[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;
	size_t mem_size;
	int nodes = 0;
	int registers = 0;
	int this_registers, average;

	map->lock(map->lock_arg);

	mem_size = sizeof(*rbtree_ctx);
	mem_size += BITS_TO_LONGS(map->cache_present_nbits) * sizeof(long);

	for (node = rb_first(&rbtree_ctx->root); node != NULL;
	     node = rb_next(node)) {
		n = container_of(node, struct regcache_rbtree_node, node);
		mem_size += sizeof(*n);
		mem_size += (n->blklen * map->cache_word_size);

		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, used %zu bytes\n",
		   nodes, registers, average, mem_size);

	map->unlock(map->lock_arg);

	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;
		if (!regcache_reg_present(map, reg))
			return -ENOENT;
		*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;
	/* update the reg_present bitmap, make space if necessary */
	ret = regcache_set_reg_present(map, reg);
	if (ret < 0)
		return ret;

	/* 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 = sizeof(*rbnode);
		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;
	int ret;
	int 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 > 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 = max - rbnode->base_reg + 1;
		else
			end = rbnode->blklen;

		ret = regcache_sync_block(map, rbnode->block, rbnode->base_reg,
					  base, end);
		if (ret != 0)
			return ret;
	}

	return regmap_async_complete(map);
}

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;
a42277c7	141	size_t mem_size;
bad2ab4b MB	142	int nodes = 0;
bad2ab4b MB	143	int registers = 0;
f01ee60f	144	int this_registers, average;
bad2ab4b	145
f20c783c	146	map->lock(map->lock_arg);
bad2ab4b	147
a42277c7	148	mem_size = sizeof(*rbtree_ctx);
78493f2d	149	mem_size += BITS_TO_LONGS(map->cache_present_nbits) * sizeof(long);
a42277c7	150
bad2ab4b MB	151	for (node = rb_first(&rbtree_ctx->root); node != NULL;
	152	node = rb_next(node)) {
	153	n = container_of(node, struct regcache_rbtree_node, node);
a42277c7 DP	154	mem_size += sizeof(*n);
a42277c7 DP	155	mem_size += (n->blklen * map->cache_word_size);
bad2ab4b	156
f01ee60f SW	157	regcache_rbtree_get_base_top_reg(map, n, &base, &top);
	158	this_registers = ((top - base) / map->reg_stride) + 1;
	159	seq_printf(s, "%x-%x (%d)\n", base, top, this_registers);
bad2ab4b MB	160
bad2ab4b MB	161	nodes++;
f01ee60f	162	registers += this_registers;
bad2ab4b MB	163	}
bad2ab4b MB	164
c04c1b9e SW	165	if (nodes)
	166	average = registers / nodes;
	167	else
	168	average = 0;
	169
a42277c7 DP	170	seq_printf(s, "%d nodes, %d registers, average %d registers, used %zu bytes\n",
a42277c7 DP	171	nodes, registers, average, mem_size);
bad2ab4b	172
f20c783c	173	map->unlock(map->lock_arg);
bad2ab4b MB	174
	175	return 0;
	176	}
	177
	178	static int rbtree_open(struct inode inode, struct file file)
	179	{
	180	return single_open(file, rbtree_show, inode->i_private);
	181	}
	182
	183	static const struct file_operations rbtree_fops = {
	184	.open = rbtree_open,
	185	.read = seq_read,
	186	.llseek = seq_lseek,
	187	.release = single_release,
	188	};
cce585ce MB	189
	190	static void rbtree_debugfs_init(struct regmap *map)
	191	{
	192	debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
	193	}
	194	#else
	195	static void rbtree_debugfs_init(struct regmap *map)
	196	{
	197	}
bad2ab4b MB	198	#endif
bad2ab4b MB	199
28644c80 DP	200	static int regcache_rbtree_init(struct regmap *map)
	201	{
	202	struct regcache_rbtree_ctx *rbtree_ctx;
	203	int i;
	204	int ret;
	205
	206	map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
	207	if (!map->cache)
	208	return -ENOMEM;
	209
	210	rbtree_ctx = map->cache;
	211	rbtree_ctx->root = RB_ROOT;
	212	rbtree_ctx->cached_rbnode = NULL;
	213
	214	for (i = 0; i < map->num_reg_defaults; i++) {
	215	ret = regcache_rbtree_write(map,
	216	map->reg_defaults[i].reg,
	217	map->reg_defaults[i].def);
	218	if (ret)
	219	goto err;
	220	}
	221
cce585ce	222	rbtree_debugfs_init(map);
bad2ab4b	223
28644c80 DP	224	return 0;
	225
	226	err:
462a185c	227	regcache_rbtree_exit(map);
28644c80 DP	228	return ret;
	229	}
	230
	231	static int regcache_rbtree_exit(struct regmap *map)
	232	{
	233	struct rb_node *next;
	234	struct regcache_rbtree_ctx *rbtree_ctx;
	235	struct regcache_rbtree_node *rbtree_node;
	236
	237	/* if we've already been called then just return */
	238	rbtree_ctx = map->cache;
	239	if (!rbtree_ctx)
	240	return 0;
	241
	242	/* free up the rbtree */
	243	next = rb_first(&rbtree_ctx->root);
	244	while (next) {
	245	rbtree_node = rb_entry(next, struct regcache_rbtree_node, node);
	246	next = rb_next(&rbtree_node->node);
	247	rb_erase(&rbtree_node->node, &rbtree_ctx->root);
	248	kfree(rbtree_node->block);
	249	kfree(rbtree_node);
	250	}
	251
	252	/* release the resources */
	253	kfree(map->cache);
	254	map->cache = NULL;
	255
	256	return 0;
	257	}
	258
	259	static int regcache_rbtree_read(struct regmap *map,
	260	unsigned int reg, unsigned int *value)
	261	{
28644c80	262	struct regcache_rbtree_node *rbnode;
28644c80 DP	263	unsigned int reg_tmp;
28644c80 DP	264
3405addd	265	rbnode = regcache_rbtree_lookup(map, reg);
28644c80	266	if (rbnode) {
f01ee60f	267	reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
0c7ed856 DP	268	if (!regcache_reg_present(map, reg))
0c7ed856 DP	269	return -ENOENT;
879082c9	270	*value = regcache_rbtree_get_register(map, rbnode, reg_tmp);
28644c80	271	} else {
6e6ace00	272	return -ENOENT;
28644c80 DP	273	}
	274
	275	return 0;
	276	}
	277
	278
879082c9 MB	279	static int regcache_rbtree_insert_to_block(struct regmap *map,
879082c9 MB	280	struct regcache_rbtree_node *rbnode,
28644c80	281	unsigned int pos, unsigned int reg,
879082c9	282	unsigned int value)
28644c80 DP	283	{
	284	u8 *blk;
	285
	286	blk = krealloc(rbnode->block,
879082c9 MB	287	(rbnode->blklen + 1) * map->cache_word_size,
879082c9 MB	288	GFP_KERNEL);
28644c80 DP	289	if (!blk)
	290	return -ENOMEM;
	291
	292	/* insert the register value in the correct place in the rbnode block */
879082c9 MB	293	memmove(blk + (pos + 1) * map->cache_word_size,
	294	blk + pos * map->cache_word_size,
	295	(rbnode->blklen - pos) * map->cache_word_size);
28644c80 DP	296
	297	/* update the rbnode block, its size and the base register */
	298	rbnode->block = blk;
	299	rbnode->blklen++;
	300	if (!pos)
	301	rbnode->base_reg = reg;
	302
879082c9	303	regcache_rbtree_set_register(map, rbnode, pos, value);
28644c80 DP	304	return 0;
	305	}
	306
	307	static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
	308	unsigned int value)
	309	{
	310	struct regcache_rbtree_ctx *rbtree_ctx;
	311	struct regcache_rbtree_node rbnode, rbnode_tmp;
	312	struct rb_node *node;
28644c80	313	unsigned int reg_tmp;
28644c80 DP	314	unsigned int pos;
	315	int i;
	316	int ret;
	317
	318	rbtree_ctx = map->cache;
0c7ed856	319	/* update the reg_present bitmap, make space if necessary */
78493f2d	320	ret = regcache_set_reg_present(map, reg);
0c7ed856 DP	321	if (ret < 0)
0c7ed856 DP	322	return ret;
0c7ed856	323
28644c80 DP	324	/* if we can't locate it in the cached rbnode we'll have
	325	* to traverse the rbtree looking for it.
	326	*/
3405addd	327	rbnode = regcache_rbtree_lookup(map, reg);
28644c80	328	if (rbnode) {
f01ee60f	329	reg_tmp = (reg - rbnode->base_reg) / map->reg_stride;
879082c9	330	regcache_rbtree_set_register(map, rbnode, reg_tmp, value);
28644c80	331	} else {
28644c80 DP	332	/* look for an adjacent register to the one we are about to add */
	333	for (node = rb_first(&rbtree_ctx->root); node;
	334	node = rb_next(node)) {
f01ee60f SW	335	rbnode_tmp = rb_entry(node, struct regcache_rbtree_node,
f01ee60f SW	336	node);
28644c80	337	for (i = 0; i < rbnode_tmp->blklen; i++) {
f01ee60f SW	338	reg_tmp = rbnode_tmp->base_reg +
	339	(i * map->reg_stride);
	340	if (abs(reg_tmp - reg) != map->reg_stride)
28644c80 DP	341	continue;
28644c80 DP	342	/* decide where in the block to place our register */
f01ee60f	343	if (reg_tmp + map->reg_stride == reg)
28644c80 DP	344	pos = i + 1;
	345	else
	346	pos = i;
879082c9 MB	347	ret = regcache_rbtree_insert_to_block(map,
	348	rbnode_tmp,
	349	pos, reg,
	350	value);
28644c80 DP	351	if (ret)
	352	return ret;
	353	rbtree_ctx->cached_rbnode = rbnode_tmp;
	354	return 0;
	355	}
	356	}
	357	/* we did not manage to find a place to insert it in an existing
	358	* block so create a new rbnode with a single register in its block.
	359	* This block will get populated further if any other adjacent
	360	* registers get modified in the future.
	361	*/
	362	rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL);
	363	if (!rbnode)
	364	return -ENOMEM;
0c7ed856	365	rbnode->blklen = sizeof(*rbnode);
28644c80	366	rbnode->base_reg = reg;
25ed1156	367	rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,
28644c80 DP	368	GFP_KERNEL);
	369	if (!rbnode->block) {
	370	kfree(rbnode);
	371	return -ENOMEM;
	372	}
879082c9	373	regcache_rbtree_set_register(map, rbnode, 0, value);
f01ee60f	374	regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);
28644c80 DP	375	rbtree_ctx->cached_rbnode = rbnode;
	376	}
	377
	378	return 0;
	379	}
	380
ac8d91c8 MB	381	static int regcache_rbtree_sync(struct regmap *map, unsigned int min,
ac8d91c8 MB	382	unsigned int max)
28644c80 DP	383	{
	384	struct regcache_rbtree_ctx *rbtree_ctx;
	385	struct rb_node *node;
	386	struct regcache_rbtree_node *rbnode;
28644c80	387	int ret;
f8bd822c	388	int base, end;
28644c80 DP	389
	390	rbtree_ctx = map->cache;
	391	for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
	392	rbnode = rb_entry(node, struct regcache_rbtree_node, node);
ac8d91c8	393
ac8d91c8 MB	394	if (rbnode->base_reg > max)
	395	break;
	396	if (rbnode->base_reg + rbnode->blklen < min)
	397	continue;
	398
f9353e70	399	if (min > rbnode->base_reg)
ac8d91c8 MB	400	base = min - rbnode->base_reg;
	401	else
	402	base = 0;
	403
	404	if (max < rbnode->base_reg + rbnode->blklen)
8abac3ba	405	end = max - rbnode->base_reg + 1;
ac8d91c8 MB	406	else
	407	end = rbnode->blklen;
	408
f8bd822c MB	409	ret = regcache_sync_block(map, rbnode->block, rbnode->base_reg,
	410	base, end);
	411	if (ret != 0)
	412	return ret;
28644c80 DP	413	}
28644c80 DP	414
f8bd822c	415	return regmap_async_complete(map);
28644c80 DP	416	}
	417
	418	struct regcache_ops regcache_rbtree_ops = {
	419	.type = REGCACHE_RBTREE,
	420	.name = "rbtree",
	421	.init = regcache_rbtree_init,
	422	.exit = regcache_rbtree_exit,
	423	.read = regcache_rbtree_read,
	424	.write = regcache_rbtree_write,
	425	.sync = regcache_rbtree_sync
	426	};