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b83a313b MB |
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 | #include <linux/regmap.h> | |
19 | ||
fb2736bb MB |
20 | #define CREATE_TRACE_POINTS |
21 | #include <trace/events/regmap.h> | |
22 | ||
b83a313b MB |
23 | struct regmap; |
24 | ||
25 | struct regmap_format { | |
26 | size_t buf_size; | |
27 | size_t reg_bytes; | |
28 | size_t val_bytes; | |
29 | void (*format_write)(struct regmap *map, | |
30 | unsigned int reg, unsigned int val); | |
31 | void (*format_reg)(void *buf, unsigned int reg); | |
32 | void (*format_val)(void *buf, unsigned int val); | |
33 | unsigned int (*parse_val)(void *buf); | |
34 | }; | |
35 | ||
36 | struct regmap { | |
37 | struct mutex lock; | |
38 | ||
39 | struct device *dev; /* Device we do I/O on */ | |
40 | void *work_buf; /* Scratch buffer used to format I/O */ | |
41 | struct regmap_format format; /* Buffer format */ | |
42 | const struct regmap_bus *bus; | |
2e2ae66d MB |
43 | |
44 | unsigned int max_register; | |
45 | bool (*writeable_reg)(struct device *dev, unsigned int reg); | |
46 | bool (*readable_reg)(struct device *dev, unsigned int reg); | |
47 | bool (*volatile_reg)(struct device *dev, unsigned int reg); | |
b83a313b MB |
48 | }; |
49 | ||
50 | static void regmap_format_4_12_write(struct regmap *map, | |
51 | unsigned int reg, unsigned int val) | |
52 | { | |
53 | __be16 *out = map->work_buf; | |
54 | *out = cpu_to_be16((reg << 12) | val); | |
55 | } | |
56 | ||
57 | static void regmap_format_7_9_write(struct regmap *map, | |
58 | unsigned int reg, unsigned int val) | |
59 | { | |
60 | __be16 *out = map->work_buf; | |
61 | *out = cpu_to_be16((reg << 9) | val); | |
62 | } | |
63 | ||
64 | static void regmap_format_8(void *buf, unsigned int val) | |
65 | { | |
66 | u8 *b = buf; | |
67 | ||
68 | b[0] = val; | |
69 | } | |
70 | ||
71 | static void regmap_format_16(void *buf, unsigned int val) | |
72 | { | |
73 | __be16 *b = buf; | |
74 | ||
75 | b[0] = cpu_to_be16(val); | |
76 | } | |
77 | ||
78 | static unsigned int regmap_parse_8(void *buf) | |
79 | { | |
80 | u8 *b = buf; | |
81 | ||
82 | return b[0]; | |
83 | } | |
84 | ||
85 | static unsigned int regmap_parse_16(void *buf) | |
86 | { | |
87 | __be16 *b = buf; | |
88 | ||
89 | b[0] = be16_to_cpu(b[0]); | |
90 | ||
91 | return b[0]; | |
92 | } | |
93 | ||
94 | /** | |
95 | * regmap_init(): Initialise register map | |
96 | * | |
97 | * @dev: Device that will be interacted with | |
98 | * @bus: Bus-specific callbacks to use with device | |
99 | * @config: Configuration for register map | |
100 | * | |
101 | * The return value will be an ERR_PTR() on error or a valid pointer to | |
102 | * a struct regmap. This function should generally not be called | |
103 | * directly, it should be called by bus-specific init functions. | |
104 | */ | |
105 | struct regmap *regmap_init(struct device *dev, | |
106 | const struct regmap_bus *bus, | |
107 | const struct regmap_config *config) | |
108 | { | |
109 | struct regmap *map; | |
110 | int ret = -EINVAL; | |
111 | ||
112 | if (!bus || !config) | |
113 | return NULL; | |
114 | ||
115 | map = kzalloc(sizeof(*map), GFP_KERNEL); | |
116 | if (map == NULL) { | |
117 | ret = -ENOMEM; | |
118 | goto err; | |
119 | } | |
120 | ||
121 | mutex_init(&map->lock); | |
122 | map->format.buf_size = (config->reg_bits + config->val_bits) / 8; | |
123 | map->format.reg_bytes = config->reg_bits / 8; | |
124 | map->format.val_bytes = config->val_bits / 8; | |
125 | map->dev = dev; | |
126 | map->bus = bus; | |
2e2ae66d MB |
127 | map->max_register = config->max_register; |
128 | map->writeable_reg = config->writeable_reg; | |
129 | map->readable_reg = config->readable_reg; | |
130 | map->volatile_reg = config->volatile_reg; | |
b83a313b MB |
131 | |
132 | switch (config->reg_bits) { | |
133 | case 4: | |
134 | switch (config->val_bits) { | |
135 | case 12: | |
136 | map->format.format_write = regmap_format_4_12_write; | |
137 | break; | |
138 | default: | |
139 | goto err_map; | |
140 | } | |
141 | break; | |
142 | ||
143 | case 7: | |
144 | switch (config->val_bits) { | |
145 | case 9: | |
146 | map->format.format_write = regmap_format_7_9_write; | |
147 | break; | |
148 | default: | |
149 | goto err_map; | |
150 | } | |
151 | break; | |
152 | ||
153 | case 8: | |
154 | map->format.format_reg = regmap_format_8; | |
155 | break; | |
156 | ||
157 | case 16: | |
158 | map->format.format_reg = regmap_format_16; | |
159 | break; | |
160 | ||
161 | default: | |
162 | goto err_map; | |
163 | } | |
164 | ||
165 | switch (config->val_bits) { | |
166 | case 8: | |
167 | map->format.format_val = regmap_format_8; | |
168 | map->format.parse_val = regmap_parse_8; | |
169 | break; | |
170 | case 16: | |
171 | map->format.format_val = regmap_format_16; | |
172 | map->format.parse_val = regmap_parse_16; | |
173 | break; | |
174 | } | |
175 | ||
176 | if (!map->format.format_write && | |
177 | !(map->format.format_reg && map->format.format_val)) | |
178 | goto err_map; | |
179 | ||
180 | map->work_buf = kmalloc(map->format.buf_size, GFP_KERNEL); | |
181 | if (map->work_buf == NULL) { | |
182 | ret = -ENOMEM; | |
183 | goto err_bus; | |
184 | } | |
185 | ||
186 | return map; | |
187 | ||
188 | err_bus: | |
189 | module_put(map->bus->owner); | |
190 | err_map: | |
191 | kfree(map); | |
192 | err: | |
193 | return ERR_PTR(ret); | |
194 | } | |
195 | EXPORT_SYMBOL_GPL(regmap_init); | |
196 | ||
197 | /** | |
198 | * regmap_exit(): Free a previously allocated register map | |
199 | */ | |
200 | void regmap_exit(struct regmap *map) | |
201 | { | |
202 | kfree(map->work_buf); | |
203 | module_put(map->bus->owner); | |
204 | kfree(map); | |
205 | } | |
206 | EXPORT_SYMBOL_GPL(regmap_exit); | |
207 | ||
208 | static int _regmap_raw_write(struct regmap *map, unsigned int reg, | |
209 | const void *val, size_t val_len) | |
210 | { | |
211 | void *buf; | |
212 | int ret = -ENOTSUPP; | |
213 | size_t len; | |
73304781 MB |
214 | int i; |
215 | ||
216 | /* Check for unwritable registers before we start */ | |
217 | if (map->writeable_reg) | |
218 | for (i = 0; i < val_len / map->format.val_bytes; i++) | |
219 | if (!map->writeable_reg(map->dev, reg + i)) | |
220 | return -EINVAL; | |
b83a313b MB |
221 | |
222 | map->format.format_reg(map->work_buf, reg); | |
223 | ||
fb2736bb MB |
224 | trace_regmap_hw_write_start(map->dev, reg, |
225 | val_len / map->format.val_bytes); | |
226 | ||
2547e201 MB |
227 | /* If we're doing a single register write we can probably just |
228 | * send the work_buf directly, otherwise try to do a gather | |
229 | * write. | |
230 | */ | |
231 | if (val == map->work_buf + map->format.reg_bytes) | |
232 | ret = map->bus->write(map->dev, map->work_buf, | |
233 | map->format.reg_bytes + val_len); | |
234 | else if (map->bus->gather_write) | |
b83a313b MB |
235 | ret = map->bus->gather_write(map->dev, map->work_buf, |
236 | map->format.reg_bytes, | |
237 | val, val_len); | |
238 | ||
2547e201 | 239 | /* If that didn't work fall back on linearising by hand. */ |
b83a313b MB |
240 | if (ret == -ENOTSUPP) { |
241 | len = map->format.reg_bytes + val_len; | |
242 | buf = kmalloc(len, GFP_KERNEL); | |
243 | if (!buf) | |
244 | return -ENOMEM; | |
245 | ||
246 | memcpy(buf, map->work_buf, map->format.reg_bytes); | |
247 | memcpy(buf + map->format.reg_bytes, val, val_len); | |
248 | ret = map->bus->write(map->dev, buf, len); | |
249 | ||
250 | kfree(buf); | |
251 | } | |
252 | ||
fb2736bb MB |
253 | trace_regmap_hw_write_done(map->dev, reg, |
254 | val_len / map->format.val_bytes); | |
255 | ||
b83a313b MB |
256 | return ret; |
257 | } | |
258 | ||
259 | static int _regmap_write(struct regmap *map, unsigned int reg, | |
260 | unsigned int val) | |
261 | { | |
fb2736bb | 262 | int ret; |
b83a313b MB |
263 | BUG_ON(!map->format.format_write && !map->format.format_val); |
264 | ||
fb2736bb MB |
265 | trace_regmap_reg_write(map->dev, reg, val); |
266 | ||
b83a313b MB |
267 | if (map->format.format_write) { |
268 | map->format.format_write(map, reg, val); | |
269 | ||
fb2736bb MB |
270 | trace_regmap_hw_write_start(map->dev, reg, 1); |
271 | ||
272 | ret = map->bus->write(map->dev, map->work_buf, | |
273 | map->format.buf_size); | |
274 | ||
275 | trace_regmap_hw_write_done(map->dev, reg, 1); | |
276 | ||
277 | return ret; | |
b83a313b MB |
278 | } else { |
279 | map->format.format_val(map->work_buf + map->format.reg_bytes, | |
280 | val); | |
281 | return _regmap_raw_write(map, reg, | |
282 | map->work_buf + map->format.reg_bytes, | |
283 | map->format.val_bytes); | |
284 | } | |
285 | } | |
286 | ||
287 | /** | |
288 | * regmap_write(): Write a value to a single register | |
289 | * | |
290 | * @map: Register map to write to | |
291 | * @reg: Register to write to | |
292 | * @val: Value to be written | |
293 | * | |
294 | * A value of zero will be returned on success, a negative errno will | |
295 | * be returned in error cases. | |
296 | */ | |
297 | int regmap_write(struct regmap *map, unsigned int reg, unsigned int val) | |
298 | { | |
299 | int ret; | |
300 | ||
301 | mutex_lock(&map->lock); | |
302 | ||
303 | ret = _regmap_write(map, reg, val); | |
304 | ||
305 | mutex_unlock(&map->lock); | |
306 | ||
307 | return ret; | |
308 | } | |
309 | EXPORT_SYMBOL_GPL(regmap_write); | |
310 | ||
311 | /** | |
312 | * regmap_raw_write(): Write raw values to one or more registers | |
313 | * | |
314 | * @map: Register map to write to | |
315 | * @reg: Initial register to write to | |
316 | * @val: Block of data to be written, laid out for direct transmission to the | |
317 | * device | |
318 | * @val_len: Length of data pointed to by val. | |
319 | * | |
320 | * This function is intended to be used for things like firmware | |
321 | * download where a large block of data needs to be transferred to the | |
322 | * device. No formatting will be done on the data provided. | |
323 | * | |
324 | * A value of zero will be returned on success, a negative errno will | |
325 | * be returned in error cases. | |
326 | */ | |
327 | int regmap_raw_write(struct regmap *map, unsigned int reg, | |
328 | const void *val, size_t val_len) | |
329 | { | |
330 | int ret; | |
331 | ||
332 | mutex_lock(&map->lock); | |
333 | ||
334 | ret = _regmap_raw_write(map, reg, val, val_len); | |
335 | ||
336 | mutex_unlock(&map->lock); | |
337 | ||
338 | return ret; | |
339 | } | |
340 | EXPORT_SYMBOL_GPL(regmap_raw_write); | |
341 | ||
342 | static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val, | |
343 | unsigned int val_len) | |
344 | { | |
345 | u8 *u8 = map->work_buf; | |
346 | int ret; | |
347 | ||
348 | map->format.format_reg(map->work_buf, reg); | |
349 | ||
350 | /* | |
351 | * Some buses flag reads by setting the high bits in the | |
352 | * register addresss; since it's always the high bits for all | |
353 | * current formats we can do this here rather than in | |
354 | * formatting. This may break if we get interesting formats. | |
355 | */ | |
356 | if (map->bus->read_flag_mask) | |
357 | u8[0] |= map->bus->read_flag_mask; | |
358 | ||
fb2736bb MB |
359 | trace_regmap_hw_read_start(map->dev, reg, |
360 | val_len / map->format.val_bytes); | |
361 | ||
b83a313b | 362 | ret = map->bus->read(map->dev, map->work_buf, map->format.reg_bytes, |
40c5cc26 | 363 | val, val_len); |
b83a313b | 364 | |
fb2736bb MB |
365 | trace_regmap_hw_read_done(map->dev, reg, |
366 | val_len / map->format.val_bytes); | |
367 | ||
368 | return ret; | |
b83a313b MB |
369 | } |
370 | ||
371 | static int _regmap_read(struct regmap *map, unsigned int reg, | |
372 | unsigned int *val) | |
373 | { | |
374 | int ret; | |
375 | ||
376 | if (!map->format.parse_val) | |
377 | return -EINVAL; | |
378 | ||
379 | ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes); | |
fb2736bb | 380 | if (ret == 0) { |
b83a313b | 381 | *val = map->format.parse_val(map->work_buf); |
fb2736bb MB |
382 | trace_regmap_reg_read(map->dev, reg, *val); |
383 | } | |
b83a313b MB |
384 | |
385 | return ret; | |
386 | } | |
387 | ||
388 | /** | |
389 | * regmap_read(): Read a value from a single register | |
390 | * | |
391 | * @map: Register map to write to | |
392 | * @reg: Register to be read from | |
393 | * @val: Pointer to store read value | |
394 | * | |
395 | * A value of zero will be returned on success, a negative errno will | |
396 | * be returned in error cases. | |
397 | */ | |
398 | int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val) | |
399 | { | |
400 | int ret; | |
401 | ||
402 | mutex_lock(&map->lock); | |
403 | ||
404 | ret = _regmap_read(map, reg, val); | |
405 | ||
406 | mutex_unlock(&map->lock); | |
407 | ||
408 | return ret; | |
409 | } | |
410 | EXPORT_SYMBOL_GPL(regmap_read); | |
411 | ||
412 | /** | |
413 | * regmap_raw_read(): Read raw data from the device | |
414 | * | |
415 | * @map: Register map to write to | |
416 | * @reg: First register to be read from | |
417 | * @val: Pointer to store read value | |
418 | * @val_len: Size of data to read | |
419 | * | |
420 | * A value of zero will be returned on success, a negative errno will | |
421 | * be returned in error cases. | |
422 | */ | |
423 | int regmap_raw_read(struct regmap *map, unsigned int reg, void *val, | |
424 | size_t val_len) | |
425 | { | |
426 | int ret; | |
427 | ||
428 | mutex_lock(&map->lock); | |
429 | ||
430 | ret = _regmap_raw_read(map, reg, val, val_len); | |
431 | ||
432 | mutex_unlock(&map->lock); | |
433 | ||
434 | return ret; | |
435 | } | |
436 | EXPORT_SYMBOL_GPL(regmap_raw_read); | |
437 | ||
438 | /** | |
439 | * regmap_bulk_read(): Read multiple registers from the device | |
440 | * | |
441 | * @map: Register map to write to | |
442 | * @reg: First register to be read from | |
443 | * @val: Pointer to store read value, in native register size for device | |
444 | * @val_count: Number of registers to read | |
445 | * | |
446 | * A value of zero will be returned on success, a negative errno will | |
447 | * be returned in error cases. | |
448 | */ | |
449 | int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val, | |
450 | size_t val_count) | |
451 | { | |
452 | int ret, i; | |
453 | size_t val_bytes = map->format.val_bytes; | |
454 | ||
455 | if (!map->format.parse_val) | |
456 | return -EINVAL; | |
457 | ||
458 | ret = regmap_raw_read(map, reg, val, val_bytes * val_count); | |
459 | if (ret != 0) | |
460 | return ret; | |
461 | ||
462 | for (i = 0; i < val_count * val_bytes; i += val_bytes) | |
463 | map->format.parse_val(val + i); | |
464 | ||
465 | return 0; | |
466 | } | |
467 | EXPORT_SYMBOL_GPL(regmap_bulk_read); | |
468 | ||
469 | /** | |
470 | * remap_update_bits: Perform a read/modify/write cycle on the register map | |
471 | * | |
472 | * @map: Register map to update | |
473 | * @reg: Register to update | |
474 | * @mask: Bitmask to change | |
475 | * @val: New value for bitmask | |
476 | * | |
477 | * Returns zero for success, a negative number on error. | |
478 | */ | |
479 | int regmap_update_bits(struct regmap *map, unsigned int reg, | |
480 | unsigned int mask, unsigned int val) | |
481 | { | |
482 | int ret; | |
483 | unsigned int tmp; | |
484 | ||
485 | mutex_lock(&map->lock); | |
486 | ||
487 | ret = _regmap_read(map, reg, &tmp); | |
488 | if (ret != 0) | |
489 | goto out; | |
490 | ||
491 | tmp &= ~mask; | |
492 | tmp |= val & mask; | |
493 | ||
494 | ret = _regmap_write(map, reg, tmp); | |
495 | ||
496 | out: | |
497 | mutex_unlock(&map->lock); | |
498 | ||
499 | return ret; | |
500 | } | |
501 | EXPORT_SYMBOL_GPL(regmap_update_bits); |