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 hardware
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
);