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regmap: Support raw reads from cached registers 

Fall back to a register by register read to do so; most likely we'll be
cache only so the overhead will be low.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Mark Brown 2012-02-21 19:12:47 +00:00
parent 7d5e525b9c
commit b8fb5ab156
1 changed files with 22 additions and 6 deletions
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28
drivers/base/regmap/regmap.c
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@ -604,16 +604,32 @@ EXPORT_SYMBOL_GPL(regmap_read);
int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
size_t val_len)
{
size_t val_count = val_len / map->format.val_bytes;
int ret;
WARN_ON(!regmap_volatile_range(map, reg, val_count) &&
map->cache_type != REGCACHE_NONE);
size_t val_bytes = map->format.val_bytes;
size_t val_count = val_len / val_bytes;
unsigned int v;
int ret, i;
mutex_lock(&map->lock);
ret = _regmap_raw_read(map, reg, val, val_len);
if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
map->cache_type == REGCACHE_NONE) {
/* Physical block read if there's no cache involved */
ret = _regmap_raw_read(map, reg, val, val_len);
} else {
/* Otherwise go word by word for the cache; should be low
* cost as we expect to hit the cache.
*/
for (i = 0; i < val_count; i++) {
ret = _regmap_read(map, reg + i, &v);
if (ret != 0)
goto out;
map->format.format_val(val + (i * val_bytes), v);
}
}
out:
mutex_unlock(&map->lock);
return ret;