[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/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 regmap *map,
	struct regcache_rbtree_node *rbnode,
	unsigned int *base, unsigned int *top)
{
	*base = rbnode->base_reg;
	*top = rbnode->base_reg + ((rbnode->blklen - 1) * map->reg_stride);
}

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(map, 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(map, 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 regmap *map, 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(map, 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 this_registers, average;

	map->lock(map);

	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(map, n, &base, &top);
		this_registers = ((top - base) / map->reg_stride) + 1;
		seq_printf(s, "%x-%x (%d)\n", base, top, this_registers);

		nodes++;
		registers += this_registers;
	}

	if (nodes)
		average = registers / nodes;
	else
		average = 0;

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

	map->unlock(map);

	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) / map->reg_stride;
		*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) / map->reg_stride;
		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 * map->reg_stride);
				if (abs(reg_tmp - reg) != map->reg_stride)
					continue;
				/* decide where in the block to place our register */
				if (reg_tmp + map->reg_stride == 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(map, &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 * map->reg_stride);
			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
};
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>
51990e82	14	#include <linux/device.h>
bad2ab4b	15	#include <linux/debugfs.h>
28644c80	16	#include <linux/rbtree.h>
bad2ab4b	17	#include <linux/seq_file.h>
28644c80 DP	18
	19	#include "internal.h"
	20
	21	static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
	22	unsigned int value);
462a185c	23	static int regcache_rbtree_exit(struct regmap *map);
28644c80 DP	24
	25	struct regcache_rbtree_node {
	26	/* the actual rbtree node holding this block */
	27	struct rb_node node;
	28	/* base register handled by this block */
	29	unsigned int base_reg;
28644c80 DP	30	/* block of adjacent registers */
	31	void *block;
	32	/* number of registers available in the block */
	33	unsigned int blklen;
	34	} __attribute__ ((packed));
	35
	36	struct regcache_rbtree_ctx {
	37	struct rb_root root;
	38	struct regcache_rbtree_node *cached_rbnode;
	39	};
	40
	41	static inline void regcache_rbtree_get_base_top_reg(
f01ee60f	42	struct regmap *map,
28644c80 DP	43	struct regcache_rbtree_node *rbnode,
	44	unsigned int base, unsigned int top)
	45	{
	46	*base = rbnode->base_reg;
f01ee60f	47	top = rbnode->base_reg + ((rbnode->blklen - 1) map->reg_stride);
28644c80 DP	48	}
	49
	50	static unsigned int regcache_rbtree_get_register(
25ed1156 DP	51	struct regcache_rbtree_node *rbnode, unsigned int idx,
25ed1156 DP	52	unsigned int word_size)
28644c80	53	{
c5713004	54	return regcache_get_val(rbnode->block, idx, word_size);
28644c80 DP	55	}
	56
	57	static void regcache_rbtree_set_register(struct regcache_rbtree_node *rbnode,
25ed1156 DP	58	unsigned int idx, unsigned int val,
25ed1156 DP	59	unsigned int word_size)
28644c80	60	{
c5713004	61	regcache_set_val(rbnode->block, idx, val, word_size);
28644c80 DP	62	}
28644c80 DP	63
3405addd LPC	64	static struct regcache_rbtree_node regcache_rbtree_lookup(struct regmap map,
3405addd LPC	65	unsigned int reg)
28644c80	66	{
3405addd	67	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
28644c80 DP	68	struct rb_node *node;
	69	struct regcache_rbtree_node *rbnode;
	70	unsigned int base_reg, top_reg;
	71
3405addd LPC	72	rbnode = rbtree_ctx->cached_rbnode;
3405addd LPC	73	if (rbnode) {
f01ee60f SW	74	regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
f01ee60f SW	75	&top_reg);
3405addd LPC	76	if (reg >= base_reg && reg <= top_reg)
	77	return rbnode;
	78	}
	79
	80	node = rbtree_ctx->root.rb_node;
28644c80 DP	81	while (node) {
28644c80 DP	82	rbnode = container_of(node, struct regcache_rbtree_node, node);
f01ee60f SW	83	regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
f01ee60f SW	84	&top_reg);
3405addd LPC	85	if (reg >= base_reg && reg <= top_reg) {
3405addd LPC	86	rbtree_ctx->cached_rbnode = rbnode;
28644c80	87	return rbnode;
3405addd	88	} else if (reg > top_reg) {
28644c80	89	node = node->rb_right;
3405addd	90	} else if (reg < base_reg) {
28644c80	91	node = node->rb_left;
3405addd	92	}
28644c80 DP	93	}
	94
	95	return NULL;
	96	}
	97
f01ee60f	98	static int regcache_rbtree_insert(struct regmap map, struct rb_root root,
28644c80 DP	99	struct regcache_rbtree_node *rbnode)
	100	{
	101	struct rb_node *new, parent;
	102	struct regcache_rbtree_node *rbnode_tmp;
	103	unsigned int base_reg_tmp, top_reg_tmp;
	104	unsigned int base_reg;
	105
	106	parent = NULL;
	107	new = &root->rb_node;
	108	while (*new) {
	109	rbnode_tmp = container_of(*new, struct regcache_rbtree_node,
	110	node);
	111	/* base and top registers of the current rbnode */
f01ee60f	112	regcache_rbtree_get_base_top_reg(map, rbnode_tmp, &base_reg_tmp,
28644c80 DP	113	&top_reg_tmp);
	114	/* base register of the rbnode to be added */
	115	base_reg = rbnode->base_reg;
	116	parent = *new;
	117	/* if this register has already been inserted, just return */
	118	if (base_reg >= base_reg_tmp &&
	119	base_reg <= top_reg_tmp)
	120	return 0;
	121	else if (base_reg > top_reg_tmp)
	122	new = &((*new)->rb_right);
	123	else if (base_reg < base_reg_tmp)
	124	new = &((*new)->rb_left);
	125	}
	126
	127	/* insert the node into the rbtree */
	128	rb_link_node(&rbnode->node, parent, new);
	129	rb_insert_color(&rbnode->node, root);
	130
	131	return 1;
	132	}
	133
bad2ab4b MB	134	#ifdef CONFIG_DEBUG_FS
	135	static int rbtree_show(struct seq_file s, void ignored)
	136	{
	137	struct regmap *map = s->private;
	138	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
	139	struct regcache_rbtree_node *n;
	140	struct rb_node *node;
	141	unsigned int base, top;
	142	int nodes = 0;
	143	int registers = 0;
f01ee60f	144	int this_registers, average;
bad2ab4b	145
bacdbe07	146	map->lock(map);
bad2ab4b MB	147
	148	for (node = rb_first(&rbtree_ctx->root); node != NULL;
	149	node = rb_next(node)) {
	150	n = container_of(node, struct regcache_rbtree_node, node);
	151
f01ee60f SW	152	regcache_rbtree_get_base_top_reg(map, n, &base, &top);
	153	this_registers = ((top - base) / map->reg_stride) + 1;
	154	seq_printf(s, "%x-%x (%d)\n", base, top, this_registers);
bad2ab4b MB	155
bad2ab4b MB	156	nodes++;
f01ee60f	157	registers += this_registers;
bad2ab4b MB	158	}
bad2ab4b MB	159
c04c1b9e SW	160	if (nodes)
	161	average = registers / nodes;
	162	else
	163	average = 0;
	164
bad2ab4b	165	seq_printf(s, "%d nodes, %d registers, average %d registers\n",
c04c1b9e	166	nodes, registers, average);
bad2ab4b	167
bacdbe07	168	map->unlock(map);
bad2ab4b MB	169
	170	return 0;
	171	}
	172
	173	static int rbtree_open(struct inode inode, struct file file)
	174	{
	175	return single_open(file, rbtree_show, inode->i_private);
	176	}
	177
	178	static const struct file_operations rbtree_fops = {
	179	.open = rbtree_open,
	180	.read = seq_read,
	181	.llseek = seq_lseek,
	182	.release = single_release,
	183	};
cce585ce MB	184
	185	static void rbtree_debugfs_init(struct regmap *map)
	186	{
	187	debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
	188	}
	189	#else
	190	static void rbtree_debugfs_init(struct regmap *map)
	191	{
	192	}
bad2ab4b MB	193	#endif
bad2ab4b MB	194
28644c80 DP	195	static int regcache_rbtree_init(struct regmap *map)
	196	{
	197	struct regcache_rbtree_ctx *rbtree_ctx;
	198	int i;
	199	int ret;
	200
	201	map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
	202	if (!map->cache)
	203	return -ENOMEM;
	204
	205	rbtree_ctx = map->cache;
	206	rbtree_ctx->root = RB_ROOT;
	207	rbtree_ctx->cached_rbnode = NULL;
	208
	209	for (i = 0; i < map->num_reg_defaults; i++) {
	210	ret = regcache_rbtree_write(map,
	211	map->reg_defaults[i].reg,
	212	map->reg_defaults[i].def);
	213	if (ret)
	214	goto err;
	215	}
	216
cce585ce	217	rbtree_debugfs_init(map);
bad2ab4b	218
28644c80 DP	219	return 0;
	220
	221	err:
462a185c	222	regcache_rbtree_exit(map);
28644c80 DP	223	return ret;
	224	}
	225
	226	static int regcache_rbtree_exit(struct regmap *map)
	227	{
	228	struct rb_node *next;
	229	struct regcache_rbtree_ctx *rbtree_ctx;
	230	struct regcache_rbtree_node *rbtree_node;
	231
	232	/* if we've already been called then just return */
	233	rbtree_ctx = map->cache;
	234	if (!rbtree_ctx)
	235	return 0;
	236
	237	/* free up the rbtree */
	238	next = rb_first(&rbtree_ctx->root);
	239	while (next) {
	240	rbtree_node = rb_entry(next, struct regcache_rbtree_node, node);
	241	next = rb_next(&rbtree_node->node);
	242	rb_erase(&rbtree_node->node, &rbtree_ctx->root);
	243	kfree(rbtree_node->block);
	244	kfree(rbtree_node);
	245	}
	246
	247	/* release the resources */
	248	kfree(map->cache);
	249	map->cache = NULL;
	250
	251	return 0;
	252	}
	253
	254	static int regcache_rbtree_read(struct regmap *map,
	255	unsigned int reg, unsigned int *value)
	256	{
28644c80	257	struct regcache_rbtree_node *rbnode;
28644c80 DP	258	unsigned int reg_tmp;
28644c80 DP	259
3405addd	260	rbnode = regcache_rbtree_lookup(map, reg);
28644c80	261	if (rbnode) {
f01ee60f	262	reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
25ed1156 DP	263	*value = regcache_rbtree_get_register(rbnode, reg_tmp,
25ed1156 DP	264	map->cache_word_size);
28644c80	265	} else {
6e6ace00	266	return -ENOENT;
28644c80 DP	267	}
	268
	269	return 0;
	270	}
	271
	272
	273	static int regcache_rbtree_insert_to_block(struct regcache_rbtree_node *rbnode,
	274	unsigned int pos, unsigned int reg,
25ed1156	275	unsigned int value, unsigned int word_size)
28644c80 DP	276	{
	277	u8 *blk;
	278
	279	blk = krealloc(rbnode->block,
25ed1156	280	(rbnode->blklen + 1) * word_size, GFP_KERNEL);
28644c80 DP	281	if (!blk)
	282	return -ENOMEM;
	283
	284	/* insert the register value in the correct place in the rbnode block */
25ed1156 DP	285	memmove(blk + (pos + 1) * word_size,
	286	blk + pos * word_size,
	287	(rbnode->blklen - pos) * word_size);
28644c80 DP	288
	289	/* update the rbnode block, its size and the base register */
	290	rbnode->block = blk;
	291	rbnode->blklen++;
	292	if (!pos)
	293	rbnode->base_reg = reg;
	294
25ed1156	295	regcache_rbtree_set_register(rbnode, pos, value, word_size);
28644c80 DP	296	return 0;
	297	}
	298
	299	static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
	300	unsigned int value)
	301	{
	302	struct regcache_rbtree_ctx *rbtree_ctx;
	303	struct regcache_rbtree_node rbnode, rbnode_tmp;
	304	struct rb_node *node;
	305	unsigned int val;
	306	unsigned int reg_tmp;
28644c80 DP	307	unsigned int pos;
	308	int i;
	309	int ret;
	310
	311	rbtree_ctx = map->cache;
28644c80 DP	312	/* if we can't locate it in the cached rbnode we'll have
	313	* to traverse the rbtree looking for it.
	314	*/
3405addd	315	rbnode = regcache_rbtree_lookup(map, reg);
28644c80	316	if (rbnode) {
f01ee60f	317	reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
25ed1156 DP	318	val = regcache_rbtree_get_register(rbnode, reg_tmp,
25ed1156 DP	319	map->cache_word_size);
28644c80 DP	320	if (val == value)
28644c80 DP	321	return 0;
25ed1156 DP	322	regcache_rbtree_set_register(rbnode, reg_tmp, value,
25ed1156 DP	323	map->cache_word_size);
28644c80	324	} else {
28644c80 DP	325	/* look for an adjacent register to the one we are about to add */
	326	for (node = rb_first(&rbtree_ctx->root); node;
	327	node = rb_next(node)) {
f01ee60f SW	328	rbnode_tmp = rb_entry(node, struct regcache_rbtree_node,
f01ee60f SW	329	node);
28644c80	330	for (i = 0; i < rbnode_tmp->blklen; i++) {
f01ee60f SW	331	reg_tmp = rbnode_tmp->base_reg +
	332	(i * map->reg_stride);
	333	if (abs(reg_tmp - reg) != map->reg_stride)
28644c80 DP	334	continue;
28644c80 DP	335	/* decide where in the block to place our register */
f01ee60f	336	if (reg_tmp + map->reg_stride == reg)
28644c80 DP	337	pos = i + 1;
	338	else
	339	pos = i;
	340	ret = regcache_rbtree_insert_to_block(rbnode_tmp, pos,
25ed1156 DP	341	reg, value,
25ed1156 DP	342	map->cache_word_size);
28644c80 DP	343	if (ret)
	344	return ret;
	345	rbtree_ctx->cached_rbnode = rbnode_tmp;
	346	return 0;
	347	}
	348	}
	349	/* we did not manage to find a place to insert it in an existing
	350	* block so create a new rbnode with a single register in its block.
	351	* This block will get populated further if any other adjacent
	352	* registers get modified in the future.
	353	*/
	354	rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL);
	355	if (!rbnode)
	356	return -ENOMEM;
	357	rbnode->blklen = 1;
	358	rbnode->base_reg = reg;
25ed1156	359	rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,
28644c80 DP	360	GFP_KERNEL);
	361	if (!rbnode->block) {
	362	kfree(rbnode);
	363	return -ENOMEM;
	364	}
25ed1156	365	regcache_rbtree_set_register(rbnode, 0, value, map->cache_word_size);
f01ee60f	366	regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);
28644c80 DP	367	rbtree_ctx->cached_rbnode = rbnode;
	368	}
	369
	370	return 0;
	371	}
	372
ac8d91c8 MB	373	static int regcache_rbtree_sync(struct regmap *map, unsigned int min,
ac8d91c8 MB	374	unsigned int max)
28644c80 DP	375	{
	376	struct regcache_rbtree_ctx *rbtree_ctx;
	377	struct rb_node *node;
	378	struct regcache_rbtree_node *rbnode;
	379	unsigned int regtmp;
b03622a8	380	unsigned int val;
28644c80	381	int ret;
ac8d91c8	382	int i, base, end;
28644c80 DP	383
	384	rbtree_ctx = map->cache;
	385	for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
	386	rbnode = rb_entry(node, struct regcache_rbtree_node, node);
ac8d91c8 MB	387
	388	if (rbnode->base_reg < min)
	389	continue;
	390	if (rbnode->base_reg > max)
	391	break;
	392	if (rbnode->base_reg + rbnode->blklen < min)
	393	continue;
	394
f9353e70	395	if (min > rbnode->base_reg)
ac8d91c8 MB	396	base = min - rbnode->base_reg;
	397	else
	398	base = 0;
	399
	400	if (max < rbnode->base_reg + rbnode->blklen)
	401	end = rbnode->base_reg + rbnode->blklen - max;
	402	else
	403	end = rbnode->blklen;
	404
	405	for (i = base; i < end; i++) {
f01ee60f	406	regtmp = rbnode->base_reg + (i * map->reg_stride);
25ed1156 DP	407	val = regcache_rbtree_get_register(rbnode, i,
25ed1156 DP	408	map->cache_word_size);
b03622a8 MB	409
b03622a8 MB	410	/* Is this the hardware default? If so skip. */
4b4e9e43	411	ret = regcache_lookup_reg(map, regtmp);
994f5db6	412	if (ret >= 0 && val == map->reg_defaults[ret].def)
28644c80	413	continue;
b03622a8	414
28644c80	415	map->cache_bypass = 1;
13753a90	416	ret = _regmap_write(map, regtmp, val);
28644c80 DP	417	map->cache_bypass = 0;
	418	if (ret)
	419	return ret;
	420	dev_dbg(map->dev, "Synced register %#x, value %#x\n",
	421	regtmp, val);
	422	}
	423	}
	424
	425	return 0;
	426	}
	427
	428	struct regcache_ops regcache_rbtree_ops = {
	429	.type = REGCACHE_RBTREE,
	430	.name = "rbtree",
	431	.init = regcache_rbtree_init,
	432	.exit = regcache_rbtree_exit,
	433	.read = regcache_rbtree_read,
	434	.write = regcache_rbtree_write,
	435	.sync = regcache_rbtree_sync
	436	};