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9fabe24e DP |
1 | /* |
2 | * Register cache access API | |
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> | |
14 | #include <trace/events/regmap.h> | |
15 | ||
16 | #include "internal.h" | |
17 | ||
18 | static const struct regcache_ops *cache_types[] = { | |
195af65c | 19 | ®cache_indexed_ops, |
28644c80 | 20 | ®cache_rbtree_ops, |
2cbbb579 | 21 | ®cache_lzo_ops, |
9fabe24e DP |
22 | }; |
23 | ||
24 | static int regcache_hw_init(struct regmap *map) | |
25 | { | |
26 | int i, j; | |
27 | int ret; | |
28 | int count; | |
29 | unsigned int val; | |
30 | void *tmp_buf; | |
31 | ||
32 | if (!map->num_reg_defaults_raw) | |
33 | return -EINVAL; | |
34 | ||
35 | if (!map->reg_defaults_raw) { | |
36 | dev_warn(map->dev, "No cache defaults, reading back from HW\n"); | |
37 | tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL); | |
38 | if (!tmp_buf) | |
39 | return -EINVAL; | |
40 | ret = regmap_bulk_read(map, 0, tmp_buf, | |
41 | map->num_reg_defaults_raw); | |
42 | if (ret < 0) { | |
43 | kfree(tmp_buf); | |
44 | return ret; | |
45 | } | |
46 | map->reg_defaults_raw = tmp_buf; | |
47 | map->cache_free = 1; | |
48 | } | |
49 | ||
50 | /* calculate the size of reg_defaults */ | |
51 | for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++) { | |
52 | val = regcache_get_val(map->reg_defaults_raw, | |
53 | i, map->cache_word_size); | |
54 | if (!val) | |
55 | continue; | |
56 | count++; | |
57 | } | |
58 | ||
59 | map->reg_defaults = kmalloc(count * sizeof(struct reg_default), | |
60 | GFP_KERNEL); | |
61 | if (!map->reg_defaults) | |
62 | return -ENOMEM; | |
63 | ||
64 | /* fill the reg_defaults */ | |
65 | map->num_reg_defaults = count; | |
66 | for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) { | |
67 | val = regcache_get_val(map->reg_defaults_raw, | |
68 | i, map->cache_word_size); | |
69 | if (!val) | |
70 | continue; | |
71 | map->reg_defaults[j].reg = i; | |
72 | map->reg_defaults[j].def = val; | |
73 | j++; | |
74 | } | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | int regcache_init(struct regmap *map) | |
80 | { | |
81 | int ret; | |
82 | int i; | |
83 | void *tmp_buf; | |
84 | ||
e7a6db30 MB |
85 | if (map->cache_type == REGCACHE_NONE) { |
86 | map->cache_bypass = true; | |
9fabe24e | 87 | return 0; |
e7a6db30 | 88 | } |
9fabe24e DP |
89 | |
90 | for (i = 0; i < ARRAY_SIZE(cache_types); i++) | |
91 | if (cache_types[i]->type == map->cache_type) | |
92 | break; | |
93 | ||
94 | if (i == ARRAY_SIZE(cache_types)) { | |
95 | dev_err(map->dev, "Could not match compress type: %d\n", | |
96 | map->cache_type); | |
97 | return -EINVAL; | |
98 | } | |
99 | ||
100 | map->cache = NULL; | |
101 | map->cache_ops = cache_types[i]; | |
102 | ||
103 | if (!map->cache_ops->read || | |
104 | !map->cache_ops->write || | |
105 | !map->cache_ops->name) | |
106 | return -EINVAL; | |
107 | ||
108 | /* We still need to ensure that the reg_defaults | |
109 | * won't vanish from under us. We'll need to make | |
110 | * a copy of it. | |
111 | */ | |
112 | if (map->reg_defaults) { | |
113 | if (!map->num_reg_defaults) | |
114 | return -EINVAL; | |
115 | tmp_buf = kmemdup(map->reg_defaults, map->num_reg_defaults * | |
116 | sizeof(struct reg_default), GFP_KERNEL); | |
117 | if (!tmp_buf) | |
118 | return -ENOMEM; | |
119 | map->reg_defaults = tmp_buf; | |
120 | } else { | |
5fcd2560 | 121 | /* Some devices such as PMICs don't have cache defaults, |
9fabe24e DP |
122 | * we cope with this by reading back the HW registers and |
123 | * crafting the cache defaults by hand. | |
124 | */ | |
125 | ret = regcache_hw_init(map); | |
126 | if (ret < 0) | |
127 | return ret; | |
128 | } | |
129 | ||
130 | if (!map->max_register) | |
131 | map->max_register = map->num_reg_defaults_raw; | |
132 | ||
133 | if (map->cache_ops->init) { | |
134 | dev_dbg(map->dev, "Initializing %s cache\n", | |
135 | map->cache_ops->name); | |
136 | return map->cache_ops->init(map); | |
137 | } | |
138 | return 0; | |
139 | } | |
140 | ||
141 | void regcache_exit(struct regmap *map) | |
142 | { | |
143 | if (map->cache_type == REGCACHE_NONE) | |
144 | return; | |
145 | ||
146 | BUG_ON(!map->cache_ops); | |
147 | ||
148 | kfree(map->reg_defaults); | |
149 | if (map->cache_free) | |
150 | kfree(map->reg_defaults_raw); | |
151 | ||
152 | if (map->cache_ops->exit) { | |
153 | dev_dbg(map->dev, "Destroying %s cache\n", | |
154 | map->cache_ops->name); | |
155 | map->cache_ops->exit(map); | |
156 | } | |
157 | } | |
158 | ||
159 | /** | |
160 | * regcache_read: Fetch the value of a given register from the cache. | |
161 | * | |
162 | * @map: map to configure. | |
163 | * @reg: The register index. | |
164 | * @value: The value to be returned. | |
165 | * | |
166 | * Return a negative value on failure, 0 on success. | |
167 | */ | |
168 | int regcache_read(struct regmap *map, | |
169 | unsigned int reg, unsigned int *value) | |
170 | { | |
171 | if (map->cache_type == REGCACHE_NONE) | |
172 | return -ENOSYS; | |
173 | ||
174 | BUG_ON(!map->cache_ops); | |
175 | ||
176 | if (!regmap_readable(map, reg)) | |
177 | return -EIO; | |
178 | ||
179 | if (!regmap_volatile(map, reg)) | |
180 | return map->cache_ops->read(map, reg, value); | |
181 | ||
182 | return -EINVAL; | |
183 | } | |
184 | EXPORT_SYMBOL_GPL(regcache_read); | |
185 | ||
186 | /** | |
187 | * regcache_write: Set the value of a given register in the cache. | |
188 | * | |
189 | * @map: map to configure. | |
190 | * @reg: The register index. | |
191 | * @value: The new register value. | |
192 | * | |
193 | * Return a negative value on failure, 0 on success. | |
194 | */ | |
195 | int regcache_write(struct regmap *map, | |
196 | unsigned int reg, unsigned int value) | |
197 | { | |
198 | if (map->cache_type == REGCACHE_NONE) | |
199 | return 0; | |
200 | ||
201 | BUG_ON(!map->cache_ops); | |
202 | ||
203 | if (!regmap_writeable(map, reg)) | |
204 | return -EIO; | |
205 | ||
206 | if (!regmap_volatile(map, reg)) | |
207 | return map->cache_ops->write(map, reg, value); | |
208 | ||
209 | return 0; | |
210 | } | |
211 | EXPORT_SYMBOL_GPL(regcache_write); | |
212 | ||
213 | /** | |
214 | * regcache_sync: Sync the register cache with the hardware. | |
215 | * | |
216 | * @map: map to configure. | |
217 | * | |
218 | * Any registers that should not be synced should be marked as | |
219 | * volatile. In general drivers can choose not to use the provided | |
220 | * syncing functionality if they so require. | |
221 | * | |
222 | * Return a negative value on failure, 0 on success. | |
223 | */ | |
224 | int regcache_sync(struct regmap *map) | |
225 | { | |
954757d7 DP |
226 | int ret = 0; |
227 | unsigned int val; | |
228 | unsigned int i; | |
59360089 DP |
229 | const char *name; |
230 | ||
9fabe24e DP |
231 | BUG_ON(!map->cache_ops); |
232 | ||
13753a90 | 233 | mutex_lock(&map->lock); |
954757d7 DP |
234 | dev_dbg(map->dev, "Syncing %s cache\n", |
235 | map->cache_ops->name); | |
236 | name = map->cache_ops->name; | |
237 | trace_regcache_sync(map->dev, name, "start"); | |
9fabe24e | 238 | if (map->cache_ops->sync) { |
59360089 | 239 | ret = map->cache_ops->sync(map); |
954757d7 DP |
240 | } else { |
241 | for (i = 0; i < map->num_reg_defaults; i++) { | |
242 | ret = regcache_read(map, i, &val); | |
243 | if (ret < 0) | |
244 | goto out; | |
ec8a365f | 245 | map->cache_bypass = 1; |
13753a90 | 246 | ret = _regmap_write(map, i, val); |
ec8a365f | 247 | map->cache_bypass = 0; |
954757d7 DP |
248 | if (ret < 0) |
249 | goto out; | |
250 | dev_dbg(map->dev, "Synced register %#x, value %#x\n", | |
251 | map->reg_defaults[i].reg, | |
252 | map->reg_defaults[i].def); | |
253 | } | |
254 | ||
9fabe24e | 255 | } |
954757d7 DP |
256 | out: |
257 | trace_regcache_sync(map->dev, name, "stop"); | |
13753a90 | 258 | mutex_unlock(&map->lock); |
954757d7 DP |
259 | |
260 | return ret; | |
9fabe24e DP |
261 | } |
262 | EXPORT_SYMBOL_GPL(regcache_sync); | |
263 | ||
92afb286 MB |
264 | /** |
265 | * regcache_cache_only: Put a register map into cache only mode | |
266 | * | |
267 | * @map: map to configure | |
268 | * @cache_only: flag if changes should be written to the hardware | |
269 | * | |
270 | * When a register map is marked as cache only writes to the register | |
271 | * map API will only update the register cache, they will not cause | |
272 | * any hardware changes. This is useful for allowing portions of | |
273 | * drivers to act as though the device were functioning as normal when | |
274 | * it is disabled for power saving reasons. | |
275 | */ | |
276 | void regcache_cache_only(struct regmap *map, bool enable) | |
277 | { | |
2cd148f1 | 278 | mutex_lock(&map->lock); |
92afb286 | 279 | map->cache_only = enable; |
2cd148f1 | 280 | mutex_unlock(&map->lock); |
92afb286 MB |
281 | } |
282 | EXPORT_SYMBOL_GPL(regcache_cache_only); | |
283 | ||
9fabe24e DP |
284 | bool regcache_set_val(void *base, unsigned int idx, |
285 | unsigned int val, unsigned int word_size) | |
286 | { | |
287 | switch (word_size) { | |
288 | case 1: { | |
289 | u8 *cache = base; | |
290 | if (cache[idx] == val) | |
291 | return true; | |
292 | cache[idx] = val; | |
293 | break; | |
294 | } | |
295 | case 2: { | |
296 | u16 *cache = base; | |
297 | if (cache[idx] == val) | |
298 | return true; | |
299 | cache[idx] = val; | |
300 | break; | |
301 | } | |
302 | default: | |
303 | BUG(); | |
304 | } | |
305 | /* unreachable */ | |
306 | return false; | |
307 | } | |
308 | ||
309 | unsigned int regcache_get_val(const void *base, unsigned int idx, | |
310 | unsigned int word_size) | |
311 | { | |
312 | if (!base) | |
313 | return -EINVAL; | |
314 | ||
315 | switch (word_size) { | |
316 | case 1: { | |
317 | const u8 *cache = base; | |
318 | return cache[idx]; | |
319 | } | |
320 | case 2: { | |
321 | const u16 *cache = base; | |
322 | return cache[idx]; | |
323 | } | |
324 | default: | |
325 | BUG(); | |
326 | } | |
327 | /* unreachable */ | |
328 | return -1; | |
329 | } | |
330 | ||
331 | int regcache_lookup_reg(struct regmap *map, unsigned int reg) | |
332 | { | |
333 | unsigned int i; | |
334 | ||
335 | for (i = 0; i < map->num_reg_defaults; i++) | |
336 | if (map->reg_defaults[i].reg == reg) | |
337 | return i; | |
338 | return -1; | |
339 | } | |
340 | ||
341 | int regcache_insert_reg(struct regmap *map, unsigned int reg, | |
342 | unsigned int val) | |
343 | { | |
344 | void *tmp; | |
345 | ||
346 | tmp = krealloc(map->reg_defaults, | |
347 | (map->num_reg_defaults + 1) * sizeof(struct reg_default), | |
348 | GFP_KERNEL); | |
349 | if (!tmp) | |
350 | return -ENOMEM; | |
351 | map->reg_defaults = tmp; | |
352 | map->num_reg_defaults++; | |
353 | map->reg_defaults[map->num_reg_defaults - 1].reg = reg; | |
354 | map->reg_defaults[map->num_reg_defaults - 1].def = val; | |
355 | return 0; | |
356 | } |