include/linux/usb_gadgetfs.h

   1
   2 #include <asm/types.h>
   3 #include <asm/ioctl.h>
   4
   5 #include <linux/usb_ch9.h>
   6
   7 /*
   8  * Filesystem based user-mode API to USB Gadget controller hardware
   9  *
  10  * Almost everything can be done with only read and write operations,
  11  * on endpoint files found in one directory.  They are configured by
  12  * writing descriptors, and then may be used for normal stream style
  13  * i/o requests.  When ep0 is configured, the device can enumerate;
  14  * when it's closed, the device disconnects from usb.
  15  *
  16  * Configuration and device descriptors get written to /dev/gadget/$CHIP,
  17  * which may then be used to read usb_gadgetfs_event structs.  The driver
  18  * may activate endpoints as it handles SET_CONFIGURATION setup events,
  19  * or earlier; writing endpoint descriptors to /dev/gadget/$ENDPOINT
  20  * then performing data transfers by reading or writing.
  21  */
  22
  23 /*
  24  * Events are delivered on the ep0 file descriptor, if the user mode driver
  25  * reads from this file descriptor after writing the descriptors.  Don't
  26  * stop polling this descriptor, if you write that kind of driver.
  27  */
  28
  29 enum usb_gadgetfs_event_type {
  30         GADGETFS_NOP = 0,
  31
  32         GADGETFS_CONNECT,
  33         GADGETFS_DISCONNECT,
  34         GADGETFS_SETUP,
  35         GADGETFS_SUSPEND,
  36         // and likely more !
  37 };
  38
  39 struct usb_gadgetfs_event {
  40         enum usb_gadgetfs_event_type    type;
  41         union {
  42                 // NOP, DISCONNECT, SUSPEND: nothing
  43                 // ... some hardware can't report disconnection
  44
  45                 // CONNECT: just the speed
  46                 enum usb_device_speed   speed;
  47
  48                 // SETUP: packet; DATA phase i/o precedes next event
  49                 // (setup.bmRequestType & USB_DIR_IN) flags direction
  50                 // ... includes SET_CONFIGURATION, SET_INTERFACE
  51                 struct usb_ctrlrequest  setup;
  52         } u;
  53 };
  54
  55
  56 /* endpoint ioctls */
  57
  58 /* IN transfers may be reported to the gadget driver as complete
  59  *      when the fifo is loaded, before the host reads the data;
  60  * OUT transfers may be reported to the host's "client" driver as
  61  *      complete when they're sitting in the FIFO unread.
  62  * THIS returns how many bytes are "unclaimed" in the endpoint fifo
  63  * (needed for precise fault handling, when the hardware allows it)
  64  */
  65 #define GADGETFS_FIFO_STATUS    _IO('g',1)
  66
  67 /* discards any unclaimed data in the fifo. */
  68 #define GADGETFS_FIFO_FLUSH     _IO('g',2)
  69
  70 /* resets endpoint halt+toggle; used to implement set_interface.
  71  * some hardware (like pxa2xx) can't support this.
  72  */
  73 #define GADGETFS_CLEAR_HALT     _IO('g',3)
  74
  75