (!map->num_reg_defaults_raw)
+		return -EINVAL;
+
+	if (!map->reg_defaults_raw) {
+		dev_warn(map->dev, "No cache defaults, reading back from HW\n");
+		tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL);
+		if (!tmp_buf)
+			return -EINVAL;
+		ret = regmap_bulk_read(map, 0, tmp_buf,
+				       map->num_reg_defaults_raw);
+		if (ret < 0) {
+			kfree(tmp_buf);
+			return ret;
+		}
+		map->reg_defaults_raw = tmp_buf;
+		map->cache_free = 1;
+	}
+
+	/* calculate the size of reg_defaults */
+	for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++) {
+		val = regcache_get_val(map->reg_defaults_raw,
+				       i, map->cache_word_size);
+		if (!val)
+			continue;
+		count++;
+	}
+
+	map->reg_defaults = kmalloc(count * sizeof(struct reg_default),
+				      GFP_KERNEL);
+	if (!map->reg_defaults)
+		return -ENOMEM;
+
+	/* fill the reg_defaults */
+	map->num_reg_defaults = count;
+	for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) {
+		val = regcache_get_val(map->reg_defaults_raw,
+				       i, map->cache_word_size);
+		if (!val)
+			continue;
+		map->reg_defaults[j].reg = i;
+		map->reg_defaults[j].def = val;
+		j++;
+	}
+
+	return 0;
+}
+
+int regcache_init(struct regmap *map)
+{
+	int ret;
+	int i;
+	void *tmp_buf;
+
+	if (map->cache_type == REGCACHE_NONE) {
+		map->cache_bypass = true;
+		return 0;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(cache_types); i++)
+		if (cache_types[i]->type == map->cache_type)
+			break;
+
+	if (i == ARRAY_SIZE(cache_types)) {
+		dev_err(map->dev, "Could not match compress type: %d\n",
+			map->cache_type);
+		return -EINVAL;
+	}
+
+	map->cache = NULL;
+	map->cache_ops = cache_types[i];
+
+	if (!map->cache_ops->read ||
+	    !map->cache_ops->write ||
+	    !map->cache_ops->name)
+		return -EINVAL;
+
+	/* We still need to ensure that the reg_defaults
+	 * won't vanish from under us.  We'll need to make
+	 * a copy of it.
+	 */
+	if (map->reg_defaults) {
+		if (!map->num_reg_defaults)
+			return -EINVAL;
+		tmp_buf = kmemdup(map->reg_defaults, map->num_reg_defaults *
+				  sizeof(struct reg_default), GFP_KERNEL);
+		if (!tmp_buf)
+			return -ENOMEM;
+		map->reg_defaults = tmp_buf;
+	} else if (map->num_reg_defaults_raw) {
+		/* Some devices such as PMICs don't have cache defaults,
+		 * we cope with this by reading back the HW registers and
+		 * crafting the cache defaults by hand.
+		 */
+		ret = regcache_hw_init(map);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (!map->max_register)
+		map->max_register = map->num_reg_defaults_raw;
+
+	if (map->cache_ops->init) {
+		dev_dbg(map->dev, "Initializing %s cache\n",
+			map->cache_ops->name);
+		return map->cache_ops->init(map);
+	}
+	return 0;
+}
+
+void regcache_exit(struct regmap *map)
+{
+	if (map->cache_type == REGCACHE_NONE)
+		return;
+
+	BUG_ON(!map->cache_ops);
+
+	kfree(map->reg_defaults);
+	if (map->cache_free)
+		kfree(map->reg_defaults_raw);
+
+	if (map->cache_ops->exit) {
+		dev_dbg(map->dev, "Destroying %s cache\n",
+			map->cache_ops->name);
+		map->cache_ops->exit(map);
+	}
+}
+
+/**
+ * regcache_read: Fetch the value of a given register from the cache.
+ *
+ * @map: map to configure.
+ * @reg: The register index.
+ * @value: The value to be returned.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_read(struct regmap *map,
+		  unsigned int reg, unsigned int *value)
+{
+	if (map->cache_type == REGCACHE_NONE)
+		return -ENOSYS;
+
+	BUG_ON(!map->cache_ops);
+
+	if (!regmap_readable(map, reg))
+		return -EIO;
+
+	if (!regmap_volatile(map, reg))
+		return map->cache_ops->read(map, reg, value);
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(regcache_read);
+
+/**
+ * regcache_write: Set the value of a given register in the cache.
+ *
+ * @map: map to configure.
+ * @reg: The register index.
+ * @value: The new register value.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_write(struct regmap *map,
+		   unsigned int reg, unsigned int value)
+{
+	if (map->cache_type == REGCACHE_NONE)
+		return 0;
+
+	BUG_ON(!map->cache_ops);
+
+	if (!regmap_writeable(map, reg))
+		return -EIO;
+
+	if (!regmap_volatile(map, reg))
+		return map->cache_ops->write(map, reg, value);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(regcache_write);
+
+/**
+ * regcache_sync: Sync the register cache with the hardware.
+ *
+ * @map: map to configure.
+ *
+ * Any registers that should not be synced should be marked as
+ * volatile.  In general drivers can choose not to use the provided
+ * syncing functionality if they so require.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_sync(struct regmap *map)
+{
+	int ret = 0;
+	unsigned int val;
+	unsigned int i;
+	const char *name;
+	unsigned int bypass;
+
+	BUG_ON(!map->cache_ops);
+
+	mutex_lock(&map->lock);
+	/* Remember the initial bypass state */
+	bypass = map->cache_bypass;
+	dev_dbg(map->dev, "Syncing %s cache\n",
+		map->cache_ops->name);
+	name = map->cache_ops->name;
+	trace_regcache_sync(map->dev, name, "start");
+	if (map->cache_ops->sync) {
+		ret = map->cache_ops->sync(map);
+	} else {
+		for (i = 0; i < map->num_reg_defaults; i++) {
+			ret = regcache_read(map, i, &val);
+			if (ret < 0)
+				goto out;
+			map->cache_bypass = 1;
+			ret = _regmap_write(map, i, val);
+			map->cache_bypass = 0;
+			if (ret < 0)
+				goto out;
+			dev_dbg(map->dev, "Synced register %#x, value %#x\n",
+				map->reg_defaults[i].reg,
+				map->reg_defaults[i].def);
+		}
+
+	}
+out:
+	trace_regcache_sync(map->dev, name, "stop");
+	/* Restore the bypass state */
+	map->cache_bypass = bypass;
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regcache_sync);
+
+/**
+ * regcache_cache_only: Put a register map into cache only mode
+ *
+ * @map: map to configure
+ * @cache_only: flag if changes should be written to the hardware
+ *
+ * When a register map is marked as cache only writes to the register
+ * map API will only update the register cache, they will not cause
+ * any hardware changes.  This is useful for allowing portions of
+ * drivers to act as though the device were functioning as normal when
+ * it is disabled for power saving reasons.
+ */
+void regcache_cache_only(struct regmap *map, bool enable)
+{
+	mutex_lock(&map->lock);
+	WARN_ON(map->cache_bypass && enable);
+	map->cache_only = enable;
+	mutex_unlock(&map->lock);
+}
+EXPORT_SYMBOL_GPL(regcache_cache_only);
+
+/**
+ * regcache_cache_bypass: Put a register map into cache bypass mode
+ *
+ * @map: map to configure
+ * @cache_bypass: flag if changes should not be written to the hardware
+ *
+ * When a register map is marked with the cache bypass option, writes
+ * to the register map API will only update the hardware and not the
+ * the cache directly.  This is useful when syncing the cache back to
+ * the hardware.
+ */
+void regcache_cache_bypass(struct regmap *map, bool enable)
+{
+	mutex_lock(&map->lock);
+	WARN_ON(map->cache_only && enable);
+	map->cache_bypass = enable;
+	mutex_unlock(&map->lock);
+}
+EXPORT_SYMBOL_GPL(regcache_cache_bypass);
+
+bool regcache_set_val(void *base, unsigned int idx,
+		      unsigned int val, unsigned int word_size)
+{
+	switch (word_size) {
+	case 1: {
+		u8 *cache = base;
+		if (cache[idx] == val)
+			return true;
+		cache[idx] = val;
+		break;
+	}
+	case 2: {
+		u16 *cache = base;
+		if (cache[idx] == val)
+			return true;
+		cache[idx] = val;
+		break;
+	}
+	default:
+		BUG();
+	}
+	/* unreachable */
+	return false;
+}
+
+unsigned int regcache_get_val(const void *base, unsigned int idx,
+			      unsigned int word_size)
+{
+	if (!base)
+		return -EINVAL;
+
+	switch (word_size) {
+	case 1: {
+		const u8 *cache = base;
+		return cache[idx];
+	}
+	case 2: {
+		const u16 *cache = base;
+		return cache[idx];
+	}
+	default:
+		BUG();
+	}
+	/* unreachable */
+	return -1;
+}
+
+static int regcache_default_cmp(const void *a, const void *b)
+{
+	const struct reg_default *_a = a;
+	const struct reg_default *_b = b;
+
+	return _a->reg - _b->reg;
+}
+
+int regcache_lookup_reg(struct regmap *map, unsigned int reg)
+{
+	struct reg_default key;
+	struct reg_default *r;
+
+	key.reg = reg;
+	key.def = 0;
+
+	r = bsearch(&key, map->reg_defaults, map->num_reg_defaults,
+		    sizeof(struct reg_default), regcache_default_cmp);
+
+	if (r)
+		return r - map->reg_defaults;
+	else
+		return -ENOENT;
+}
+
+int regcache_insert_reg(struct regmap *map, unsigned int reg,
+			unsigned int val)
+{
+	void *tmp;
+
+	tmp = krealloc(map->reg_defaults,
+		       (map->num_reg_defaults + 1) * sizeof(struct reg_default),
+		       GFP_KERNEL);
+	if (!tmp)
+		return -ENOMEM;
+	map->reg_defaults = tmp;
+	map->num_reg_defaults++;
+	map->reg_defaults[map->num_reg_defaults - 1].reg = reg;
+	map->reg_defaults[map->num_reg_defaults - 1].def = val;
+	sort(map->reg_defaults, map->num_reg_defaults,
+	     sizeof(struct reg_default), regcache_default_cmp, NULL);
+	return 0;
+}

drivers/base/regmap/regmap-debugfs.c

+/*
+ * Register map access API - debugfs
+ *
+ * Copyright 2011 Wolfson Microelectronics plc
+ *
+ * Author: Mark Brown <broonie@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/module.h>
+#include <linux/mutex.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+
+#include "internal.h"
+
+static struct dentry *regmap_debugfs_root;
+
+/* Calculate the length of a fixed format  */
+static size_t regmap_calc_reg_len(int max_val, char *buf, size_t buf_size)
+{
+	snprintf(buf, buf_size, "%x", max_val);
+	return strlen(buf);
+}
+
+static int regmap_open_file(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
+				    size_t count, loff_t *ppos)
+{
+	int reg_len, val_len, tot_len;
+	size_t buf_pos = 0;
+	loff_t p = 0;
+	ssize_t ret;
+	int i;
+	struct regmap *map = file->private_data;
+	char *buf;
+	unsigned int val;
+
+	if (*ppos < 0 || !count)
+		return -EINVAL;
+
+	buf = kmalloc(count, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Calculate the length of a fixed format  */
+	reg_len = regmap_calc_reg_len(map->max_register, buf, count);
+	val_len = 2 * map->format.val_bytes;
+	tot_len = reg_len + val_len + 3;      /* : \n */
+
+	for (i = 0; i < map->max_register + 1; i++) {
+		if (!regmap_readable(map, i))
+			continue;
+
+		if (regmap_precious(map, i))
+			continue;
+
+		/* If we're in the region the user is trying to read */
+		if (p >= *ppos) {
+			/* ...but not beyond it */
+			if (buf_pos >= count - 1 - tot_len)
+				break;
+
+			/* Format the register */
+			snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
+				 reg_len, i);
+			buf_pos += reg_len + 2;
+
+			/* Format the value, write all X if we can't read */
+			ret = regmap_read(map, i, &val);
+			if (ret == 0)
+				snprintf(buf + buf_pos, count - buf_pos,
+					 "%.*x", val_len, val);
+			else
+				memset(buf + buf_pos, 'X', val_len);
+			buf_pos += 2 * map->format.val_bytes;
+
+			buf[buf_pos++] = '\n';
+		}
+		p += tot_len;
+	}
+
+	ret = buf_pos;
+
+	if (copy_to_user(user_buf, buf, buf_pos)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	*ppos += buf_pos;
+
+out:
+	kfree(buf);
+	return ret;
+}
+
+static const struct file_operations regmap_map_fops = {
+	.open = regmap_open_file,
+	.read = regmap_map_read_file,
+	.llseek = default_llseek,
+};
+
+static ssize_t regmap_access_read_file(struct file *file,
+				       char __user *user_buf, size_t count,
+				       loff_t *ppos)
+{
+	int reg_len, tot_len;
+	size_t buf_pos = 0;
+	loff_t p = 0;
+	ssize_t ret;
+	int i;
+	struct regmap *map = file->private_data;
+	char *buf;
+
+	if (*ppos < 0 || !count)
+		return -EINVAL;
+
+	buf = kmalloc(count, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Calculate the length of a fixed format  */
+	reg_len = regmap_calc_reg_len(map->max_register, buf, count);
+	tot_len = reg_len + 10; /* ': R W V P\n' */
+
+	for (i = 0; i < map->max_register + 1; i++) {
+		/* Ignore registers which are neither readable nor writable */
+		if (!regmap_readable(map, i) && !regmap_writeable(map, i))
+			continue;
+
+		/* If we're in the region the user is trying to read */
+		if (p >= *ppos) {
+			/* ...but not beyond it */
+			if (buf_pos >= count - 1 - tot_len)
+				break;
+
+			/* Format the register */
+			snprintf(buf + buf_pos, count - buf_pos,
+				 "%.*x: %c %c %c %c\n",
+				 reg_len, i,
+				 regmap_readable(map, i) ? 'y' : 'n',
+				 regmap_writeable(map, i) ? 'y' : 'n',
+				 regmap_volatile(map, i) ? 'y' : 'n',
+				 regmap_precious(map, i) ? 'y' : 'n');
+
+			buf_pos += tot_len;
+		}
+		p += tot_len;
+	}
+
+	ret = buf_pos;
+
+	if (copy_to_user(user_buf, buf, buf_pos)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	*ppos += buf_pos;
+
+out:
+	kfree(buf);
+	return ret;
+}
+
+static const struct file_operations regmap_access_fops = {
+	.open = regmap_open_file,
+	.read = regmap_access_read_file,
+	.llseek = default_llseek,
+};
+
+void regmap_debugfs_init(struct regmap *map)
+{
+	map->debugfs = debugfs_create_dir(dev_name(map->dev),
+					  regmap_debugfs_root);
+	if (!map->debugfs) {
+		dev_warn(map->dev, "Failed to create debugfs directory\n");
+		return;
+	}
+
+	if (map->max_register) {
+		debugfs_create_file("registers", 0400, map->debugfs,
+				    map, &regmap_map_fops);
+		debugfs_create_file("access", 0400, map->debugfs,
+				    map, &regmap_access_fops);
+	}
+}
+
+void regmap_debugfs_exit(struct regmap *map)
+{
+	debugfs_remove_recursive(map->debugfs);
+}
+
+void regmap_debugfs_initcall(void)
+{
+	regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
+	if (!regmap_debugfs_root) {
+		pr_warn("regmap: Failed to create debugfs root\n");
+		return;
+	}
+}

drivers/base/regmap/regmap-i2c.c

@@ -90,11 +90,9 @@ static int regmap_i2c_read(struct device *dev,
 }
 
 static struct regmap_bus regmap_i2c = {
-	.type = &i2c_bus_type,
 	.write = regmap_i2c_write,
 	.gather_write = regmap_i2c_gather_write,
 	.read = regmap_i2c_read,
-	.owner = THIS_MODULE,
 };
 
 /**

drivers/base/regmap/regmap-spi.c

@@ -48,11 +48,9 @@ static int regmap_spi_read(struct device *dev,
 }
 
 static struct regmap_bus regmap_spi = {
-	.type = &spi_bus_type,
 	.write = regmap_spi_write,
 	.gather_write = regmap_spi_gather_write,
 	.read = regmap_spi_read,
-	.owner = THIS_MODULE,
 	.read_flag_mask = 0x80,
 };
 

drivers/base/regmap/regmap.c

@@ -15,29 +15,54 @@
 #include <linux/mutex.h>
 #include <linux/err.h>
 
-#include <linux/regmap.h>
-
-struct regmap;
-
-struct regmap_format {
-	size_t buf_size;
-	size_t reg_bytes;
-	size_t val_bytes;
-	void (*format_write)(struct regmap *map,
-			     unsigned int reg, unsigned int val);
-	void (*format_reg)(void *buf, unsigned int reg);
-	void (*format_val)(void *buf, unsigned int val);
-	unsigned int (*parse_val)(void *buf);
-};
-
-struct regmap {
-	struct mutex lock;
-
-	struct device *dev; /* Device we do I/O on */
-	void *work_buf;     /* Scratch buffer used to format I/O */
-	struct regmap_format format;  /* Buffer format */
-	const struct regmap_bus *bus;
-};
+#define CREATE_TRACE_POINTS
+#include <trace/events/regmap.h>
+
+#include "internal.h"
+
+bool regmap_writeable(struct regmap *map, unsigned int reg)
+{
+	if (map->max_register && reg > map->max_register)
+		return false;
+
+	if (map->writeable_reg)
+		return map->writeable_reg(map->dev, reg);
+
+	return true;
+}
+
+bool regmap_readable(struct regmap *map, unsigned int reg)
+{
+	if (map->max_register && reg > map->max_register)
+		return false;
+
+	if (map->readable_reg)
+		return map->readable_reg(map->dev, reg);
+
+	return true;
+}
+
+bool regmap_volatile(struct regmap *map, unsigned int reg)
+{
+	if (map->max_register && reg > map->max_register)
+		return false;
+
+	if (map->volatile_reg)
+		return map->volatile_reg(map->dev, reg);
+
+	return true;
+}
+
+bool regmap_precious(struct regmap *map, unsigned int reg)
+{
+	if (map->max_register && reg > map->max_register)
+		return false;
+
+	if (map->precious_reg)
+		return map->precious_reg(map->dev, reg);
+
+	return false;
+}
 
 static void regmap_format_4_12_write(struct regmap *map,
 				     unsigned int reg, unsigned int val)
@@ -116,6 +141,25 @@ struct regmap *regmap_init(struct device *dev,
 	map->format.val_bytes = config->val_bits / 8;
 	map->dev = dev;
 	map->bus = bus;
+	map->max_register = config->max_register;
+	map->writeable_reg = config->writeable_reg;
+	map->readable_reg = config->readable_reg;
+	map->volatile_reg = config->volatile_reg;
+	map->precious_reg = config->precious_reg;
+	map->cache_type = config->cache_type;
+	map->reg_defaults = config->reg_defaults;
+	map->num_reg_defaults = config->num_reg_defaults;
+	map->num_reg_defaults_raw = config->num_reg_defaults_raw;
+	map->reg_defaults_raw = config->reg_defaults_raw;
+	map->cache_size_raw = (config->val_bits / 8) * config->num_reg_defaults_raw;
+	map->cache_word_size = config->val_bits / 8;
+
+	if (config->read_flag_mask || config->write_flag_mask) {
+		map->read_flag_mask = config->read_flag_mask;
+		map->write_flag_mask = config->write_flag_mask;
+	} else {
+		map->read_flag_mask = bus->read_flag_mask;
+	}
 
 	switch (config->reg_bits) {
 	case 4:
@@ -171,6 +215,12 @@ struct regmap *regmap_init(struct device *dev,
 		goto err_map;
 	}
 
+	ret = regcache_init(map);
+	if (ret < 0)
+		goto err_map;
+
+	regmap_debugfs_init(map);
+
 	return map;
 
 err_map:
@@ -185,6 +235,8 @@ EXPORT_SYMBOL_GPL(regmap_init);
  */
 void regmap_exit(struct regmap *map)
 {
+	regcache_exit(map);
+	regmap_debugfs_exit(map);
 	kfree(map->work_buf);
 	kfree(map);
 }
@@ -193,19 +245,38 @@ EXPORT_SYMBOL_GPL(regmap_exit);
 static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 			     const void *val, size_t val_len)
 {
+	u8 *u8 = map->work_buf;
 	void *buf;
 	int ret = -ENOTSUPP;
 	size_t len;
+	int i;
+
+	/* Check for unwritable registers before we start */
+	if (map->writeable_reg)
+		for (i = 0; i < val_len / map->format.val_bytes; i++)
+			if (!map->writeable_reg(map->dev, reg + i))
+				return -EINVAL;
 
 	map->format.format_reg(map->work_buf, reg);
 
-	/* Try to do a gather write if we can */
-	if (map->bus->gather_write)
+	u8[0] |= map->write_flag_mask;
+
+	trace_regmap_hw_write_start(map->dev, reg,
+				    val_len / map->format.val_bytes);
+
+	/* If we're doing a single register write we can probably just
+	 * send the work_buf directly, otherwise try to do a gather
+	 * write.
+	 */
+	if (val == map->work_buf + map->format.reg_bytes)
+		ret = map->bus->write(map->dev, map->work_buf,
+				      map->format.reg_bytes + val_len);
+	else if (map->bus->gather_write)
 		ret = map->bus->gather_write(map->dev, map->work_buf,
 					     map->format.reg_bytes,
 					     val, val_len);
 
-	/* Otherwise fall back on linearising by hand. */
+	/* If that didn't work fall back on linearising by hand. */
 	if (ret == -ENOTSUPP) {
 		len = map->format.reg_bytes + val_len;
 		buf = kmalloc(len, GFP_KERNEL);
@@ -219,19 +290,39 @@ static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 		kfree(buf);
 	}
 
+	trace_regmap_hw_write_done(map->dev, reg,
+				   val_len / map->format.val_bytes);
+
 	return ret;
 }
 
-static int _regmap_write(struct regmap *map, unsigned int reg,
+int _regmap_write(struct regmap *map, unsigned int reg,
 		  unsigned int val)
 {
+	int ret;
 	BUG_ON(!map->format.format_write && !map->format.format_val);
 
+	if (!map->cache_bypass) {
+		ret = regcache_write(map, reg, val);
+		if (ret != 0)
+			return ret;
+		if (map->cache_only)
+			return 0;
+	}
+
+	trace_regmap_reg_write(map->dev, reg, val);
+
 	if (map->format.format_write) {
 		map->format.format_write(map, reg, val);
 
-		return map->bus->write(map->dev, map->work_buf,
+		trace_regmap_hw_write_start(map->dev, reg, 1);
+
+		ret = map->bus->write(map->dev, map->work_buf,
 				      map->format.buf_size);
+
+		trace_regmap_hw_write_done(map->dev, reg, 1);
+
+		return ret;
 	} else {
 		map->format.format_val(map->work_buf + map->format.reg_bytes,
 				       val);
@@ -286,6 +377,8 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
 {
 	int ret;
 
+	WARN_ON(map->cache_type != REGCACHE_NONE);
+
 	mutex_lock(&map->lock);
 
 	ret = _regmap_raw_write(map, reg, val, val_len);
@@ -305,20 +398,23 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 	map->format.format_reg(map->work_buf, reg);
 
 	/*
-	 * Some buses flag reads by setting the high bits in the
+	 * Some buses or devices flag reads by setting the high bits in the
 	 * register addresss; since it's always the high bits for all
 	 * current formats we can do this here rather than in
 	 * formatting.  This may break if we get interesting formats.
 	 */
-	if (map->bus->read_flag_mask)
-		u8[0] |= map->bus->read_flag_mask;
+	u8[0] |= map->read_flag_mask;
+
+	trace_regmap_hw_read_start(map->dev, reg,
+				   val_len / map->format.val_bytes);
 
 	ret = map->bus->read(map->dev, map->work_buf, map->format.reg_bytes,
 			     val, val_len);
-	if (ret != 0)
-		return ret;
 
-	return 0;
+	trace_regmap_hw_read_done(map->dev, reg,
+				  val_len / map->format.val_bytes);
+
+	return ret;
 }
 
 static int _regmap_read(struct regmap *map, unsigned int reg,
@@ -329,9 +425,20 @@ static int _regmap_read(struct regmap *map, unsigned int reg,
 	if (!map->format.parse_val)
 		return -EINVAL;
 
-	ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
+	if (!map->cache_bypass) {
+		ret = regcache_read(map, reg, val);
 		if (ret == 0)
+			return 0;
+	}
+
+	if (map->cache_only)
+		return -EBUSY;
+
+	ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
+	if (ret == 0) {
 		*val = map->format.parse_val(map->work_buf);
+		trace_regmap_reg_read(map->dev, reg, *val);
+	}
 
 	return ret;
 }
@@ -375,6 +482,14 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 		    size_t val_len)
 {
 	int ret;
+	int i;
+	bool vol = true;
+
+	for (i = 0; i < val_len / map->format.val_bytes; i++)
+		if (!regmap_volatile(map, reg + i))
+			vol = false;
+
+	WARN_ON(!vol && map->cache_type != REGCACHE_NONE);
 
 	mutex_lock(&map->lock);
 
@@ -402,16 +517,30 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 {
 	int ret, i;
 	size_t val_bytes = map->format.val_bytes;
+	bool vol = true;
 
 	if (!map->format.parse_val)
 		return -EINVAL;
 
+	/* Is this a block of volatile registers? */
+	for (i = 0; i < val_count; i++)
+		if (!regmap_volatile(map, reg + i))
+			vol = false;
+
+	if (vol || map->cache_type == REGCACHE_NONE) {
 		ret = regmap_raw_read(map, reg, val, val_bytes * val_count);
 		if (ret != 0)
 			return ret;
 
 		for (i = 0; i < val_count * val_bytes; i += val_bytes)
 			map->format.parse_val(val + i);
+	} else {
+		for (i = 0; i < val_count; i++) {
+			ret = regmap_read(map, reg + i, val + (i * val_bytes));
+			if (ret != 0)
+				return ret;
+		}
+	}
 
 	return 0;
 }
@@ -450,3 +579,11 @@ int regmap_update_bits(struct regmap *map, unsigned int reg,
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regmap_update_bits);
+
+static int __init regmap_initcall(void)
+{
+	regmap_debugfs_initcall();
+
+	return 0;
+}
+postcore_initcall(regmap_initcall);

drivers/mfd/Kconfig

@@ -404,6 +404,7 @@ config MFD_WM831X_I2C
 	bool "Support Wolfson Microelectronics WM831x/2x PMICs with I2C"
 	select MFD_CORE
 	select MFD_WM831X
+	select REGMAP_I2C
 	depends on I2C=y && GENERIC_HARDIRQS
 	help
 	  Support for the Wolfson Microelecronics WM831x and WM832x PMICs
@@ -415,6 +416,7 @@ config MFD_WM831X_SPI
 	bool "Support Wolfson Microelectronics WM831x/2x PMICs with SPI"
 	select MFD_CORE
 	select MFD_WM831X
+	select REGMAP_SPI
 	depends on SPI_MASTER && GENERIC_HARDIRQS
 	help
 	  Support for the Wolfson Microelecronics WM831x and WM832x PMICs
@@ -488,6 +490,7 @@ config MFD_WM8350_I2C
 config MFD_WM8994
 	bool "Support Wolfson Microelectronics WM8994"
 	select MFD_CORE
+	select REGMAP_I2C
 	depends on I2C=y && GENERIC_HARDIRQS
 	help
 	  The WM8994 is a highly integrated hi-fi CODEC designed for

drivers/mfd/wm831x-i2c.c

@@ -18,67 +18,17 @@
 #include <linux/delay.h>
 #include <linux/mfd/core.h>
 #include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/regmap.h>
 
 #include <linux/mfd/wm831x/core.h>
 #include <linux/mfd/wm831x/pdata.h>
 
-static int wm831x_i2c_read_device(struct wm831x *wm831x, unsigned short reg,
-				  int bytes, void *dest)
-{
-	struct i2c_client *i2c = wm831x->control_data;
-	int ret;
-	u16 r = cpu_to_be16(reg);
-
-	ret = i2c_master_send(i2c, (unsigned char *)&r, 2);
-	if (ret < 0)
-		return ret;
-	if (ret != 2)
-		return -EIO;
-
-	ret = i2c_master_recv(i2c, dest, bytes);
-	if (ret < 0)
-		return ret;
-	if (ret != bytes)
-		return -EIO;
-	return 0;
-}
-
-/* Currently we allocate the write buffer on the stack; this is OK for
- * small writes - if we need to do large writes this will need to be
- * revised.
- */
-static int wm831x_i2c_write_device(struct wm831x *wm831x, unsigned short reg,
-				   int bytes, void *src)
-{
-	struct i2c_client *i2c = wm831x->control_data;
-	struct i2c_msg xfer[2];
-	int ret;
-
-	reg = cpu_to_be16(reg);
-
-	xfer[0].addr = i2c->addr;
-	xfer[0].flags = 0;
-	xfer[0].len = 2;
-	xfer[0].buf = (char *)&reg;
-
-	xfer[1].addr = i2c->addr;
-	xfer[1].flags = I2C_M_NOSTART;
-	xfer[1].len = bytes;
-	xfer[1].buf = (char *)src;
-
-	ret = i2c_transfer(i2c->adapter, xfer, 2);
-	if (ret < 0)
-		return ret;
-	if (ret != 2)
-		return -EIO;
-
-	return 0;
-}
-
 static int wm831x_i2c_probe(struct i2c_client *i2c,
 			    const struct i2c_device_id *id)
 {
 	struct wm831x *wm831x;
+	int ret;
 
 	wm831x = kzalloc(sizeof(struct wm831x), GFP_KERNEL);
 	if (wm831x == NULL)
@@ -86,9 +36,15 @@ static int wm831x_i2c_probe(struct i2c_client *i2c,
 
 	i2c_set_clientdata(i2c, wm831x);
 	wm831x->dev = &i2c->dev;
-	wm831x->control_data = i2c;
-	wm831x->read_dev = wm831x_i2c_read_device;
-	wm831x->write_dev = wm831x_i2c_write_device;
+
+	wm831x->regmap = regmap_init_i2c(i2c, &wm831x_regmap_config);
+	if (IS_ERR(wm831x->regmap)) {
+		ret = PTR_ERR(wm831x->regmap);
+		dev_err(wm831x->dev, "Failed to allocate register map: %d\n",
+			ret);
+		kfree(wm831x);
+		return ret;
+	}
 
 	return wm831x_device_init(wm831x, id->driver_data, i2c->irq);
 }
@@ -109,6 +65,13 @@ static int wm831x_i2c_suspend(struct device *dev)
 	return wm831x_device_suspend(wm831x);
 }
 
+static void wm831x_i2c_shutdown(struct i2c_client *i2c)
+{
+	struct wm831x *wm831x = i2c_get_clientdata(i2c);
+
+	wm831x_device_shutdown(wm831x);
+}
+
 static const struct i2c_device_id wm831x_i2c_id[] = {
 	{ "wm8310", WM8310 },
 	{ "wm8311", WM8311 },
@@ -133,6 +96,7 @@ static struct i2c_driver wm831x_i2c_driver = {
 	},
 	.probe = wm831x_i2c_probe,
 	.remove = wm831x_i2c_remove,
+	.shutdown = wm831x_i2c_shutdown,
 	.id_table = wm831x_i2c_id,
 };
 

drivers/mfd/wm831x-spi.c

@@ -16,78 +16,19 @@
 #include <linux/module.h>
 #include <linux/pm.h>
 #include <linux/spi/spi.h>
+#include <linux/regmap.h>
+#include <linux/err.h>
 
 #include <linux/mfd/wm831x/core.h>
 
-static int wm831x_spi_read_device(struct wm831x *wm831x, unsigned short reg,
-				  int bytes, void *dest)
-{
-	u16 tx_val;
-	u16 *d = dest;
-	int r, ret;
-
-	/* Go register at a time */
-	for (r = reg; r < reg + (bytes / 2); r++) {
-		tx_val = r | 0x8000;
-
-		ret = spi_write_then_read(wm831x->control_data,
-					  (u8 *)&tx_val, 2, (u8 *)d, 2);
-		if (ret != 0)
-			return ret;
-
-		*d = be16_to_cpu(*d);
-
-		d++;
-	}
-
-	return 0;
-}
-
-static int wm831x_spi_write_device(struct wm831x *wm831x, unsigned short reg,
-				   int bytes, void *src)
-{
-	struct spi_device *spi = wm831x->control_data;
-	u16 *s = src;
-	u16 data[2];
-	int ret, r;
-
-	/* Go register at a time */
-	for (r = reg; r < reg + (bytes / 2); r++) {
-		data[0] = r;
-		data[1] = *s++;
-
-		ret = spi_write(spi, (char *)&data, sizeof(data));
-		if (ret != 0)
-			return ret;
-	}
-
-	return 0;
-}
-
 static int __devinit wm831x_spi_probe(struct spi_device *spi)
 {
+	const struct spi_device_id *id = spi_get_device_id(spi);
 	struct wm831x *wm831x;
 	enum wm831x_parent type;
+	int ret;
 
-	/* Currently SPI support for ID tables is unmerged, we're faking it */
-	if (strcmp(spi->modalias, "wm8310") == 0)
-		type = WM8310;
-	else if (strcmp(spi->modalias, "wm8311") == 0)
-		type = WM8311;
-	else if (strcmp(spi->modalias, "wm8312") == 0)
-		type = WM8312;
-	else if (strcmp(spi->modalias, "wm8320") == 0)
-		type = WM8320;
-	else if (strcmp(spi->modalias, "wm8321") == 0)
-		type = WM8321;
-	else if (strcmp(spi->modalias, "wm8325") == 0)
-		type = WM8325;
-	else if (strcmp(spi->modalias, "wm8326") == 0)
-		type = WM8326;
-	else {
-		dev_err(&spi->dev, "Unknown device type\n");
-		return -EINVAL;
-	}
+	type = (enum wm831x_parent)id->driver_data;
 
 	wm831x = kzalloc(sizeof(struct wm831x), GFP_KERNEL);
 	if (wm831x == NULL)
@@ -98,9 +39,15 @@ static int __devinit wm831x_spi_probe(struct spi_device *spi)
 
 	dev_set_drvdata(&spi->dev, wm831x);
 	wm831x->dev = &spi->dev;
-	wm831x->control_data = spi;
-	wm831x->read_dev = wm831x_spi_read_device;
-	wm831x->write_dev = wm831x_spi_write_device;
+
+	wm831x->regmap = regmap_init_spi(spi, &wm831x_regmap_config);
+	if (IS_ERR(wm831x->regmap)) {
+		ret = PTR_ERR(wm831x->regmap);
+		dev_err(wm831x->dev, "Failed to allocate register map: %d\n",
+			ret);
+		kfree(wm831x);
+		return ret;
+	}
 
 	return wm831x_device_init(wm831x, type, spi->irq);
 }
@@ -121,119 +68,50 @@ static int wm831x_spi_suspend(struct device *dev)
 	return wm831x_device_suspend(wm831x);
 }
 
+static void wm831x_spi_shutdown(struct spi_device *spi)
+{
+	struct wm831x *wm831x = dev_get_drvdata(&spi->dev);
+
+	wm831x_device_shutdown(wm831x);
+}
+
 static const struct dev_pm_ops wm831x_spi_pm = {
 	.freeze = wm831x_spi_suspend,
 	.suspend = wm831x_spi_suspend,
 };
 
-static struct spi_driver wm8310_spi_driver = {
-	.driver = {
-		.name	= "wm8310",
-		.bus	= &spi_bus_type,
-		.owner	= THIS_MODULE,
-		.pm	= &wm831x_spi_pm,
-	},
-	.probe		= wm831x_spi_probe,
-	.remove		= __devexit_p(wm831x_spi_remove),
-};
-
-static struct spi_driver wm8311_spi_driver = {
-	.driver = {
-		.name	= "wm8311",
-		.bus	= &spi_bus_type,
-		.owner	= THIS_MODULE,
-		.pm	= &wm831x_spi_pm,
-	},
-	.probe		= wm831x_spi_probe,
-	.remove		= __devexit_p(wm831x_spi_remove),
-};
-
-static struct spi_driver wm8312_spi_driver = {
-	.driver = {
-		.name	= "wm8312",
-		.bus	= &spi_bus_type,
-		.owner	= THIS_MODULE,
-		.pm	= &wm831x_spi_pm,
-	},
-	.probe		= wm831x_spi_probe,
-	.remove		= __devexit_p(wm831x_spi_remove),
-};
-
-static struct spi_driver wm8320_spi_driver = {
-	.driver = {
-		.name	= "wm8320",
-		.bus	= &spi_bus_type,
-		.owner	= THIS_MODULE,
-		.pm	= &wm831x_spi_pm,
-	},
-	.probe		= wm831x_spi_probe,
-	.remove		= __devexit_p(wm831x_spi_remove),
-};
-
-static struct spi_driver wm8321_spi_driver = {
-	.driver = {
-		.name	= "wm8321",
-		.bus	= &spi_bus_type,
-		.owner	= THIS_MODULE,
-		.pm	= &wm831x_spi_pm,
-	},
-	.probe		= wm831x_spi_probe,
-	.remove		= __devexit_p(wm831x_spi_remove),
-};
-
-static struct spi_driver wm8325_spi_driver = {
-	.driver = {
-		.name	= "wm8325",
-		.bus	= &spi_bus_type,
-		.owner	= THIS_MODULE,
-		.pm	= &wm831x_spi_pm,
-	},
-	.probe		= wm831x_spi_probe,
-	.remove		= __devexit_p(wm831x_spi_remove),
+static const struct spi_device_id wm831x_spi_ids[] = {
+	{ "wm8310", WM8310 },
+	{ "wm8311", WM8311 },
+	{ "wm8312", WM8312 },
+	{ "wm8320", WM8320 },
+	{ "wm8321", WM8321 },
+	{ "wm8325", WM8325 },
+	{ "wm8326", WM8326 },
+	{ },
 };
+MODULE_DEVICE_TABLE(spi, wm831x_spi_id);
 
-static struct spi_driver wm8326_spi_driver = {
+static struct spi_driver wm831x_spi_driver = {
 	.driver = {
-		.name	= "wm8326",
+		.name	= "wm831x",
 		.bus	= &spi_bus_type,
 		.owner	= THIS_MODULE,
 		.pm	= &wm831x_spi_pm,
 	},
+	.id_table	= wm831x_spi_ids,
 	.probe		= wm831x_spi_probe,
 	.remove		= __devexit_p(wm831x_spi_remove),
+	.shutdown	= wm831x_spi_shutdown,
 };
 
 static int __init wm831x_spi_init(void)
 {
 	int ret;
 
-	ret = spi_register_driver(&wm8310_spi_driver);
-	if (ret != 0)
-		pr_err("Failed to register WM8310 SPI driver: %d\n", ret);
-
-	ret = spi_register_driver(&wm8311_spi_driver);
-	if (ret != 0)
-		pr_err("Failed to register WM8311 SPI driver: %d\n", ret);
-
-	ret = spi_register_driver(&wm8312_spi_driver);
-	if (ret != 0)
-		pr_err("Failed to register WM8312 SPI driver: %d\n", ret);
-
-	ret = spi_register_driver(&wm8320_spi_driver);
-	if (ret != 0)
-		pr_err("Failed to register WM8320 SPI driver: %d\n", ret);
-
-	ret = spi_register_driver(&wm8321_spi_driver);
-	if (ret != 0)
-		pr_err("Failed to register WM8321 SPI driver: %d\n", ret);
-
-	ret = spi_register_driver(&wm8325_spi_driver);
-	if (ret != 0)
-		pr_err("Failed to register WM8325 SPI driver: %d\n", ret);
-
-	ret = spi_register_driver(&wm8326_spi_driver);
+	ret = spi_register_driver(&wm831x_spi_driver);
 	if (ret != 0)
-		pr_err("Failed to register WM8326 SPI driver: %d\n", ret);
+		pr_err("Failed to register WM831x SPI driver: %d\n", ret);
 
 	return 0;
 }
@@ -241,13 +119,7 @@ subsys_initcall(wm831x_spi_init);
 
 static void __exit wm831x_spi_exit(void)
 {
-	spi_unregister_driver(&wm8326_spi_driver);
-	spi_unregister_driver(&wm8325_spi_driver);
-	spi_unregister_driver(&wm8321_spi_driver);
-	spi_unregister_driver(&wm8320_spi_driver);
-	spi_unregister_driver(&wm8312_spi_driver);
-	spi_unregister_driver(&wm8311_spi_driver);
-	spi_unregister_driver(&wm8310_spi_driver);
+	spi_unregister_driver(&wm831x_spi_driver);
 }
 module_exit(wm831x_spi_exit);
 

drivers/mfd/wm8400-core.c

@@ -13,11 +13,13 @@
  */
 
 #include <linux/bug.h>
+#include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/wm8400-private.h>
 #include <linux/mfd/wm8400-audio.h>
+#include <linux/regmap.h>
 #include <linux/slab.h>
 
 static struct {
@@ -123,14 +125,9 @@ static int wm8400_read(struct wm8400 *wm8400, u8 reg, int num_regs, u16 *dest)
 	/* If there are any volatile reads then read back the entire block */
 	for (i = reg; i < reg + num_regs; i++)
 		if (reg_data[i].vol) {
-			ret = wm8400->read_dev(wm8400->io_data, reg,
-					       num_regs, dest);
-			if (ret != 0)
+			ret = regmap_bulk_read(wm8400->regmap, reg, dest,
+					       num_regs);
 			return ret;
-			for (i = 0; i < num_regs; i++)
-				dest[i] = be16_to_cpu(dest[i]);
-
-			return 0;
 		}
 
 	/* Otherwise use the cache */
@@ -149,13 +146,10 @@ static int wm8400_write(struct wm8400 *wm8400, u8 reg, int num_regs,
 	for (i = 0; i < num_regs; i++) {
 		BUG_ON(!reg_data[reg + i].writable);
 		wm8400->reg_cache[reg + i] = src[i];
-		src[i] = cpu_to_be16(src[i]);
-	}
-
-	/* Do the actual I/O */
-	ret = wm8400->write_dev(wm8400->io_data, reg, num_regs, src);
+		ret = regmap_write(wm8400->regmap, reg, src[i]);
 		if (ret != 0)
-		return -EIO;
+			return ret;
+	}
 
 	return 0;
 }
@@ -270,14 +264,14 @@ static int wm8400_init(struct wm8400 *wm8400,
 	dev_set_drvdata(wm8400->dev, wm8400);
 
 	/* Check that this is actually a WM8400 */
-	ret = wm8400->read_dev(wm8400->io_data, WM8400_RESET_ID, 1, &reg);
+	ret = regmap_read(wm8400->regmap, WM8400_RESET_ID, &i);
 	if (ret != 0) {
 		dev_err(wm8400->dev, "Chip ID register read failed\n");
 		return -EIO;
 	}
-	if (be16_to_cpu(reg) != reg_data[WM8400_RESET_ID].default_val) {
+	if (i != reg_data[WM8400_RESET_ID].default_val) {
 		dev_err(wm8400->dev, "Device is not a WM8400, ID is %x\n",
-			be16_to_cpu(reg));
+			reg);
 		return -ENODEV;
 	}
 
@@ -285,9 +279,8 @@ static int wm8400_init(struct wm8400 *wm8400,
 	 * is a PMIC we can't reset it safely so initialise the register
 	 * cache from the hardware.
 	 */
-	ret = wm8400->read_dev(wm8400->io_data, 0,
-			       ARRAY_SIZE(wm8400->reg_cache),
-			       wm8400->reg_cache);
+	ret = regmap_raw_read(wm8400->regmap, 0, wm8400->reg_cache,
+			      ARRAY_SIZE(wm8400->reg_cache));
 	if (ret != 0) {
 		dev_err(wm8400->dev, "Register cache read failed\n");
 		return -EIO;
@@ -337,60 +330,13 @@ static void wm8400_release(struct wm8400 *wm8400)
 	mfd_remove_devices(wm8400->dev);
 }
 
-#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
-static int wm8400_i2c_read(void *io_data, char reg, int count, u16 *dest)
-{
-	struct i2c_client *i2c = io_data;
-	struct i2c_msg xfer[2];
-	int ret;
-
-	/* Write register */
-	xfer[0].addr = i2c->addr;
-	xfer[0].flags = 0;
-	xfer[0].len = 1;
-	xfer[0].buf = &reg;
-
-	/* Read data */
-	xfer[1].addr = i2c->addr;
-	xfer[1].flags = I2C_M_RD;
-	xfer[1].len = count * sizeof(u16);
-	xfer[1].buf = (u8 *)dest;
-
-	ret = i2c_transfer(i2c->adapter, xfer, 2);
-	if (ret == 2)
-		ret = 0;
-	else if (ret >= 0)
-		ret = -EIO;
-
-	return ret;
-}
-
-static int wm8400_i2c_write(void *io_data, char reg, int count, const u16 *src)
-{
-	struct i2c_client *i2c = io_data;
-	u8 *msg;
-	int ret;
-
-	/* We add 1 byte for device register - ideally I2C would gather. */
-	msg = kmalloc((count * sizeof(u16)) + 1, GFP_KERNEL);
-	if (msg == NULL)
-		return -ENOMEM;
-
-	msg[0] = reg;
-	memcpy(&msg[1], src, count * sizeof(u16));
-
-	ret = i2c_master_send(i2c, msg, (count * sizeof(u16)) + 1);
-
-	if (ret == (count * 2) + 1)
-		ret = 0;
-	else if (ret >= 0)
-		ret = -EIO;
-
-	kfree(msg);
-
-	return ret;
-}
+static const struct regmap_config wm8400_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+	.max_register = WM8400_REGISTER_COUNT - 1,
+};
 
+#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
 static int wm8400_i2c_probe(struct i2c_client *i2c,
 			    const struct i2c_device_id *id)
 {
@@ -403,18 +349,23 @@ static int wm8400_i2c_probe(struct i2c_client *i2c,
 		goto err;
 	}
 
-	wm8400->io_data = i2c;
-	wm8400->read_dev = wm8400_i2c_read;
-	wm8400->write_dev = wm8400_i2c_write;
+	wm8400->regmap = regmap_init_i2c(i2c, &wm8400_regmap_config);
+	if (IS_ERR(wm8400->regmap)) {
+		ret = PTR_ERR(wm8400->regmap);
+		goto struct_err;
+	}
+
 	wm8400->dev = &i2c->dev;
 	i2c_set_clientdata(i2c, wm8400);
 
 	ret = wm8400_init(wm8400, i2c->dev.platform_data);
 	if (ret != 0)
-		goto struct_err;
+		goto map_err;
 
 	return 0;
 
+map_err:
+	regmap_exit(wm8400->regmap);
 struct_err:
 	kfree(wm8400);
 err:
@@ -426,6 +377,7 @@ static int wm8400_i2c_remove(struct i2c_client *i2c)
 	struct wm8400 *wm8400 = i2c_get_clientdata(i2c);
 
 	wm8400_release(wm8400);
+	regmap_exit(wm8400->regmap);
 	kfree(wm8400);
 
 	return 0;

drivers/mfd/wm8994-core.c

@@ -16,9 +16,11 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/i2c.h>
+#include <linux/err.h>
 #include <linux/delay.h>
 #include <linux/mfd/core.h>
 #include <linux/pm_runtime.h>
+#include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/regulator/machine.h>
 
@@ -29,22 +31,7 @@
 static int wm8994_read(struct wm8994 *wm8994, unsigned short reg,
 		       int bytes, void *dest)
 {
-	int ret, i;
-	u16 *buf = dest;
-
-	BUG_ON(bytes % 2);
-	BUG_ON(bytes <= 0);
-
-	ret = wm8994->read_dev(wm8994, reg, bytes, dest);
-	if (ret < 0)
-		return ret;
-
-	for (i = 0; i < bytes / 2; i++) {
-		dev_vdbg(wm8994->dev, "Read %04x from R%d(0x%x)\n",
-			 be16_to_cpu(buf[i]), reg + i, reg + i);
-	}
-
-	return 0;
+	return regmap_raw_read(wm8994->regmap, reg, dest, bytes);
 }
 
 /**
@@ -55,19 +42,15 @@ static int wm8994_read(struct wm8994 *wm8994, unsigned short reg,
  */
 int wm8994_reg_read(struct wm8994 *wm8994, unsigned short reg)
 {
-	unsigned short val;
+	unsigned int val;
 	int ret;
 
-	mutex_lock(&wm8994->io_lock);
-
-	ret = wm8994_read(wm8994, reg, 2, &val);
-
-	mutex_unlock(&wm8994->io_lock);
+	ret = regmap_read(wm8994->regmap, reg, &val);
 
 	if (ret < 0)
 		return ret;
 	else
-		return be16_to_cpu(val);
+		return val;
 }
 EXPORT_SYMBOL_GPL(wm8994_reg_read);
 
@@ -82,33 +65,13 @@ EXPORT_SYMBOL_GPL(wm8994_reg_read);
 int wm8994_bulk_read(struct wm8994 *wm8994, unsigned short reg,
 		     int count, u16 *buf)
 {
-	int ret;
-
-	mutex_lock(&wm8994->io_lock);
-
-	ret = wm8994_read(wm8994, reg, count * 2, buf);
-
-	mutex_unlock(&wm8994->io_lock);
-
-	return ret;
+	return regmap_bulk_read(wm8994->regmap, reg, buf, count);
 }
-EXPORT_SYMBOL_GPL(wm8994_bulk_read);
 
 static int wm8994_write(struct wm8994 *wm8994, unsigned short reg,
 			int bytes, const void *src)
 {
-	const u16 *buf = src;
-	int i;
-
-	BUG_ON(bytes % 2);
-	BUG_ON(bytes <= 0);
-
-	for (i = 0; i < bytes / 2; i++) {
-		dev_vdbg(wm8994->dev, "Write %04x to R%d(0x%x)\n",
-			 be16_to_cpu(buf[i]), reg + i, reg + i);
-	}
-
-	return wm8994->write_dev(wm8994, reg, bytes, src);
+	return regmap_raw_write(wm8994->regmap, reg, src, bytes);
 }
 
 /**
@@ -121,17 +84,7 @@ static int wm8994_write(struct wm8994 *wm8994, unsigned short reg,
 int wm8994_reg_write(struct wm8994 *wm8994, unsigned short reg,
 		     unsigned short val)
 {
-	int ret;
-
-	val = cpu_to_be16(val);
-
-	mutex_lock(&wm8994->io_lock);
-
-	ret = wm8994_write(wm8994, reg, 2, &val);
-
-	mutex_unlock(&wm8994->io_lock);
-
-	return ret;
+	return regmap_write(wm8994->regmap, reg, val);
 }
 EXPORT_SYMBOL_GPL(wm8994_reg_write);
 
@@ -146,15 +99,7 @@ EXPORT_SYMBOL_GPL(wm8994_reg_write);
 int wm8994_bulk_write(struct wm8994 *wm8994, unsigned short reg,
 		      int count, const u16 *buf)
 {
-	int ret;
-
-	mutex_lock(&wm8994->io_lock);
-
-	ret = wm8994_write(wm8994, reg, count * 2, buf);
-
-	mutex_unlock(&wm8994->io_lock);
-
-	return ret;
+	return regmap_raw_write(wm8994->regmap, reg, buf, count * sizeof(u16));
 }
 EXPORT_SYMBOL_GPL(wm8994_bulk_write);
 
@@ -169,28 +114,7 @@ EXPORT_SYMBOL_GPL(wm8994_bulk_write);
 int wm8994_set_bits(struct wm8994 *wm8994, unsigned short reg,
 		    unsigned short mask, unsigned short val)
 {
-	int ret;
-	u16 r;
-
-	mutex_lock(&wm8994->io_lock);
-
-	ret = wm8994_read(wm8994, reg, 2, &r);
-	if (ret < 0)
-		goto out;
-
-	r = be16_to_cpu(r);
-
-	r &= ~mask;
-	r |= val;
-
-	r = cpu_to_be16(r);
-
-	ret = wm8994_write(wm8994, reg, 2, &r);
-
-out:
-	mutex_unlock(&wm8994->io_lock);
-
-	return ret;
+	return regmap_update_bits(wm8994->regmap, reg, mask, val);
 }
 EXPORT_SYMBOL_GPL(wm8994_set_bits);
 
@@ -378,6 +302,11 @@ static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
 }
 #endif
 
+static struct regmap_config wm8994_regmap_config = {
+	.reg_bits = 16,
+	.val_bits = 16,
+};
+
 /*
  * Instantiate the generic non-control parts of the device.
  */
@@ -387,7 +316,6 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 	const char *devname;
 	int ret, i;
 
-	mutex_init(&wm8994->io_lock);
 	dev_set_drvdata(wm8994->dev, wm8994);
 
 	/* Add the on-chip regulators first for bootstrapping */
@@ -397,7 +325,7 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 			      NULL, 0);
 	if (ret != 0) {
 		dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
-		goto err;
+		goto err_regmap;
 	}
 
 	switch (wm8994->type) {
@@ -409,7 +337,7 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 		break;
 	default:
 		BUG();
-		goto err;
+		goto err_regmap;
 	}
 
 	wm8994->supplies = kzalloc(sizeof(struct regulator_bulk_data) *
@@ -417,7 +345,7 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 				   GFP_KERNEL);
 	if (!wm8994->supplies) {
 		ret = -ENOMEM;
-		goto err;
+		goto err_regmap;
 	}
 
 	switch (wm8994->type) {
@@ -431,7 +359,7 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 		break;
 	default:
 		BUG();
-		goto err;
+		goto err_regmap;
 	}
 		
 	ret = regulator_bulk_get(wm8994->dev, wm8994->num_supplies,
@@ -554,7 +482,8 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
 	regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
 err_supplies:
 	kfree(wm8994->supplies);
-err:
+err_regmap:
+	regmap_exit(wm8994->regmap);
 	mfd_remove_devices(wm8994->dev);
 	kfree(wm8994);
 	return ret;
@@ -569,62 +498,15 @@ static void wm8994_device_exit(struct wm8994 *wm8994)
 			       wm8994->supplies);
 	regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
 	kfree(wm8994->supplies);
+	regmap_exit(wm8994->regmap);
 	kfree(wm8994);
 }
 
-static int wm8994_i2c_read_device(struct wm8994 *wm8994, unsigned short reg,
-				  int bytes, void *dest)
-{
-	struct i2c_client *i2c = wm8994->control_data;
-	int ret;
-	u16 r = cpu_to_be16(reg);
-
-	ret = i2c_master_send(i2c, (unsigned char *)&r, 2);
-	if (ret < 0)
-		return ret;
-	if (ret != 2)
-		return -EIO;
-
-	ret = i2c_master_recv(i2c, dest, bytes);
-	if (ret < 0)
-		return ret;
-	if (ret != bytes)
-		return -EIO;
-	return 0;
-}
-
-static int wm8994_i2c_write_device(struct wm8994 *wm8994, unsigned short reg,
-				   int bytes, const void *src)
-{
-	struct i2c_client *i2c = wm8994->control_data;
-	struct i2c_msg xfer[2];
-	int ret;
-
-	reg = cpu_to_be16(reg);
-
-	xfer[0].addr = i2c->addr;
-	xfer[0].flags = 0;
-	xfer[0].len = 2;
-	xfer[0].buf = (char *)&reg;
-
-	xfer[1].addr = i2c->addr;
-	xfer[1].flags = I2C_M_NOSTART;
-	xfer[1].len = bytes;
-	xfer[1].buf = (char *)src;
-
-	ret = i2c_transfer(i2c->adapter, xfer, 2);
-	if (ret < 0)
-		return ret;
-	if (ret != 2)
-		return -EIO;
-
-	return 0;
-}
-
 static int wm8994_i2c_probe(struct i2c_client *i2c,
 			    const struct i2c_device_id *id)
 {
 	struct wm8994 *wm8994;
+	int ret;
 
 	wm8994 = kzalloc(sizeof(struct wm8994), GFP_KERNEL);
 	if (wm8994 == NULL)
@@ -632,12 +514,18 @@ static int wm8994_i2c_probe(struct i2c_client *i2c,
 
 	i2c_set_clientdata(i2c, wm8994);
 	wm8994->dev = &i2c->dev;
-	wm8994->control_data = i2c;
-	wm8994->read_dev = wm8994_i2c_read_device;
-	wm8994->write_dev = wm8994_i2c_write_device;
 	wm8994->irq = i2c->irq;
 	wm8994->type = id->driver_data;
 
+	wm8994->regmap = regmap_init_i2c(i2c, &wm8994_regmap_config);
+	if (IS_ERR(wm8994->regmap)) {
+		ret = PTR_ERR(wm8994->regmap);
+		dev_err(wm8994->dev, "Failed to allocate register map: %d\n",
+			ret);
+		kfree(wm8994);
+		return ret;
+	}
+
 	return wm8994_device_init(wm8994, i2c->irq);
 }
 

include/linux/mfd/wm831x/core.h

@@ -18,6 +18,7 @@
 #include <linux/completion.h>
 #include <linux/interrupt.h>
 #include <linux/list.h>
+#include <linux/regmap.h>
 
 /*
  * Register values.
@@ -361,12 +362,8 @@ struct wm831x {
 	struct mutex io_lock;
 
 	struct device *dev;
-	int (*read_dev)(struct wm831x *wm831x, unsigned short reg,
-			int bytes, void *dest);
-	int (*write_dev)(struct wm831x *wm831x, unsigned short reg,
-			 int bytes, void *src);
 
-	void *control_data;
+	struct regmap *regmap;
 
 	int irq;  /* Our chip IRQ */
 	struct mutex irq_lock;
@@ -374,6 +371,8 @@ struct wm831x {
 	int irq_masks_cur[WM831X_NUM_IRQ_REGS];   /* Currently active value */
 	int irq_masks_cache[WM831X_NUM_IRQ_REGS]; /* Cached hardware value */
 
+	bool soft_shutdown;
+
 	/* Chip revision based flags */
 	unsigned has_gpio_ena:1;         /* Has GPIO enable bit */
 	unsigned has_cs_sts:1;           /* Has current sink status bit */
@@ -412,8 +411,11 @@ int wm831x_bulk_read(struct wm831x *wm831x, unsigned short reg,
 int wm831x_device_init(struct wm831x *wm831x, unsigned long id, int irq);
 void wm831x_device_exit(struct wm831x *wm831x);
 int wm831x_device_suspend(struct wm831x *wm831x);
+void wm831x_device_shutdown(struct wm831x *wm831x);
 int wm831x_irq_init(struct wm831x *wm831x, int irq);
 void wm831x_irq_exit(struct wm831x *wm831x);
 void wm831x_auxadc_init(struct wm831x *wm831x);
 
+extern struct regmap_config wm831x_regmap_config;
+
 #endif

include/linux/mfd/wm831x/pdata.h

@@ -123,6 +123,9 @@ struct wm831x_pdata {
 	/** Disable the touchscreen */
 	bool disable_touch;
 
+	/** The driver should initiate a power off sequence during shutdown */
+	bool soft_shutdown;
+
 	int irq_base;
 	int gpio_base;
 	int gpio_defaults[WM831X_GPIO_NUM];

include/linux/mfd/wm8400-private.h

@@ -25,16 +25,15 @@
 #include <linux/mutex.h>
 #include <linux/platform_device.h>
 
+struct regmap;
+
 #define WM8400_REGISTER_COUNT 0x55
 
 struct wm8400 {
 	struct device *dev;
 
-	int (*read_dev)(void *data, char reg, int count, u16 *dst);
-	int (*write_dev)(void *data, char reg, int count, const u16 *src);
-
 	struct mutex io_lock;
-	void *io_data;
+	struct regmap *regmap;
 
 	u16 reg_cache[WM8400_REGISTER_COUNT];
 

include/linux/mfd/wm8994/core.h

@@ -24,6 +24,7 @@ enum wm8994_type {
 
 struct regulator_dev;
 struct regulator_bulk_data;
+struct regmap;
 
 #define WM8994_NUM_GPIO_REGS 11
 #define WM8994_NUM_LDO_REGS   2
@@ -50,18 +51,12 @@ struct regulator_bulk_data;
 #define WM8994_IRQ_GPIO(x) (x + WM8994_IRQ_TEMP_WARN)
 
 struct wm8994 {
-	struct mutex io_lock;
 	struct mutex irq_lock;
 
 	enum wm8994_type type;
 
 	struct device *dev;
-	int (*read_dev)(struct wm8994 *wm8994, unsigned short reg,
-			int bytes, void *dest);
-	int (*write_dev)(struct wm8994 *wm8994, unsigned short reg,
-			 int bytes, const void *src);
-
-	void *control_data;
+	struct regmap *regmap;
 
 	int gpio_base;
 	int irq_base;

include/linux/regmap.h

@@ -20,9 +20,77 @@
 struct i2c_client;
 struct spi_device;
 
+/* An enum of all the supported cache types */
+enum regcache_type {
+	REGCACHE_NONE,
+	REGCACHE_INDEXED,
+	REGCACHE_RBTREE,
+	REGCACHE_LZO
+};
+
+/**
+ * Default value for a register.  We use an array of structs rather
+ * than a simple array as many modern devices have very sparse
+ * register maps.
+ *
+ * @reg: Register address.
+ * @def: Register default value.
+ */
+struct reg_default {
+	unsigned int reg;
+	unsigned int def;
+};
+
+/**
+ * Configuration for the register map of a device.
+ *
+ * @reg_bits: Number of bits in a register address, mandatory.
+ * @val_bits: Number of bits in a register value, mandatory.
+ *
+ * @writeable_reg: Optional callback returning true if the register
+ *                 can be written to.
+ * @readable_reg: Optional callback returning true if the register
+ *                can be read from.
+ * @volatile_reg: Optional callback returning true if the register
+ *                value can't be cached.
+ * @precious_reg: Optional callback returning true if the rgister
+ *                should not be read outside of a call from the driver
+ *                (eg, a clear on read interrupt status register).
+ *
+ * @max_register: Optional, specifies the maximum valid register index.
+ * @reg_defaults: Power on reset values for registers (for use with
+ *                register cache support).
+ * @num_reg_defaults: Number of elements in reg_defaults.
+ *
+ * @read_flag_mask: Mask to be set in the top byte of the register when doing
+ *                  a read.
+ * @write_flag_mask: Mask to be set in the top byte of the register when doing
+ *                   a write. If both read_flag_mask and write_flag_mask are
+ *                   empty the regmap_bus default masks are used.
+ *
+ * @cache_type: The actual cache type.
+ * @reg_defaults_raw: Power on reset values for registers (for use with
+ *                    register cache support).
+ * @num_reg_defaults_raw: Number of elements in reg_defaults_raw.
+ */
 struct regmap_config {
 	int reg_bits;
 	int val_bits;
+
+	bool (*writeable_reg)(struct device *dev, unsigned int reg);
+	bool (*readable_reg)(struct device *dev, unsigned int reg);
+	bool (*volatile_reg)(struct device *dev, unsigned int reg);
+	bool (*precious_reg)(struct device *dev, unsigned int reg);
+
+	unsigned int max_register;
+	struct reg_default *reg_defaults;
+	unsigned int num_reg_defaults;
+	enum regcache_type cache_type;
+	const void *reg_defaults_raw;
+	unsigned int num_reg_defaults_raw;
+
+	u8 read_flag_mask;
+	u8 write_flag_mask;
 };
 
 typedef int (*regmap_hw_write)(struct device *dev, const void *data,
@@ -37,25 +105,18 @@ typedef int (*regmap_hw_read)(struct device *dev,
 /**
  * Description of a hardware bus for the register map infrastructure.
  *
- * @list: Internal use.
- * @type: Bus type, used to identify bus to be used for a device.
  * @write: Write operation.
  * @gather_write: Write operation with split register/value, return -ENOTSUPP
  *                if not implemented  on a given device.
  * @read: Read operation.  Data is returned in the buffer used to transmit
  *         data.
- * @owner: Module with the bus implementation, used to pin the implementation
- *         in memory.
  * @read_flag_mask: Mask to be set in the top byte of the register when doing
  *                  a read.
  */
 struct regmap_bus {
-	struct list_head list;
-	struct bus_type *type;
 	regmap_hw_write write;
 	regmap_hw_gather_write gather_write;
 	regmap_hw_read read;
-	struct module *owner;
 	u8 read_flag_mask;
 };
 
@@ -79,4 +140,8 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 int regmap_update_bits(struct regmap *map, unsigned int reg,
 		       unsigned int mask, unsigned int val);
 
+int regcache_sync(struct regmap *map);
+void regcache_cache_only(struct regmap *map, bool enable);
+void regcache_cache_bypass(struct regmap *map, bool enable);
+
 #endif

include/trace/events/regmap.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM regmap
+
+#if !defined(_TRACE_REGMAP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_REGMAP_H
+
+#include <linux/device.h>
+#include <linux/ktime.h>
+#include <linux/tracepoint.h>
+
+struct regmap;
+
+/*
+ * Log register events
+ */
+DECLARE_EVENT_CLASS(regmap_reg,
+
+	TP_PROTO(struct device *dev, unsigned int reg,
+		 unsigned int val),
+
+	TP_ARGS(dev, reg, val),
+
+	TP_STRUCT__entry(
+		__string(	name,		dev_name(dev)	)
+		__field(	unsigned int,	reg		)
+		__field(	unsigned int,	val		)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, dev_name(dev));
+		__entry->reg = reg;
+		__entry->val = val;
+	),
+
+	TP_printk("%s reg=%x val=%x", __get_str(name),
+		  (unsigned int)__entry->reg,
+		  (unsigned int)__entry->val)
+);
+
+DEFINE_EVENT(regmap_reg, regmap_reg_write,
+
+	TP_PROTO(struct device *dev, unsigned int reg,
+		 unsigned int val),
+
+	TP_ARGS(dev, reg, val)
+
+);
+
+DEFINE_EVENT(regmap_reg, regmap_reg_read,
+
+	TP_PROTO(struct device *dev, unsigned int reg,
+		 unsigned int val),
+
+	TP_ARGS(dev, reg, val)
+
+);
+
+DECLARE_EVENT_CLASS(regmap_block,
+
+	TP_PROTO(struct device *dev, unsigned int reg, int count),
+
+	TP_ARGS(dev, reg, count),
+
+	TP_STRUCT__entry(
+		__string(	name,		dev_name(dev)	)
+		__field(	unsigned int,	reg		)
+		__field(	int,		count		)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, dev_name(dev));
+		__entry->reg = reg;
+		__entry->count = count;
+	),
+
+	TP_printk("%s reg=%x count=%d", __get_str(name),
+		  (unsigned int)__entry->reg,
+		  (int)__entry->count)
+);
+
+DEFINE_EVENT(regmap_block, regmap_hw_read_start,
+
+	TP_PROTO(struct device *dev, unsigned int reg, int count),
+
+	TP_ARGS(dev, reg, count)
+);
+
+DEFINE_EVENT(regmap_block, regmap_hw_read_done,
+
+	TP_PROTO(struct device *dev, unsigned int reg, int count),
+
+	TP_ARGS(dev, reg, count)
+);
+
+DEFINE_EVENT(regmap_block, regmap_hw_write_start,
+
+	TP_PROTO(struct device *dev, unsigned int reg, int count),
+
+	TP_ARGS(dev, reg, count)
+);
+
+DEFINE_EVENT(regmap_block, regmap_hw_write_done,
+
+	TP_PROTO(struct device *dev, unsigned int reg, int count),
+
+	TP_ARGS(dev, reg, count)
+);
+
+TRACE_EVENT(regcache_sync,
+
+	TP_PROTO(struct device *dev, const char *type,
+		 const char *status),
+
+	TP_ARGS(dev, type, status),
+
+	TP_STRUCT__entry(
+		__string(       name,           dev_name(dev)   )
+		__string(	status,		status		)
+		__string(	type,		type		)
+		__field(	int,		type		)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, dev_name(dev));
+		__assign_str(status, status);
+		__assign_str(type, type);
+	),
+
+	TP_printk("%s type=%s status=%s", __get_str(name),
+		  __get_str(type), __get_str(status))
+);
+
+#endif /* _TRACE_REGMAP_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>