1 // SPDX-License-Identifier: GPL-2.0
3 // Register cache access API
5 // Copyright 2011 Wolfson Microelectronics plc
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>
18 static const struct regcache_ops
*cache_types
[] = {
20 #if IS_ENABLED(CONFIG_REGCACHE_COMPRESSED)
26 static int regcache_hw_init(struct regmap
*map
)
31 unsigned int reg
, val
;
34 if (!map
->num_reg_defaults_raw
)
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
))
43 /* all registers are unreadable or volatile, so just bypass */
45 map
->cache_bypass
= true;
49 map
->num_reg_defaults
= count
;
50 map
->reg_defaults
= kmalloc_array(count
, sizeof(struct reg_default
),
52 if (!map
->reg_defaults
)
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
);
66 ret
= regmap_raw_read(map
, 0, tmp_buf
,
68 map
->cache_bypass
= cache_bypass
;
70 map
->reg_defaults_raw
= 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
))
84 if (regmap_volatile(map
, reg
))
87 if (map
->reg_defaults_raw
) {
88 val
= regcache_get_val(map
, map
->reg_defaults_raw
, i
);
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
;
96 dev_err(map
->dev
, "Failed to read %d: %d\n",
102 map
->reg_defaults
[j
].reg
= reg
;
103 map
->reg_defaults
[j
].def
= val
;
110 kfree(map
->reg_defaults
);
115 int regcache_init(struct regmap
*map
, const struct regmap_config
*config
)
121 if (map
->cache_type
== REGCACHE_NONE
) {
122 if (config
->reg_defaults
|| config
->num_reg_defaults_raw
)
124 "No cache used with register defaults set!\n");
126 map
->cache_bypass
= true;
130 if (config
->reg_defaults
&& !config
->num_reg_defaults
) {
132 "Register defaults are set without the number!\n");
136 for (i
= 0; i
< config
->num_reg_defaults
; i
++)
137 if (config
->reg_defaults
[i
].reg
% map
->reg_stride
)
140 for (i
= 0; i
< ARRAY_SIZE(cache_types
); i
++)
141 if (cache_types
[i
]->type
== map
->cache_type
)
144 if (i
== ARRAY_SIZE(cache_types
)) {
145 dev_err(map
->dev
, "Could not match compress type: %d\n",
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
;
157 map
->cache_ops
= cache_types
[i
];
159 if (!map
->cache_ops
->read
||
160 !map
->cache_ops
->write
||
161 !map
->cache_ops
->name
)
164 /* We still need to ensure that the reg_defaults
165 * won't vanish from under us. We'll need to make
168 if (config
->reg_defaults
) {
169 tmp_buf
= kmemdup(config
->reg_defaults
, map
->num_reg_defaults
*
170 sizeof(struct reg_default
), GFP_KERNEL
);
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
);
182 if (map
->cache_bypass
)
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
);
199 kfree(map
->reg_defaults
);
201 kfree(map
->reg_defaults_raw
);
206 void regcache_exit(struct regmap
*map
)
208 if (map
->cache_type
== REGCACHE_NONE
)
211 BUG_ON(!map
->cache_ops
);
213 kfree(map
->reg_defaults
);
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
)
238 if (map
->cache_type
== REGCACHE_NONE
)
241 BUG_ON(!map
->cache_ops
);
243 if (!regmap_volatile(map
, reg
)) {
244 ret
= map
->cache_ops
->read(map
, reg
, value
);
247 trace_regmap_reg_read_cache(map
, reg
, *value
);
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
)
270 BUG_ON(!map
->cache_ops
);
272 if (!regmap_volatile(map
, reg
))
273 return map
->cache_ops
->write(map
, reg
, value
);
278 static bool regcache_reg_needs_sync(struct regmap
*map
, unsigned int reg
,
283 /* If we don't know the chip just got reset, then sync everything. */
284 if (!map
->no_sync_defaults
)
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
)
294 static int regcache_default_sync(struct regmap
*map
, unsigned int min
,
299 for (reg
= min
; reg
<= max
; reg
+= map
->reg_stride
) {
303 if (regmap_volatile(map
, reg
) ||
304 !regmap_writeable(map
, reg
))
307 ret
= regcache_read(map
, reg
, &val
);
311 if (!regcache_reg_needs_sync(map
, reg
, val
))
314 map
->cache_bypass
= true;
315 ret
= _regmap_write(map
, reg
, val
);
316 map
->cache_bypass
= false;
318 dev_err(map
->dev
, "Unable to sync register %#x. %d\n",
322 dev_dbg(map
->dev
, "Synced register %#x, value %#x\n", reg
, val
);
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
)
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
)
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
);
366 dev_err(map
->dev
, "Failed to write %x = %x: %d\n",
367 map
->patch
[i
].reg
, map
->patch
[i
].def
, ret
);
371 map
->cache_bypass
= false;
373 if (map
->cache_ops
->sync
)
374 ret
= map
->cache_ops
->sync(map
, 0, map
->max_register
);
376 ret
= regcache_default_sync(map
, 0, map
->max_register
);
379 map
->cache_dirty
= false;
382 /* Restore the bypass state */
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");
394 EXPORT_SYMBOL_GPL(regcache_sync
);
397 * regcache_sync_region - Sync part of the register cache with the hardware.
400 * @min: first register to sync
401 * @max: last register to sync
403 * Write all non-default register values in the specified region to
406 * Return a negative value on failure, 0 on success.
408 int regcache_sync_region(struct regmap
*map
, unsigned int min
,
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
)
432 if (map
->cache_ops
->sync
)
433 ret
= map
->cache_ops
->sync(map
, min
, max
);
435 ret
= regcache_default_sync(map
, min
, max
);
438 /* Restore the bypass state */
439 map
->cache_bypass
= bypass
;
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");
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
,
468 if (!map
->cache_ops
|| !map
->cache_ops
->drop
)
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
);
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
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
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
,
551 if (regcache_get_val(map
, base
, idx
) == val
)
554 /* Use device native format if possible */
555 if (map
->format
.format_val
) {
556 map
->format
.format_val(base
+ (map
->cache_word_size
* idx
),
561 switch (map
->cache_word_size
) {
594 unsigned int regcache_get_val(struct regmap
*map
, const void *base
,
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
,
605 switch (map
->cache_word_size
) {
607 const u8
*cache
= base
;
612 const u16
*cache
= base
;
617 const u32
*cache
= base
;
623 const u64
*cache
= base
;
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
;
651 r
= bsearch(&key
, map
->reg_defaults
, map
->num_reg_defaults
,
652 sizeof(struct reg_default
), regcache_default_cmp
);
655 return r
- map
->reg_defaults
;
660 static bool regcache_reg_present(unsigned long *cache_present
, unsigned int idx
)
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
;
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
))
683 val
= regcache_get_val(map
, block
, i
);
684 if (!regcache_reg_needs_sync(map
, regtmp
, val
))
687 map
->cache_bypass
= true;
689 ret
= _regmap_write(map
, regtmp
, val
);
691 map
->cache_bypass
= false;
693 dev_err(map
->dev
, "Unable to sync register %#x. %d\n",
697 dev_dbg(map
->dev
, "Synced register %#x, value %#x\n",
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
;
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
);
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;
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
,
738 unsigned int regtmp
= 0;
739 unsigned int base
= 0;
740 const void *data
= NULL
;
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
,
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
,
765 data
= regcache_get_val_addr(map
, block
, i
);
770 return regcache_sync_block_raw_flush(map
, &data
, base
, regtmp
+
774 int regcache_sync_block(struct regmap
*map
, void *block
,
775 unsigned long *cache_present
,
776 unsigned int block_base
, unsigned int start
,
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
);
783 return regcache_sync_block_single(map
, block
, cache_present
,
784 block_base
, start
, end
);