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1 | /* | |
2 | * Register map access API | |
3 | * | |
4 | * Copyright 2011 Wolfson Microelectronics plc | |
5 | * | |
6 | * Author: Mark Brown <broonie@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 <linux/module.h> | |
15 | #include <linux/mutex.h> | |
16 | #include <linux/err.h> | |
17 | ||
18 | #define CREATE_TRACE_POINTS | |
19 | #include <trace/events/regmap.h> | |
20 | ||
21 | #include "internal.h" | |
22 | ||
23 | bool regmap_writeable(struct regmap *map, unsigned int reg) | |
24 | { | |
25 | if (map->max_register && reg > map->max_register) | |
26 | return false; | |
27 | ||
28 | if (map->writeable_reg) | |
29 | return map->writeable_reg(map->dev, reg); | |
30 | ||
31 | return true; | |
32 | } | |
33 | ||
34 | bool regmap_readable(struct regmap *map, unsigned int reg) | |
35 | { | |
36 | if (map->max_register && reg > map->max_register) | |
37 | return false; | |
38 | ||
39 | if (map->readable_reg) | |
40 | return map->readable_reg(map->dev, reg); | |
41 | ||
42 | return true; | |
43 | } | |
44 | ||
45 | bool regmap_volatile(struct regmap *map, unsigned int reg) | |
46 | { | |
47 | if (map->max_register && reg > map->max_register) | |
48 | return false; | |
49 | ||
50 | if (map->volatile_reg) | |
51 | return map->volatile_reg(map->dev, reg); | |
52 | ||
53 | return true; | |
54 | } | |
55 | ||
56 | bool regmap_precious(struct regmap *map, unsigned int reg) | |
57 | { | |
58 | if (map->max_register && reg > map->max_register) | |
59 | return false; | |
60 | ||
61 | if (map->precious_reg) | |
62 | return map->precious_reg(map->dev, reg); | |
63 | ||
64 | return false; | |
65 | } | |
66 | ||
67 | static void regmap_format_4_12_write(struct regmap *map, | |
68 | unsigned int reg, unsigned int val) | |
69 | { | |
70 | __be16 *out = map->work_buf; | |
71 | *out = cpu_to_be16((reg << 12) | val); | |
72 | } | |
73 | ||
74 | static void regmap_format_7_9_write(struct regmap *map, | |
75 | unsigned int reg, unsigned int val) | |
76 | { | |
77 | __be16 *out = map->work_buf; | |
78 | *out = cpu_to_be16((reg << 9) | val); | |
79 | } | |
80 | ||
81 | static void regmap_format_8(void *buf, unsigned int val) | |
82 | { | |
83 | u8 *b = buf; | |
84 | ||
85 | b[0] = val; | |
86 | } | |
87 | ||
88 | static void regmap_format_16(void *buf, unsigned int val) | |
89 | { | |
90 | __be16 *b = buf; | |
91 | ||
92 | b[0] = cpu_to_be16(val); | |
93 | } | |
94 | ||
95 | static unsigned int regmap_parse_8(void *buf) | |
96 | { | |
97 | u8 *b = buf; | |
98 | ||
99 | return b[0]; | |
100 | } | |
101 | ||
102 | static unsigned int regmap_parse_16(void *buf) | |
103 | { | |
104 | __be16 *b = buf; | |
105 | ||
106 | b[0] = be16_to_cpu(b[0]); | |
107 | ||
108 | return b[0]; | |
109 | } | |
110 | ||
111 | /** | |
112 | * regmap_init(): Initialise register map | |
113 | * | |
114 | * @dev: Device that will be interacted with | |
115 | * @bus: Bus-specific callbacks to use with device | |
116 | * @config: Configuration for register map | |
117 | * | |
118 | * The return value will be an ERR_PTR() on error or a valid pointer to | |
119 | * a struct regmap. This function should generally not be called | |
120 | * directly, it should be called by bus-specific init functions. | |
121 | */ | |
122 | struct regmap *regmap_init(struct device *dev, | |
123 | const struct regmap_bus *bus, | |
124 | const struct regmap_config *config) | |
125 | { | |
126 | struct regmap *map; | |
127 | int ret = -EINVAL; | |
128 | ||
129 | if (!bus || !config) | |
130 | return NULL; | |
131 | ||
132 | map = kzalloc(sizeof(*map), GFP_KERNEL); | |
133 | if (map == NULL) { | |
134 | ret = -ENOMEM; | |
135 | goto err; | |
136 | } | |
137 | ||
138 | mutex_init(&map->lock); | |
139 | map->format.buf_size = (config->reg_bits + config->val_bits) / 8; | |
140 | map->format.reg_bytes = config->reg_bits / 8; | |
141 | map->format.val_bytes = config->val_bits / 8; | |
142 | map->dev = dev; | |
143 | map->bus = bus; | |
144 | map->max_register = config->max_register; | |
145 | map->writeable_reg = config->writeable_reg; | |
146 | map->readable_reg = config->readable_reg; | |
147 | map->volatile_reg = config->volatile_reg; | |
148 | map->precious_reg = config->precious_reg; | |
149 | map->cache_type = config->cache_type; | |
150 | map->reg_defaults = config->reg_defaults; | |
151 | map->num_reg_defaults = config->num_reg_defaults; | |
152 | map->num_reg_defaults_raw = config->num_reg_defaults_raw; | |
153 | map->reg_defaults_raw = config->reg_defaults_raw; | |
154 | map->cache_size_raw = (config->val_bits / 8) * config->num_reg_defaults_raw; | |
155 | map->cache_word_size = config->val_bits / 8; | |
156 | ||
157 | if (config->read_flag_mask || config->write_flag_mask) { | |
158 | map->read_flag_mask = config->read_flag_mask; | |
159 | map->write_flag_mask = config->write_flag_mask; | |
160 | } else { | |
161 | map->read_flag_mask = bus->read_flag_mask; | |
162 | } | |
163 | ||
164 | switch (config->reg_bits) { | |
165 | case 4: | |
166 | switch (config->val_bits) { | |
167 | case 12: | |
168 | map->format.format_write = regmap_format_4_12_write; | |
169 | break; | |
170 | default: | |
171 | goto err_map; | |
172 | } | |
173 | break; | |
174 | ||
175 | case 7: | |
176 | switch (config->val_bits) { | |
177 | case 9: | |
178 | map->format.format_write = regmap_format_7_9_write; | |
179 | break; | |
180 | default: | |
181 | goto err_map; | |
182 | } | |
183 | break; | |
184 | ||
185 | case 8: | |
186 | map->format.format_reg = regmap_format_8; | |
187 | break; | |
188 | ||
189 | case 16: | |
190 | map->format.format_reg = regmap_format_16; | |
191 | break; | |
192 | ||
193 | default: | |
194 | goto err_map; | |
195 | } | |
196 | ||
197 | switch (config->val_bits) { | |
198 | case 8: | |
199 | map->format.format_val = regmap_format_8; | |
200 | map->format.parse_val = regmap_parse_8; | |
201 | break; | |
202 | case 16: | |
203 | map->format.format_val = regmap_format_16; | |
204 | map->format.parse_val = regmap_parse_16; | |
205 | break; | |
206 | } | |
207 | ||
208 | if (!map->format.format_write && | |
209 | !(map->format.format_reg && map->format.format_val)) | |
210 | goto err_map; | |
211 | ||
212 | map->work_buf = kmalloc(map->format.buf_size, GFP_KERNEL); | |
213 | if (map->work_buf == NULL) { | |
214 | ret = -ENOMEM; | |
215 | goto err_map; | |
216 | } | |
217 | ||
218 | ret = regcache_init(map); | |
219 | if (ret < 0) | |
220 | goto err_map; | |
221 | ||
222 | regmap_debugfs_init(map); | |
223 | ||
224 | return map; | |
225 | ||
226 | err_map: | |
227 | kfree(map); | |
228 | err: | |
229 | return ERR_PTR(ret); | |
230 | } | |
231 | EXPORT_SYMBOL_GPL(regmap_init); | |
232 | ||
233 | /** | |
234 | * regmap_exit(): Free a previously allocated register map | |
235 | */ | |
236 | void regmap_exit(struct regmap *map) | |
237 | { | |
238 | regcache_exit(map); | |
239 | regmap_debugfs_exit(map); | |
240 | kfree(map->work_buf); | |
241 | kfree(map); | |
242 | } | |
243 | EXPORT_SYMBOL_GPL(regmap_exit); | |
244 | ||
245 | static int _regmap_raw_write(struct regmap *map, unsigned int reg, | |
246 | const void *val, size_t val_len) | |
247 | { | |
248 | u8 *u8 = map->work_buf; | |
249 | void *buf; | |
250 | int ret = -ENOTSUPP; | |
251 | size_t len; | |
252 | int i; | |
253 | ||
254 | /* Check for unwritable registers before we start */ | |
255 | if (map->writeable_reg) | |
256 | for (i = 0; i < val_len / map->format.val_bytes; i++) | |
257 | if (!map->writeable_reg(map->dev, reg + i)) | |
258 | return -EINVAL; | |
259 | ||
260 | map->format.format_reg(map->work_buf, reg); | |
261 | ||
262 | u8[0] |= map->write_flag_mask; | |
263 | ||
264 | trace_regmap_hw_write_start(map->dev, reg, | |
265 | val_len / map->format.val_bytes); | |
266 | ||
267 | /* If we're doing a single register write we can probably just | |
268 | * send the work_buf directly, otherwise try to do a gather | |
269 | * write. | |
270 | */ | |
271 | if (val == map->work_buf + map->format.reg_bytes) | |
272 | ret = map->bus->write(map->dev, map->work_buf, | |
273 | map->format.reg_bytes + val_len); | |
274 | else if (map->bus->gather_write) | |
275 | ret = map->bus->gather_write(map->dev, map->work_buf, | |
276 | map->format.reg_bytes, | |
277 | val, val_len); | |
278 | ||
279 | /* If that didn't work fall back on linearising by hand. */ | |
280 | if (ret == -ENOTSUPP) { | |
281 | len = map->format.reg_bytes + val_len; | |
282 | buf = kmalloc(len, GFP_KERNEL); | |
283 | if (!buf) | |
284 | return -ENOMEM; | |
285 | ||
286 | memcpy(buf, map->work_buf, map->format.reg_bytes); | |
287 | memcpy(buf + map->format.reg_bytes, val, val_len); | |
288 | ret = map->bus->write(map->dev, buf, len); | |
289 | ||
290 | kfree(buf); | |
291 | } | |
292 | ||
293 | trace_regmap_hw_write_done(map->dev, reg, | |
294 | val_len / map->format.val_bytes); | |
295 | ||
296 | return ret; | |
297 | } | |
298 | ||
299 | int _regmap_write(struct regmap *map, unsigned int reg, | |
300 | unsigned int val) | |
301 | { | |
302 | int ret; | |
303 | BUG_ON(!map->format.format_write && !map->format.format_val); | |
304 | ||
305 | if (!map->cache_bypass) { | |
306 | ret = regcache_write(map, reg, val); | |
307 | if (ret != 0) | |
308 | return ret; | |
309 | if (map->cache_only) | |
310 | return 0; | |
311 | } | |
312 | ||
313 | trace_regmap_reg_write(map->dev, reg, val); | |
314 | ||
315 | if (map->format.format_write) { | |
316 | map->format.format_write(map, reg, val); | |
317 | ||
318 | trace_regmap_hw_write_start(map->dev, reg, 1); | |
319 | ||
320 | ret = map->bus->write(map->dev, map->work_buf, | |
321 | map->format.buf_size); | |
322 | ||
323 | trace_regmap_hw_write_done(map->dev, reg, 1); | |
324 | ||
325 | return ret; | |
326 | } else { | |
327 | map->format.format_val(map->work_buf + map->format.reg_bytes, | |
328 | val); | |
329 | return _regmap_raw_write(map, reg, | |
330 | map->work_buf + map->format.reg_bytes, | |
331 | map->format.val_bytes); | |
332 | } | |
333 | } | |
334 | ||
335 | /** | |
336 | * regmap_write(): Write a value to a single register | |
337 | * | |
338 | * @map: Register map to write to | |
339 | * @reg: Register to write to | |
340 | * @val: Value to be written | |
341 | * | |
342 | * A value of zero will be returned on success, a negative errno will | |
343 | * be returned in error cases. | |
344 | */ | |
345 | int regmap_write(struct regmap *map, unsigned int reg, unsigned int val) | |
346 | { | |
347 | int ret; | |
348 | ||
349 | mutex_lock(&map->lock); | |
350 | ||
351 | ret = _regmap_write(map, reg, val); | |
352 | ||
353 | mutex_unlock(&map->lock); | |
354 | ||
355 | return ret; | |
356 | } | |
357 | EXPORT_SYMBOL_GPL(regmap_write); | |
358 | ||
359 | /** | |
360 | * regmap_raw_write(): Write raw values to one or more registers | |
361 | * | |
362 | * @map: Register map to write to | |
363 | * @reg: Initial register to write to | |
364 | * @val: Block of data to be written, laid out for direct transmission to the | |
365 | * device | |
366 | * @val_len: Length of data pointed to by val. | |
367 | * | |
368 | * This function is intended to be used for things like firmware | |
369 | * download where a large block of data needs to be transferred to the | |
370 | * device. No formatting will be done on the data provided. | |
371 | * | |
372 | * A value of zero will be returned on success, a negative errno will | |
373 | * be returned in error cases. | |
374 | */ | |
375 | int regmap_raw_write(struct regmap *map, unsigned int reg, | |
376 | const void *val, size_t val_len) | |
377 | { | |
378 | int ret; | |
379 | ||
380 | WARN_ON(map->cache_type != REGCACHE_NONE); | |
381 | ||
382 | mutex_lock(&map->lock); | |
383 | ||
384 | ret = _regmap_raw_write(map, reg, val, val_len); | |
385 | ||
386 | mutex_unlock(&map->lock); | |
387 | ||
388 | return ret; | |
389 | } | |
390 | EXPORT_SYMBOL_GPL(regmap_raw_write); | |
391 | ||
392 | static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val, | |
393 | unsigned int val_len) | |
394 | { | |
395 | u8 *u8 = map->work_buf; | |
396 | int ret; | |
397 | ||
398 | map->format.format_reg(map->work_buf, reg); | |
399 | ||
400 | /* | |
401 | * Some buses or devices flag reads by setting the high bits in the | |
402 | * register addresss; since it's always the high bits for all | |
403 | * current formats we can do this here rather than in | |
404 | * formatting. This may break if we get interesting formats. | |
405 | */ | |
406 | u8[0] |= map->read_flag_mask; | |
407 | ||
408 | trace_regmap_hw_read_start(map->dev, reg, | |
409 | val_len / map->format.val_bytes); | |
410 | ||
411 | ret = map->bus->read(map->dev, map->work_buf, map->format.reg_bytes, | |
412 | val, val_len); | |
413 | ||
414 | trace_regmap_hw_read_done(map->dev, reg, | |
415 | val_len / map->format.val_bytes); | |
416 | ||
417 | return ret; | |
418 | } | |
419 | ||
420 | static int _regmap_read(struct regmap *map, unsigned int reg, | |
421 | unsigned int *val) | |
422 | { | |
423 | int ret; | |
424 | ||
425 | if (!map->format.parse_val) | |
426 | return -EINVAL; | |
427 | ||
428 | if (!map->cache_bypass) { | |
429 | ret = regcache_read(map, reg, val); | |
430 | if (ret == 0) | |
431 | return 0; | |
432 | } | |
433 | ||
434 | if (map->cache_only) | |
435 | return -EBUSY; | |
436 | ||
437 | ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes); | |
438 | if (ret == 0) { | |
439 | *val = map->format.parse_val(map->work_buf); | |
440 | trace_regmap_reg_read(map->dev, reg, *val); | |
441 | } | |
442 | ||
443 | return ret; | |
444 | } | |
445 | ||
446 | /** | |
447 | * regmap_read(): Read a value from a single register | |
448 | * | |
449 | * @map: Register map to write to | |
450 | * @reg: Register to be read from | |
451 | * @val: Pointer to store read value | |
452 | * | |
453 | * A value of zero will be returned on success, a negative errno will | |
454 | * be returned in error cases. | |
455 | */ | |
456 | int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val) | |
457 | { | |
458 | int ret; | |
459 | ||
460 | mutex_lock(&map->lock); | |
461 | ||
462 | ret = _regmap_read(map, reg, val); | |
463 | ||
464 | mutex_unlock(&map->lock); | |
465 | ||
466 | return ret; | |
467 | } | |
468 | EXPORT_SYMBOL_GPL(regmap_read); | |
469 | ||
470 | /** | |
471 | * regmap_raw_read(): Read raw data from the device | |
472 | * | |
473 | * @map: Register map to write to | |
474 | * @reg: First register to be read from | |
475 | * @val: Pointer to store read value | |
476 | * @val_len: Size of data to read | |
477 | * | |
478 | * A value of zero will be returned on success, a negative errno will | |
479 | * be returned in error cases. | |
480 | */ | |
481 | int regmap_raw_read(struct regmap *map, unsigned int reg, void *val, | |
482 | size_t val_len) | |
483 | { | |
484 | int ret; | |
485 | int i; | |
486 | bool vol = true; | |
487 | ||
488 | for (i = 0; i < val_len / map->format.val_bytes; i++) | |
489 | if (!regmap_volatile(map, reg + i)) | |
490 | vol = false; | |
491 | ||
492 | WARN_ON(!vol && map->cache_type != REGCACHE_NONE); | |
493 | ||
494 | mutex_lock(&map->lock); | |
495 | ||
496 | ret = _regmap_raw_read(map, reg, val, val_len); | |
497 | ||
498 | mutex_unlock(&map->lock); | |
499 | ||
500 | return ret; | |
501 | } | |
502 | EXPORT_SYMBOL_GPL(regmap_raw_read); | |
503 | ||
504 | /** | |
505 | * regmap_bulk_read(): Read multiple registers from the device | |
506 | * | |
507 | * @map: Register map to write to | |
508 | * @reg: First register to be read from | |
509 | * @val: Pointer to store read value, in native register size for device | |
510 | * @val_count: Number of registers to read | |
511 | * | |
512 | * A value of zero will be returned on success, a negative errno will | |
513 | * be returned in error cases. | |
514 | */ | |
515 | int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val, | |
516 | size_t val_count) | |
517 | { | |
518 | int ret, i; | |
519 | size_t val_bytes = map->format.val_bytes; | |
520 | bool vol = true; | |
521 | ||
522 | if (!map->format.parse_val) | |
523 | return -EINVAL; | |
524 | ||
525 | /* Is this a block of volatile registers? */ | |
526 | for (i = 0; i < val_count; i++) | |
527 | if (!regmap_volatile(map, reg + i)) | |
528 | vol = false; | |
529 | ||
530 | if (vol || map->cache_type == REGCACHE_NONE) { | |
531 | ret = regmap_raw_read(map, reg, val, val_bytes * val_count); | |
532 | if (ret != 0) | |
533 | return ret; | |
534 | ||
535 | for (i = 0; i < val_count * val_bytes; i += val_bytes) | |
536 | map->format.parse_val(val + i); | |
537 | } else { | |
538 | for (i = 0; i < val_count; i++) { | |
539 | ret = regmap_read(map, reg + i, val + (i * val_bytes)); | |
540 | if (ret != 0) | |
541 | return ret; | |
542 | } | |
543 | } | |
544 | ||
545 | return 0; | |
546 | } | |
547 | EXPORT_SYMBOL_GPL(regmap_bulk_read); | |
548 | ||
549 | /** | |
550 | * remap_update_bits: Perform a read/modify/write cycle on the register map | |
551 | * | |
552 | * @map: Register map to update | |
553 | * @reg: Register to update | |
554 | * @mask: Bitmask to change | |
555 | * @val: New value for bitmask | |
556 | * | |
557 | * Returns zero for success, a negative number on error. | |
558 | */ | |
559 | int regmap_update_bits(struct regmap *map, unsigned int reg, | |
560 | unsigned int mask, unsigned int val) | |
561 | { | |
562 | int ret; | |
563 | unsigned int tmp; | |
564 | ||
565 | mutex_lock(&map->lock); | |
566 | ||
567 | ret = _regmap_read(map, reg, &tmp); | |
568 | if (ret != 0) | |
569 | goto out; | |
570 | ||
571 | tmp &= ~mask; | |
572 | tmp |= val & mask; | |
573 | ||
574 | ret = _regmap_write(map, reg, tmp); | |
575 | ||
576 | out: | |
577 | mutex_unlock(&map->lock); | |
578 | ||
579 | return ret; | |
580 | } | |
581 | EXPORT_SYMBOL_GPL(regmap_update_bits); | |
582 | ||
583 | static int __init regmap_initcall(void) | |
584 | { | |
585 | regmap_debugfs_initcall(); | |
586 | ||
587 | return 0; | |
588 | } | |
589 | postcore_initcall(regmap_initcall); |