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/slab.h>
14 #include <trace/events/regmap.h>
18 static const struct regcache_ops
*cache_types
[] = {
19 ®cache_indexed_ops
,
24 static int regcache_hw_init(struct regmap
*map
)
32 if (!map
->num_reg_defaults_raw
)
35 if (!map
->reg_defaults_raw
) {
36 dev_warn(map
->dev
, "No cache defaults, reading back from HW\n");
37 tmp_buf
= kmalloc(map
->cache_size_raw
, GFP_KERNEL
);
40 ret
= regmap_bulk_read(map
, 0, tmp_buf
,
41 map
->num_reg_defaults_raw
);
46 map
->reg_defaults_raw
= tmp_buf
;
50 /* calculate the size of reg_defaults */
51 for (count
= 0, i
= 0; i
< map
->num_reg_defaults_raw
; i
++) {
52 val
= regcache_get_val(map
->reg_defaults_raw
,
53 i
, map
->cache_word_size
);
59 map
->reg_defaults
= kmalloc(count
* sizeof(struct reg_default
),
61 if (!map
->reg_defaults
)
64 /* fill the reg_defaults */
65 map
->num_reg_defaults
= count
;
66 for (i
= 0, j
= 0; i
< map
->num_reg_defaults_raw
; i
++) {
67 val
= regcache_get_val(map
->reg_defaults_raw
,
68 i
, map
->cache_word_size
);
71 map
->reg_defaults
[j
].reg
= i
;
72 map
->reg_defaults
[j
].def
= val
;
79 int regcache_init(struct regmap
*map
)
85 if (map
->cache_type
== REGCACHE_NONE
) {
86 map
->cache_bypass
= true;
90 for (i
= 0; i
< ARRAY_SIZE(cache_types
); i
++)
91 if (cache_types
[i
]->type
== map
->cache_type
)
94 if (i
== ARRAY_SIZE(cache_types
)) {
95 dev_err(map
->dev
, "Could not match compress type: %d\n",
101 map
->cache_ops
= cache_types
[i
];
103 if (!map
->cache_ops
->read
||
104 !map
->cache_ops
->write
||
105 !map
->cache_ops
->name
)
108 /* We still need to ensure that the reg_defaults
109 * won't vanish from under us. We'll need to make
112 if (map
->reg_defaults
) {
113 if (!map
->num_reg_defaults
)
115 tmp_buf
= kmemdup(map
->reg_defaults
, map
->num_reg_defaults
*
116 sizeof(struct reg_default
), GFP_KERNEL
);
119 map
->reg_defaults
= tmp_buf
;
121 /* Some devices such as PMICs don't have cache defaults,
122 * we cope with this by reading back the HW registers and
123 * crafting the cache defaults by hand.
125 ret
= regcache_hw_init(map
);
130 if (!map
->max_register
)
131 map
->max_register
= map
->num_reg_defaults_raw
;
133 if (map
->cache_ops
->init
) {
134 dev_dbg(map
->dev
, "Initializing %s cache\n",
135 map
->cache_ops
->name
);
136 return map
->cache_ops
->init(map
);
141 void regcache_exit(struct regmap
*map
)
143 if (map
->cache_type
== REGCACHE_NONE
)
146 BUG_ON(!map
->cache_ops
);
148 kfree(map
->reg_defaults
);
150 kfree(map
->reg_defaults_raw
);
152 if (map
->cache_ops
->exit
) {
153 dev_dbg(map
->dev
, "Destroying %s cache\n",
154 map
->cache_ops
->name
);
155 map
->cache_ops
->exit(map
);
160 * regcache_read: Fetch the value of a given register from the cache.
162 * @map: map to configure.
163 * @reg: The register index.
164 * @value: The value to be returned.
166 * Return a negative value on failure, 0 on success.
168 int regcache_read(struct regmap
*map
,
169 unsigned int reg
, unsigned int *value
)
171 if (map
->cache_type
== REGCACHE_NONE
)
174 BUG_ON(!map
->cache_ops
);
176 if (!regmap_readable(map
, reg
))
179 if (!regmap_volatile(map
, reg
))
180 return map
->cache_ops
->read(map
, reg
, value
);
184 EXPORT_SYMBOL_GPL(regcache_read
);
187 * regcache_write: Set the value of a given register in the cache.
189 * @map: map to configure.
190 * @reg: The register index.
191 * @value: The new register value.
193 * Return a negative value on failure, 0 on success.
195 int regcache_write(struct regmap
*map
,
196 unsigned int reg
, unsigned int value
)
198 if (map
->cache_type
== REGCACHE_NONE
)
201 BUG_ON(!map
->cache_ops
);
203 if (!regmap_writeable(map
, reg
))
206 if (!regmap_volatile(map
, reg
))
207 return map
->cache_ops
->write(map
, reg
, value
);
211 EXPORT_SYMBOL_GPL(regcache_write
);
214 * regcache_sync: Sync the register cache with the hardware.
216 * @map: map to configure.
218 * Any registers that should not be synced should be marked as
219 * volatile. In general drivers can choose not to use the provided
220 * syncing functionality if they so require.
222 * Return a negative value on failure, 0 on success.
224 int regcache_sync(struct regmap
*map
)
231 BUG_ON(!map
->cache_ops
);
233 mutex_lock(&map
->lock
);
234 dev_dbg(map
->dev
, "Syncing %s cache\n",
235 map
->cache_ops
->name
);
236 name
= map
->cache_ops
->name
;
237 trace_regcache_sync(map
->dev
, name
, "start");
238 if (map
->cache_ops
->sync
) {
239 ret
= map
->cache_ops
->sync(map
);
241 for (i
= 0; i
< map
->num_reg_defaults
; i
++) {
242 ret
= regcache_read(map
, i
, &val
);
245 map
->cache_bypass
= 1;
246 ret
= _regmap_write(map
, i
, val
);
247 map
->cache_bypass
= 0;
250 dev_dbg(map
->dev
, "Synced register %#x, value %#x\n",
251 map
->reg_defaults
[i
].reg
,
252 map
->reg_defaults
[i
].def
);
257 trace_regcache_sync(map
->dev
, name
, "stop");
258 mutex_unlock(&map
->lock
);
262 EXPORT_SYMBOL_GPL(regcache_sync
);
265 * regcache_cache_only: Put a register map into cache only mode
267 * @map: map to configure
268 * @cache_only: flag if changes should be written to the hardware
270 * When a register map is marked as cache only writes to the register
271 * map API will only update the register cache, they will not cause
272 * any hardware changes. This is useful for allowing portions of
273 * drivers to act as though the device were functioning as normal when
274 * it is disabled for power saving reasons.
276 void regcache_cache_only(struct regmap
*map
, bool enable
)
278 mutex_lock(&map
->lock
);
279 map
->cache_only
= enable
;
280 mutex_unlock(&map
->lock
);
282 EXPORT_SYMBOL_GPL(regcache_cache_only
);
284 bool regcache_set_val(void *base
, unsigned int idx
,
285 unsigned int val
, unsigned int word_size
)
290 if (cache
[idx
] == val
)
297 if (cache
[idx
] == val
)
309 unsigned int regcache_get_val(const void *base
, unsigned int idx
,
310 unsigned int word_size
)
317 const u8
*cache
= base
;
321 const u16
*cache
= base
;
331 int regcache_lookup_reg(struct regmap
*map
, unsigned int reg
)
335 for (i
= 0; i
< map
->num_reg_defaults
; i
++)
336 if (map
->reg_defaults
[i
].reg
== reg
)
341 int regcache_insert_reg(struct regmap
*map
, unsigned int reg
,
346 tmp
= krealloc(map
->reg_defaults
,
347 (map
->num_reg_defaults
+ 1) * sizeof(struct reg_default
),
351 map
->reg_defaults
= tmp
;
352 map
->num_reg_defaults
++;
353 map
->reg_defaults
[map
->num_reg_defaults
- 1].reg
= reg
;
354 map
->reg_defaults
[map
->num_reg_defaults
- 1].def
= val
;