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authorBartosz Golaszewski <brgl@bgdev.pl>2017-12-06 15:26:21 +0100
committerMark Brown <broonie@kernel.org>2017-12-06 15:30:02 +0000
commitc9b41fcf272b4926b373d21c2b83dfe374313780 (patch)
treef65469c68d6f4bc64c9365a42e482f1e9b54fc8e /include/linux/regmap.h
parent4fbd8d194f06c8a3fd2af1ce560ddb31f7ec8323 (diff)
downloadlwn-c9b41fcf272b4926b373d21c2b83dfe374313780.tar.gz
lwn-c9b41fcf272b4926b373d21c2b83dfe374313780.zip
regmap: allow to disable all locking mechanisms
We have a use case in the at24 EEPROM driver (recently converted to using regmap instead of raw i2c/smbus calls) where we read from/write to the regmap in a loop, while protecting the entire loop with a mutex. Currently this implicitly makes us use two mutexes - one in the driver and one in regmap. While browsing the code for similar use cases I noticed a significant number of places where locking *seems* redundant. Allow users to completely disable any locking mechanisms in regmap config. Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'include/linux/regmap.h')
-rw-r--r--include/linux/regmap.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 15eddc1353ba..072a90229e34 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -264,6 +264,9 @@ typedef void (*regmap_unlock)(void *);
* field is NULL but precious_table (see below) is not, the
* check is performed on such table (a register is precious if
* it belongs to one of the ranges specified by precious_table).
+ * @disable_locking: This regmap is either protected by external means or
+ * is guaranteed not be be accessed from multiple threads.
+ * Don't use any locking mechanisms.
* @lock: Optional lock callback (overrides regmap's default lock
* function, based on spinlock or mutex).
* @unlock: As above for unlocking.
@@ -333,6 +336,8 @@ struct regmap_config {
bool (*readable_reg)(struct device *dev, unsigned int reg);
bool (*volatile_reg)(struct device *dev, unsigned int reg);
bool (*precious_reg)(struct device *dev, unsigned int reg);
+
+ bool disable_locking;
regmap_lock lock;
regmap_unlock unlock;
void *lock_arg;