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regmap: Introduce max_raw_read/write for regmap_bulk_read/write

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There are some buses which have a limit on the maximum number of bytes
that can be send/received. An example for this is
I2C_FUNC_SMBUS_I2C_BLOCK which does not support any reads/writes of more
than 32 bytes. The regmap_bulk operations should still be able to
utilize the full 32 bytes in this case.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Markus Pargmann 2015-08-30 09:33:53 +02:00 committed by Mark Brown
parent 10524612e8
commit adaac45975
3 changed files with 78 additions and 15 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

4
drivers/base/regmap/internal.h
View file

@ -146,6 +146,10 @@ struct regmap {
/* if set, the device supports multi write mode */
bool can_multi_write;
/* if set, raw reads/writes are limited to this size */
size_t max_raw_read;
size_t max_raw_write;
struct rb_root range_tree;
void *selector_work_buf; /* Scratch buffer used for selector */
};

85
drivers/base/regmap/regmap.c
View file

@ -579,6 +579,8 @@ struct regmap *regmap_init(struct device *dev,
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;
map->max_raw_read = bus->max_raw_read;
map->max_raw_write = bus->max_raw_write;
map->dev = dev;
map->bus = bus;
map->bus_context = bus_context;
@ -1674,6 +1676,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
{
int ret = 0, i;
size_t val_bytes = map->format.val_bytes;
size_t total_size = val_bytes * val_count;
if (map->bus && !map->format.parse_inplace)
return -EINVAL;
@ -1722,16 +1725,37 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
}
out:
map->unlock(map->lock_arg);
} else if (map->use_single_write) {
} else if (map->use_single_write ||
(map->max_raw_write && map->max_raw_write < total_size)) {
int chunk_stride = map->reg_stride;
size_t chunk_size = val_bytes;
size_t chunk_count = val_count;
if (!map->use_single_write) {
chunk_size = map->max_raw_write;
if (chunk_size % val_bytes)
chunk_size -= chunk_size % val_bytes;
chunk_count = total_size / chunk_size;
chunk_stride *= chunk_size / val_bytes;
}
map->lock(map->lock_arg);
for (i = 0; i < val_count; i++) {
/* Write as many bytes as possible with chunk_size */
for (i = 0; i < chunk_count; i++) {
ret = _regmap_raw_write(map,
reg + (i * map->reg_stride),
val + (i * val_bytes),
val_bytes);
reg + (i * chunk_stride),
val + (i * chunk_size),
chunk_size);
if (ret)
break;
}
/* Write remaining bytes */
if (!ret && chunk_size * i < total_size) {
ret = _regmap_raw_write(map, reg + (i * chunk_stride),
val + (i * chunk_size),
total_size - i * chunk_size);
}
map->unlock(map->lock_arg);
} else {
void *wval;
@ -2319,20 +2343,51 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
* Some devices does not support bulk read, for
* them we have a series of single read operations.
*/
if (map->use_single_read) {
for (i = 0; i < val_count; i++) {
ret = regmap_raw_read(map,
reg + (i * map->reg_stride),
val + (i * val_bytes),
val_bytes);
if (ret != 0)
return ret;
}
} else {
size_t total_size = val_bytes * val_count;
if (!map->use_single_read &&
(!map->max_raw_read || map->max_raw_read > total_size)) {
ret = regmap_raw_read(map, reg, val,
val_bytes * val_count);
if (ret != 0)
return ret;
} else {
/*
* Some devices do not support bulk read or do not
* support large bulk reads, for them we have a series
* of read operations.
*/
int chunk_stride = map->reg_stride;
size_t chunk_size = val_bytes;
size_t chunk_count = val_count;
if (!map->use_single_read) {
chunk_size = map->max_raw_read;
if (chunk_size % val_bytes)
chunk_size -= chunk_size % val_bytes;
chunk_count = total_size / chunk_size;
chunk_stride *= chunk_size / val_bytes;
}
/* Read bytes that fit into a multiple of chunk_size */
for (i = 0; i < chunk_count; i++) {
ret = regmap_raw_read(map,
reg + (i * chunk_stride),
val + (i * chunk_size),
chunk_size);
if (ret != 0)
return ret;
}
/* Read remaining bytes */
if (chunk_size * i < total_size) {
ret = regmap_raw_read(map,
reg + (i * chunk_stride),
val + (i * chunk_size),
total_size - i * chunk_size);
if (ret != 0)
return ret;
}
}
for (i = 0; i < val_count * val_bytes; i += val_bytes)

4
include/linux/regmap.h
View file

@ -311,6 +311,8 @@ typedef void (*regmap_hw_free_context)(void *context);
* @val_format_endian_default: Default endianness for formatted register
* values. Used when the regmap_config specifies DEFAULT. If this is
* DEFAULT, BIG is assumed.
* @max_raw_read: Max raw read size that can be used on the bus.
* @max_raw_write: Max raw write size that can be used on the bus.
*/
struct regmap_bus {
bool fast_io;
@ -325,6 +327,8 @@ struct regmap_bus {
u8 read_flag_mask;
enum regmap_endian reg_format_endian_default;
enum regmap_endian val_format_endian_default;
size_t max_raw_read;
size_t max_raw_write;
};
struct regmap *regmap_init(struct device *dev,