gpio_attach
struct gpio_attach *attach;
attach = (struct gpio_attach *)data;
attach = (struct gpio_attach *)data;
void gpio_attach(struct device *, struct device *, void *);
gpio_attach,
#define GPIOATTACH _IOWR('G', 6, struct gpio_attach)
#define GPIODETACH _IOWR('G', 7, struct gpio_attach)
struct gpio_attach attach;
struct gpio_attach attach;