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