regmap: Add the indexed cache support

This is the simplest form of a cache available in regcache.  Any
registers whose default value is 0 are ignored.  If any of those
registers are modified in the future, they will be placed in the
cache on demand.  The cache layout is essentially using the provided
register defaults by the regcache core directly and does not re-map
it to another representation.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
index 2e103ea9a3a069f95e8ee5db1a808e3df2532c81..418d151eb30bef7112321f538bbcf5ead6f58554 100644 (file)
--- a/drivers/base/regmap/Makefile
+++ b/drivers/base/regmap/Makefile
@@ -1,4 +1,4 @@
-obj-$(CONFIG_REGMAP) += regmap.o regcache.o
+obj-$(CONFIG_REGMAP) += regmap.o regcache.o regcache-indexed.o
 obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o
 obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o
 obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 615f5581d5db1f8e472adb32416cb416e0c39b0d..5bd5759efd5c4d005506d536e41792bf15e69738 100644 (file)
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -118,4 +118,5 @@ int regcache_lookup_reg(struct regmap *map, unsigned int reg);
 int regcache_insert_reg(struct regmap *map, unsigned int reg,
                        unsigned int val);
 
+extern struct regcache_ops regcache_indexed_ops;
 #endif

diff --git a/drivers/base/regmap/regcache-indexed.c b/drivers/base/regmap/regcache-indexed.c
new file mode 100644 (file)
index 0000000..ff8b44c
--- /dev/null
+++ b/drivers/base/regmap/regcache-indexed.c
@@ -0,0 +1,65 @@
+/*
+ * Register cache access API - indexed caching support
+ *
+ * Copyright 2011 Wolfson Microelectronics plc
+ *
+ * Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+
+#include "internal.h"
+
+static int regcache_indexed_read(struct regmap *map, unsigned int reg,
+                                unsigned int *value)
+{
+       int ret;
+
+       ret = regcache_lookup_reg(map, reg);
+       if (ret < 0)
+               *value = 0;
+       else
+               *value = map->reg_defaults[ret].def;
+       return 0;
+}
+
+static int regcache_indexed_write(struct regmap *map, unsigned int reg,
+                                 unsigned int value)
+{
+       int ret;
+
+       ret = regcache_lookup_reg(map, reg);
+       if (ret < 0)
+               return regcache_insert_reg(map, reg, value);
+       map->reg_defaults[ret].def = value;
+       return 0;
+}
+
+static int regcache_indexed_sync(struct regmap *map)
+{
+       int i;
+       int ret;
+
+       for (i = 0; i < map->num_reg_defaults; i++) {
+               ret = regmap_write(map, map->reg_defaults[i].reg,
+                                  map->reg_defaults[i].def);
+               if (ret < 0)
+                       return ret;
+               dev_dbg(map->dev, "Synced register %#x, value %#x\n",
+                       map->reg_defaults[i].reg,
+                       map->reg_defaults[i].def);
+       }
+       return 0;
+}
+
+struct regcache_ops regcache_indexed_ops = {
+       .type = REGCACHE_INDEXED,
+       .name = "indexed",
+       .read = regcache_indexed_read,
+       .write = regcache_indexed_write,
+       .sync = regcache_indexed_sync
+};

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 9575e4c5f34af7782657df0a3995f45891315194..22b73ec12fd526803a979c8fd22a0daf994dae60 100644 (file)
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -16,6 +16,7 @@
 #include "internal.h"
 
 static const struct regcache_ops *cache_types[] = {
+       &regcache_indexed_ops,
 };
 
 static int regcache_hw_init(struct regmap *map)

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 9d8029449292ec73e3d4b2758162a72498e620a9..ae6d3a4cee978c4c47a31eff6a5bfdbf60d8b313 100644 (file)
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -23,6 +23,7 @@ struct spi_device;
 /* An enum of all the supported cache types */
 enum regcache_type {
        REGCACHE_NONE,
+       REGCACHE_INDEXED,
 };
 
 /**