[deliverable/linux.git] / 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/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;

	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;
	}

	seq_printf(s, "%d nodes, %d registers, average %d registers\n",
		   nodes, registers, registers / nodes);

	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, 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
};
Commit	Line	Data
28644c80 DP	1	/*
	2	* Register cache access API - rbtree caching support
	3	*
	4	* Copyright 2011 Wolfson Microelectronics plc
	5	*
	6	* Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/slab.h>
bad2ab4b	14	#include <linux/debugfs.h>
28644c80	15	#include <linux/rbtree.h>
bad2ab4b	16	#include <linux/seq_file.h>
28644c80 DP	17
	18	#include "internal.h"
	19
	20	static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
	21	unsigned int value);
462a185c	22	static int regcache_rbtree_exit(struct regmap *map);
28644c80 DP	23
	24	struct regcache_rbtree_node {
	25	/* the actual rbtree node holding this block */
	26	struct rb_node node;
	27	/* base register handled by this block */
	28	unsigned int base_reg;
28644c80 DP	29	/* block of adjacent registers */
	30	void *block;
	31	/* number of registers available in the block */
	32	unsigned int blklen;
	33	} __attribute__ ((packed));
	34
	35	struct regcache_rbtree_ctx {
	36	struct rb_root root;
	37	struct regcache_rbtree_node *cached_rbnode;
	38	};
	39
	40	static inline void regcache_rbtree_get_base_top_reg(
	41	struct regcache_rbtree_node *rbnode,
	42	unsigned int base, unsigned int top)
	43	{
	44	*base = rbnode->base_reg;
	45	*top = rbnode->base_reg + rbnode->blklen - 1;
	46	}
	47
	48	static unsigned int regcache_rbtree_get_register(
25ed1156 DP	49	struct regcache_rbtree_node *rbnode, unsigned int idx,
25ed1156 DP	50	unsigned int word_size)
28644c80	51	{
c5713004	52	return regcache_get_val(rbnode->block, idx, word_size);
28644c80 DP	53	}
	54
	55	static void regcache_rbtree_set_register(struct regcache_rbtree_node *rbnode,
25ed1156 DP	56	unsigned int idx, unsigned int val,
25ed1156 DP	57	unsigned int word_size)
28644c80	58	{
c5713004	59	regcache_set_val(rbnode->block, idx, val, word_size);
28644c80 DP	60	}
28644c80 DP	61
3405addd LPC	62	static struct regcache_rbtree_node regcache_rbtree_lookup(struct regmap map,
3405addd LPC	63	unsigned int reg)
28644c80	64	{
3405addd	65	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
28644c80 DP	66	struct rb_node *node;
	67	struct regcache_rbtree_node *rbnode;
	68	unsigned int base_reg, top_reg;
	69
3405addd LPC	70	rbnode = rbtree_ctx->cached_rbnode;
	71	if (rbnode) {
	72	regcache_rbtree_get_base_top_reg(rbnode, &base_reg, &top_reg);
	73	if (reg >= base_reg && reg <= top_reg)
	74	return rbnode;
	75	}
	76
	77	node = rbtree_ctx->root.rb_node;
28644c80 DP	78	while (node) {
	79	rbnode = container_of(node, struct regcache_rbtree_node, node);
	80	regcache_rbtree_get_base_top_reg(rbnode, &base_reg, &top_reg);
3405addd LPC	81	if (reg >= base_reg && reg <= top_reg) {
3405addd LPC	82	rbtree_ctx->cached_rbnode = rbnode;
28644c80	83	return rbnode;
3405addd	84	} else if (reg > top_reg) {
28644c80	85	node = node->rb_right;
3405addd	86	} else if (reg < base_reg) {
28644c80	87	node = node->rb_left;
3405addd	88	}
28644c80 DP	89	}
	90
	91	return NULL;
	92	}
	93
	94	static int regcache_rbtree_insert(struct rb_root *root,
	95	struct regcache_rbtree_node *rbnode)
	96	{
	97	struct rb_node *new, parent;
	98	struct regcache_rbtree_node *rbnode_tmp;
	99	unsigned int base_reg_tmp, top_reg_tmp;
	100	unsigned int base_reg;
	101
	102	parent = NULL;
	103	new = &root->rb_node;
	104	while (*new) {
	105	rbnode_tmp = container_of(*new, struct regcache_rbtree_node,
	106	node);
	107	/* base and top registers of the current rbnode */
	108	regcache_rbtree_get_base_top_reg(rbnode_tmp, &base_reg_tmp,
	109	&top_reg_tmp);
	110	/* base register of the rbnode to be added */
	111	base_reg = rbnode->base_reg;
	112	parent = *new;
	113	/* if this register has already been inserted, just return */
	114	if (base_reg >= base_reg_tmp &&
	115	base_reg <= top_reg_tmp)
	116	return 0;
	117	else if (base_reg > top_reg_tmp)
	118	new = &((*new)->rb_right);
	119	else if (base_reg < base_reg_tmp)
	120	new = &((*new)->rb_left);
	121	}
	122
	123	/* insert the node into the rbtree */
	124	rb_link_node(&rbnode->node, parent, new);
	125	rb_insert_color(&rbnode->node, root);
	126
	127	return 1;
	128	}
	129
bad2ab4b MB	130	#ifdef CONFIG_DEBUG_FS
	131	static int rbtree_show(struct seq_file s, void ignored)
	132	{
	133	struct regmap *map = s->private;
	134	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
	135	struct regcache_rbtree_node *n;
	136	struct rb_node *node;
	137	unsigned int base, top;
	138	int nodes = 0;
	139	int registers = 0;
	140
	141	mutex_lock(&map->lock);
	142
	143	for (node = rb_first(&rbtree_ctx->root); node != NULL;
	144	node = rb_next(node)) {
	145	n = container_of(node, struct regcache_rbtree_node, node);
	146
	147	regcache_rbtree_get_base_top_reg(n, &base, &top);
	148	seq_printf(s, "%x-%x (%d)\n", base, top, top - base + 1);
	149
	150	nodes++;
	151	registers += top - base + 1;
	152	}
	153
	154	seq_printf(s, "%d nodes, %d registers, average %d registers\n",
	155	nodes, registers, registers / nodes);
	156
	157	mutex_unlock(&map->lock);
	158
	159	return 0;
	160	}
	161
	162	static int rbtree_open(struct inode inode, struct file file)
	163	{
	164	return single_open(file, rbtree_show, inode->i_private);
	165	}
	166
	167	static const struct file_operations rbtree_fops = {
	168	.open = rbtree_open,
	169	.read = seq_read,
	170	.llseek = seq_lseek,
	171	.release = single_release,
	172	};
cce585ce MB	173
	174	static void rbtree_debugfs_init(struct regmap *map)
	175	{
	176	debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
	177	}
	178	#else
	179	static void rbtree_debugfs_init(struct regmap *map)
	180	{
	181	}
bad2ab4b MB	182	#endif
bad2ab4b MB	183
28644c80 DP	184	static int regcache_rbtree_init(struct regmap *map)
	185	{
	186	struct regcache_rbtree_ctx *rbtree_ctx;
	187	int i;
	188	int ret;
	189
	190	map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
	191	if (!map->cache)
	192	return -ENOMEM;
	193
	194	rbtree_ctx = map->cache;
	195	rbtree_ctx->root = RB_ROOT;
	196	rbtree_ctx->cached_rbnode = NULL;
	197
	198	for (i = 0; i < map->num_reg_defaults; i++) {
	199	ret = regcache_rbtree_write(map,
	200	map->reg_defaults[i].reg,
	201	map->reg_defaults[i].def);
	202	if (ret)
	203	goto err;
	204	}
	205
cce585ce	206	rbtree_debugfs_init(map);
bad2ab4b	207
28644c80 DP	208	return 0;
	209
	210	err:
462a185c	211	regcache_rbtree_exit(map);
28644c80 DP	212	return ret;
	213	}
	214
	215	static int regcache_rbtree_exit(struct regmap *map)
	216	{
	217	struct rb_node *next;
	218	struct regcache_rbtree_ctx *rbtree_ctx;
	219	struct regcache_rbtree_node *rbtree_node;
	220
	221	/* if we've already been called then just return */
	222	rbtree_ctx = map->cache;
	223	if (!rbtree_ctx)
	224	return 0;
	225
	226	/* free up the rbtree */
	227	next = rb_first(&rbtree_ctx->root);
	228	while (next) {
	229	rbtree_node = rb_entry(next, struct regcache_rbtree_node, node);
	230	next = rb_next(&rbtree_node->node);
	231	rb_erase(&rbtree_node->node, &rbtree_ctx->root);
	232	kfree(rbtree_node->block);
	233	kfree(rbtree_node);
	234	}
	235
	236	/* release the resources */
	237	kfree(map->cache);
	238	map->cache = NULL;
	239
	240	return 0;
	241	}
	242
	243	static int regcache_rbtree_read(struct regmap *map,
	244	unsigned int reg, unsigned int *value)
	245	{
28644c80	246	struct regcache_rbtree_node *rbnode;
28644c80 DP	247	unsigned int reg_tmp;
28644c80 DP	248
3405addd	249	rbnode = regcache_rbtree_lookup(map, reg);
28644c80 DP	250	if (rbnode) {
28644c80 DP	251	reg_tmp = reg - rbnode->base_reg;
25ed1156 DP	252	*value = regcache_rbtree_get_register(rbnode, reg_tmp,
25ed1156 DP	253	map->cache_word_size);
28644c80	254	} else {
6e6ace00	255	return -ENOENT;
28644c80 DP	256	}
	257
	258	return 0;
	259	}
	260
	261
	262	static int regcache_rbtree_insert_to_block(struct regcache_rbtree_node *rbnode,
	263	unsigned int pos, unsigned int reg,
25ed1156	264	unsigned int value, unsigned int word_size)
28644c80 DP	265	{
	266	u8 *blk;
	267
	268	blk = krealloc(rbnode->block,
25ed1156	269	(rbnode->blklen + 1) * word_size, GFP_KERNEL);
28644c80 DP	270	if (!blk)
	271	return -ENOMEM;
	272
	273	/* insert the register value in the correct place in the rbnode block */
25ed1156 DP	274	memmove(blk + (pos + 1) * word_size,
	275	blk + pos * word_size,
	276	(rbnode->blklen - pos) * word_size);
28644c80 DP	277
	278	/* update the rbnode block, its size and the base register */
	279	rbnode->block = blk;
	280	rbnode->blklen++;
	281	if (!pos)
	282	rbnode->base_reg = reg;
	283
25ed1156	284	regcache_rbtree_set_register(rbnode, pos, value, word_size);
28644c80 DP	285	return 0;
	286	}
	287
	288	static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
	289	unsigned int value)
	290	{
	291	struct regcache_rbtree_ctx *rbtree_ctx;
	292	struct regcache_rbtree_node rbnode, rbnode_tmp;
	293	struct rb_node *node;
	294	unsigned int val;
	295	unsigned int reg_tmp;
28644c80 DP	296	unsigned int pos;
	297	int i;
	298	int ret;
	299
	300	rbtree_ctx = map->cache;
28644c80 DP	301	/* if we can't locate it in the cached rbnode we'll have
	302	* to traverse the rbtree looking for it.
	303	*/
3405addd	304	rbnode = regcache_rbtree_lookup(map, reg);
28644c80 DP	305	if (rbnode) {
28644c80 DP	306	reg_tmp = reg - rbnode->base_reg;
25ed1156 DP	307	val = regcache_rbtree_get_register(rbnode, reg_tmp,
25ed1156 DP	308	map->cache_word_size);
28644c80 DP	309	if (val == value)
28644c80 DP	310	return 0;
25ed1156 DP	311	regcache_rbtree_set_register(rbnode, reg_tmp, value,
25ed1156 DP	312	map->cache_word_size);
28644c80	313	} else {
28644c80 DP	314	/* look for an adjacent register to the one we are about to add */
	315	for (node = rb_first(&rbtree_ctx->root); node;
	316	node = rb_next(node)) {
	317	rbnode_tmp = rb_entry(node, struct regcache_rbtree_node, node);
	318	for (i = 0; i < rbnode_tmp->blklen; i++) {
	319	reg_tmp = rbnode_tmp->base_reg + i;
	320	if (abs(reg_tmp - reg) != 1)
	321	continue;
	322	/* decide where in the block to place our register */
	323	if (reg_tmp + 1 == reg)
	324	pos = i + 1;
	325	else
	326	pos = i;
	327	ret = regcache_rbtree_insert_to_block(rbnode_tmp, pos,
25ed1156 DP	328	reg, value,
25ed1156 DP	329	map->cache_word_size);
28644c80 DP	330	if (ret)
	331	return ret;
	332	rbtree_ctx->cached_rbnode = rbnode_tmp;
	333	return 0;
	334	}
	335	}
	336	/* we did not manage to find a place to insert it in an existing
	337	* block so create a new rbnode with a single register in its block.
	338	* This block will get populated further if any other adjacent
	339	* registers get modified in the future.
	340	*/
	341	rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL);
	342	if (!rbnode)
	343	return -ENOMEM;
	344	rbnode->blklen = 1;
	345	rbnode->base_reg = reg;
25ed1156	346	rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,
28644c80 DP	347	GFP_KERNEL);
	348	if (!rbnode->block) {
	349	kfree(rbnode);
	350	return -ENOMEM;
	351	}
25ed1156	352	regcache_rbtree_set_register(rbnode, 0, value, map->cache_word_size);
28644c80 DP	353	regcache_rbtree_insert(&rbtree_ctx->root, rbnode);
	354	rbtree_ctx->cached_rbnode = rbnode;
	355	}
	356
	357	return 0;
	358	}
	359
ac8d91c8 MB	360	static int regcache_rbtree_sync(struct regmap *map, unsigned int min,
ac8d91c8 MB	361	unsigned int max)
28644c80 DP	362	{
	363	struct regcache_rbtree_ctx *rbtree_ctx;
	364	struct rb_node *node;
	365	struct regcache_rbtree_node *rbnode;
	366	unsigned int regtmp;
b03622a8	367	unsigned int val;
28644c80	368	int ret;
ac8d91c8	369	int i, base, end;
28644c80 DP	370
	371	rbtree_ctx = map->cache;
	372	for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
	373	rbnode = rb_entry(node, struct regcache_rbtree_node, node);
ac8d91c8 MB	374
	375	if (rbnode->base_reg < min)
	376	continue;
	377	if (rbnode->base_reg > max)
	378	break;
	379	if (rbnode->base_reg + rbnode->blklen < min)
	380	continue;
	381
f9353e70	382	if (min > rbnode->base_reg)
ac8d91c8 MB	383	base = min - rbnode->base_reg;
	384	else
	385	base = 0;
	386
	387	if (max < rbnode->base_reg + rbnode->blklen)
	388	end = rbnode->base_reg + rbnode->blklen - max;
	389	else
	390	end = rbnode->blklen;
	391
	392	for (i = base; i < end; i++) {
28644c80	393	regtmp = rbnode->base_reg + i;
25ed1156 DP	394	val = regcache_rbtree_get_register(rbnode, i,
25ed1156 DP	395	map->cache_word_size);
b03622a8 MB	396
b03622a8 MB	397	/* Is this the hardware default? If so skip. */
28644c80	398	ret = regcache_lookup_reg(map, i);
b03622a8	399	if (ret > 0 && val == map->reg_defaults[ret].def)
28644c80	400	continue;
b03622a8	401
28644c80	402	map->cache_bypass = 1;
13753a90	403	ret = _regmap_write(map, regtmp, val);
28644c80 DP	404	map->cache_bypass = 0;
	405	if (ret)
	406	return ret;
	407	dev_dbg(map->dev, "Synced register %#x, value %#x\n",
	408	regtmp, val);
	409	}
	410	}
	411
	412	return 0;
	413	}
	414
	415	struct regcache_ops regcache_rbtree_ops = {
	416	.type = REGCACHE_RBTREE,
	417	.name = "rbtree",
	418	.init = regcache_rbtree_init,
	419	.exit = regcache_rbtree_exit,
	420	.read = regcache_rbtree_read,
	421	.write = regcache_rbtree_write,
	422	.sync = regcache_rbtree_sync
	423	};