regmap: add regmap_might_sleep()

With the dawn of MMIO gpio-regmap users, it is desirable to let
gpio-regmap ask the regmap if it might sleep during an access so
it can pass that information to gpiochip. Add a new regmap_might_sleep()
to query the regmap.

Signed-off-by: Michael Walle <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/base/regmap/regmap.c

···
 }
 EXPORT_SYMBOL_GPL(regmap_get_reg_stride);
 
+/**
+ * regmap_might_sleep() - Returns whether a regmap access might sleep.
+ *
+ * @map: Register map to operate on.
+ *
+ * Returns true if an access to the register might sleep, else false.
+ */
+bool regmap_might_sleep(struct regmap *map)
+{
+	return map->can_sleep;
+}
+EXPORT_SYMBOL_GPL(regmap_might_sleep);
+
 int regmap_parse_val(struct regmap *map, const void *buf,
 			unsigned int *val)
 {

include/linux/regmap.h

···
 int regmap_get_val_bytes(struct regmap *map);
 int regmap_get_max_register(struct regmap *map);
 int regmap_get_reg_stride(struct regmap *map);
+bool regmap_might_sleep(struct regmap *map);
 int regmap_async_complete(struct regmap *map);
 bool regmap_can_raw_write(struct regmap *map);
 size_t regmap_get_raw_read_max(struct regmap *map);
···
 {
 	WARN_ONCE(1, "regmap API is disabled");
 	return -EINVAL;
+}
+
+static inline bool regmap_might_sleep(struct regmap *map)
+{
+	WARN_ONCE(1, "regmap API is disabled");
+	return true;
 }
 
 static inline int regcache_sync(struct regmap *map)