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Commit ca747be2 authored by Xiubo Li's avatar Xiubo Li Committed by Mark Brown
Browse files

regmap: core: Introduce register stride order 



Since the register stride should always equal to 2^N, and bit rotation is
much faster than multiplication and division. So introducing the stride
order and using bit rotation to get the offset of the register from the
index to improve the performance.

Signed-off-by: default avatarXiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 92e963f5

drivers/base/regmap/internal.h

+10 −0
Original line number Diff line number Diff line
@@ -110,6 +110,7 @@ struct regmap { 
	/* number of bits to (left) shift the reg value when formatting*/

	int reg_shift;

	int reg_stride;

	int reg_stride_order;



	/* regcache specific members */

	const struct regcache_ops *cache_ops;
@@ -263,4 +264,13 @@ static inline const char *regmap_name(const struct regmap *map) 
	return map->name;

}



static inline unsigned int regmap_get_offset(const struct regmap *map,

					     unsigned int index)

{

	if (map->reg_stride_order >= 0)

		return index << map->reg_stride_order;

	else

		return index * map->reg_stride;

}



#endif

drivers/base/regmap/regmap.c

+13 −6
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/rbtree.h>

#include <linux/sched.h>

#include <linux/delay.h>

#include <linux/log2.h>



#define CREATE_TRACE_POINTS

#include "trace.h"
@@ -638,6 +639,10 @@ struct regmap *__regmap_init(struct device *dev, 
		map->reg_stride = config->reg_stride;

	else

		map->reg_stride = 1;

	if (is_power_of_2(map->reg_stride))

		map->reg_stride_order = ilog2(map->reg_stride);

	else

		map->reg_stride_order = -1;

	map->use_single_read = config->use_single_rw || !bus || !bus->read;

	map->use_single_write = config->use_single_rw || !bus || !bus->write;

	map->can_multi_write = config->can_multi_write && bus && bus->write;
@@ -1308,7 +1313,7 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg, 
	if (map->writeable_reg)

		for (i = 0; i < val_len / map->format.val_bytes; i++)

			if (!map->writeable_reg(map->dev,

						reg + (i * map->reg_stride)))

					       reg + regmap_get_offset(map, i)))

				return -EINVAL;



	if (!map->cache_bypass && map->format.parse_val) {
@@ -1316,7 +1321,8 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg, 
		int val_bytes = map->format.val_bytes;

		for (i = 0; i < val_len / val_bytes; i++) {

			ival = map->format.parse_val(val + (i * val_bytes));

			ret = regcache_write(map, reg + (i * map->reg_stride),

			ret = regcache_write(map,

					     reg + regmap_get_offset(map, i),

					     ival);

			if (ret) {

				dev_err(map->dev,
@@ -1846,7 +1852,8 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val, 
				goto out;

			}



			ret = _regmap_write(map, reg + (i * map->reg_stride),

			ret = _regmap_write(map,

					    reg + regmap_get_offset(map, i),

					    ival);

			if (ret != 0)

				goto out;
@@ -2416,7 +2423,7 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val, 
		 * cost as we expect to hit the cache.

		 */

		for (i = 0; i < val_count; i++) {

			ret = _regmap_read(map, reg + (i * map->reg_stride),

			ret = _regmap_read(map, reg + regmap_get_offset(map, i),

					   &v);

			if (ret != 0)

				goto out;
@@ -2568,7 +2575,7 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val, 
	} else {

		for (i = 0; i < val_count; i++) {

			unsigned int ival;

			ret = regmap_read(map, reg + (i * map->reg_stride),

			ret = regmap_read(map, reg + regmap_get_offset(map, i),

					  &ival);

			if (ret != 0)

				return ret;