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regmap: introduce fast_io busses, and use a spinlock for them

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Some bus types have very fast IO. For these, acquiring a mutex for every
IO operation is a significant overhead. Allow busses to indicate their IO
is fast, and enhance regmap to use a spinlock for those busses.

[Currently limited to native endian registers -- broonie]

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Stephen Warren
2012-04-04 15:48:28 -06:00
committed by Mark Brown
parent 0135bbcc7a
commit bacdbe0773
5 changed files with 67 additions and 30 deletions
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62
drivers/base/regmap/regmap.c
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@@ -158,6 +158,26 @@ static unsigned int regmap_parse_32(void *buf)
return b[0];
}
static void regmap_lock_mutex(struct regmap *map)
{
mutex_lock(&map->mutex);
}
static void regmap_unlock_mutex(struct regmap *map)
{
mutex_unlock(&map->mutex);
}
static void regmap_lock_spinlock(struct regmap *map)
{
spin_lock(&map->spinlock);
}
static void regmap_unlock_spinlock(struct regmap *map)
{
spin_unlock(&map->spinlock);
}
/**
* regmap_init(): Initialise register map
*
@@ -187,7 +207,15 @@ struct regmap *regmap_init(struct device *dev,
goto err;
}
mutex_init(&map->lock);
if (bus->fast_io) {
spin_lock_init(&map->spinlock);
map->lock = regmap_lock_spinlock;
map->unlock = regmap_unlock_spinlock;
} else {
mutex_init(&map->mutex);
map->lock = regmap_lock_mutex;
map->unlock = regmap_unlock_mutex;
}
map->format.buf_size = (config->reg_bits + config->val_bits) / 8;
map->format.reg_bytes = DIV_ROUND_UP(config->reg_bits, 8);
map->format.pad_bytes = config->pad_bits / 8;
@@ -365,7 +393,7 @@ int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
{
int ret;
mutex_lock(&map->lock);
map->lock(map);
regcache_exit(map);
regmap_debugfs_exit(map);
@@ -384,7 +412,7 @@ int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
ret = regcache_init(map, config);
mutex_unlock(&map->lock);
map->unlock(map);
return ret;
}
@@ -536,11 +564,11 @@ int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
{
int ret;
mutex_lock(&map->lock);
map->lock(map);
ret = _regmap_write(map, reg, val);
mutex_unlock(&map->lock);
map->unlock(map);
return ret;
}
@@ -567,11 +595,11 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
{
int ret;
mutex_lock(&map->lock);
map->lock(map);
ret = _regmap_raw_write(map, reg, val, val_len);
mutex_unlock(&map->lock);
map->unlock(map);
return ret;
}
@@ -601,7 +629,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
if (!map->format.parse_val)
return -EINVAL;
mutex_lock(&map->lock);
map->lock(map);
/* No formatting is require if val_byte is 1 */
if (val_bytes == 1) {
@@ -622,7 +650,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
kfree(wval);
out:
mutex_unlock(&map->lock);
map->unlock(map);
return ret;
}
EXPORT_SYMBOL_GPL(regmap_bulk_write);
@@ -696,11 +724,11 @@ int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
{
int ret;
mutex_lock(&map->lock);
map->lock(map);
ret = _regmap_read(map, reg, val);
mutex_unlock(&map->lock);
map->unlock(map);
return ret;
}
@@ -725,7 +753,7 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
unsigned int v;
int ret, i;
mutex_lock(&map->lock);
map->lock(map);
if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
map->cache_type == REGCACHE_NONE) {
@@ -746,7 +774,7 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
}
out:
mutex_unlock(&map->lock);
map->unlock(map);
return ret;
}
@@ -799,7 +827,7 @@ static int _regmap_update_bits(struct regmap *map, unsigned int reg,
int ret;
unsigned int tmp, orig;
mutex_lock(&map->lock);
map->lock(map);
ret = _regmap_read(map, reg, &orig);
if (ret != 0)
@@ -816,7 +844,7 @@ static int _regmap_update_bits(struct regmap *map, unsigned int reg,
}
out:
mutex_unlock(&map->lock);
map->unlock(map);
return ret;
}
@@ -883,7 +911,7 @@ int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
if (map->patch)
return -EBUSY;
mutex_lock(&map->lock);
map->lock(map);
bypass = map->cache_bypass;
@@ -911,7 +939,7 @@ int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
out:
map->cache_bypass = bypass;
mutex_unlock(&map->lock);
map->unlock(map);
return ret;
}