2 * Register map access API
4 * Copyright 2011 Wolfson Microelectronics plc
6 * Author: Mark Brown <broonie@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 <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/err.h>
18 #define CREATE_TRACE_POINTS
19 #include <trace/events/regmap.h>
23 bool regmap_writeable(struct regmap
*map
, unsigned int reg
)
25 if (map
->max_register
&& reg
> map
->max_register
)
28 if (map
->writeable_reg
)
29 return map
->writeable_reg(map
->dev
, reg
);
34 bool regmap_readable(struct regmap
*map
, unsigned int reg
)
36 if (map
->max_register
&& reg
> map
->max_register
)
39 if (map
->readable_reg
)
40 return map
->readable_reg(map
->dev
, reg
);
45 bool regmap_volatile(struct regmap
*map
, unsigned int reg
)
47 if (map
->max_register
&& reg
> map
->max_register
)
50 if (map
->volatile_reg
)
51 return map
->volatile_reg(map
->dev
, reg
);
56 bool regmap_precious(struct regmap
*map
, unsigned int reg
)
58 if (map
->max_register
&& reg
> map
->max_register
)
61 if (map
->precious_reg
)
62 return map
->precious_reg(map
->dev
, reg
);
67 static void regmap_format_4_12_write(struct regmap
*map
,
68 unsigned int reg
, unsigned int val
)
70 __be16
*out
= map
->work_buf
;
71 *out
= cpu_to_be16((reg
<< 12) | val
);
74 static void regmap_format_7_9_write(struct regmap
*map
,
75 unsigned int reg
, unsigned int val
)
77 __be16
*out
= map
->work_buf
;
78 *out
= cpu_to_be16((reg
<< 9) | val
);
81 static void regmap_format_8(void *buf
, unsigned int val
)
88 static void regmap_format_16(void *buf
, unsigned int val
)
92 b
[0] = cpu_to_be16(val
);
95 static unsigned int regmap_parse_8(void *buf
)
102 static unsigned int regmap_parse_16(void *buf
)
106 b
[0] = be16_to_cpu(b
[0]);
112 * regmap_init(): Initialise register map
114 * @dev: Device that will be interacted with
115 * @bus: Bus-specific callbacks to use with device
116 * @config: Configuration for register map
118 * The return value will be an ERR_PTR() on error or a valid pointer to
119 * a struct regmap. This function should generally not be called
120 * directly, it should be called by bus-specific init functions.
122 struct regmap
*regmap_init(struct device
*dev
,
123 const struct regmap_bus
*bus
,
124 const struct regmap_config
*config
)
132 map
= kzalloc(sizeof(*map
), GFP_KERNEL
);
138 mutex_init(&map
->lock
);
139 map
->format
.buf_size
= (config
->reg_bits
+ config
->val_bits
) / 8;
140 map
->format
.reg_bytes
= config
->reg_bits
/ 8;
141 map
->format
.val_bytes
= config
->val_bits
/ 8;
144 map
->max_register
= config
->max_register
;
145 map
->writeable_reg
= config
->writeable_reg
;
146 map
->readable_reg
= config
->readable_reg
;
147 map
->volatile_reg
= config
->volatile_reg
;
148 map
->precious_reg
= config
->precious_reg
;
150 switch (config
->reg_bits
) {
152 switch (config
->val_bits
) {
154 map
->format
.format_write
= regmap_format_4_12_write
;
162 switch (config
->val_bits
) {
164 map
->format
.format_write
= regmap_format_7_9_write
;
172 map
->format
.format_reg
= regmap_format_8
;
176 map
->format
.format_reg
= regmap_format_16
;
183 switch (config
->val_bits
) {
185 map
->format
.format_val
= regmap_format_8
;
186 map
->format
.parse_val
= regmap_parse_8
;
189 map
->format
.format_val
= regmap_format_16
;
190 map
->format
.parse_val
= regmap_parse_16
;
194 if (!map
->format
.format_write
&&
195 !(map
->format
.format_reg
&& map
->format
.format_val
))
198 map
->work_buf
= kmalloc(map
->format
.buf_size
, GFP_KERNEL
);
199 if (map
->work_buf
== NULL
) {
204 regmap_debugfs_init(map
);
213 EXPORT_SYMBOL_GPL(regmap_init
);
216 * regmap_exit(): Free a previously allocated register map
218 void regmap_exit(struct regmap
*map
)
220 regmap_debugfs_exit(map
);
221 kfree(map
->work_buf
);
224 EXPORT_SYMBOL_GPL(regmap_exit
);
226 static int _regmap_raw_write(struct regmap
*map
, unsigned int reg
,
227 const void *val
, size_t val_len
)
234 /* Check for unwritable registers before we start */
235 if (map
->writeable_reg
)
236 for (i
= 0; i
< val_len
/ map
->format
.val_bytes
; i
++)
237 if (!map
->writeable_reg(map
->dev
, reg
+ i
))
240 map
->format
.format_reg(map
->work_buf
, reg
);
242 trace_regmap_hw_write_start(map
->dev
, reg
,
243 val_len
/ map
->format
.val_bytes
);
245 /* If we're doing a single register write we can probably just
246 * send the work_buf directly, otherwise try to do a gather
249 if (val
== map
->work_buf
+ map
->format
.reg_bytes
)
250 ret
= map
->bus
->write(map
->dev
, map
->work_buf
,
251 map
->format
.reg_bytes
+ val_len
);
252 else if (map
->bus
->gather_write
)
253 ret
= map
->bus
->gather_write(map
->dev
, map
->work_buf
,
254 map
->format
.reg_bytes
,
257 /* If that didn't work fall back on linearising by hand. */
258 if (ret
== -ENOTSUPP
) {
259 len
= map
->format
.reg_bytes
+ val_len
;
260 buf
= kmalloc(len
, GFP_KERNEL
);
264 memcpy(buf
, map
->work_buf
, map
->format
.reg_bytes
);
265 memcpy(buf
+ map
->format
.reg_bytes
, val
, val_len
);
266 ret
= map
->bus
->write(map
->dev
, buf
, len
);
271 trace_regmap_hw_write_done(map
->dev
, reg
,
272 val_len
/ map
->format
.val_bytes
);
277 static int _regmap_write(struct regmap
*map
, unsigned int reg
,
281 BUG_ON(!map
->format
.format_write
&& !map
->format
.format_val
);
283 trace_regmap_reg_write(map
->dev
, reg
, val
);
285 if (map
->format
.format_write
) {
286 map
->format
.format_write(map
, reg
, val
);
288 trace_regmap_hw_write_start(map
->dev
, reg
, 1);
290 ret
= map
->bus
->write(map
->dev
, map
->work_buf
,
291 map
->format
.buf_size
);
293 trace_regmap_hw_write_done(map
->dev
, reg
, 1);
297 map
->format
.format_val(map
->work_buf
+ map
->format
.reg_bytes
,
299 return _regmap_raw_write(map
, reg
,
300 map
->work_buf
+ map
->format
.reg_bytes
,
301 map
->format
.val_bytes
);
306 * regmap_write(): Write a value to a single register
308 * @map: Register map to write to
309 * @reg: Register to write to
310 * @val: Value to be written
312 * A value of zero will be returned on success, a negative errno will
313 * be returned in error cases.
315 int regmap_write(struct regmap
*map
, unsigned int reg
, unsigned int val
)
319 mutex_lock(&map
->lock
);
321 ret
= _regmap_write(map
, reg
, val
);
323 mutex_unlock(&map
->lock
);
327 EXPORT_SYMBOL_GPL(regmap_write
);
330 * regmap_raw_write(): Write raw values to one or more registers
332 * @map: Register map to write to
333 * @reg: Initial register to write to
334 * @val: Block of data to be written, laid out for direct transmission to the
336 * @val_len: Length of data pointed to by val.
338 * This function is intended to be used for things like firmware
339 * download where a large block of data needs to be transferred to the
340 * device. No formatting will be done on the data provided.
342 * A value of zero will be returned on success, a negative errno will
343 * be returned in error cases.
345 int regmap_raw_write(struct regmap
*map
, unsigned int reg
,
346 const void *val
, size_t val_len
)
350 mutex_lock(&map
->lock
);
352 ret
= _regmap_raw_write(map
, reg
, val
, val_len
);
354 mutex_unlock(&map
->lock
);
358 EXPORT_SYMBOL_GPL(regmap_raw_write
);
360 static int _regmap_raw_read(struct regmap
*map
, unsigned int reg
, void *val
,
361 unsigned int val_len
)
363 u8
*u8
= map
->work_buf
;
366 map
->format
.format_reg(map
->work_buf
, reg
);
369 * Some buses flag reads by setting the high bits in the
370 * register addresss; since it's always the high bits for all
371 * current formats we can do this here rather than in
372 * formatting. This may break if we get interesting formats.
374 if (map
->bus
->read_flag_mask
)
375 u8
[0] |= map
->bus
->read_flag_mask
;
377 trace_regmap_hw_read_start(map
->dev
, reg
,
378 val_len
/ map
->format
.val_bytes
);
380 ret
= map
->bus
->read(map
->dev
, map
->work_buf
, map
->format
.reg_bytes
,
383 trace_regmap_hw_read_done(map
->dev
, reg
,
384 val_len
/ map
->format
.val_bytes
);
389 static int _regmap_read(struct regmap
*map
, unsigned int reg
,
394 if (!map
->format
.parse_val
)
397 ret
= _regmap_raw_read(map
, reg
, map
->work_buf
, map
->format
.val_bytes
);
399 *val
= map
->format
.parse_val(map
->work_buf
);
400 trace_regmap_reg_read(map
->dev
, reg
, *val
);
407 * regmap_read(): Read a value from a single register
409 * @map: Register map to write to
410 * @reg: Register to be read from
411 * @val: Pointer to store read value
413 * A value of zero will be returned on success, a negative errno will
414 * be returned in error cases.
416 int regmap_read(struct regmap
*map
, unsigned int reg
, unsigned int *val
)
420 mutex_lock(&map
->lock
);
422 ret
= _regmap_read(map
, reg
, val
);
424 mutex_unlock(&map
->lock
);
428 EXPORT_SYMBOL_GPL(regmap_read
);
431 * regmap_raw_read(): Read raw data from the device
433 * @map: Register map to write to
434 * @reg: First register to be read from
435 * @val: Pointer to store read value
436 * @val_len: Size of data to read
438 * A value of zero will be returned on success, a negative errno will
439 * be returned in error cases.
441 int regmap_raw_read(struct regmap
*map
, unsigned int reg
, void *val
,
446 mutex_lock(&map
->lock
);
448 ret
= _regmap_raw_read(map
, reg
, val
, val_len
);
450 mutex_unlock(&map
->lock
);
454 EXPORT_SYMBOL_GPL(regmap_raw_read
);
457 * regmap_bulk_read(): Read multiple registers from the device
459 * @map: Register map to write to
460 * @reg: First register to be read from
461 * @val: Pointer to store read value, in native register size for device
462 * @val_count: Number of registers to read
464 * A value of zero will be returned on success, a negative errno will
465 * be returned in error cases.
467 int regmap_bulk_read(struct regmap
*map
, unsigned int reg
, void *val
,
471 size_t val_bytes
= map
->format
.val_bytes
;
473 if (!map
->format
.parse_val
)
476 ret
= regmap_raw_read(map
, reg
, val
, val_bytes
* val_count
);
480 for (i
= 0; i
< val_count
* val_bytes
; i
+= val_bytes
)
481 map
->format
.parse_val(val
+ i
);
485 EXPORT_SYMBOL_GPL(regmap_bulk_read
);
488 * remap_update_bits: Perform a read/modify/write cycle on the register map
490 * @map: Register map to update
491 * @reg: Register to update
492 * @mask: Bitmask to change
493 * @val: New value for bitmask
495 * Returns zero for success, a negative number on error.
497 int regmap_update_bits(struct regmap
*map
, unsigned int reg
,
498 unsigned int mask
, unsigned int val
)
503 mutex_lock(&map
->lock
);
505 ret
= _regmap_read(map
, reg
, &tmp
);
512 ret
= _regmap_write(map
, reg
, tmp
);
515 mutex_unlock(&map
->lock
);
519 EXPORT_SYMBOL_GPL(regmap_update_bits
);
521 static int __init
regmap_initcall(void)
523 regmap_debugfs_initcall();
527 postcore_initcall(regmap_initcall
);
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