composite.h

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/*
 * composite.h -- framework for usb gadgets which are composite devices
 *
 * Copyright (C) 2006-2008 David Brownell
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef __LINUX_USB_COMPOSITE_H
#define __LINUX_USB_COMPOSITE_H

/*
 * This framework is an optional layer on top of the USB Gadget interface,
 * making it easier to build (a) Composite devices, supporting multiple
 * functions within any single configuration, and (b) Multi-configuration
 * devices, also supporting multiple functions but without necessarily
 * having more than one function per configuration.
 *
 * Example:  a device with a single configuration supporting both network
 * link and mass storage functions is a composite device.  Those functions
 * might alternatively be packaged in individual configurations, but in
 * the composite model the host can use both functions at the same time.
 */

#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

/*
 * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
 * wish to delay the data/status stages of the control transfer till they
 * are ready. The control transfer will then be kept from completing till
 * all the function drivers that requested for USB_GADGET_DELAYED_STAUS
 * invoke usb_composite_setup_continue().
 */
#define USB_GADGET_DELAYED_STATUS       0x7fff  /* Impossibly large value */

struct usb_configuration;

struct usb_function {
    const char          *name;
    struct usb_gadget_strings   **strings;
    struct usb_descriptor_header    **descriptors;
    struct usb_descriptor_header    **hs_descriptors;
    struct usb_descriptor_header    **ss_descriptors;

    struct usb_configuration    *config;

    /* REVISIT:  bind() functions can be marked __init, which
     * makes trouble for section mismatch analysis.  See if
     * we can't restructure things to avoid mismatching.
     * Related:  unbind() may kfree() but bind() won't...
     */

    /* configuration management:  bind/unbind */
    int         (*bind)(struct usb_configuration *,
                    struct usb_function *);
    void            (*unbind)(struct usb_configuration *,
                    struct usb_function *);

    /* runtime state management */
    int         (*set_alt)(struct usb_function *,
                    unsigned interface, unsigned alt);
    int         (*get_alt)(struct usb_function *,
                    unsigned interface);
    void            (*disable)(struct usb_function *);
    int         (*setup)(struct usb_function *,
                    const struct usb_ctrlrequest *);
    void            (*suspend)(struct usb_function *);
    void            (*resume)(struct usb_function *);

    /* USB 3.0 additions */
    int         (*get_status)(struct usb_function *);
    int         (*func_suspend)(struct usb_function *,
                        u8 suspend_opt);
    /* private: */
    /* internals */
    struct list_head        list;
    DECLARE_BITMAP(endpoints, 32);
};

int usb_add_function(struct usb_configuration *, struct usb_function *);

int usb_function_deactivate(struct usb_function *);
int usb_function_activate(struct usb_function *);

int usb_interface_id(struct usb_configuration *, struct usb_function *);

int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
            struct usb_ep *_ep);

#define MAX_CONFIG_INTERFACES       16  /* arbitrary; max 255 */

struct usb_configuration {
    const char          *label;
    struct usb_gadget_strings   **strings;
    const struct usb_descriptor_header **descriptors;

    /* REVISIT:  bind() functions can be marked __init, which
     * makes trouble for section mismatch analysis.  See if
     * we can't restructure things to avoid mismatching...
     */

    /* configuration management: unbind/setup */
    void            (*unbind)(struct usb_configuration *);
    int         (*setup)(struct usb_configuration *,
                    const struct usb_ctrlrequest *);

    /* fields in the config descriptor */
    u8          bConfigurationValue;
    u8          iConfiguration;
    u8          bmAttributes;
    u8          bMaxPower;

    struct usb_composite_dev    *cdev;

    /* private: */
    /* internals */
    struct list_head    list;
    struct list_head    functions;
    u8          next_interface_id;
    unsigned        superspeed:1;
    unsigned        highspeed:1;
    unsigned        fullspeed:1;
    struct usb_function *interface[MAX_CONFIG_INTERFACES];
};

int usb_add_config(struct usb_composite_dev *,
        struct usb_configuration *,
        int (*)(struct usb_configuration *));

void usb_remove_config(struct usb_composite_dev *,
        struct usb_configuration *);

struct usb_composite_driver {
    const char              *name;
    const char              *iProduct;
    const char              *iManufacturer;
    const char              *iSerialNumber;
    const struct usb_device_descriptor  *dev;
    struct usb_gadget_strings       **strings;
    enum usb_device_speed           max_speed;
    unsigned        needs_serial:1;

    int         (*bind)(struct usb_composite_dev *cdev);
    int         (*unbind)(struct usb_composite_dev *);

    void            (*disconnect)(struct usb_composite_dev *);

    /* global suspend hooks */
    void            (*suspend)(struct usb_composite_dev *);
    void            (*resume)(struct usb_composite_dev *);
};

extern int usb_composite_probe(struct usb_composite_driver *driver);
extern void usb_composite_unregister(struct usb_composite_driver *driver);
extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);


struct usb_composite_dev {
    struct usb_gadget       *gadget;
    struct usb_request      *req;
    unsigned            bufsiz;

    struct usb_configuration    *config;

    /* private: */
    /* internals */
    unsigned int            suspended:1;
    struct usb_device_descriptor    desc;
    struct list_head        configs;
    struct usb_composite_driver *driver;
    u8              next_string_id;
    u8              manufacturer_override;
    u8              product_override;
    u8              serial_override;

    /* the gadget driver won't enable the data pullup
     * while the deactivation count is nonzero.
     */
    unsigned            deactivations;

    /* the composite driver won't complete the control transfer's
     * data/status stages till delayed_status is zero.
     */
    int             delayed_status;

    /* protects deactivations and delayed_status counts*/
    spinlock_t          lock;
};

extern int usb_string_id(struct usb_composite_dev *c);
extern int usb_string_ids_tab(struct usb_composite_dev *c,
                  struct usb_string *str);
extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);


/* messaging utils */
#define DBG(d, fmt, args...) \
    dev_dbg(&(d)->gadget->dev , fmt , ## args)
#define VDBG(d, fmt, args...) \
    dev_vdbg(&(d)->gadget->dev , fmt , ## args)
#define ERROR(d, fmt, args...) \
    dev_err(&(d)->gadget->dev , fmt , ## args)
#define WARNING(d, fmt, args...) \
    dev_warn(&(d)->gadget->dev , fmt , ## args)
#define INFO(d, fmt, args...) \
    dev_info(&(d)->gadget->dev , fmt , ## args)

#endif  /* __LINUX_USB_COMPOSITE_H */