treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / base / regmap / regcache.c
bloba93cafd7be4f237a83bc169d7095d307349d6db0
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Register cache access API
4 //
5 // Copyright 2011 Wolfson Microelectronics plc
6 //
7 // Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
9 #include <linux/bsearch.h>
10 #include <linux/device.h>
11 #include <linux/export.h>
12 #include <linux/slab.h>
13 #include <linux/sort.h>
15 #include "trace.h"
16 #include "internal.h"
18 static const struct regcache_ops *cache_types[] = {
19 &regcache_rbtree_ops,
20 #if IS_ENABLED(CONFIG_REGCACHE_COMPRESSED)
21 &regcache_lzo_ops,
22 #endif
23 &regcache_flat_ops,
26 static int regcache_hw_init(struct regmap *map)
28 int i, j;
29 int ret;
30 int count;
31 unsigned int reg, val;
32 void *tmp_buf;
34 if (!map->num_reg_defaults_raw)
35 return -EINVAL;
37 /* calculate the size of reg_defaults */
38 for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++)
39 if (regmap_readable(map, i * map->reg_stride) &&
40 !regmap_volatile(map, i * map->reg_stride))
41 count++;
43 /* all registers are unreadable or volatile, so just bypass */
44 if (!count) {
45 map->cache_bypass = true;
46 return 0;
49 map->num_reg_defaults = count;
50 map->reg_defaults = kmalloc_array(count, sizeof(struct reg_default),
51 GFP_KERNEL);
52 if (!map->reg_defaults)
53 return -ENOMEM;
55 if (!map->reg_defaults_raw) {
56 bool cache_bypass = map->cache_bypass;
57 dev_warn(map->dev, "No cache defaults, reading back from HW\n");
59 /* Bypass the cache access till data read from HW */
60 map->cache_bypass = true;
61 tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL);
62 if (!tmp_buf) {
63 ret = -ENOMEM;
64 goto err_free;
66 ret = regmap_raw_read(map, 0, tmp_buf,
67 map->cache_size_raw);
68 map->cache_bypass = cache_bypass;
69 if (ret == 0) {
70 map->reg_defaults_raw = tmp_buf;
71 map->cache_free = 1;
72 } else {
73 kfree(tmp_buf);
77 /* fill the reg_defaults */
78 for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) {
79 reg = i * map->reg_stride;
81 if (!regmap_readable(map, reg))
82 continue;
84 if (regmap_volatile(map, reg))
85 continue;
87 if (map->reg_defaults_raw) {
88 val = regcache_get_val(map, map->reg_defaults_raw, i);
89 } else {
90 bool cache_bypass = map->cache_bypass;
92 map->cache_bypass = true;
93 ret = regmap_read(map, reg, &val);
94 map->cache_bypass = cache_bypass;
95 if (ret != 0) {
96 dev_err(map->dev, "Failed to read %d: %d\n",
97 reg, ret);
98 goto err_free;
102 map->reg_defaults[j].reg = reg;
103 map->reg_defaults[j].def = val;
104 j++;
107 return 0;
109 err_free:
110 kfree(map->reg_defaults);
112 return ret;
115 int regcache_init(struct regmap *map, const struct regmap_config *config)
117 int ret;
118 int i;
119 void *tmp_buf;
121 if (map->cache_type == REGCACHE_NONE) {
122 if (config->reg_defaults || config->num_reg_defaults_raw)
123 dev_warn(map->dev,
124 "No cache used with register defaults set!\n");
126 map->cache_bypass = true;
127 return 0;
130 if (config->reg_defaults && !config->num_reg_defaults) {
131 dev_err(map->dev,
132 "Register defaults are set without the number!\n");
133 return -EINVAL;
136 for (i = 0; i < config->num_reg_defaults; i++)
137 if (config->reg_defaults[i].reg % map->reg_stride)
138 return -EINVAL;
140 for (i = 0; i < ARRAY_SIZE(cache_types); i++)
141 if (cache_types[i]->type == map->cache_type)
142 break;
144 if (i == ARRAY_SIZE(cache_types)) {
145 dev_err(map->dev, "Could not match compress type: %d\n",
146 map->cache_type);
147 return -EINVAL;
150 map->num_reg_defaults = config->num_reg_defaults;
151 map->num_reg_defaults_raw = config->num_reg_defaults_raw;
152 map->reg_defaults_raw = config->reg_defaults_raw;
153 map->cache_word_size = DIV_ROUND_UP(config->val_bits, 8);
154 map->cache_size_raw = map->cache_word_size * config->num_reg_defaults_raw;
156 map->cache = NULL;
157 map->cache_ops = cache_types[i];
159 if (!map->cache_ops->read ||
160 !map->cache_ops->write ||
161 !map->cache_ops->name)
162 return -EINVAL;
164 /* We still need to ensure that the reg_defaults
165 * won't vanish from under us. We'll need to make
166 * a copy of it.
168 if (config->reg_defaults) {
169 tmp_buf = kmemdup(config->reg_defaults, map->num_reg_defaults *
170 sizeof(struct reg_default), GFP_KERNEL);
171 if (!tmp_buf)
172 return -ENOMEM;
173 map->reg_defaults = tmp_buf;
174 } else if (map->num_reg_defaults_raw) {
175 /* Some devices such as PMICs don't have cache defaults,
176 * we cope with this by reading back the HW registers and
177 * crafting the cache defaults by hand.
179 ret = regcache_hw_init(map);
180 if (ret < 0)
181 return ret;
182 if (map->cache_bypass)
183 return 0;
186 if (!map->max_register)
187 map->max_register = map->num_reg_defaults_raw;
189 if (map->cache_ops->init) {
190 dev_dbg(map->dev, "Initializing %s cache\n",
191 map->cache_ops->name);
192 ret = map->cache_ops->init(map);
193 if (ret)
194 goto err_free;
196 return 0;
198 err_free:
199 kfree(map->reg_defaults);
200 if (map->cache_free)
201 kfree(map->reg_defaults_raw);
203 return ret;
206 void regcache_exit(struct regmap *map)
208 if (map->cache_type == REGCACHE_NONE)
209 return;
211 BUG_ON(!map->cache_ops);
213 kfree(map->reg_defaults);
214 if (map->cache_free)
215 kfree(map->reg_defaults_raw);
217 if (map->cache_ops->exit) {
218 dev_dbg(map->dev, "Destroying %s cache\n",
219 map->cache_ops->name);
220 map->cache_ops->exit(map);
225 * regcache_read - Fetch the value of a given register from the cache.
227 * @map: map to configure.
228 * @reg: The register index.
229 * @value: The value to be returned.
231 * Return a negative value on failure, 0 on success.
233 int regcache_read(struct regmap *map,
234 unsigned int reg, unsigned int *value)
236 int ret;
238 if (map->cache_type == REGCACHE_NONE)
239 return -ENOSYS;
241 BUG_ON(!map->cache_ops);
243 if (!regmap_volatile(map, reg)) {
244 ret = map->cache_ops->read(map, reg, value);
246 if (ret == 0)
247 trace_regmap_reg_read_cache(map, reg, *value);
249 return ret;
252 return -EINVAL;
256 * regcache_write - Set the value of a given register in the cache.
258 * @map: map to configure.
259 * @reg: The register index.
260 * @value: The new register value.
262 * Return a negative value on failure, 0 on success.
264 int regcache_write(struct regmap *map,
265 unsigned int reg, unsigned int value)
267 if (map->cache_type == REGCACHE_NONE)
268 return 0;
270 BUG_ON(!map->cache_ops);
272 if (!regmap_volatile(map, reg))
273 return map->cache_ops->write(map, reg, value);
275 return 0;
278 static bool regcache_reg_needs_sync(struct regmap *map, unsigned int reg,
279 unsigned int val)
281 int ret;
283 /* If we don't know the chip just got reset, then sync everything. */
284 if (!map->no_sync_defaults)
285 return true;
287 /* Is this the hardware default? If so skip. */
288 ret = regcache_lookup_reg(map, reg);
289 if (ret >= 0 && val == map->reg_defaults[ret].def)
290 return false;
291 return true;
294 static int regcache_default_sync(struct regmap *map, unsigned int min,
295 unsigned int max)
297 unsigned int reg;
299 for (reg = min; reg <= max; reg += map->reg_stride) {
300 unsigned int val;
301 int ret;
303 if (regmap_volatile(map, reg) ||
304 !regmap_writeable(map, reg))
305 continue;
307 ret = regcache_read(map, reg, &val);
308 if (ret)
309 return ret;
311 if (!regcache_reg_needs_sync(map, reg, val))
312 continue;
314 map->cache_bypass = true;
315 ret = _regmap_write(map, reg, val);
316 map->cache_bypass = false;
317 if (ret) {
318 dev_err(map->dev, "Unable to sync register %#x. %d\n",
319 reg, ret);
320 return ret;
322 dev_dbg(map->dev, "Synced register %#x, value %#x\n", reg, val);
325 return 0;
329 * regcache_sync - Sync the register cache with the hardware.
331 * @map: map to configure.
333 * Any registers that should not be synced should be marked as
334 * volatile. In general drivers can choose not to use the provided
335 * syncing functionality if they so require.
337 * Return a negative value on failure, 0 on success.
339 int regcache_sync(struct regmap *map)
341 int ret = 0;
342 unsigned int i;
343 const char *name;
344 bool bypass;
346 BUG_ON(!map->cache_ops);
348 map->lock(map->lock_arg);
349 /* Remember the initial bypass state */
350 bypass = map->cache_bypass;
351 dev_dbg(map->dev, "Syncing %s cache\n",
352 map->cache_ops->name);
353 name = map->cache_ops->name;
354 trace_regcache_sync(map, name, "start");
356 if (!map->cache_dirty)
357 goto out;
359 map->async = true;
361 /* Apply any patch first */
362 map->cache_bypass = true;
363 for (i = 0; i < map->patch_regs; i++) {
364 ret = _regmap_write(map, map->patch[i].reg, map->patch[i].def);
365 if (ret != 0) {
366 dev_err(map->dev, "Failed to write %x = %x: %d\n",
367 map->patch[i].reg, map->patch[i].def, ret);
368 goto out;
371 map->cache_bypass = false;
373 if (map->cache_ops->sync)
374 ret = map->cache_ops->sync(map, 0, map->max_register);
375 else
376 ret = regcache_default_sync(map, 0, map->max_register);
378 if (ret == 0)
379 map->cache_dirty = false;
381 out:
382 /* Restore the bypass state */
383 map->async = false;
384 map->cache_bypass = bypass;
385 map->no_sync_defaults = false;
386 map->unlock(map->lock_arg);
388 regmap_async_complete(map);
390 trace_regcache_sync(map, name, "stop");
392 return ret;
394 EXPORT_SYMBOL_GPL(regcache_sync);
397 * regcache_sync_region - Sync part of the register cache with the hardware.
399 * @map: map to sync.
400 * @min: first register to sync
401 * @max: last register to sync
403 * Write all non-default register values in the specified region to
404 * the hardware.
406 * Return a negative value on failure, 0 on success.
408 int regcache_sync_region(struct regmap *map, unsigned int min,
409 unsigned int max)
411 int ret = 0;
412 const char *name;
413 bool bypass;
415 BUG_ON(!map->cache_ops);
417 map->lock(map->lock_arg);
419 /* Remember the initial bypass state */
420 bypass = map->cache_bypass;
422 name = map->cache_ops->name;
423 dev_dbg(map->dev, "Syncing %s cache from %d-%d\n", name, min, max);
425 trace_regcache_sync(map, name, "start region");
427 if (!map->cache_dirty)
428 goto out;
430 map->async = true;
432 if (map->cache_ops->sync)
433 ret = map->cache_ops->sync(map, min, max);
434 else
435 ret = regcache_default_sync(map, min, max);
437 out:
438 /* Restore the bypass state */
439 map->cache_bypass = bypass;
440 map->async = false;
441 map->no_sync_defaults = false;
442 map->unlock(map->lock_arg);
444 regmap_async_complete(map);
446 trace_regcache_sync(map, name, "stop region");
448 return ret;
450 EXPORT_SYMBOL_GPL(regcache_sync_region);
453 * regcache_drop_region - Discard part of the register cache
455 * @map: map to operate on
456 * @min: first register to discard
457 * @max: last register to discard
459 * Discard part of the register cache.
461 * Return a negative value on failure, 0 on success.
463 int regcache_drop_region(struct regmap *map, unsigned int min,
464 unsigned int max)
466 int ret = 0;
468 if (!map->cache_ops || !map->cache_ops->drop)
469 return -EINVAL;
471 map->lock(map->lock_arg);
473 trace_regcache_drop_region(map, min, max);
475 ret = map->cache_ops->drop(map, min, max);
477 map->unlock(map->lock_arg);
479 return ret;
481 EXPORT_SYMBOL_GPL(regcache_drop_region);
484 * regcache_cache_only - Put a register map into cache only mode
486 * @map: map to configure
487 * @enable: flag if changes should be written to the hardware
489 * When a register map is marked as cache only writes to the register
490 * map API will only update the register cache, they will not cause
491 * any hardware changes. This is useful for allowing portions of
492 * drivers to act as though the device were functioning as normal when
493 * it is disabled for power saving reasons.
495 void regcache_cache_only(struct regmap *map, bool enable)
497 map->lock(map->lock_arg);
498 WARN_ON(map->cache_bypass && enable);
499 map->cache_only = enable;
500 trace_regmap_cache_only(map, enable);
501 map->unlock(map->lock_arg);
503 EXPORT_SYMBOL_GPL(regcache_cache_only);
506 * regcache_mark_dirty - Indicate that HW registers were reset to default values
508 * @map: map to mark
510 * Inform regcache that the device has been powered down or reset, so that
511 * on resume, regcache_sync() knows to write out all non-default values
512 * stored in the cache.
514 * If this function is not called, regcache_sync() will assume that
515 * the hardware state still matches the cache state, modulo any writes that
516 * happened when cache_only was true.
518 void regcache_mark_dirty(struct regmap *map)
520 map->lock(map->lock_arg);
521 map->cache_dirty = true;
522 map->no_sync_defaults = true;
523 map->unlock(map->lock_arg);
525 EXPORT_SYMBOL_GPL(regcache_mark_dirty);
528 * regcache_cache_bypass - Put a register map into cache bypass mode
530 * @map: map to configure
531 * @enable: flag if changes should not be written to the cache
533 * When a register map is marked with the cache bypass option, writes
534 * to the register map API will only update the hardware and not the
535 * the cache directly. This is useful when syncing the cache back to
536 * the hardware.
538 void regcache_cache_bypass(struct regmap *map, bool enable)
540 map->lock(map->lock_arg);
541 WARN_ON(map->cache_only && enable);
542 map->cache_bypass = enable;
543 trace_regmap_cache_bypass(map, enable);
544 map->unlock(map->lock_arg);
546 EXPORT_SYMBOL_GPL(regcache_cache_bypass);
548 bool regcache_set_val(struct regmap *map, void *base, unsigned int idx,
549 unsigned int val)
551 if (regcache_get_val(map, base, idx) == val)
552 return true;
554 /* Use device native format if possible */
555 if (map->format.format_val) {
556 map->format.format_val(base + (map->cache_word_size * idx),
557 val, 0);
558 return false;
561 switch (map->cache_word_size) {
562 case 1: {
563 u8 *cache = base;
565 cache[idx] = val;
566 break;
568 case 2: {
569 u16 *cache = base;
571 cache[idx] = val;
572 break;
574 case 4: {
575 u32 *cache = base;
577 cache[idx] = val;
578 break;
580 #ifdef CONFIG_64BIT
581 case 8: {
582 u64 *cache = base;
584 cache[idx] = val;
585 break;
587 #endif
588 default:
589 BUG();
591 return false;
594 unsigned int regcache_get_val(struct regmap *map, const void *base,
595 unsigned int idx)
597 if (!base)
598 return -EINVAL;
600 /* Use device native format if possible */
601 if (map->format.parse_val)
602 return map->format.parse_val(regcache_get_val_addr(map, base,
603 idx));
605 switch (map->cache_word_size) {
606 case 1: {
607 const u8 *cache = base;
609 return cache[idx];
611 case 2: {
612 const u16 *cache = base;
614 return cache[idx];
616 case 4: {
617 const u32 *cache = base;
619 return cache[idx];
621 #ifdef CONFIG_64BIT
622 case 8: {
623 const u64 *cache = base;
625 return cache[idx];
627 #endif
628 default:
629 BUG();
631 /* unreachable */
632 return -1;
635 static int regcache_default_cmp(const void *a, const void *b)
637 const struct reg_default *_a = a;
638 const struct reg_default *_b = b;
640 return _a->reg - _b->reg;
643 int regcache_lookup_reg(struct regmap *map, unsigned int reg)
645 struct reg_default key;
646 struct reg_default *r;
648 key.reg = reg;
649 key.def = 0;
651 r = bsearch(&key, map->reg_defaults, map->num_reg_defaults,
652 sizeof(struct reg_default), regcache_default_cmp);
654 if (r)
655 return r - map->reg_defaults;
656 else
657 return -ENOENT;
660 static bool regcache_reg_present(unsigned long *cache_present, unsigned int idx)
662 if (!cache_present)
663 return true;
665 return test_bit(idx, cache_present);
668 static int regcache_sync_block_single(struct regmap *map, void *block,
669 unsigned long *cache_present,
670 unsigned int block_base,
671 unsigned int start, unsigned int end)
673 unsigned int i, regtmp, val;
674 int ret;
676 for (i = start; i < end; i++) {
677 regtmp = block_base + (i * map->reg_stride);
679 if (!regcache_reg_present(cache_present, i) ||
680 !regmap_writeable(map, regtmp))
681 continue;
683 val = regcache_get_val(map, block, i);
684 if (!regcache_reg_needs_sync(map, regtmp, val))
685 continue;
687 map->cache_bypass = true;
689 ret = _regmap_write(map, regtmp, val);
691 map->cache_bypass = false;
692 if (ret != 0) {
693 dev_err(map->dev, "Unable to sync register %#x. %d\n",
694 regtmp, ret);
695 return ret;
697 dev_dbg(map->dev, "Synced register %#x, value %#x\n",
698 regtmp, val);
701 return 0;
704 static int regcache_sync_block_raw_flush(struct regmap *map, const void **data,
705 unsigned int base, unsigned int cur)
707 size_t val_bytes = map->format.val_bytes;
708 int ret, count;
710 if (*data == NULL)
711 return 0;
713 count = (cur - base) / map->reg_stride;
715 dev_dbg(map->dev, "Writing %zu bytes for %d registers from 0x%x-0x%x\n",
716 count * val_bytes, count, base, cur - map->reg_stride);
718 map->cache_bypass = true;
720 ret = _regmap_raw_write(map, base, *data, count * val_bytes);
721 if (ret)
722 dev_err(map->dev, "Unable to sync registers %#x-%#x. %d\n",
723 base, cur - map->reg_stride, ret);
725 map->cache_bypass = false;
727 *data = NULL;
729 return ret;
732 static int regcache_sync_block_raw(struct regmap *map, void *block,
733 unsigned long *cache_present,
734 unsigned int block_base, unsigned int start,
735 unsigned int end)
737 unsigned int i, val;
738 unsigned int regtmp = 0;
739 unsigned int base = 0;
740 const void *data = NULL;
741 int ret;
743 for (i = start; i < end; i++) {
744 regtmp = block_base + (i * map->reg_stride);
746 if (!regcache_reg_present(cache_present, i) ||
747 !regmap_writeable(map, regtmp)) {
748 ret = regcache_sync_block_raw_flush(map, &data,
749 base, regtmp);
750 if (ret != 0)
751 return ret;
752 continue;
755 val = regcache_get_val(map, block, i);
756 if (!regcache_reg_needs_sync(map, regtmp, val)) {
757 ret = regcache_sync_block_raw_flush(map, &data,
758 base, regtmp);
759 if (ret != 0)
760 return ret;
761 continue;
764 if (!data) {
765 data = regcache_get_val_addr(map, block, i);
766 base = regtmp;
770 return regcache_sync_block_raw_flush(map, &data, base, regtmp +
771 map->reg_stride);
774 int regcache_sync_block(struct regmap *map, void *block,
775 unsigned long *cache_present,
776 unsigned int block_base, unsigned int start,
777 unsigned int end)
779 if (regmap_can_raw_write(map) && !map->use_single_write)
780 return regcache_sync_block_raw(map, block, cache_present,
781 block_base, start, end);
782 else
783 return regcache_sync_block_single(map, block, cache_present,
784 block_base, start, end);