Introduction to the Regmap data structures
The Regmap framework, which is enabled via the CONFIG_REGMAP kernel configuration option, is made of a few data structures, among which the most important are struct regmap_config, which represents the Regmap configuration, and struct regmap, which is the Regmap instance itself. That said, all of the Regmap data structures are defined in include/linux/regmap.h. It then goes without saying that this header must be included in all Regmap-based drivers:
#include <linux/regmap.h>
Including the preceding header is sufficient to make the most out of the Regmap framework. With this header, a lot of data structures will be made available, among which, struct regmap_config is the most important, which we will describe in the next section.
Understanding the struct regmap_config structure
struct regmap_config stores the configuration of the register map during the driver's lifetime. What you set there affects the memory read/write...
