From b8fb5ab156055b745254609f4635fcfd6b7dabc8 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 21 Feb 2012 19:12:47 +0000 Subject: [PATCH] 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 --- drivers/base/regmap/regmap.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) 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 @@ 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; -- 2.7.4