gadgetfs.h 2.7 KB

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  1. /*
  2. * Filesystem based user-mode API to USB Gadget controller hardware
  3. *
  4. * Other than ep0 operations, most things are done by read() and write()
  5. * on endpoint files found in one directory. They are configured by
  6. * writing descriptors, and then may be used for normal stream style
  7. * i/o requests. When ep0 is configured, the device can enumerate;
  8. * when it's closed, the device disconnects from usb. Operations on
  9. * ep0 require ioctl() operations.
  10. *
  11. * Configuration and device descriptors get written to /dev/gadget/$CHIP,
  12. * which may then be used to read usb_gadgetfs_event structs. The driver
  13. * may activate endpoints as it handles SET_CONFIGURATION setup events,
  14. * or earlier; writing endpoint descriptors to /dev/gadget/$ENDPOINT
  15. * then performing data transfers by reading or writing.
  16. */
  17. #ifndef __LINUX_USB_GADGETFS_H
  18. #define __LINUX_USB_GADGETFS_H
  19. #include <linux/types.h>
  20. #include <linux/ioctl.h>
  21. #include <linux/usb/ch9.h>
  22. /*
  23. * Events are delivered on the ep0 file descriptor, when the user mode driver
  24. * reads from this file descriptor after writing the descriptors. Don't
  25. * stop polling this descriptor.
  26. */
  27. enum usb_gadgetfs_event_type {
  28. GADGETFS_NOP = 0,
  29. GADGETFS_CONNECT,
  30. GADGETFS_DISCONNECT,
  31. GADGETFS_SETUP,
  32. GADGETFS_SUSPEND,
  33. /* and likely more ! */
  34. };
  35. /* NOTE: this structure must stay the same size and layout on
  36. * both 32-bit and 64-bit kernels.
  37. */
  38. struct usb_gadgetfs_event {
  39. union {
  40. /* NOP, DISCONNECT, SUSPEND: nothing
  41. * ... some hardware can't report disconnection
  42. */
  43. /* CONNECT: just the speed */
  44. enum usb_device_speed speed;
  45. /* SETUP: packet; DATA phase i/o precedes next event
  46. *(setup.bmRequestType & USB_DIR_IN) flags direction
  47. * ... includes SET_CONFIGURATION, SET_INTERFACE
  48. */
  49. struct usb_ctrlrequest setup;
  50. } u;
  51. enum usb_gadgetfs_event_type type;
  52. };
  53. /* The 'g' code is also used by printer gadget ioctl requests.
  54. * Don't add any colliding codes to either driver, and keep
  55. * them in unique ranges (size 0x20 for now).
  56. */
  57. /* endpoint ioctls */
  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. /* discards any unclaimed data in the fifo. */
  67. #define GADGETFS_FIFO_FLUSH _IO('g', 2)
  68. /* resets endpoint halt+toggle; used to implement set_interface.
  69. * some hardware (like pxa2xx) can't support this.
  70. */
  71. #define GADGETFS_CLEAR_HALT _IO('g', 3)
  72. #endif /* __LINUX_USB_GADGETFS_H */