USB: f_fs: the FunctionFS driver

#ifndef __LINUX_FUNCTIONFS_H__

#define __LINUX_FUNCTIONFS_H__ 1

#include <linux/types.h>

#include <linux/ioctl.h>

#include <linux/usb/ch9.h>

enum {

	FUNCTIONFS_DESCRIPTORS_MAGIC = 1,

	FUNCTIONFS_STRINGS_MAGIC     = 2

};

#ifndef __KERNEL__

/* Descriptor of an non-audio endpoint */

struct usb_endpoint_descriptor_no_audio {

	__u8  bLength;

	__u8  bDescriptorType;

	__u8  bEndpointAddress;

	__u8  bmAttributes;

	__le16 wMaxPacketSize;

	__u8  bInterval;

} __attribute__((packed));

/*

 * All numbers must be in little endian order.

 */

struct usb_functionfs_descs_head {

	__le32 magic;

	__le32 length;

	__le32 fs_count;

	__le32 hs_count;

} __attribute__((packed));

/*

 * Descriptors format:

 *

 * | off | name      | type         | description                          |

 * |-----+-----------+--------------+--------------------------------------|

 * |   0 | magic     | LE32         | FUNCTIONFS_{FS,HS}_DESCRIPTORS_MAGIC |

 * |   4 | lenght    | LE32         | length of the whole data chunk       |

 * |   8 | fs_count  | LE32         | number of full-speed descriptors     |

 * |  12 | hs_count  | LE32         | number of high-speed descriptors     |

 * |  16 | fs_descrs | Descriptor[] | list of full-speed descriptors       |

 * |     | hs_descrs | Descriptor[] | list of high-speed descriptors       |

 *

 * descs are just valid USB descriptors and have the following format:

 *

 * | off | name            | type | description              |

 * |-----+-----------------+------+--------------------------|

 * |   0 | bLength         | U8   | length of the descriptor |

 * |   1 | bDescriptorType | U8   | descriptor type          |

 * |   2 | payload         |      | descriptor's payload     |

 */

struct usb_functionfs_strings_head {

	__le32 magic;

	__le32 length;

	__le32 str_count;

	__le32 lang_count;

} __attribute__((packed));

/*

 * Strings format:

 *

 * | off | name       | type                  | description                |

 * |-----+------------+-----------------------+----------------------------|

 * |   0 | magic      | LE32                  | FUNCTIONFS_STRINGS_MAGIC   |

 * |   4 | length     | LE32                  | length of the data chunk   |

 * |   8 | str_count  | LE32                  | number of strings          |

 * |  12 | lang_count | LE32                  | number of languages        |

 * |  16 | stringtab  | StringTab[lang_count] | table of strings per lang  |

 *

 * For each language there is one stringtab entry (ie. there are lang_count

 * stringtab entires).  Each StringTab has following format:

 *

 * | off | name    | type              | description                        |

 * |-----+---------+-------------------+------------------------------------|

 * |   0 | lang    | LE16              | language code                      |

 * |   2 | strings | String[str_count] | array of strings in given language |

 *

 * For each string ther is one strings entry (ie. there are str_count

 * string entries).  Each String is a NUL terminated string encoded in

 * UTF-8.

 */

#endif

/*

 * Events are delivered on the ep0 file descriptor, when the user mode driver

 * reads from this file descriptor after writing the descriptors.  Don't

 * stop polling this descriptor.

 */

enum usb_functionfs_event_type {

	FUNCTIONFS_BIND,

	FUNCTIONFS_UNBIND,

	FUNCTIONFS_ENABLE,

	FUNCTIONFS_DISABLE,

	FUNCTIONFS_SETUP,

	FUNCTIONFS_SUSPEND,

	FUNCTIONFS_RESUME

};

/* NOTE:  this structure must stay the same size and layout on

 * both 32-bit and 64-bit kernels.

 */

struct usb_functionfs_event {

	union {

		/* SETUP: packet; DATA phase i/o precedes next event

		 *(setup.bmRequestType & USB_DIR_IN) flags direction */

		struct usb_ctrlrequest	setup;

	} __attribute__((packed)) u;

	/* enum usb_functionfs_event_type */

	__u8				type;

	__u8				_pad[3];

} __attribute__((packed));

/* Endpoint ioctls */

/* The same as in gadgetfs */

/* IN transfers may be reported to the gadget driver as complete

 *	when the fifo is loaded, before the host reads the data;

 * OUT transfers may be reported to the host's "client" driver as

 *	complete when they're sitting in the FIFO unread.

 * THIS returns how many bytes are "unclaimed" in the endpoint fifo

 * (needed for precise fault handling, when the hardware allows it)

 */

#define	FUNCTIONFS_FIFO_STATUS	_IO('g', 1)

/* discards any unclaimed data in the fifo. */

#define	FUNCTIONFS_FIFO_FLUSH	_IO('g', 2)

/* resets endpoint halt+toggle; used to implement set_interface.

 * some hardware (like pxa2xx) can't support this.

 */

#define	FUNCTIONFS_CLEAR_HALT	_IO('g', 3)

/* Specific for functionfs */

/*

 * Returns reverse mapping of an interface.  Called on EP0.  If there

 * is no such interface returns -EDOM.  If function is not active

 * returns -ENODEV.

 */

#define	FUNCTIONFS_INTERFACE_REVMAP	_IO('g', 128)

/*

 * Returns real bEndpointAddress of an endpoint.  If function is not

 * active returns -ENODEV.

 */

#define	FUNCTIONFS_ENDPOINT_REVMAP	_IO('g', 129)

#ifdef __KERNEL__

struct ffs_data;

struct usb_composite_dev;

struct usb_configuration;

static int  functionfs_init(void) __attribute__((warn_unused_result));

static void functionfs_cleanup(void);

static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)

	__attribute__((warn_unused_result, nonnull));

static void functionfs_unbind(struct ffs_data *ffs)

	__attribute__((nonnull));

static int functionfs_add(struct usb_composite_dev *cdev,

			  struct usb_configuration *c,

			  struct ffs_data *ffs)

	__attribute__((warn_unused_result, nonnull));

static int functionfs_ready_callback(struct ffs_data *ffs)

	__attribute__((warn_unused_result, nonnull));

static void functionfs_closed_callback(struct ffs_data *ffs)

	__attribute__((nonnull));

static int functionfs_check_dev_callback(const char *dev_name)

	__attribute__((warn_unused_result, nonnull));

#endif

#endif