[PATCH v2 1/2] regmap: Properly round cache_word_size

[PATCH v2 1/2] regmap: Properly round cache_word_size

[Lars-Peter Clausen]

regcache currently only properly works with val bit sizes of 8 or 16, since
it will, when calculating the cache word size, round down. This causes the
cache storage to be too small to hold the full register value. Fix this by
rounding up instead.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

---
Changes since v1:
 * Use DIV_ROUND_UP
---
 drivers/base/regmap/regcache.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index d687df6..6d93e49 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -111,8 +111,8 @@ int regcache_init(struct regmap *map, const struct regmap_config *config)
 	map->num_reg_defaults = config->num_reg_defaults;
 	map->num_reg_defaults_raw = config->num_reg_defaults_raw;
 	map->reg_defaults_raw = config->reg_defaults_raw;
-	map->cache_size_raw = (config->val_bits / 8) * config->num_reg_defaults_raw;
-	map->cache_word_size = config->val_bits / 8;
+	map->cache_word_size = DIV_ROUND_UP(config->val_bits, 8);
+	map->cache_size_raw = map->cache_word_size * config->num_reg_defaults_raw;
 
 	map->cache = NULL;
 	map->cache_ops = cache_types[i];
-- 
1.7.7.1

[PATCH v2 2/2] regmap: Drop check whether a register is readable in regcache_read

[Lars-Peter Clausen]

One of the reasons for using a cache is to have a software shadow of a register
which is writable but not readable. This allows us to do a read-modify-write
operation on such a register.

Currently regcache checks whether a register is readable when performing a
cached read and returns an error if it is not. Drop this check, since it will
prevent us from using the cache for registers where read-back is not possible.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

---
Changes since v1:
	* Drop the check instead of replaceing it with a check whether the register
	  is writable since this would break once we start adding read-back values
	  to the cache.
---
 drivers/base/regmap/regcache.c |    3 ---
 1 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 6d93e49..e21eebd 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -199,9 +199,6 @@ int regcache_read(struct regmap *map,
 
 	BUG_ON(!map->cache_ops);
 
-	if (!regmap_readable(map, reg))
-		return -EIO;
-
 	if (!regmap_volatile(map, reg))
 		return map->cache_ops->read(map, reg, value);
 
-- 
1.7.7.1

Re: [PATCH v2 1/2] regmap: Properly round cache_word_size

[Mark Brown]

On Wed, Nov 16, 2011 at 08:34:03PM +0100, Lars-Peter Clausen wrote:
> regcache currently only properly works with val bit sizes of 8 or 16, since
> it will, when calculating the cache word size, round down. This causes the
> cache storage to be too small to hold the full register value. Fix this by
> rounding up instead.

Applied, thanks.

Re: [PATCH v2 2/2] regmap: Drop check whether a register is readable in regcache_read

[Mark Brown]

On Wed, Nov 16, 2011 at 08:34:04PM +0100, Lars-Peter Clausen wrote:
> One of the reasons for using a cache is to have a software shadow of a register
> which is writable but not readable. This allows us to do a read-modify-write
> operation on such a register.

Applied, thanks.