Introduction to the pin control subsystem

The pin controller allows gathering pins, the modes these pins should operate in, and their configurations. The driver is responsible for providing the appropriate set of callbacks according to the features that are to be implemented, provided the underlying hardware supports these features.

The pin controller descriptor data structure is defined as follows:

struct pinctrl_desc {
     const char *name;
     const struct pinctrl_pin_desc *pins;
     unsigned int npins;
     const struct pinctrl_ops *pctlops;
     const struct pinmux_ops *pmxops;
     const struct pinconf_ops *confops;
     struct module *owner;
[...]
};

In that pin controller data structure, only relevant elements have been listed, and the following are their meanings:

• name is the name...