4 files changed, 81 insertions, 25 deletions

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index abd76678ed73..fcafc5b2e651 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -88,7 +88,7 @@ struct regcache_ops {
         int (*exit)(struct regmap *map);
         int (*read)(struct regmap *map, unsigned int reg, unsigned int *value);
         int (*write)(struct regmap *map, unsigned int reg, unsigned int value);
-        int (*sync)(struct regmap *map);
+        int (*sync)(struct regmap *map, unsigned int min, unsigned int max);
 };
 
 bool regmap_writeable(struct regmap *map, unsigned int reg);
diff --git a/drivers/base/regmap/regcache-lzo.c b/drivers/base/regmap/regcache-lzo.c
index 3025cf920f25..8d0061569326 100644
--- a/drivers/base/regmap/regcache-lzo.c
+++ b/drivers/base/regmap/regcache-lzo.c
@@ -331,7 +331,8 @@ out:
         return ret;
 }
 
-static int regcache_lzo_sync(struct regmap *map)
+static int regcache_lzo_sync(struct regmap *map, unsigned int min,
+                             unsigned int max)
 {
         struct regcache_lzo_ctx **lzo_blocks;
         unsigned int val;
@@ -339,7 +340,12 @@ static int regcache_lzo_sync(struct regmap *map)
         int ret;
 
         lzo_blocks = map->cache;
-        for_each_set_bit(i, lzo_blocks[0]->sync_bmp, lzo_blocks[0]->sync_bmp_nbits) {
+        i = min;
+        for_each_set_bit_cont(i, lzo_blocks[0]->sync_bmp,
+                              lzo_blocks[0]->sync_bmp_nbits) {
+                if (i > max)
+                        continue;
+
                 ret = regcache_read(map, i, &val);
                 if (ret)
                         return ret;
diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index 861ad2c81dff..8d51916a283d 100644
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -357,7 +357,8 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
         return 0;
 }
 
-static int regcache_rbtree_sync(struct regmap *map)
+static int regcache_rbtree_sync(struct regmap *map, unsigned int min,
+                                unsigned int max)
 {
         struct regcache_rbtree_ctx *rbtree_ctx;
         struct rb_node *node;
@@ -365,12 +366,30 @@ static int regcache_rbtree_sync(struct regmap *map)
         unsigned int regtmp;
         unsigned int val;
         int ret;
-        int i;
+        int i, base, end;
 
         rbtree_ctx = map->cache;
         for (node = rb_first(&rbtree_ctx->root); node; node = rb_next(node)) {
                 rbnode = rb_entry(node, struct regcache_rbtree_node, node);
-                for (i = 0; i < rbnode->blklen; i++) {
+
+                if (rbnode->base_reg < min)
+                        continue;
+                if (rbnode->base_reg > max)
+                        break;
+                if (rbnode->base_reg + rbnode->blklen < min)
+                        continue;
+
+                if (min > rbnode->base_reg)
+                        base = min - rbnode->base_reg;
+                else
+                        base = 0;
+
+                if (max < rbnode->base_reg + rbnode->blklen)
+                        end = rbnode->base_reg + rbnode->blklen - max;
+                else
+                        end = rbnode->blklen;
+
+                for (i = base; i < end; i++) {
                         regtmp = rbnode->base_reg + i;
                         val = regcache_rbtree_get_register(rbnode, i,
                                                            map->cache_word_size);
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 8db713ffef66..fb84d711fbb4 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -252,12 +252,11 @@ int regcache_write(struct regmap *map,
 int regcache_sync(struct regmap *map)
 {
         int ret = 0;
-        unsigned int val;
         unsigned int i;
         const char *name;
         unsigned int bypass;
 
-        BUG_ON(!map->cache_ops);
+        BUG_ON(!map->cache_ops || !map->cache_ops->sync);
 
         mutex_lock(&map->lock);
         /* Remember the initial bypass state */
@@ -282,24 +281,11 @@ int regcache_sync(struct regmap *map)
         }
         map->cache_bypass = 0;
 
-        if (map->cache_ops->sync) {
-                ret = map->cache_ops->sync(map);
-        } else {
-                for (i = 0; i < map->num_reg_defaults; i++) {
-                        ret = regcache_read(map, i, &val);
-                        if (ret < 0)
-                                goto out;
-                        map->cache_bypass = 1;
-                        ret = _regmap_write(map, i, val);
-                        map->cache_bypass = 0;
-                        if (ret < 0)
-                                goto out;
-                        dev_dbg(map->dev, "Synced register %#x, value %#x\n",
-                                map->reg_defaults[i].reg,
-                                map->reg_defaults[i].def);
-                }
+        ret = map->cache_ops->sync(map, 0, map->max_register);
+
+        if (ret == 0)
+                map->cache_dirty = false;
 
-        }
 out:
         trace_regcache_sync(map->dev, name, "stop");
         /* Restore the bypass state */
@@ -311,6 +297,51 @@ out:
 EXPORT_SYMBOL_GPL(regcache_sync);
 
 /**
+ * regcache_sync_region: Sync part  of the register cache with the hardware.
+ *
+ * @map: map to sync.
+ * @min: first register to sync
+ * @max: last register to sync
+ *
+ * Write all non-default register values in the specified region to
+ * the hardware.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_sync_region(struct regmap *map, unsigned int min,
+                         unsigned int max)
+{
+        int ret = 0;
+        const char *name;
+        unsigned int bypass;
+
+        BUG_ON(!map->cache_ops || !map->cache_ops->sync);
+
+        mutex_lock(&map->lock);
+
+        /* Remember the initial bypass state */
+        bypass = map->cache_bypass;
+
+        name = map->cache_ops->name;
+        dev_dbg(map->dev, "Syncing %s cache from %d-%d\n", name, min, max);
+
+        trace_regcache_sync(map->dev, name, "start region");
+
+        if (!map->cache_dirty)
+                goto out;
+
+        ret = map->cache_ops->sync(map, min, max);
+
+out:
+        trace_regcache_sync(map->dev, name, "stop region");
+        /* Restore the bypass state */
+        map->cache_bypass = bypass;
+        mutex_unlock(&map->lock);
+
+        return ret;
+}
+
+/**
  * regcache_cache_only: Put a register map into cache only mode
  *
  * @map: map to configure