regmap: Implemented default cache sync operation

This can be used for cache types for which syncing values one by one is
equally efficient as syncing a range, such as the flat cache.

Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 4bfa219..e691026 100644 (file)
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -250,6 +250,38 @@ int regcache_write(struct regmap *map,
        return 0;
 }
 
+static int regcache_default_sync(struct regmap *map, unsigned int min,
+                                unsigned int max)
+{
+       unsigned int reg;
+
+       for (reg = min; reg <= max; reg++) {
+               unsigned int val;
+               int ret;
+
+               if (regmap_volatile(map, reg))
+                       continue;
+
+               ret = regcache_read(map, reg, &val);
+               if (ret)
+                       return ret;
+
+               /* Is this the hardware default?  If so skip. */
+               ret = regcache_lookup_reg(map, reg);
+               if (ret >= 0 && val == map->reg_defaults[ret].def)
+                       continue;
+
+               map->cache_bypass = 1;
+               ret = _regmap_write(map, reg, val);
+               map->cache_bypass = 0;
+               if (ret)
+                       return ret;
+               dev_dbg(map->dev, "Synced register %#x, value %#x\n", reg, val);
+       }
+
+       return 0;
+}
+
 /**
  * regcache_sync: Sync the register cache with the hardware.
  *
@@ -268,7 +300,7 @@ int regcache_sync(struct regmap *map)
        const char *name;
        unsigned int bypass;
 
-       BUG_ON(!map->cache_ops || !map->cache_ops->sync);
+       BUG_ON(!map->cache_ops);
 
        map->lock(map->lock_arg);
        /* Remember the initial bypass state */
@@ -297,7 +329,10 @@ int regcache_sync(struct regmap *map)
        }
        map->cache_bypass = 0;
 
-       ret = map->cache_ops->sync(map, 0, map->max_register);
+       if (map->cache_ops->sync)
+               ret = map->cache_ops->sync(map, 0, map->max_register);
+       else
+               ret = regcache_default_sync(map, 0, map->max_register);
 
        if (ret == 0)
                map->cache_dirty = false;
@@ -331,7 +366,7 @@ int regcache_sync_region(struct regmap *map, unsigned int min,
        const char *name;
        unsigned int bypass;
 
-       BUG_ON(!map->cache_ops || !map->cache_ops->sync);
+       BUG_ON(!map->cache_ops);
 
        map->lock(map->lock_arg);
 
@@ -346,7 +381,10 @@ int regcache_sync_region(struct regmap *map, unsigned int min,
        if (!map->cache_dirty)
                goto out;
 
-       ret = map->cache_ops->sync(map, min, max);
+       if (map->cache_ops->sync)
+               ret = map->cache_ops->sync(map, min, max);
+       else
+               ret = regcache_default_sync(map, min, max);
 
 out:
        trace_regcache_sync(map->dev, name, "stop region");