regmap: Merge up fix for window/paging issue

This was too late and could potentially impact too many drivers for me
to be comfortable sending it before the merge window.

Author: broonie

drivers/base/regmap/regcache-rbtree.c

@@ -453,7 +453,8 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
 		if (!rbnode)
 			return -ENOMEM;
 		regcache_rbtree_set_register(map, rbnode,
-					     reg - rbnode->base_reg, value);
+					     (reg - rbnode->base_reg) / map->reg_stride,
+					     value);
 		regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);
 		rbtree_ctx->cached_rbnode = rbnode;
 	}

drivers/base/regmap/regcache.c

@@ -334,6 +334,11 @@ static int regcache_default_sync(struct regmap *map, unsigned int min,
 	return 0;
 }
 
+static int rbtree_all(const void *key, const struct rb_node *node)
+{
+	return 0;
+}
+
 /**
  * regcache_sync - Sync the register cache with the hardware.
  *
@@ -351,6 +356,7 @@ int regcache_sync(struct regmap *map)
 	unsigned int i;
 	const char *name;
 	bool bypass;
+	struct rb_node *node;
 
 	if (WARN_ON(map->cache_type == REGCACHE_NONE))
 		return -EINVAL;
@@ -392,6 +398,30 @@ int regcache_sync(struct regmap *map)
 	/* Restore the bypass state */
 	map->cache_bypass = bypass;
 	map->no_sync_defaults = false;
+
+	/*
+	 * If we did any paging with cache bypassed and a cached
+	 * paging register then the register and cache state might
+	 * have gone out of sync, force writes of all the paging
+	 * registers.
+	 */
+	rb_for_each(node, 0, &map->range_tree, rbtree_all) {
+		struct regmap_range_node *this =
+			rb_entry(node, struct regmap_range_node, node);
+
+		/* If there's nothing in the cache there's nothing to sync */
+		ret = regcache_read(map, this->selector_reg, &i);
+		if (ret != 0)
+			continue;
+
+		ret = _regmap_write(map, this->selector_reg, i);
+		if (ret != 0) {
+			dev_err(map->dev, "Failed to write %x = %x: %d\n",
+				this->selector_reg, i, ret);
+			break;
+		}
+	}
+
 	map->unlock(map->lock_arg);
 
 	regmap_async_complete(map);

drivers/base/regmap/regmap.c

@@ -1478,7 +1478,7 @@ static int dev_get_regmap_match(struct device *dev, void *res, void *data)
 
 	/* If the user didn't specify a name match any */
 	if (data)
-		return !strcmp((*r)->name, data);
+		return (*r)->name && !strcmp((*r)->name, data);
 	else
 		return 1;
 }