Programming with the regmap API

The regmap API is quite simple. There are only a few structures to know about. The two most important structures of this API are struct regmap_config, which represents the configuration of the regmap, and struct regmap, which is the regmap instance itself. All of the regmap data structures are defined in include/linux/regmap.h.

regmap_config structure

struct regmap_config stores the configuration of the regmap during the driver's lifetime. What you set here affects read/write operations. It is the most important structure in the regmap API. The source looks like this:

struct regmap_config { 
    const char *name; 
 
    int reg_bits; 
    int reg_stride; 
    int pad_bits; 
    int val_bits; 
 
    bool (*writeable_reg)(struct device *dev, unsigned int reg); 
    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...