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authorMark Brown <broonie@opensource.wolfsonmicro.com>2012-02-21 19:12:47 +0000
committerMark Brown <broonie@opensource.wolfsonmicro.com>2012-02-21 19:29:18 +0000
commitb8fb5ab156055b745254609f4635fcfd6b7dabc8 (patch)
tree3b38473273181e316dd0db25ea4966cb1e7f946e /drivers/base
parent7d5e525b9ceda0e3b85da0acdaa2de19fea51edc (diff)
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>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/regmap/regmap.c28
1 files changed, 22 insertions, 6 deletions
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 73a8111aea93..ef7022d45744 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -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;