2 * Register cache access API
4 * Copyright 2011 Wolfson Microelectronics plc
6 * Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
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.
13 #include <linux/bsearch.h>
14 #include <linux/device.h>
15 #include <linux/export.h>
16 #include <linux/slab.h>
17 #include <linux/sort.h>
22 static const struct regcache_ops *cache_types[] = {
28 static int regcache_hw_init(struct regmap *map)
33 unsigned int reg, val;
36 if (!map->num_reg_defaults_raw)
39 /* calculate the size of reg_defaults */
40 for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++)
41 if (!regmap_volatile(map, i * map->reg_stride))
44 /* all registers are volatile, so just bypass */
46 map->cache_bypass = true;
50 map->num_reg_defaults = count;
51 map->reg_defaults = kmalloc_array(count, sizeof(struct reg_default),
53 if (!map->reg_defaults)
56 if (!map->reg_defaults_raw) {
57 bool cache_bypass = map->cache_bypass;
58 dev_warn(map->dev, "No cache defaults, reading back from HW\n");
60 /* Bypass the cache access till data read from HW */
61 map->cache_bypass = true;
62 tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL);
67 ret = regmap_raw_read(map, 0, tmp_buf,
69 map->cache_bypass = cache_bypass;
71 map->reg_defaults_raw = tmp_buf;
78 /* fill the reg_defaults */
79 for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) {
80 reg = i * map->reg_stride;
82 if (!regmap_readable(map, reg))
85 if (regmap_volatile(map, reg))
88 if (map->reg_defaults_raw) {
89 val = regcache_get_val(map, map->reg_defaults_raw, i);
91 bool cache_bypass = map->cache_bypass;
93 map->cache_bypass = true;
94 ret = regmap_read(map, reg, &val);
95 map->cache_bypass = cache_bypass;
97 dev_err(map->dev, "Failed to read %d: %d\n",
103 map->reg_defaults[j].reg = reg;
104 map->reg_defaults[j].def = val;
111 kfree(map->reg_defaults);
116 int regcache_init(struct regmap *map, const struct regmap_config *config)
122 if (map->cache_type == REGCACHE_NONE) {
123 if (config->reg_defaults || config->num_reg_defaults_raw)
125 "No cache used with register defaults set!\n");
127 map->cache_bypass = true;
131 if (config->reg_defaults && !config->num_reg_defaults) {
133 "Register defaults are set without the number!\n");
137 for (i = 0; i < config->num_reg_defaults; i++)
138 if (config->reg_defaults[i].reg % map->reg_stride)
141 for (i = 0; i < ARRAY_SIZE(cache_types); i++)
142 if (cache_types[i]->type == map->cache_type)
145 if (i == ARRAY_SIZE(cache_types)) {
146 dev_err(map->dev, "Could not match compress type: %d\n",
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_word_size = DIV_ROUND_UP(config->val_bits, 8);
155 map->cache_size_raw = map->cache_word_size * config->num_reg_defaults_raw;
158 map->cache_ops = cache_types[i];
160 if (!map->cache_ops->read ||
161 !map->cache_ops->write ||
162 !map->cache_ops->name)
165 /* We still need to ensure that the reg_defaults
166 * won't vanish from under us. We'll need to make
169 if (config->reg_defaults) {
170 tmp_buf = kmemdup(config->reg_defaults, map->num_reg_defaults *
171 sizeof(struct reg_default), GFP_KERNEL);
174 map->reg_defaults = tmp_buf;
175 } else if (map->num_reg_defaults_raw) {
176 /* Some devices such as PMICs don't have cache defaults,
177 * we cope with this by reading back the HW registers and
178 * crafting the cache defaults by hand.
180 ret = regcache_hw_init(map);
183 if (map->cache_bypass)
187 if (!map->max_register)
188 map->max_register = map->num_reg_defaults_raw;
190 if (map->cache_ops->init) {
191 dev_dbg(map->dev, "Initializing %s cache\n",
192 map->cache_ops->name);
193 ret = map->cache_ops->init(map);
200 kfree(map->reg_defaults);
202 kfree(map->reg_defaults_raw);
207 void regcache_exit(struct regmap *map)
209 if (map->cache_type == REGCACHE_NONE)
212 BUG_ON(!map->cache_ops);
214 kfree(map->reg_defaults);
216 kfree(map->reg_defaults_raw);
218 if (map->cache_ops->exit) {
219 dev_dbg(map->dev, "Destroying %s cache\n",
220 map->cache_ops->name);
221 map->cache_ops->exit(map);
226 * regcache_read: Fetch the value of a given register from the cache.
228 * @map: map to configure.
229 * @reg: The register index.
230 * @value: The value to be returned.
232 * Return a negative value on failure, 0 on success.
234 int regcache_read(struct regmap *map,
235 unsigned int reg, unsigned int *value)
239 if (map->cache_type == REGCACHE_NONE)
242 BUG_ON(!map->cache_ops);
244 if (!regmap_volatile(map, reg)) {
245 ret = map->cache_ops->read(map, reg, value);
248 trace_regmap_reg_read_cache(map, reg, *value);
257 * regcache_write: Set the value of a given register in the cache.
259 * @map: map to configure.
260 * @reg: The register index.
261 * @value: The new register value.
263 * Return a negative value on failure, 0 on success.
265 int regcache_write(struct regmap *map,
266 unsigned int reg, unsigned int value)
268 if (map->cache_type == REGCACHE_NONE)
271 BUG_ON(!map->cache_ops);
273 if (!regmap_volatile(map, reg))
274 return map->cache_ops->write(map, reg, value);
279 static bool regcache_reg_needs_sync(struct regmap *map, unsigned int reg,
284 /* If we don't know the chip just got reset, then sync everything. */
285 if (!map->no_sync_defaults)
288 /* Is this the hardware default? If so skip. */
289 ret = regcache_lookup_reg(map, reg);
290 if (ret >= 0 && val == map->reg_defaults[ret].def)
295 static int regcache_default_sync(struct regmap *map, unsigned int min,
300 for (reg = min; reg <= max; reg += map->reg_stride) {
304 if (regmap_volatile(map, reg) ||
305 !regmap_writeable(map, reg))
308 ret = regcache_read(map, reg, &val);
312 if (!regcache_reg_needs_sync(map, reg, val))
315 map->cache_bypass = true;
316 ret = _regmap_write(map, reg, val);
317 map->cache_bypass = false;
319 dev_err(map->dev, "Unable to sync register %#x. %d\n",
323 dev_dbg(map->dev, "Synced register %#x, value %#x\n", reg, val);
330 * regcache_sync: Sync the register cache with the hardware.
332 * @map: map to configure.
334 * Any registers that should not be synced should be marked as
335 * volatile. In general drivers can choose not to use the provided
336 * syncing functionality if they so require.
338 * Return a negative value on failure, 0 on success.
340 int regcache_sync(struct regmap *map)
347 BUG_ON(!map->cache_ops);
349 map->lock(map->lock_arg);
350 /* Remember the initial bypass state */
351 bypass = map->cache_bypass;
352 dev_dbg(map->dev, "Syncing %s cache\n",
353 map->cache_ops->name);
354 name = map->cache_ops->name;
355 trace_regcache_sync(map, name, "start");
357 if (!map->cache_dirty)
362 /* Apply any patch first */
363 map->cache_bypass = true;
364 for (i = 0; i < map->patch_regs; i++) {
365 ret = _regmap_write(map, map->patch[i].reg, map->patch[i].def);
367 dev_err(map->dev, "Failed to write %x = %x: %d\n",
368 map->patch[i].reg, map->patch[i].def, ret);
372 map->cache_bypass = false;
374 if (map->cache_ops->sync)
375 ret = map->cache_ops->sync(map, 0, map->max_register);
377 ret = regcache_default_sync(map, 0, map->max_register);
380 map->cache_dirty = false;
383 /* Restore the bypass state */
385 map->cache_bypass = bypass;
386 map->no_sync_defaults = false;
387 map->unlock(map->lock_arg);
389 regmap_async_complete(map);
391 trace_regcache_sync(map, name, "stop");
395 EXPORT_SYMBOL_GPL(regcache_sync);
398 * regcache_sync_region: Sync part of the register cache with the hardware.
401 * @min: first register to sync
402 * @max: last register to sync
404 * Write all non-default register values in the specified region to
407 * Return a negative value on failure, 0 on success.
409 int regcache_sync_region(struct regmap *map, unsigned int min,
416 BUG_ON(!map->cache_ops);
418 map->lock(map->lock_arg);
420 /* Remember the initial bypass state */
421 bypass = map->cache_bypass;
423 name = map->cache_ops->name;
424 dev_dbg(map->dev, "Syncing %s cache from %d-%d\n", name, min, max);
426 trace_regcache_sync(map, name, "start region");
428 if (!map->cache_dirty)
433 if (map->cache_ops->sync)
434 ret = map->cache_ops->sync(map, min, max);
436 ret = regcache_default_sync(map, min, max);
439 /* Restore the bypass state */
440 map->cache_bypass = bypass;
442 map->no_sync_defaults = false;
443 map->unlock(map->lock_arg);
445 regmap_async_complete(map);
447 trace_regcache_sync(map, name, "stop region");
451 EXPORT_SYMBOL_GPL(regcache_sync_region);
454 * regcache_drop_region: Discard part of the register cache
456 * @map: map to operate on
457 * @min: first register to discard
458 * @max: last register to discard
460 * Discard part of the register cache.
462 * Return a negative value on failure, 0 on success.
464 int regcache_drop_region(struct regmap *map, unsigned int min,
469 if (!map->cache_ops || !map->cache_ops->drop)
472 map->lock(map->lock_arg);
474 trace_regcache_drop_region(map, min, max);
476 ret = map->cache_ops->drop(map, min, max);
478 map->unlock(map->lock_arg);
482 EXPORT_SYMBOL_GPL(regcache_drop_region);
485 * regcache_cache_only: Put a register map into cache only mode
487 * @map: map to configure
488 * @cache_only: flag if changes should be written to the hardware
490 * When a register map is marked as cache only writes to the register
491 * map API will only update the register cache, they will not cause
492 * any hardware changes. This is useful for allowing portions of
493 * drivers to act as though the device were functioning as normal when
494 * it is disabled for power saving reasons.
496 void regcache_cache_only(struct regmap *map, bool enable)
498 map->lock(map->lock_arg);
499 WARN_ON(map->cache_bypass && enable);
500 map->cache_only = enable;
501 trace_regmap_cache_only(map, enable);
502 map->unlock(map->lock_arg);
504 EXPORT_SYMBOL_GPL(regcache_cache_only);
507 * regcache_mark_dirty: Indicate that HW registers were reset to default values
511 * Inform regcache that the device has been powered down or reset, so that
512 * on resume, regcache_sync() knows to write out all non-default values
513 * stored in the cache.
515 * If this function is not called, regcache_sync() will assume that
516 * the hardware state still matches the cache state, modulo any writes that
517 * happened when cache_only was true.
519 void regcache_mark_dirty(struct regmap *map)
521 map->lock(map->lock_arg);
522 map->cache_dirty = true;
523 map->no_sync_defaults = true;
524 map->unlock(map->lock_arg);
526 EXPORT_SYMBOL_GPL(regcache_mark_dirty);
529 * regcache_cache_bypass: Put a register map into cache bypass mode
531 * @map: map to configure
532 * @cache_bypass: flag if changes should not be written to the cache
534 * When a register map is marked with the cache bypass option, writes
535 * to the register map API will only update the hardware and not the
536 * the cache directly. This is useful when syncing the cache back to
539 void regcache_cache_bypass(struct regmap *map, bool enable)
541 map->lock(map->lock_arg);
542 WARN_ON(map->cache_only && enable);
543 map->cache_bypass = enable;
544 trace_regmap_cache_bypass(map, enable);
545 map->unlock(map->lock_arg);
547 EXPORT_SYMBOL_GPL(regcache_cache_bypass);
549 bool regcache_set_val(struct regmap *map, void *base, unsigned int idx,
552 if (regcache_get_val(map, base, idx) == val)
555 /* Use device native format if possible */
556 if (map->format.format_val) {
557 map->format.format_val(base + (map->cache_word_size * idx),
562 switch (map->cache_word_size) {
595 unsigned int regcache_get_val(struct regmap *map, const void *base,
601 /* Use device native format if possible */
602 if (map->format.parse_val)
603 return map->format.parse_val(regcache_get_val_addr(map, base,
606 switch (map->cache_word_size) {
608 const u8 *cache = base;
613 const u16 *cache = base;
618 const u32 *cache = base;
624 const u64 *cache = base;
636 static int regcache_default_cmp(const void *a, const void *b)
638 const struct reg_default *_a = a;
639 const struct reg_default *_b = b;
641 return _a->reg - _b->reg;
644 int regcache_lookup_reg(struct regmap *map, unsigned int reg)
646 struct reg_default key;
647 struct reg_default *r;
652 r = bsearch(&key, map->reg_defaults, map->num_reg_defaults,
653 sizeof(struct reg_default), regcache_default_cmp);
656 return r - map->reg_defaults;
661 static bool regcache_reg_present(unsigned long *cache_present, unsigned int idx)
666 return test_bit(idx, cache_present);
669 static int regcache_sync_block_single(struct regmap *map, void *block,
670 unsigned long *cache_present,
671 unsigned int block_base,
672 unsigned int start, unsigned int end)
674 unsigned int i, regtmp, val;
677 for (i = start; i < end; i++) {
678 regtmp = block_base + (i * map->reg_stride);
680 if (!regcache_reg_present(cache_present, i) ||
681 !regmap_writeable(map, regtmp))
684 val = regcache_get_val(map, block, i);
685 if (!regcache_reg_needs_sync(map, regtmp, val))
688 map->cache_bypass = true;
690 ret = _regmap_write(map, regtmp, val);
692 map->cache_bypass = false;
694 dev_err(map->dev, "Unable to sync register %#x. %d\n",
698 dev_dbg(map->dev, "Synced register %#x, value %#x\n",
705 static int regcache_sync_block_raw_flush(struct regmap *map, const void **data,
706 unsigned int base, unsigned int cur)
708 size_t val_bytes = map->format.val_bytes;
714 count = (cur - base) / map->reg_stride;
716 dev_dbg(map->dev, "Writing %zu bytes for %d registers from 0x%x-0x%x\n",
717 count * val_bytes, count, base, cur - map->reg_stride);
719 map->cache_bypass = true;
721 ret = _regmap_raw_write(map, base, *data, count * val_bytes);
723 dev_err(map->dev, "Unable to sync registers %#x-%#x. %d\n",
724 base, cur - map->reg_stride, ret);
726 map->cache_bypass = false;
733 static int regcache_sync_block_raw(struct regmap *map, void *block,
734 unsigned long *cache_present,
735 unsigned int block_base, unsigned int start,
739 unsigned int regtmp = 0;
740 unsigned int base = 0;
741 const void *data = NULL;
744 for (i = start; i < end; i++) {
745 regtmp = block_base + (i * map->reg_stride);
747 if (!regcache_reg_present(cache_present, i) ||
748 !regmap_writeable(map, regtmp)) {
749 ret = regcache_sync_block_raw_flush(map, &data,
756 val = regcache_get_val(map, block, i);
757 if (!regcache_reg_needs_sync(map, regtmp, val)) {
758 ret = regcache_sync_block_raw_flush(map, &data,
766 data = regcache_get_val_addr(map, block, i);
771 return regcache_sync_block_raw_flush(map, &data, base, regtmp +
775 int regcache_sync_block(struct regmap *map, void *block,
776 unsigned long *cache_present,
777 unsigned int block_base, unsigned int start,
780 if (regmap_can_raw_write(map) && !map->use_single_write)
781 return regcache_sync_block_raw(map, block, cache_present,
782 block_base, start, end);
784 return regcache_sync_block_single(map, block, cache_present,
785 block_base, start, end);