M7350v1_en_gpl

kernel/drivers/base/regmap/Kconfig

@@ -0,0 +1,18 @@
+# Generic register map support.  There are no user servicable options here,
+# this is an API intended to be used by other kernel subsystems.  These
+# subsystems should select the appropriate symbols.
+
+config REGMAP
+	default y if (REGMAP_I2C || REGMAP_SPI)
+	select LZO_COMPRESS
+	select LZO_DECOMPRESS
+	bool
+
+config REGMAP_I2C
+	tristate
+
+config REGMAP_SPI
+	tristate
+
+config REGMAP_IRQ
+	bool

kernel/drivers/base/regmap/Makefile

@@ -0,0 +1,6 @@
+obj-$(CONFIG_REGMAP) += regmap.o regcache.o
+obj-$(CONFIG_REGMAP) += regcache-rbtree.o regcache-lzo.o
+obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o
+obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o
+obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o
+obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o

kernel/drivers/base/regmap/internal.h

@@ -0,0 +1,130 @@
+/*
+ * 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 pad_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 */
+	u32 cache_only;
+	/* if set, only the HW is modified not the cache */
+	u32 cache_bypass;
+	/* if set, remember to free reg_defaults_raw */
+	bool cache_free;
+
+	struct reg_default *reg_defaults;
+	const void *reg_defaults_raw;
+	void *cache;
+	u32 cache_dirty;
+
+	struct reg_default *patch;
+	int patch_regs;
+};
+
+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, unsigned int min, unsigned int max);
+};
+
+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, const struct regmap_config *config);
+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);
+
+extern struct regcache_ops regcache_rbtree_ops;
+extern struct regcache_ops regcache_lzo_ops;
+
+#endif

kernel/drivers/base/regmap/regcache-lzo.c

@@ -0,0 +1,379 @@
+/*
+ * 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/device.h>
+#include <linux/lzo.h>
+
+#include "internal.h"
+
+static int regcache_lzo_exit(struct regmap *map);
+
+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(struct regmap *map)
+{
+	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(map));
+}
+
+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)) /
+		      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(map));
+}
+
+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);
+	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_lzo_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(map);
+	/*
+	 * 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, unsigned int min,
+			     unsigned int max)
+{
+	struct regcache_lzo_ctx **lzo_blocks;
+	unsigned int val;
+	int i;
+	int ret;
+
+	lzo_blocks = map->cache;
+	i = min;
+	for_each_set_bit_from(i, lzo_blocks[0]->sync_bmp,
+			      lzo_blocks[0]->sync_bmp_nbits) {
+		if (i > max)
+			continue;
+
+		ret = regcache_read(map, i, &val);
+		if (ret)
+			return ret;
+
+		/* 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, 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_COMPRESSED,
+	.name = "lzo",
+	.init = regcache_lzo_init,
+	.exit = regcache_lzo_exit,
+	.read = regcache_lzo_read,
+	.write = regcache_lzo_write,
+	.sync = regcache_lzo_sync
+};

kernel/drivers/base/regmap/regcache-rbtree.c

@@ -0,0 +1,430 @@
+/*
+ * 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/device.h>
+#include <linux/debugfs.h>
+#include <linux/rbtree.h>
+#include <linux/seq_file.h>
+
+#include "internal.h"
+
+static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
+				 unsigned int value);
+static int regcache_rbtree_exit(struct regmap *map);
+
+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;
+}
+
+#ifdef CONFIG_DEBUG_FS
+static int rbtree_show(struct seq_file *s, void *ignored)
+{
+	struct regmap *map = s->private;
+	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
+	struct regcache_rbtree_node *n;
+	struct rb_node *node;
+	unsigned int base, top;
+	int nodes = 0;
+	int registers = 0;
+	int average;
+
+	mutex_lock(&map->lock);
+
+	for (node = rb_first(&rbtree_ctx->root); node != NULL;
+	     node = rb_next(node)) {
+		n = container_of(node, struct regcache_rbtree_node, node);
+
+		regcache_rbtree_get_base_top_reg(n, &base, &top);
+		seq_printf(s, "%x-%x (%d)\n", base, top, top - base + 1);
+
+		nodes++;
+		registers += top - base + 1;
+	}
+
+	if (nodes)
+		average = registers / nodes;
+	else
+		average = 0;
+
+	seq_printf(s, "%d nodes, %d registers, average %d registers\n",
+		   nodes, registers, average);
+
+	mutex_unlock(&map->lock);
+
+	return 0;
+}
+
+static int rbtree_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, rbtree_show, inode->i_private);
+}
+
+static const struct file_operations rbtree_fops = {
+	.open		= rbtree_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static void rbtree_debugfs_init(struct regmap *map)
+{
+	debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
+}
+#else
+static void rbtree_debugfs_init(struct regmap *map)
+{
+}
+#endif
+
+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;
+	}
+
+	rbtree_debugfs_init(map);
+
+	return 0;
+
+err:
+	regcache_rbtree_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, unsigned int min,
+				unsigned int max)
+{
+	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, base, end;
+
+	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);
+
+		if (rbnode->base_reg < min)
+			continue;
+		if (rbnode->base_reg > max)
+			break;
+		if (rbnode->base_reg + rbnode->blklen < min)
+			continue;
+
+		if (min > rbnode->base_reg)
+			base = min - rbnode->base_reg;
+		else
+			base = 0;
+
+		if (max < rbnode->base_reg + rbnode->blklen)
+			end = rbnode->base_reg + rbnode->blklen - max;
+		else
+			end = rbnode->blklen;
+
+		for (i = base; i < end; 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, regtmp);
+			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
+};

kernel/drivers/base/regmap/regcache.c

@@ -0,0 +1,491 @@
+/*
+ * 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 <linux/export.h>
+#include <linux/device.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_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) {
+		u32 cache_bypass = map->cache_bypass;
+		dev_warn(map->dev, "No cache defaults, reading back from HW\n");
+
+		/* Bypass the cache access till data read from HW*/
+		map->cache_bypass = 1;
+		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);
+		map->cache_bypass = cache_bypass;
+		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 (regmap_volatile(map, i))
+			continue;
+		count++;
+	}
+
+	map->reg_defaults = kmalloc(count * sizeof(struct reg_default),
+				      GFP_KERNEL);
+	if (!map->reg_defaults) {
+		ret = -ENOMEM;
+		goto err_free;
+	}
+
+	/* 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 (regmap_volatile(map, i))
+			continue;
+		map->reg_defaults[j].reg = i;
+		map->reg_defaults[j].def = val;
+		j++;
+	}
+
+	return 0;
+
+err_free:
+	if (map->cache_free)
+		kfree(map->reg_defaults_raw);
+
+	return ret;
+}
+
+int regcache_init(struct regmap *map, const struct regmap_config *config)
+{
+	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->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_word_size = DIV_ROUND_UP(config->val_bits, 8);
+	map->cache_size_raw = map->cache_word_size * config->num_reg_defaults_raw;
+
+	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 (config->reg_defaults) {
+		if (!map->num_reg_defaults)
+			return -EINVAL;
+		tmp_buf = kmemdup(config->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);
+		ret = map->cache_ops->init(map);
+		if (ret)
+			goto err_free;
+	}
+	return 0;
+
+err_free:
+	kfree(map->reg_defaults);
+	if (map->cache_free)
+		kfree(map->reg_defaults_raw);
+
+	return ret;
+}
+
+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)
+{
+	int ret;
+
+	if (map->cache_type == REGCACHE_NONE)
+		return -ENOSYS;
+
+	BUG_ON(!map->cache_ops);
+
+	if (!regmap_volatile(map, reg)) {
+		ret = map->cache_ops->read(map, reg, value);
+
+		if (ret == 0)
+			trace_regmap_reg_read_cache(map->dev, reg, *value);
+
+		return ret;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * 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;
+}
+
+/**
+ * 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 i;
+	const char *name;
+	unsigned int bypass;
+
+	BUG_ON(!map->cache_ops || !map->cache_ops->sync);
+
+	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_dirty)
+		goto out;
+
+	/* Apply any patch first */
+	map->cache_bypass = 1;
+	for (i = 0; i < map->patch_regs; i++) {
+		ret = _regmap_write(map, map->patch[i].reg, map->patch[i].def);
+		if (ret != 0) {
+			dev_err(map->dev, "Failed to write %x = %x: %d\n",
+				map->patch[i].reg, map->patch[i].def, ret);
+			goto out;
+		}
+	}
+	map->cache_bypass = 0;
+
+	ret = map->cache_ops->sync(map, 0, map->max_register);
+
+	if (ret == 0)
+		map->cache_dirty = false;
+
+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_sync_region: Sync part  of the register cache with the hardware.
+ *
+ * @map: map to sync.
+ * @min: first register to sync
+ * @max: last register to sync
+ *
+ * Write all non-default register values in the specified region to
+ * the hardware.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_sync_region(struct regmap *map, unsigned int min,
+			 unsigned int max)
+{
+	int ret = 0;
+	const char *name;
+	unsigned int bypass;
+
+	BUG_ON(!map->cache_ops || !map->cache_ops->sync);
+
+	mutex_lock(&map->lock);
+
+	/* Remember the initial bypass state */
+	bypass = map->cache_bypass;
+
+	name = map->cache_ops->name;
+	dev_dbg(map->dev, "Syncing %s cache from %d-%d\n", name, min, max);
+
+	trace_regcache_sync(map->dev, name, "start region");
+
+	if (!map->cache_dirty)
+		goto out;
+
+	ret = map->cache_ops->sync(map, min, max);
+
+out:
+	trace_regcache_sync(map->dev, name, "stop region");
+	/* Restore the bypass state */
+	map->cache_bypass = bypass;
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regcache_sync_region);
+
+/**
+ * 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;
+	trace_regmap_cache_only(map->dev, enable);
+	mutex_unlock(&map->lock);
+}
+EXPORT_SYMBOL_GPL(regcache_cache_only);
+
+/**
+ * regcache_mark_dirty: Mark the register cache as dirty
+ *
+ * @map: map to mark
+ *
+ * Mark the register cache as dirty, for example due to the device
+ * having been powered down for suspend.  If the cache is not marked
+ * as dirty then the cache sync will be suppressed.
+ */
+void regcache_mark_dirty(struct regmap *map)
+{
+	mutex_lock(&map->lock);
+	map->cache_dirty = true;
+	mutex_unlock(&map->lock);
+}
+EXPORT_SYMBOL_GPL(regcache_mark_dirty);
+
+/**
+ * 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;
+	trace_regmap_cache_bypass(map->dev, 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;
+	}
+	case 4: {
+		u32 *cache = base;
+		if (cache[idx] == val)
+			return true;
+		cache[idx] = val;
+		break;
+	}
+	default:
+		BUG();
+	}
+	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];
+	}
+	case 4: {
+		const u32 *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;
+}

kernel/drivers/base/regmap/regmap-debugfs.c

@@ -0,0 +1,286 @@
+/*
+ * 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/mutex.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/device.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 ssize_t regmap_name_read_file(struct file *file,
+				     char __user *user_buf, size_t count,
+				     loff_t *ppos)
+{
+	struct regmap *map = file->private_data;
+	int ret;
+	char *buf;
+
+	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = snprintf(buf, PAGE_SIZE, "%s\n", map->dev->driver->name);
+	if (ret < 0) {
+		kfree(buf);
+		return ret;
+	}
+
+	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+	kfree(buf);
+	return ret;
+}
+
+static const struct file_operations regmap_name_fops = {
+	.open = simple_open,
+	.read = regmap_name_read_file,
+	.llseek = default_llseek,
+};
+
+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;
+}
+
+#undef REGMAP_ALLOW_WRITE_DEBUGFS
+#ifdef REGMAP_ALLOW_WRITE_DEBUGFS
+/*
+ * This can be dangerous especially when we have clients such as
+ * PMICs, therefore don't provide any real compile time configuration option
+ * for this feature, people who want to use this will need to modify
+ * the source code directly.
+ */
+static ssize_t regmap_map_write_file(struct file *file,
+				     const char __user *user_buf,
+				     size_t count, loff_t *ppos)
+{
+	char buf[32];
+	size_t buf_size;
+	char *start = buf;
+	unsigned long reg, value;
+	struct regmap *map = file->private_data;
+
+	buf_size = min(count, (sizeof(buf)-1));
+	if (copy_from_user(buf, user_buf, buf_size))
+		return -EFAULT;
+	buf[buf_size] = 0;
+
+	while (*start == ' ')
+		start++;
+	reg = simple_strtoul(start, &start, 16);
+	while (*start == ' ')
+		start++;
+	if (strict_strtoul(start, 16, &value))
+		return -EINVAL;
+
+	/* Userspace has been fiddling around behind the kernel's back */
+	add_taint(TAINT_USER);
+
+	regmap_write(map, reg, value);
+	return buf_size;
+}
+#else
+#define regmap_map_write_file NULL
+#endif
+
+static const struct file_operations regmap_map_fops = {
+	.open = simple_open,
+	.read = regmap_map_read_file,
+	.write = regmap_map_write_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 = simple_open,
+	.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;
+	}
+
+	debugfs_create_file("name", 0400, map->debugfs,
+			    map, &regmap_name_fops);
+
+	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);
+	}
+
+	if (map->cache_type) {
+		debugfs_create_bool("cache_only", 0400, map->debugfs,
+				    &map->cache_only);
+		debugfs_create_bool("cache_dirty", 0400, map->debugfs,
+				    &map->cache_dirty);
+		debugfs_create_bool("cache_bypass", 0400, map->debugfs,
+				    &map->cache_bypass);
+	}
+}
+
+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;
+	}
+}

kernel/drivers/base/regmap/regmap-i2c.c

@@ -0,0 +1,131 @@
+/*
+ * Register map access API - I2C support
+ *
+ * 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/regmap.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+static int regmap_i2c_write(struct device *dev, const void *data, size_t count)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	int ret;
+
+	ret = i2c_master_send(i2c, data, count);
+	if (ret == count)
+		return 0;
+	else if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int regmap_i2c_gather_write(struct device *dev,
+				   const void *reg, size_t reg_size,
+				   const void *val, size_t val_size)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct i2c_msg xfer[2];
+	int ret;
+
+	/* If the I2C controller can't do a gather tell the core, it
+	 * will substitute in a linear write for us.
+	 */
+	if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_PROTOCOL_MANGLING))
+		return -ENOTSUPP;
+
+	xfer[0].addr = i2c->addr;
+	xfer[0].flags = 0;
+	xfer[0].len = reg_size;
+	xfer[0].buf = (void *)reg;
+
+	xfer[1].addr = i2c->addr;
+	xfer[1].flags = I2C_M_NOSTART;
+	xfer[1].len = val_size;
+	xfer[1].buf = (void *)val;
+
+	ret = i2c_transfer(i2c->adapter, xfer, 2);
+	if (ret == 2)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int regmap_i2c_read(struct device *dev,
+			   const void *reg, size_t reg_size,
+			   void *val, size_t val_size)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct i2c_msg xfer[2];
+	int ret;
+
+	xfer[0].addr = i2c->addr;
+	xfer[0].flags = 0;
+	xfer[0].len = reg_size;
+	xfer[0].buf = (void *)reg;
+
+	xfer[1].addr = i2c->addr;
+	xfer[1].flags = I2C_M_RD;
+	xfer[1].len = val_size;
+	xfer[1].buf = val;
+
+	ret = i2c_transfer(i2c->adapter, xfer, 2);
+	if (ret == 2)
+		return 0;
+	else if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static struct regmap_bus regmap_i2c = {
+	.write = regmap_i2c_write,
+	.gather_write = regmap_i2c_gather_write,
+	.read = regmap_i2c_read,
+};
+
+/**
+ * regmap_init_i2c(): Initialise register map
+ *
+ * @i2c: Device that will be interacted with
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer to
+ * a struct regmap.
+ */
+struct regmap *regmap_init_i2c(struct i2c_client *i2c,
+			       const struct regmap_config *config)
+{
+	return regmap_init(&i2c->dev, &regmap_i2c, config);
+}
+EXPORT_SYMBOL_GPL(regmap_init_i2c);
+
+/**
+ * devm_regmap_init_i2c(): Initialise managed register map
+ *
+ * @i2c: Device that will be interacted with
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer
+ * to a struct regmap.  The regmap will be automatically freed by the
+ * device management code.
+ */
+struct regmap *devm_regmap_init_i2c(struct i2c_client *i2c,
+				    const struct regmap_config *config)
+{
+	return devm_regmap_init(&i2c->dev, &regmap_i2c, config);
+}
+EXPORT_SYMBOL_GPL(devm_regmap_init_i2c);
+
+MODULE_LICENSE("GPL");

kernel/drivers/base/regmap/regmap-irq.c

@@ -0,0 +1,303 @@
+/*
+ * regmap based irq_chip
+ *
+ * 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/export.h>
+#include <linux/device.h>
+#include <linux/regmap.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+struct regmap_irq_chip_data {
+	struct mutex lock;
+
+	struct regmap *map;
+	struct regmap_irq_chip *chip;
+
+	int irq_base;
+
+	void *status_reg_buf;
+	unsigned int *status_buf;
+	unsigned int *mask_buf;
+	unsigned int *mask_buf_def;
+};
+
+static inline const
+struct regmap_irq *irq_to_regmap_irq(struct regmap_irq_chip_data *data,
+				     int irq)
+{
+	return &data->chip->irqs[irq - data->irq_base];
+}
+
+static void regmap_irq_lock(struct irq_data *data)
+{
+	struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
+
+	mutex_lock(&d->lock);
+}
+
+static void regmap_irq_sync_unlock(struct irq_data *data)
+{
+	struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
+	int i, ret;
+
+	/*
+	 * If there's been a change in the mask write it back to the
+	 * hardware.  We rely on the use of the regmap core cache to
+	 * suppress pointless writes.
+	 */
+	for (i = 0; i < d->chip->num_regs; i++) {
+		ret = regmap_update_bits(d->map, d->chip->mask_base + i,
+					 d->mask_buf_def[i], d->mask_buf[i]);
+		if (ret != 0)
+			dev_err(d->map->dev, "Failed to sync masks in %x\n",
+				d->chip->mask_base + i);
+	}
+
+	mutex_unlock(&d->lock);
+}
+
+static void regmap_irq_enable(struct irq_data *data)
+{
+	struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
+	const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->irq);
+
+	d->mask_buf[irq_data->reg_offset] &= ~irq_data->mask;
+}
+
+static void regmap_irq_disable(struct irq_data *data)
+{
+	struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
+	const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->irq);
+
+	d->mask_buf[irq_data->reg_offset] |= irq_data->mask;
+}
+
+static struct irq_chip regmap_irq_chip = {
+	.name			= "regmap",
+	.irq_bus_lock		= regmap_irq_lock,
+	.irq_bus_sync_unlock	= regmap_irq_sync_unlock,
+	.irq_disable		= regmap_irq_disable,
+	.irq_enable		= regmap_irq_enable,
+};
+
+static irqreturn_t regmap_irq_thread(int irq, void *d)
+{
+	struct regmap_irq_chip_data *data = d;
+	struct regmap_irq_chip *chip = data->chip;
+	struct regmap *map = data->map;
+	int ret, i;
+	u8 *buf8 = data->status_reg_buf;
+	u16 *buf16 = data->status_reg_buf;
+	u32 *buf32 = data->status_reg_buf;
+	bool handled = false;
+
+	ret = regmap_bulk_read(map, chip->status_base, data->status_reg_buf,
+			       chip->num_regs);
+	if (ret != 0) {
+		dev_err(map->dev, "Failed to read IRQ status: %d\n", ret);
+		return IRQ_NONE;
+	}
+
+	/*
+	 * Ignore masked IRQs and ack if we need to; we ack early so
+	 * there is no race between handling and acknowleding the
+	 * interrupt.  We assume that typically few of the interrupts
+	 * will fire simultaneously so don't worry about overhead from
+	 * doing a write per register.
+	 */
+	for (i = 0; i < data->chip->num_regs; i++) {
+		switch (map->format.val_bytes) {
+		case 1:
+			data->status_buf[i] = buf8[i];
+			break;
+		case 2:
+			data->status_buf[i] = buf16[i];
+			break;
+		case 4:
+			data->status_buf[i] = buf32[i];
+			break;
+		default:
+			BUG();
+			return IRQ_NONE;
+		}
+
+		data->status_buf[i] &= ~data->mask_buf[i];
+
+		if (data->status_buf[i] && chip->ack_base) {
+			ret = regmap_write(map, chip->ack_base + i,
+					   data->status_buf[i]);
+			if (ret != 0)
+				dev_err(map->dev, "Failed to ack 0x%x: %d\n",
+					chip->ack_base + i, ret);
+		}
+	}
+
+	for (i = 0; i < chip->num_irqs; i++) {
+		if (data->status_buf[chip->irqs[i].reg_offset] &
+		    chip->irqs[i].mask) {
+			handle_nested_irq(data->irq_base + i);
+			handled = true;
+		}
+	}
+
+	if (handled)
+		return IRQ_HANDLED;
+	else
+		return IRQ_NONE;
+}
+
+/**
+ * regmap_add_irq_chip(): Use standard regmap IRQ controller handling
+ *
+ * map:       The regmap for the device.
+ * irq:       The IRQ the device uses to signal interrupts
+ * irq_flags: The IRQF_ flags to use for the primary interrupt.
+ * chip:      Configuration for the interrupt controller.
+ * data:      Runtime data structure for the controller, allocated on success
+ *
+ * Returns 0 on success or an errno on failure.
+ *
+ * In order for this to be efficient the chip really should use a
+ * register cache.  The chip driver is responsible for restoring the
+ * register values used by the IRQ controller over suspend and resume.
+ */
+int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
+			int irq_base, struct regmap_irq_chip *chip,
+			struct regmap_irq_chip_data **data)
+{
+	struct regmap_irq_chip_data *d;
+	int cur_irq, i;
+	int ret = -ENOMEM;
+
+	irq_base = irq_alloc_descs(irq_base, 0, chip->num_irqs, 0);
+	if (irq_base < 0) {
+		dev_warn(map->dev, "Failed to allocate IRQs: %d\n",
+			 irq_base);
+		return irq_base;
+	}
+
+	d = kzalloc(sizeof(*d), GFP_KERNEL);
+	if (!d)
+		return -ENOMEM;
+
+	d->status_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
+				GFP_KERNEL);
+	if (!d->status_buf)
+		goto err_alloc;
+
+	d->status_reg_buf = kzalloc(map->format.val_bytes * chip->num_regs,
+				    GFP_KERNEL);
+	if (!d->status_reg_buf)
+		goto err_alloc;
+
+	d->mask_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
+			      GFP_KERNEL);
+	if (!d->mask_buf)
+		goto err_alloc;
+
+	d->mask_buf_def = kzalloc(sizeof(unsigned int) * chip->num_regs,
+				  GFP_KERNEL);
+	if (!d->mask_buf_def)
+		goto err_alloc;
+
+	d->map = map;
+	d->chip = chip;
+	d->irq_base = irq_base;
+	mutex_init(&d->lock);
+
+	for (i = 0; i < chip->num_irqs; i++)
+		d->mask_buf_def[chip->irqs[i].reg_offset]
+			|= chip->irqs[i].mask;
+
+	/* Mask all the interrupts by default */
+	for (i = 0; i < chip->num_regs; i++) {
+		d->mask_buf[i] = d->mask_buf_def[i];
+		ret = regmap_write(map, chip->mask_base + i, d->mask_buf[i]);
+		if (ret != 0) {
+			dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
+				chip->mask_base + i, ret);
+			goto err_alloc;
+		}
+	}
+
+	/* Register them with genirq */
+	for (cur_irq = irq_base;
+	     cur_irq < chip->num_irqs + irq_base;
+	     cur_irq++) {
+		irq_set_chip_data(cur_irq, d);
+		irq_set_chip_and_handler(cur_irq, &regmap_irq_chip,
+					 handle_edge_irq);
+		irq_set_nested_thread(cur_irq, 1);
+
+		/* ARM needs us to explicitly flag the IRQ as valid
+		 * and will set them noprobe when we do so. */
+#ifdef CONFIG_ARM
+		set_irq_flags(cur_irq, IRQF_VALID);
+#else
+		irq_set_noprobe(cur_irq);
+#endif
+	}
+
+	ret = request_threaded_irq(irq, NULL, regmap_irq_thread, irq_flags,
+				   chip->name, d);
+	if (ret != 0) {
+		dev_err(map->dev, "Failed to request IRQ %d: %d\n", irq, ret);
+		goto err_alloc;
+	}
+
+	return 0;
+
+err_alloc:
+	kfree(d->mask_buf_def);
+	kfree(d->mask_buf);
+	kfree(d->status_reg_buf);
+	kfree(d->status_buf);
+	kfree(d);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_add_irq_chip);
+
+/**
+ * regmap_del_irq_chip(): Stop interrupt handling for a regmap IRQ chip
+ *
+ * @irq: Primary IRQ for the device
+ * @d:   regmap_irq_chip_data allocated by regmap_add_irq_chip()
+ */
+void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *d)
+{
+	if (!d)
+		return;
+
+	free_irq(irq, d);
+	kfree(d->mask_buf_def);
+	kfree(d->mask_buf);
+	kfree(d->status_reg_buf);
+	kfree(d->status_buf);
+	kfree(d);
+}
+EXPORT_SYMBOL_GPL(regmap_del_irq_chip);
+
+/**
+ * regmap_irq_chip_get_base(): Retrieve interrupt base for a regmap IRQ chip
+ *
+ * Useful for drivers to request their own IRQs.
+ *
+ * @data: regmap_irq controller to operate on.
+ */
+int regmap_irq_chip_get_base(struct regmap_irq_chip_data *data)
+{
+	return data->irq_base;
+}
+EXPORT_SYMBOL_GPL(regmap_irq_chip_get_base);

kernel/drivers/base/regmap/regmap-spi.c

@@ -0,0 +1,90 @@
+/*
+ * Register map access API - SPI support
+ *
+ * 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/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/init.h>
+#include <linux/module.h>
+
+static int regmap_spi_write(struct device *dev, const void *data, size_t count)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	return spi_write(spi, data, count);
+}
+
+static int regmap_spi_gather_write(struct device *dev,
+				   const void *reg, size_t reg_len,
+				   const void *val, size_t val_len)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct spi_message m;
+	struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
+				     { .tx_buf = val, .len = val_len, }, };
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t[0], &m);
+	spi_message_add_tail(&t[1], &m);
+
+	return spi_sync(spi, &m);
+}
+
+static int regmap_spi_read(struct device *dev,
+			   const void *reg, size_t reg_size,
+			   void *val, size_t val_size)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	return spi_write_then_read(spi, reg, reg_size, val, val_size);
+}
+
+static struct regmap_bus regmap_spi = {
+	.write = regmap_spi_write,
+	.gather_write = regmap_spi_gather_write,
+	.read = regmap_spi_read,
+	.read_flag_mask = 0x80,
+};
+
+/**
+ * regmap_init_spi(): Initialise register map
+ *
+ * @spi: Device that will be interacted with
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer to
+ * a struct regmap.
+ */
+struct regmap *regmap_init_spi(struct spi_device *spi,
+			       const struct regmap_config *config)
+{
+	return regmap_init(&spi->dev, &regmap_spi, config);
+}
+EXPORT_SYMBOL_GPL(regmap_init_spi);
+
+/**
+ * devm_regmap_init_spi(): Initialise register map
+ *
+ * @spi: Device that will be interacted with
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer
+ * to a struct regmap.  The map will be automatically freed by the
+ * device management code.
+ */
+struct regmap *devm_regmap_init_spi(struct spi_device *spi,
+				    const struct regmap_config *config)
+{
+	return devm_regmap_init(&spi->dev, &regmap_spi, config);
+}
+EXPORT_SYMBOL_GPL(devm_regmap_init_spi);
+
+MODULE_LICENSE("GPL");

kernel/drivers/base/regmap/regmap.c

@@ -0,0 +1,936 @@
+/*
+ * Register map access API
+ *
+ * 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/device.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+
+#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->format.format_write)
+		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 (!regmap_readable(map, reg))
+		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 (!regmap_readable(map, reg))
+		return false;
+
+	if (map->precious_reg)
+		return map->precious_reg(map->dev, reg);
+
+	return false;
+}
+
+static bool regmap_volatile_range(struct regmap *map, unsigned int reg,
+	unsigned int num)
+{
+	unsigned int i;
+
+	for (i = 0; i < num; i++)
+		if (!regmap_volatile(map, reg + i))
+			return false;
+
+	return true;
+}
+
+static void regmap_format_2_6_write(struct regmap *map,
+				     unsigned int reg, unsigned int val)
+{
+	u8 *out = map->work_buf;
+
+	*out = (reg << 6) | val;
+}
+
+static void regmap_format_4_12_write(struct regmap *map,
+				     unsigned int reg, unsigned int val)
+{
+	__be16 *out = map->work_buf;
+	*out = cpu_to_be16((reg << 12) | val);
+}
+
+static void regmap_format_7_9_write(struct regmap *map,
+				    unsigned int reg, unsigned int val)
+{
+	__be16 *out = map->work_buf;
+	*out = cpu_to_be16((reg << 9) | val);
+}
+
+static void regmap_format_10_14_write(struct regmap *map,
+				    unsigned int reg, unsigned int val)
+{
+	u8 *out = map->work_buf;
+
+	out[2] = val;
+	out[1] = (val >> 8) | (reg << 6);
+	out[0] = reg >> 2;
+}
+
+static void regmap_format_8(void *buf, unsigned int val)
+{
+	u8 *b = buf;
+
+	b[0] = val;
+}
+
+static void regmap_format_16(void *buf, unsigned int val)
+{
+	__be16 *b = buf;
+
+	b[0] = cpu_to_be16(val);
+}
+
+static void regmap_format_32(void *buf, unsigned int val)
+{
+	__be32 *b = buf;
+
+	b[0] = cpu_to_be32(val);
+}
+
+static unsigned int regmap_parse_8(void *buf)
+{
+	u8 *b = buf;
+
+	return b[0];
+}
+
+static unsigned int regmap_parse_16(void *buf)
+{
+	__be16 *b = buf;
+
+	b[0] = be16_to_cpu(b[0]);
+
+	return b[0];
+}
+
+static unsigned int regmap_parse_32(void *buf)
+{
+	__be32 *b = buf;
+
+	b[0] = be32_to_cpu(b[0]);
+
+	return b[0];
+}
+
+/**
+ * regmap_init(): Initialise register map
+ *
+ * @dev: Device that will be interacted with
+ * @bus: Bus-specific callbacks to use with device
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer to
+ * a struct regmap.  This function should generally not be called
+ * directly, it should be called by bus-specific init functions.
+ */
+struct regmap *regmap_init(struct device *dev,
+			   const struct regmap_bus *bus,
+			   const struct regmap_config *config)
+{
+	struct regmap *map;
+	int ret = -EINVAL;
+
+	if (!bus || !config)
+		goto err;
+
+	map = kzalloc(sizeof(*map), GFP_KERNEL);
+	if (map == NULL) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mutex_init(&map->lock);
+	map->format.buf_size = (config->reg_bits + config->val_bits) / 8;
+	map->format.reg_bytes = DIV_ROUND_UP(config->reg_bits, 8);
+	map->format.pad_bytes = config->pad_bits / 8;
+	map->format.val_bytes = DIV_ROUND_UP(config->val_bits, 8);
+	map->format.buf_size += map->format.pad_bytes;
+	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;
+
+	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 2:
+		switch (config->val_bits) {
+		case 6:
+			map->format.format_write = regmap_format_2_6_write;
+			break;
+		default:
+			goto err_map;
+		}
+		break;
+
+	case 4:
+		switch (config->val_bits) {
+		case 12:
+			map->format.format_write = regmap_format_4_12_write;
+			break;
+		default:
+			goto err_map;
+		}
+		break;
+
+	case 7:
+		switch (config->val_bits) {
+		case 9:
+			map->format.format_write = regmap_format_7_9_write;
+			break;
+		default:
+			goto err_map;
+		}
+		break;
+
+	case 10:
+		switch (config->val_bits) {
+		case 14:
+			map->format.format_write = regmap_format_10_14_write;
+			break;
+		default:
+			goto err_map;
+		}
+		break;
+
+	case 8:
+		map->format.format_reg = regmap_format_8;
+		break;
+
+	case 16:
+		map->format.format_reg = regmap_format_16;
+		break;
+
+	case 32:
+		map->format.format_reg = regmap_format_32;
+		break;
+
+	default:
+		goto err_map;
+	}
+
+	switch (config->val_bits) {
+	case 8:
+		map->format.format_val = regmap_format_8;
+		map->format.parse_val = regmap_parse_8;
+		break;
+	case 16:
+		map->format.format_val = regmap_format_16;
+		map->format.parse_val = regmap_parse_16;
+		break;
+	case 32:
+		map->format.format_val = regmap_format_32;
+		map->format.parse_val = regmap_parse_32;
+		break;
+	}
+
+	if (!map->format.format_write &&
+	    !(map->format.format_reg && map->format.format_val))
+		goto err_map;
+
+	map->work_buf = kzalloc(map->format.buf_size, GFP_KERNEL);
+	if (map->work_buf == NULL) {
+		ret = -ENOMEM;
+		goto err_map;
+	}
+
+	regmap_debugfs_init(map);
+
+	ret = regcache_init(map, config);
+	if (ret < 0)
+		goto err_free_workbuf;
+
+	return map;
+
+err_free_workbuf:
+	kfree(map->work_buf);
+err_map:
+	kfree(map);
+err:
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(regmap_init);
+
+static void devm_regmap_release(struct device *dev, void *res)
+{
+	regmap_exit(*(struct regmap **)res);
+}
+
+/**
+ * devm_regmap_init(): Initialise managed register map
+ *
+ * @dev: Device that will be interacted with
+ * @bus: Bus-specific callbacks to use with device
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer
+ * to a struct regmap.  This function should generally not be called
+ * directly, it should be called by bus-specific init functions.  The
+ * map will be automatically freed by the device management code.
+ */
+struct regmap *devm_regmap_init(struct device *dev,
+				const struct regmap_bus *bus,
+				const struct regmap_config *config)
+{
+	struct regmap **ptr, *regmap;
+
+	ptr = devres_alloc(devm_regmap_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	regmap = regmap_init(dev, bus, config);
+	if (!IS_ERR(regmap)) {
+		*ptr = regmap;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return regmap;
+}
+EXPORT_SYMBOL_GPL(devm_regmap_init);
+
+/**
+ * regmap_reinit_cache(): Reinitialise the current register cache
+ *
+ * @map: Register map to operate on.
+ * @config: New configuration.  Only the cache data will be used.
+ *
+ * Discard any existing register cache for the map and initialize a
+ * new cache.  This can be used to restore the cache to defaults or to
+ * update the cache configuration to reflect runtime discovery of the
+ * hardware.
+ */
+int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
+{
+	int ret;
+
+	mutex_lock(&map->lock);
+
+	regcache_exit(map);
+	regmap_debugfs_exit(map);
+
+	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;
+
+	regmap_debugfs_init(map);
+
+	map->cache_bypass = false;
+	map->cache_only = false;
+
+	ret = regcache_init(map, config);
+
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+
+/**
+ * regmap_exit(): Free a previously allocated register map
+ */
+void regmap_exit(struct regmap *map)
+{
+	regcache_exit(map);
+	regmap_debugfs_exit(map);
+	kfree(map->work_buf);
+	kfree(map);
+}
+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;
+
+	if (!map->cache_bypass && map->format.parse_val) {
+		unsigned int ival;
+		int val_bytes = map->format.val_bytes;
+		for (i = 0; i < val_len / val_bytes; i++) {
+			memcpy(map->work_buf, val + (i * val_bytes), val_bytes);
+			ival = map->format.parse_val(map->work_buf);
+			ret = regcache_write(map, reg + i, ival);
+			if (ret) {
+				dev_err(map->dev,
+				   "Error in caching of register: %u ret: %d\n",
+					reg + i, ret);
+				return ret;
+			}
+		}
+		if (map->cache_only) {
+			map->cache_dirty = true;
+			return 0;
+		}
+	}
+
+	map->format.format_reg(map->work_buf, reg);
+
+	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.pad_bytes +
+		    map->format.reg_bytes))
+		ret = map->bus->write(map->dev, map->work_buf,
+				      map->format.reg_bytes +
+				      map->format.pad_bytes +
+				      val_len);
+	else if (map->bus->gather_write)
+		ret = map->bus->gather_write(map->dev, map->work_buf,
+					     map->format.reg_bytes +
+					     map->format.pad_bytes,
+					     val, val_len);
+
+	/* If that didn't work fall back on linearising by hand. */
+	if (ret == -ENOTSUPP) {
+		len = map->format.reg_bytes + map->format.pad_bytes + val_len;
+		buf = kzalloc(len, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
+
+		memcpy(buf, map->work_buf, map->format.reg_bytes);
+		memcpy(buf + map->format.reg_bytes + map->format.pad_bytes,
+		       val, val_len);
+		ret = map->bus->write(map->dev, buf, len);
+
+		kfree(buf);
+	}
+
+	trace_regmap_hw_write_done(map->dev, reg,
+				   val_len / map->format.val_bytes);
+
+	return ret;
+}
+
+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 && map->format.format_write) {
+		ret = regcache_write(map, reg, val);
+		if (ret != 0)
+			return ret;
+		if (map->cache_only) {
+			map->cache_dirty = true;
+			return 0;
+		}
+	}
+
+	trace_regmap_reg_write(map->dev, reg, val);
+
+	if (map->format.format_write) {
+		map->format.format_write(map, reg, val);
+
+		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
+				       + map->format.pad_bytes, val);
+		return _regmap_raw_write(map, reg,
+					 map->work_buf +
+					 map->format.reg_bytes +
+					 map->format.pad_bytes,
+					 map->format.val_bytes);
+	}
+}
+
+/**
+ * regmap_write(): Write a value to a single register
+ *
+ * @map: Register map to write to
+ * @reg: Register to write to
+ * @val: Value to be written
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
+{
+	int ret;
+
+	mutex_lock(&map->lock);
+
+	ret = _regmap_write(map, reg, val);
+
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_write);
+
+/**
+ * regmap_raw_write(): Write raw values to one or more registers
+ *
+ * @map: Register map to write to
+ * @reg: Initial register to write to
+ * @val: Block of data to be written, laid out for direct transmission to the
+ *       device
+ * @val_len: Length of data pointed to by val.
+ *
+ * This function is intended to be used for things like firmware
+ * download where a large block of data needs to be transferred to the
+ * device.  No formatting will be done on the data provided.
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_raw_write(struct regmap *map, unsigned int reg,
+		     const void *val, size_t val_len)
+{
+	int ret;
+
+	mutex_lock(&map->lock);
+
+	ret = _regmap_raw_write(map, reg, val, val_len);
+
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_raw_write);
+
+/*
+ * regmap_bulk_write(): Write multiple registers to the device
+ *
+ * @map: Register map to write to
+ * @reg: First register to be write from
+ * @val: Block of data to be written, in native register size for device
+ * @val_count: Number of registers to write
+ *
+ * This function is intended to be used for writing a large block of
+ * data to be device either in single transfer or multiple transfer.
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
+		     size_t val_count)
+{
+	int ret = 0, i;
+	size_t val_bytes = map->format.val_bytes;
+	void *wval;
+
+	if (!map->format.parse_val)
+		return -EINVAL;
+
+	mutex_lock(&map->lock);
+
+	/* No formatting is require if val_byte is 1 */
+	if (val_bytes == 1) {
+		wval = (void *)val;
+	} else {
+		wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
+		if (!wval) {
+			ret = -ENOMEM;
+			dev_err(map->dev, "Error in memory allocation\n");
+			goto out;
+		}
+		for (i = 0; i < val_count * val_bytes; i += val_bytes)
+			map->format.parse_val(wval + i);
+	}
+	ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);
+
+	if (val_bytes != 1)
+		kfree(wval);
+
+out:
+	mutex_unlock(&map->lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_bulk_write);
+
+static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
+			    unsigned int val_len)
+{
+	u8 *u8 = map->work_buf;
+	int ret;
+
+	map->format.format_reg(map->work_buf, reg);
+
+	/*
+	 * 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.
+	 */
+	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 + map->format.pad_bytes,
+			     val, val_len);
+
+	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,
+			unsigned int *val)
+{
+	int ret;
+
+	if (!map->cache_bypass) {
+		ret = regcache_read(map, reg, val);
+		if (ret == 0)
+			return 0;
+	}
+
+	if (!map->format.parse_val)
+		return -EINVAL;
+
+	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;
+}
+
+/**
+ * regmap_read(): Read a value from a single register
+ *
+ * @map: Register map to write to
+ * @reg: Register to be read from
+ * @val: Pointer to store read value
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
+{
+	int ret;
+
+	mutex_lock(&map->lock);
+
+	ret = _regmap_read(map, reg, val);
+
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_read);
+
+/**
+ * regmap_raw_read(): Read raw data from the device
+ *
+ * @map: Register map to write to
+ * @reg: First register to be read from
+ * @val: Pointer to store read value
+ * @val_len: Size of data to read
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
+		    size_t val_len)
+{
+	size_t val_bytes = map->format.val_bytes;
+	size_t val_count = val_len / val_bytes;
+	unsigned int v;
+	int ret, i;
+
+	mutex_lock(&map->lock);
+
+	if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
+	    map->cache_type == REGCACHE_NONE) {
+		/* Physical block read if there's no cache involved */
+		ret = _regmap_raw_read(map, reg, val, val_len);
+
+	} else {
+		/* Otherwise go word by word for the cache; should be low
+		 * cost as we expect to hit the cache.
+		 */
+		for (i = 0; i < val_count; i++) {
+			ret = _regmap_read(map, reg + i, &v);
+			if (ret != 0)
+				goto out;
+
+			map->format.format_val(val + (i * val_bytes), v);
+		}
+	}
+
+ out:
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_raw_read);
+
+/**
+ * regmap_bulk_read(): Read multiple registers from the device
+ *
+ * @map: Register map to write to
+ * @reg: First register to be read from
+ * @val: Pointer to store read value, in native register size for device
+ * @val_count: Number of registers to read
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
+		     size_t val_count)
+{
+	int ret, i;
+	size_t val_bytes = map->format.val_bytes;
+	bool vol = regmap_volatile_range(map, reg, val_count);
+
+	if (!map->format.parse_val)
+		return -EINVAL;
+
+	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++) {
+			unsigned int ival;
+			ret = regmap_read(map, reg + i, &ival);
+			if (ret != 0)
+				return ret;
+			memcpy(val + (i * val_bytes), &ival, val_bytes);
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(regmap_bulk_read);
+
+static int _regmap_update_bits(struct regmap *map, unsigned int reg,
+			       unsigned int mask, unsigned int val,
+			       bool *change)
+{
+	int ret;
+	unsigned int tmp, orig;
+
+	mutex_lock(&map->lock);
+
+	ret = _regmap_read(map, reg, &orig);
+	if (ret != 0)
+		goto out;
+
+	tmp = orig & ~mask;
+	tmp |= val & mask;
+
+	if (tmp != orig) {
+		ret = _regmap_write(map, reg, tmp);
+		*change = true;
+	} else {
+		*change = false;
+	}
+
+out:
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+
+/**
+ * regmap_update_bits: Perform a read/modify/write cycle on the register map
+ *
+ * @map: Register map to update
+ * @reg: Register to update
+ * @mask: Bitmask to change
+ * @val: New value for bitmask
+ *
+ * Returns zero for success, a negative number on error.
+ */
+int regmap_update_bits(struct regmap *map, unsigned int reg,
+		       unsigned int mask, unsigned int val)
+{
+	bool change;
+	return _regmap_update_bits(map, reg, mask, val, &change);
+}
+EXPORT_SYMBOL_GPL(regmap_update_bits);
+
+/**
+ * regmap_update_bits_check: Perform a read/modify/write cycle on the
+ *                           register map and report if updated
+ *
+ * @map: Register map to update
+ * @reg: Register to update
+ * @mask: Bitmask to change
+ * @val: New value for bitmask
+ * @change: Boolean indicating if a write was done
+ *
+ * Returns zero for success, a negative number on error.
+ */
+int regmap_update_bits_check(struct regmap *map, unsigned int reg,
+			     unsigned int mask, unsigned int val,
+			     bool *change)
+{
+	return _regmap_update_bits(map, reg, mask, val, change);
+}
+EXPORT_SYMBOL_GPL(regmap_update_bits_check);
+
+/**
+ * regmap_register_patch: Register and apply register updates to be applied
+ *                        on device initialistion
+ *
+ * @map: Register map to apply updates to.
+ * @regs: Values to update.
+ * @num_regs: Number of entries in regs.
+ *
+ * Register a set of register updates to be applied to the device
+ * whenever the device registers are synchronised with the cache and
+ * apply them immediately.  Typically this is used to apply
+ * corrections to be applied to the device defaults on startup, such
+ * as the updates some vendors provide to undocumented registers.
+ */
+int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
+			  int num_regs)
+{
+	int i, ret;
+	bool bypass;
+
+	/* If needed the implementation can be extended to support this */
+	if (map->patch)
+		return -EBUSY;
+
+	mutex_lock(&map->lock);
+
+	bypass = map->cache_bypass;
+
+	map->cache_bypass = true;
+
+	/* Write out first; it's useful to apply even if we fail later. */
+	for (i = 0; i < num_regs; i++) {
+		ret = _regmap_write(map, regs[i].reg, regs[i].def);
+		if (ret != 0) {
+			dev_err(map->dev, "Failed to write %x = %x: %d\n",
+				regs[i].reg, regs[i].def, ret);
+			goto out;
+		}
+	}
+
+	map->patch = kcalloc(num_regs, sizeof(struct reg_default), GFP_KERNEL);
+	if (map->patch != NULL) {
+		memcpy(map->patch, regs,
+		       num_regs * sizeof(struct reg_default));
+		map->patch_regs = num_regs;
+	} else {
+		ret = -ENOMEM;
+	}
+
+out:
+	map->cache_bypass = bypass;
+
+	mutex_unlock(&map->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_register_patch);
+
+/*
+ * regmap_get_val_bytes(): Report the size of a register value
+ *
+ * Report the size of a register value, mainly intended to for use by
+ * generic infrastructure built on top of regmap.
+ */
+int regmap_get_val_bytes(struct regmap *map)
+{
+	if (map->format.format_write)
+		return -EINVAL;
+
+	return map->format.val_bytes;
+}
+EXPORT_SYMBOL_GPL(regmap_get_val_bytes);
+
+static int __init regmap_initcall(void)
+{
+	regmap_debugfs_initcall();
+
+	return 0;
+}
+postcore_initcall(regmap_initcall);