From 8ae0d7e8a918e9603748abe9b31984fc5d96abb3 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Wed, 26 Oct 2011 10:34:22 +0200 Subject: [PATCH 1/3] regmap: Track if the register cache is dirty and suppress unneeded syncs Allow drivers to optimise out the register cache sync if they didn't need to do one. If the hardware is desynced from the register cache (by power loss for example) then the driver should call regcache_mark_dirty() to let the core know about this. Signed-off-by: Mark Brown --- drivers/base/regmap/internal.h | 1 + drivers/base/regmap/regcache.c | 19 +++++++++++++++++++ drivers/base/regmap/regmap.c | 4 +++- include/linux/regmap.h | 1 + 4 files changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h index 348ff02eb93e..6483e0bda0cf 100644 --- a/drivers/base/regmap/internal.h +++ b/drivers/base/regmap/internal.h @@ -74,6 +74,7 @@ struct regmap { struct reg_default *reg_defaults; const void *reg_defaults_raw; void *cache; + bool cache_dirty; }; struct regcache_ops { diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c index 666f6f5011dc..6ab9f0384d82 100644 --- a/drivers/base/regmap/regcache.c +++ b/drivers/base/regmap/regcache.c @@ -241,6 +241,8 @@ int regcache_sync(struct regmap *map) map->cache_ops->name); name = map->cache_ops->name; trace_regcache_sync(map->dev, name, "start"); + if (!map->cache_dirty) + goto out; if (map->cache_ops->sync) { ret = map->cache_ops->sync(map); } else { @@ -290,6 +292,23 @@ void regcache_cache_only(struct regmap *map, bool enable) } EXPORT_SYMBOL_GPL(regcache_cache_only); +/** + * regcache_mark_dirty: Mark the register cache as dirty + * + * @map: map to mark + * + * Mark the register cache as dirty, for example due to the device + * having been powered down for suspend. If the cache is not marked + * as dirty then the cache sync will be suppressed. + */ +void regcache_mark_dirty(struct regmap *map) +{ + mutex_lock(&map->lock); + map->cache_dirty = true; + mutex_unlock(&map->lock); +} +EXPORT_SYMBOL_GPL(regcache_mark_dirty); + /** * regcache_cache_bypass: Put a register map into cache bypass mode * diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index bf441db1ee90..3aca18dbf367 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -306,8 +306,10 @@ int _regmap_write(struct regmap *map, unsigned int reg, ret = regcache_write(map, reg, val); if (ret != 0) return ret; - if (map->cache_only) + if (map->cache_only) { + map->cache_dirty = true; return 0; + } } trace_regmap_reg_write(map->dev, reg, val); diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 690276a642cf..32043a9749e6 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -143,5 +143,6 @@ int regmap_update_bits(struct regmap *map, unsigned int reg, int regcache_sync(struct regmap *map); void regcache_cache_only(struct regmap *map, bool enable); void regcache_cache_bypass(struct regmap *map, bool enable); +void regcache_mark_dirty(struct regmap *map); #endif From 50b776fc71c13663eb7434f634f2b796de5c9885 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Wed, 2 Nov 2011 15:00:03 +0000 Subject: [PATCH 2/3] regmap: Rename LZO cache type to compressed Users probably don't care about the specific compression algorithm and we might want to use a different algorithm (snappy being the one I'm thinking of right now) so update the public interface to have a more generic name. Signed-off-by: Mark Brown --- drivers/base/regmap/regcache-lzo.c | 2 +- include/linux/regmap.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/base/regmap/regcache-lzo.c b/drivers/base/regmap/regcache-lzo.c index 066aeece3626..854448d09293 100644 --- a/drivers/base/regmap/regcache-lzo.c +++ b/drivers/base/regmap/regcache-lzo.c @@ -351,7 +351,7 @@ static int regcache_lzo_sync(struct regmap *map) } struct regcache_ops regcache_lzo_ops = { - .type = REGCACHE_LZO, + .type = REGCACHE_COMPRESSED, .name = "lzo", .init = regcache_lzo_init, .exit = regcache_lzo_exit, diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 32043a9749e6..bebda1481f23 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -25,7 +25,7 @@ enum regcache_type { REGCACHE_NONE, REGCACHE_INDEXED, REGCACHE_RBTREE, - REGCACHE_LZO + REGCACHE_COMPRESSED }; /** From bf315173359b2f3b8b8ccca4264815e91f30be12 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Sat, 3 Dec 2011 17:06:20 +0000 Subject: [PATCH 3/3] regmap: Allow drivers to reinitialise the register cache at runtime Sometimes the register map information may change in ways that drivers can discover at runtime. For example, new revisions of a device may add new registers. Support runtime discovery by drivers by allowing the register cache to be reinitialised with a new function regmap_reinit_cache() which discards the existing cache and creates a new one. Signed-off-by: Mark Brown --- drivers/base/regmap/regmap.c | 33 +++++++++++++++++++++++++++++++++ include/linux/regmap.h | 2 ++ 2 files changed, 35 insertions(+) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 3aca18dbf367..579e85b8a684 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -230,6 +230,39 @@ struct regmap *regmap_init(struct device *dev, } EXPORT_SYMBOL_GPL(regmap_init); +/** + * regmap_reinit_cache(): Reinitialise the current register cache + * + * @map: Register map to operate on. + * @config: New configuration. Only the cache data will be used. + * + * Discard any existing register cache for the map and initialize a + * new cache. This can be used to restore the cache to defaults or to + * update the cache configuration to reflect runtime discovery of the + * hardware. + */ +int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config) +{ + int ret; + + mutex_lock(&map->lock); + + regcache_exit(map); + + map->max_register = config->max_register; + map->writeable_reg = config->writeable_reg; + map->readable_reg = config->readable_reg; + map->volatile_reg = config->volatile_reg; + map->precious_reg = config->precious_reg; + map->cache_type = config->cache_type; + + ret = regcache_init(map, config); + + mutex_unlock(&map->lock); + + return ret; +} + /** * regmap_exit(): Free a previously allocated register map */ diff --git a/include/linux/regmap.h b/include/linux/regmap.h index bebda1481f23..86923a98a766 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -129,6 +129,8 @@ struct regmap *regmap_init_spi(struct spi_device *dev, const struct regmap_config *config); void regmap_exit(struct regmap *map); +int regmap_reinit_cache(struct regmap *map, + const struct regmap_config *config); int regmap_write(struct regmap *map, unsigned int reg, unsigned int val); int regmap_raw_write(struct regmap *map, unsigned int reg, const void *val, size_t val_len);