root/include/linux/usb/otg.h

DEFINITIONS

1. otg_start_hnp
2. otg_set_host
3. otg_set_peripheral
4. otg_set_power
5. otg_set_suspend
6. otg_start_srp

/* USB OTG (On The Go) defines */
/*
 *
 * These APIs may be used between USB controllers.  USB device drivers
 * (for either host or peripheral roles) don't use these calls; they
 * continue to use just usb_device and usb_gadget.
 */

#ifndef __LINUX_USB_OTG_H
#define __LINUX_USB_OTG_H

/* OTG defines lots of enumeration states before device reset */
enum usb_otg_state {
        OTG_STATE_UNDEFINED = 0,

        /* single-role peripheral, and dual-role default-b */
        OTG_STATE_B_IDLE,
        OTG_STATE_B_SRP_INIT,
        OTG_STATE_B_PERIPHERAL,

        /* extra dual-role default-b states */
        OTG_STATE_B_WAIT_ACON,
        OTG_STATE_B_HOST,

        /* dual-role default-a */
        OTG_STATE_A_IDLE,
        OTG_STATE_A_WAIT_VRISE,
        OTG_STATE_A_WAIT_BCON,
        OTG_STATE_A_HOST,
        OTG_STATE_A_SUSPEND,
        OTG_STATE_A_PERIPHERAL,
        OTG_STATE_A_WAIT_VFALL,
        OTG_STATE_A_VBUS_ERR,
};

/*
 * the otg driver needs to interact with both device side and host side
 * usb controllers.  it decides which controller is active at a given
 * moment, using the transceiver, ID signal, HNP and sometimes static
 * configuration information (including "board isn't wired for otg").
 */
struct otg_transceiver {
        struct device           *dev;
        const char              *label;

        u8                      default_a;
        enum usb_otg_state      state;

        struct usb_bus          *host;
        struct usb_gadget       *gadget;

        /* to pass extra port status to the root hub */
        u16                     port_status;
        u16                     port_change;

        /* bind/unbind the host controller */
        int     (*set_host)(struct otg_transceiver *otg,
                                struct usb_bus *host);

        /* bind/unbind the peripheral controller */
        int     (*set_peripheral)(struct otg_transceiver *otg,
                                struct usb_gadget *gadget);

        /* effective for B devices, ignored for A-peripheral */
        int     (*set_power)(struct otg_transceiver *otg,
                                unsigned mA);

        /* for non-OTG B devices: set transceiver into suspend mode */
        int     (*set_suspend)(struct otg_transceiver *otg,
                                int suspend);

        /* for B devices only:  start session with A-Host */
        int     (*start_srp)(struct otg_transceiver *otg);

        /* start or continue HNP role switch */
        int     (*start_hnp)(struct otg_transceiver *otg);

};


/* for board-specific init logic */
extern int otg_set_transceiver(struct otg_transceiver *);


/* for usb host and peripheral controller drivers */
extern struct otg_transceiver *otg_get_transceiver(void);

static inline int
otg_start_hnp(struct otg_transceiver *otg)
{
        return otg->start_hnp(otg);
}


/* for HCDs */
static inline int
otg_set_host(struct otg_transceiver *otg, struct usb_bus *host)
{
        return otg->set_host(otg, host);
}


/* for usb peripheral controller drivers */
static inline int
otg_set_peripheral(struct otg_transceiver *otg, struct usb_gadget *periph)
{
        return otg->set_peripheral(otg, periph);
}

static inline int
otg_set_power(struct otg_transceiver *otg, unsigned mA)
{
        return otg->set_power(otg, mA);
}

static inline int
otg_set_suspend(struct otg_transceiver *otg, int suspend)
{
        if (otg->set_suspend != NULL)
                return otg->set_suspend(otg, suspend);
        else
                return 0;
}

static inline int
otg_start_srp(struct otg_transceiver *otg)
{
        return otg->start_srp(otg);
}


/* for OTG controller drivers (and maybe other stuff) */
extern int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num);

#endif /* __LINUX_USB_OTG_H */