regmap: make lock/unlock functions customizable
It is sometimes convenient for a regmap user to override the standard
regmap lock/unlock functions with custom functions.
For instance this can be useful in case an already existing spinlock
or mutex has to be used for locking a set of registers instead of the
internal regmap spinlock/mutex.
Note that the fast_io field of struct regmap_bus is ignored in case
custom locking functions are used.
Signed-off-by: Davide Ciminaghi <ciminaghi@gnudd.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index e3bcc3f..5d24378 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -53,6 +53,9 @@
REGMAP_ENDIAN_NATIVE,
};
+typedef void (*regmap_lock)(void *);
+typedef void (*regmap_unlock)(void *);
+
/**
* Configuration for the register map of a device.
*
@@ -75,6 +78,12 @@
* @precious_reg: Optional callback returning true if the rgister
* should not be read outside of a call from the driver
* (eg, a clear on read interrupt status register).
+ * @lock: Optional lock callback (overrides regmap's default lock
+ * function, based on spinlock or mutex).
+ * @unlock: As above for unlocking.
+ * @lock_arg: this field is passed as the only argument of lock/unlock
+ * functions (ignored in case regular lock/unlock functions
+ * are not overridden).
*
* @max_register: Optional, specifies the maximum valid register index.
* @reg_defaults: Power on reset values for registers (for use with
@@ -116,6 +125,9 @@
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);
+ regmap_lock lock;
+ regmap_unlock unlock;
+ void *lock_arg;
unsigned int max_register;
const struct reg_default *reg_defaults;
@@ -181,7 +193,9 @@
* Description of a hardware bus for the register map infrastructure.
*
* @fast_io: Register IO is fast. Use a spinlock instead of a mutex
- * to perform locking.
+ * to perform locking. This field is ignored if custom lock/unlock
+ * functions are used (see fields lock/unlock of
+ * struct regmap_config).
* @write: Write operation.
* @gather_write: Write operation with split register/value, return -ENOTSUPP
* if not implemented on a given device.