path: root/drivers/base/regmap
diff options
authorLars-Peter Clausen <lars@metafoo.de>2015-07-13 12:26:44 +0200
committerMark Brown <broonie@kernel.org>2015-07-13 11:49:18 +0100
commit04dc91ce2cca5927159c689aa1f47663f8c51530 (patch)
treedb8d4393b3fe3d7ed21f04f6c8073993547af6d2 /drivers/base/regmap
parentd770e558e21961ad6cfdf0ff7df0eb5d7d4f0754 (diff)
regmap: Add better support for devices without readback support
Currently regmap requires that a reg_read callback is supplied, otherwise a warning is emitted each time regmap_read() is called. This means a device or bus without readback support needs to supply dummy reg_read callback. Apart from that regmap_read() will still work fine if a cache is used. Remove the warning and let regmap_readable() return false if not reg_read callback is supplied. This means a device no longer has to supply a dummy callback if it does not support readback and it also doesn't have to have a readable_reg callback that always returns false since this is now implicit. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/base/regmap')
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 7111d04f2621..8894b992043e 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -93,6 +93,9 @@ bool regmap_writeable(struct regmap *map, unsigned int reg)
bool regmap_readable(struct regmap *map, unsigned int reg)
+ if (!map->reg_read)
+ return false;
if (map->max_register && reg > map->max_register)
return false;
@@ -2097,8 +2100,6 @@ static int _regmap_read(struct regmap *map, unsigned int reg,
int ret;
void *context = _regmap_map_get_context(map);
- WARN_ON(!map->reg_read);
if (!map->cache_bypass) {
ret = regcache_read(map, reg, val);
if (ret == 0)