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>
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 73a8111..ef7022d 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -604,16 +604,32 @@
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;