[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 regmap *map,
	struct regcache_rbtree_node *rbnode, unsigned int idx)
{
	return regcache_get_val(map, rbnode->block, idx);
}

static void regcache_rbtree_set_register(struct regmap *map,
					 struct regcache_rbtree_node *rbnode,
					 unsigned int idx, unsigned int val)
{
	regcache_set_val(map, rbnode->block, idx, val);
}

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(map, rbnode, reg_tmp);
	} else {
		return -ENOENT;
	}

	return 0;
}


static int regcache_rbtree_insert_to_block(struct regmap *map,
					   struct regcache_rbtree_node *rbnode,
					   unsigned int pos, unsigned int reg,
					   unsigned int value)
{
	u8 *blk;

	blk = krealloc(rbnode->block,
		       (rbnode->blklen + 1) * map->cache_word_size,
		       GFP_KERNEL);
	if (!blk)
		return -ENOMEM;

	/* insert the register value in the correct place in the rbnode block */
	memmove(blk + (pos + 1) * map->cache_word_size,
		blk + pos * map->cache_word_size,
		(rbnode->blklen - pos) * map->cache_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(map, rbnode, pos, value);
	return 0;
}

static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
				 unsigned int value)
{
	struct regcache_rbtree_ctx *rbtree_ctx;
	struct regcache_rbtree_node *rbnode, *rbnode_tmp;
	struct rb_node *node;
	unsigned int 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;
		regcache_rbtree_set_register(map, rbnode, reg_tmp, value);
	} 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(map,
								      rbnode_tmp,
								      pos, reg,
								      value);
				if (ret)
					return ret;
				rbtree_ctx->cached_rbnode = rbnode_tmp;
				return 0;
			}
		}
		/* we did not manage to find a place to insert it in an existing
		 * block so create a new rbnode with a single register in its block.
		 * This block will get populated further if any other adjacent
		 * registers get modified in the future.
		 */
		rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL);
		if (!rbnode)
			return -ENOMEM;
		rbnode->blklen = 1;
		rbnode->base_reg = reg;
		rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,
					GFP_KERNEL);
		if (!rbnode->block) {
			kfree(rbnode);
			return -ENOMEM;
		}
		regcache_rbtree_set_register(map, rbnode, 0, value);
		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(map, rbnode, i);

			/* 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	}
28644c80 DP	49
879082c9 MB	50	static unsigned int regcache_rbtree_get_register(struct regmap *map,
879082c9 MB	51	struct regcache_rbtree_node *rbnode, unsigned int idx)
28644c80	52	{
879082c9	53	return regcache_get_val(map, rbnode->block, idx);
28644c80 DP	54	}
28644c80 DP	55
879082c9 MB	56	static void regcache_rbtree_set_register(struct regmap *map,
	57	struct regcache_rbtree_node *rbnode,
	58	unsigned int idx, unsigned int val)
28644c80	59	{
879082c9	60	regcache_set_val(map, rbnode->block, idx, val);
28644c80 DP	61	}
28644c80 DP	62
3405addd	63	static struct regcache_rbtree_node regcache_rbtree_lookup(struct regmap map,
879082c9	64	unsigned int reg)
28644c80	65	{
3405addd	66	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
28644c80 DP	67	struct rb_node *node;
	68	struct regcache_rbtree_node *rbnode;
	69	unsigned int base_reg, top_reg;
	70
3405addd LPC	71	rbnode = rbtree_ctx->cached_rbnode;
3405addd LPC	72	if (rbnode) {
f01ee60f SW	73	regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
f01ee60f SW	74	&top_reg);
3405addd LPC	75	if (reg >= base_reg && reg <= top_reg)
	76	return rbnode;
	77	}
	78
	79	node = rbtree_ctx->root.rb_node;
28644c80 DP	80	while (node) {
28644c80 DP	81	rbnode = container_of(node, struct regcache_rbtree_node, node);
f01ee60f SW	82	regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg,
f01ee60f SW	83	&top_reg);
3405addd LPC	84	if (reg >= base_reg && reg <= top_reg) {
3405addd LPC	85	rbtree_ctx->cached_rbnode = rbnode;
28644c80	86	return rbnode;
3405addd	87	} else if (reg > top_reg) {
28644c80	88	node = node->rb_right;
3405addd	89	} else if (reg < base_reg) {
28644c80	90	node = node->rb_left;
3405addd	91	}
28644c80 DP	92	}
	93
	94	return NULL;
	95	}
	96
f01ee60f	97	static int regcache_rbtree_insert(struct regmap map, struct rb_root root,
28644c80 DP	98	struct regcache_rbtree_node *rbnode)
	99	{
	100	struct rb_node *new, parent;
	101	struct regcache_rbtree_node *rbnode_tmp;
	102	unsigned int base_reg_tmp, top_reg_tmp;
	103	unsigned int base_reg;
	104
	105	parent = NULL;
	106	new = &root->rb_node;
	107	while (*new) {
	108	rbnode_tmp = container_of(*new, struct regcache_rbtree_node,
	109	node);
	110	/* base and top registers of the current rbnode */
f01ee60f	111	regcache_rbtree_get_base_top_reg(map, rbnode_tmp, &base_reg_tmp,
28644c80 DP	112	&top_reg_tmp);
	113	/* base register of the rbnode to be added */
	114	base_reg = rbnode->base_reg;
	115	parent = *new;
	116	/* if this register has already been inserted, just return */
	117	if (base_reg >= base_reg_tmp &&
	118	base_reg <= top_reg_tmp)
	119	return 0;
	120	else if (base_reg > top_reg_tmp)
	121	new = &((*new)->rb_right);
	122	else if (base_reg < base_reg_tmp)
	123	new = &((*new)->rb_left);
	124	}
	125
	126	/* insert the node into the rbtree */
	127	rb_link_node(&rbnode->node, parent, new);
	128	rb_insert_color(&rbnode->node, root);
	129
	130	return 1;
	131	}
	132
bad2ab4b MB	133	#ifdef CONFIG_DEBUG_FS
	134	static int rbtree_show(struct seq_file s, void ignored)
	135	{
	136	struct regmap *map = s->private;
	137	struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
	138	struct regcache_rbtree_node *n;
	139	struct rb_node *node;
	140	unsigned int base, top;
	141	int nodes = 0;
	142	int registers = 0;
f01ee60f	143	int this_registers, average;
bad2ab4b	144
bacdbe07	145	map->lock(map);
bad2ab4b MB	146
	147	for (node = rb_first(&rbtree_ctx->root); node != NULL;
	148	node = rb_next(node)) {
	149	n = container_of(node, struct regcache_rbtree_node, node);
	150
f01ee60f SW	151	regcache_rbtree_get_base_top_reg(map, n, &base, &top);
	152	this_registers = ((top - base) / map->reg_stride) + 1;
	153	seq_printf(s, "%x-%x (%d)\n", base, top, this_registers);
bad2ab4b MB	154
bad2ab4b MB	155	nodes++;
f01ee60f	156	registers += this_registers;
bad2ab4b MB	157	}
bad2ab4b MB	158
c04c1b9e SW	159	if (nodes)
	160	average = registers / nodes;
	161	else
	162	average = 0;
	163
bad2ab4b	164	seq_printf(s, "%d nodes, %d registers, average %d registers\n",
c04c1b9e	165	nodes, registers, average);
bad2ab4b	166
bacdbe07	167	map->unlock(map);
bad2ab4b MB	168
	169	return 0;
	170	}
	171
	172	static int rbtree_open(struct inode inode, struct file file)
	173	{
	174	return single_open(file, rbtree_show, inode->i_private);
	175	}
	176
	177	static const struct file_operations rbtree_fops = {
	178	.open = rbtree_open,
	179	.read = seq_read,
	180	.llseek = seq_lseek,
	181	.release = single_release,
	182	};
cce585ce MB	183
	184	static void rbtree_debugfs_init(struct regmap *map)
	185	{
	186	debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
	187	}
	188	#else
	189	static void rbtree_debugfs_init(struct regmap *map)
	190	{
	191	}
bad2ab4b MB	192	#endif
bad2ab4b MB	193
28644c80 DP	194	static int regcache_rbtree_init(struct regmap *map)
	195	{
	196	struct regcache_rbtree_ctx *rbtree_ctx;
	197	int i;
	198	int ret;
	199
	200	map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
	201	if (!map->cache)
	202	return -ENOMEM;
	203
	204	rbtree_ctx = map->cache;
	205	rbtree_ctx->root = RB_ROOT;
	206	rbtree_ctx->cached_rbnode = NULL;
	207
	208	for (i = 0; i < map->num_reg_defaults; i++) {
	209	ret = regcache_rbtree_write(map,
	210	map->reg_defaults[i].reg,
	211	map->reg_defaults[i].def);
	212	if (ret)
	213	goto err;
	214	}
	215
cce585ce	216	rbtree_debugfs_init(map);
bad2ab4b	217
28644c80 DP	218	return 0;
	219
	220	err:
462a185c	221	regcache_rbtree_exit(map);
28644c80 DP	222	return ret;
	223	}
	224
	225	static int regcache_rbtree_exit(struct regmap *map)
	226	{
	227	struct rb_node *next;
	228	struct regcache_rbtree_ctx *rbtree_ctx;
	229	struct regcache_rbtree_node *rbtree_node;
	230
	231	/* if we've already been called then just return */
	232	rbtree_ctx = map->cache;
	233	if (!rbtree_ctx)
	234	return 0;
	235
	236	/* free up the rbtree */
	237	next = rb_first(&rbtree_ctx->root);
	238	while (next) {
	239	rbtree_node = rb_entry(next, struct regcache_rbtree_node, node);
	240	next = rb_next(&rbtree_node->node);
	241	rb_erase(&rbtree_node->node, &rbtree_ctx->root);
	242	kfree(rbtree_node->block);
	243	kfree(rbtree_node);
	244	}
	245
	246	/* release the resources */
	247	kfree(map->cache);
	248	map->cache = NULL;
	249
	250	return 0;
	251	}
	252
	253	static int regcache_rbtree_read(struct regmap *map,
	254	unsigned int reg, unsigned int *value)
	255	{
28644c80	256	struct regcache_rbtree_node *rbnode;
28644c80 DP	257	unsigned int reg_tmp;
28644c80 DP	258
3405addd	259	rbnode = regcache_rbtree_lookup(map, reg);
28644c80	260	if (rbnode) {
f01ee60f	261	reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
879082c9	262	*value = regcache_rbtree_get_register(map, rbnode, reg_tmp);
28644c80	263	} else {
6e6ace00	264	return -ENOENT;
28644c80 DP	265	}
	266
	267	return 0;
	268	}
	269
	270
879082c9 MB	271	static int regcache_rbtree_insert_to_block(struct regmap *map,
879082c9 MB	272	struct regcache_rbtree_node *rbnode,
28644c80	273	unsigned int pos, unsigned int reg,
879082c9	274	unsigned int value)
28644c80 DP	275	{
	276	u8 *blk;
	277
	278	blk = krealloc(rbnode->block,
879082c9 MB	279	(rbnode->blklen + 1) * map->cache_word_size,
879082c9 MB	280	GFP_KERNEL);
28644c80 DP	281	if (!blk)
	282	return -ENOMEM;
	283
	284	/* insert the register value in the correct place in the rbnode block */
879082c9 MB	285	memmove(blk + (pos + 1) * map->cache_word_size,
	286	blk + pos * map->cache_word_size,
	287	(rbnode->blklen - pos) * map->cache_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
879082c9	295	regcache_rbtree_set_register(map, rbnode, pos, value);
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;
28644c80	305	unsigned int reg_tmp;
28644c80 DP	306	unsigned int pos;
	307	int i;
	308	int ret;
	309
	310	rbtree_ctx = map->cache;
28644c80 DP	311	/* if we can't locate it in the cached rbnode we'll have
	312	* to traverse the rbtree looking for it.
	313	*/
3405addd	314	rbnode = regcache_rbtree_lookup(map, reg);
28644c80	315	if (rbnode) {
f01ee60f	316	reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
879082c9	317	regcache_rbtree_set_register(map, rbnode, reg_tmp, value);
28644c80	318	} else {
28644c80 DP	319	/* look for an adjacent register to the one we are about to add */
	320	for (node = rb_first(&rbtree_ctx->root); node;
	321	node = rb_next(node)) {
f01ee60f SW	322	rbnode_tmp = rb_entry(node, struct regcache_rbtree_node,
f01ee60f SW	323	node);
28644c80	324	for (i = 0; i < rbnode_tmp->blklen; i++) {
f01ee60f SW	325	reg_tmp = rbnode_tmp->base_reg +
	326	(i * map->reg_stride);
	327	if (abs(reg_tmp - reg) != map->reg_stride)
28644c80 DP	328	continue;
28644c80 DP	329	/* decide where in the block to place our register */
f01ee60f	330	if (reg_tmp + map->reg_stride == reg)
28644c80 DP	331	pos = i + 1;
	332	else
	333	pos = i;
879082c9 MB	334	ret = regcache_rbtree_insert_to_block(map,
	335	rbnode_tmp,
	336	pos, reg,
	337	value);
28644c80 DP	338	if (ret)
	339	return ret;
	340	rbtree_ctx->cached_rbnode = rbnode_tmp;
	341	return 0;
	342	}
	343	}
	344	/* we did not manage to find a place to insert it in an existing
	345	* block so create a new rbnode with a single register in its block.
	346	* This block will get populated further if any other adjacent
	347	* registers get modified in the future.
	348	*/
	349	rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL);
	350	if (!rbnode)
	351	return -ENOMEM;
	352	rbnode->blklen = 1;
	353	rbnode->base_reg = reg;
25ed1156	354	rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,
28644c80 DP	355	GFP_KERNEL);
	356	if (!rbnode->block) {
	357	kfree(rbnode);
	358	return -ENOMEM;
	359	}
879082c9	360	regcache_rbtree_set_register(map, rbnode, 0, value);
f01ee60f	361	regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);
28644c80 DP	362	rbtree_ctx->cached_rbnode = rbnode;
	363	}
	364
	365	return 0;
	366	}
	367
ac8d91c8 MB	368	static int regcache_rbtree_sync(struct regmap *map, unsigned int min,
ac8d91c8 MB	369	unsigned int max)
28644c80 DP	370	{
	371	struct regcache_rbtree_ctx *rbtree_ctx;
	372	struct rb_node *node;
	373	struct regcache_rbtree_node *rbnode;
	374	unsigned int regtmp;
b03622a8	375	unsigned int val;
28644c80	376	int ret;
ac8d91c8	377	int i, base, end;
28644c80 DP	378
	379	rbtree_ctx = map->cache;
	380	for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
	381	rbnode = rb_entry(node, struct regcache_rbtree_node, node);
ac8d91c8 MB	382
	383	if (rbnode->base_reg < min)
	384	continue;
	385	if (rbnode->base_reg > max)
	386	break;
	387	if (rbnode->base_reg + rbnode->blklen < min)
	388	continue;
	389
f9353e70	390	if (min > rbnode->base_reg)
ac8d91c8 MB	391	base = min - rbnode->base_reg;
	392	else
	393	base = 0;
	394
	395	if (max < rbnode->base_reg + rbnode->blklen)
	396	end = rbnode->base_reg + rbnode->blklen - max;
	397	else
	398	end = rbnode->blklen;
	399
	400	for (i = base; i < end; i++) {
f01ee60f	401	regtmp = rbnode->base_reg + (i * map->reg_stride);
879082c9	402	val = regcache_rbtree_get_register(map, rbnode, i);
b03622a8 MB	403
b03622a8 MB	404	/* Is this the hardware default? If so skip. */
4b4e9e43	405	ret = regcache_lookup_reg(map, regtmp);
994f5db6	406	if (ret >= 0 && val == map->reg_defaults[ret].def)
28644c80	407	continue;
b03622a8	408
28644c80	409	map->cache_bypass = 1;
13753a90	410	ret = _regmap_write(map, regtmp, val);
28644c80 DP	411	map->cache_bypass = 0;
	412	if (ret)
	413	return ret;
	414	dev_dbg(map->dev, "Synced register %#x, value %#x\n",
	415	regtmp, val);
	416	}
	417	}
	418
	419	return 0;
	420	}
	421
	422	struct regcache_ops regcache_rbtree_ops = {
	423	.type = REGCACHE_RBTREE,
	424	.name = "rbtree",
	425	.init = regcache_rbtree_init,
	426	.exit = regcache_rbtree_exit,
	427	.read = regcache_rbtree_read,
	428	.write = regcache_rbtree_write,
	429	.sync = regcache_rbtree_sync
	430	};