1 files changed, 83 insertions, 0 deletions
diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regcache-flat.c
new file mode 100644
index 0000000000..b7e4b24641
--- /dev/null
+++ b/drivers/base/regmap/regcache-flat.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Register cache access API - flat caching support
+//
+// Copyright 2012 Wolfson Microelectronics plc
+//
+// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+
+#include <linux/device.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+static inline unsigned int regcache_flat_get_index(const struct regmap *map,
+						   unsigned int reg)
+{
+	return regcache_get_index_by_order(map, reg);
+}
+
+static int regcache_flat_init(struct regmap *map)
+{
+	int i;
+	unsigned int *cache;
+
+	if (!map || map->reg_stride_order < 0 || !map->max_register)
+		return -EINVAL;
+
+	map->cache = kcalloc(regcache_flat_get_index(map, map->max_register)
+			     + 1, sizeof(unsigned int), GFP_KERNEL);
+	if (!map->cache)
+		return -ENOMEM;
+
+	cache = map->cache;
+
+	for (i = 0; i < map->num_reg_defaults; i++) {
+		unsigned int reg = map->reg_defaults[i].reg;
+		unsigned int index = regcache_flat_get_index(map, reg);
+
+		cache[index] = map->reg_defaults[i].def;
+	}
+
+	return 0;
+}
+
+static int regcache_flat_exit(struct regmap *map)
+{
+	kfree(map->cache);
+	map->cache = NULL;
+
+	return 0;
+}
+
+static int regcache_flat_read(struct regmap *map,
+			      unsigned int reg, unsigned int *value)
+{
+	unsigned int *cache = map->cache;
+	unsigned int index = regcache_flat_get_index(map, reg);
+
+	*value = cache[index];
+
+	return 0;
+}
+
+static int regcache_flat_write(struct regmap *map, unsigned int reg,
+			       unsigned int value)
+{
+	unsigned int *cache = map->cache;
+	unsigned int index = regcache_flat_get_index(map, reg);
+
+	cache[index] = value;
+
+	return 0;
+}
+
+struct regcache_ops regcache_flat_ops = {
+	.type = REGCACHE_FLAT,
+	.name = "flat",
+	.init = regcache_flat_init,
+	.exit = regcache_flat_exit,
+	.read = regcache_flat_read,
+	.write = regcache_flat_write,
+};