Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 | /*
* 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/rbtree.h>
#include "internal.h"
static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
unsigned int value);
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;
}
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;
}
return 0;
err:
regcache_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)
{
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;
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);
for (i = 0; i < rbnode->blklen; 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
};
|