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( | |
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, |
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, |
59 | unsigned int word_size) | |
28644c80 | 60 | { |
c5713004 | 61 | regcache_set_val(rbnode->block, idx, val, word_size); |
28644c80 DP |
62 | } |
63 | ||
3405addd LPC |
64 | static struct regcache_rbtree_node *regcache_rbtree_lookup(struct regmap *map, |
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; |
73 | if (rbnode) { | |
f01ee60f SW |
74 | regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg, |
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) { |
82 | rbnode = container_of(node, struct regcache_rbtree_node, node); | |
f01ee60f SW |
83 | regcache_rbtree_get_base_top_reg(map, rbnode, &base_reg, |
84 | &top_reg); | |
3405addd LPC |
85 | if (reg >= base_reg && reg <= top_reg) { |
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 | |
156 | nodes++; | |
f01ee60f | 157 | registers += this_registers; |
bad2ab4b MB |
158 | } |
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 |
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; |
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, |
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, |
319 | map->cache_word_size); | |
28644c80 DP |
320 | if (val == value) |
321 | return 0; | |
25ed1156 DP |
322 | regcache_rbtree_set_register(rbnode, reg_tmp, value, |
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, |
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; |
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, |
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, |
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, |
408 | map->cache_word_size); | |
b03622a8 MB |
409 | |
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 | }; |