linux-kernel - [PATCH 1/3] regmap: flat: use the cache

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Date:	Fri, 09 Aug 2013 12:09:11 +0200
From:	Ionut Nicu <ioan.nicu.ext@....com>
To:	Mark Brown <broonie@...nel.org>
CC:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	linux-kernel@...r.kernel.org
Subject: [PATCH 1/3] regmap: flat: use the cache_present bitmap

As opposed to the other regmap cache implementations,
regcache_flat didn't use the cache_present bitmap for
figuring out whether a register was cached or not, nor
did it mark a register as present in the cache when
regcache_flat_write() was called.

This caused incorrect behaviour, such as returning
value 0 for non-volatile registers without first reading
their value from the device and storing it in the cache.

Signed-off-by: Ionut Nicu <ioan.nicu.ext@....com>
---
 drivers/base/regmap/regcache-flat.c |   25 ++++++++++++++++++++++---
 1 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regcache-flat.c
index d9762e4..f47278e 100644
--- a/drivers/base/regmap/regcache-flat.c
+++ b/drivers/base/regmap/regcache-flat.c
@@ -16,9 +16,13 @@
 
 #include "internal.h"
 
+static int regcache_flat_write(struct regmap *map, unsigned int reg,
+			       unsigned int value);
+static int regcache_flat_exit(struct regmap *map);
+
 static int regcache_flat_init(struct regmap *map)
 {
-	int i;
+	int i, ret;
 	unsigned int *cache;
 
 	map->cache = kzalloc(sizeof(unsigned int) * (map->max_register + 1),
@@ -28,8 +32,15 @@ static int regcache_flat_init(struct regmap *map)
 
 	cache = map->cache;
 
-	for (i = 0; i < map->num_reg_defaults; i++)
-		cache[map->reg_defaults[i].reg] = map->reg_defaults[i].def;
+	for (i = 0; i < map->num_reg_defaults; i++) {
+		ret = regcache_flat_write(map,
+				map->reg_defaults[i].reg,
+				map->reg_defaults[i].def);
+		if (ret) {
+			regcache_flat_exit(map);
+			return ret;
+		}
+	}
 
 	return 0;
 }
@@ -47,6 +58,9 @@ static int regcache_flat_read(struct regmap *map,
 {
 	unsigned int *cache = map->cache;
 
+	if (!regcache_reg_present(map, reg))
+		return -ENOENT;
+
 	*value = cache[reg];
 
 	return 0;
@@ -56,6 +70,11 @@ static int regcache_flat_write(struct regmap *map, unsigned int reg,
 			       unsigned int value)
 {
 	unsigned int *cache = map->cache;
+	int ret;
+
+	ret = regcache_set_reg_present(map, reg);
+	if (ret < 0)
+		return ret;
 
 	cache[reg] = value;
 
-- 
1.7.1

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