aboutsummaryrefslogtreecommitdiff
path: root/drivers/base
diff options
context:
space:
mode:
authorMarkus Pargmann <mpa@pengutronix.de>2015-08-30 09:33:53 +0200
committerMark Brown <broonie@kernel.org>2015-08-30 10:19:22 +0100
commitadaac459759db4a1fd35baddbe47bac700095496 (patch)
tree189657c7dffdc13de7f780eb35c1299fb8dbf3fa /drivers/base
parent10524612e8aa98804190ec7d0b380cf99c3bdbd7 (diff)
downloadlinux-linaro-stable-adaac459759db4a1fd35baddbe47bac700095496.tar.gz
regmap: Introduce max_raw_read/write for regmap_bulk_read/write
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>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/regmap/internal.h4
-rw-r--r--drivers/base/regmap/regmap.c85
2 files changed, 74 insertions, 15 deletions
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index d744ae3926dd..fc554e357c5d 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -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 */
};
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index a6b6f7ee87ee..7cbe42680877 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -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)