diff options
Diffstat (limited to 'include/linux/usb_gadgetfs.h')
-rw-r--r-- | include/linux/usb_gadgetfs.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/include/linux/usb_gadgetfs.h b/include/linux/usb_gadgetfs.h new file mode 100644 index 00000000000..b53d6ae8e55 --- /dev/null +++ b/include/linux/usb_gadgetfs.h @@ -0,0 +1,75 @@ + +#include <asm/types.h> +#include <asm/ioctl.h> + +#include <linux/usb_ch9.h> + +/* + * Filesystem based user-mode API to USB Gadget controller hardware + * + * Almost everything can be done with only read and write operations, + * on endpoint files found in one directory. They are configured by + * writing descriptors, and then may be used for normal stream style + * i/o requests. When ep0 is configured, the device can enumerate; + * when it's closed, the device disconnects from usb. + * + * Configuration and device descriptors get written to /dev/gadget/$CHIP, + * which may then be used to read usb_gadgetfs_event structs. The driver + * may activate endpoints as it handles SET_CONFIGURATION setup events, + * or earlier; writing endpoint descriptors to /dev/gadget/$ENDPOINT + * then performing data transfers by reading or writing. + */ + +/* + * Events are delivered on the ep0 file descriptor, if the user mode driver + * reads from this file descriptor after writing the descriptors. Don't + * stop polling this descriptor, if you write that kind of driver. + */ + +enum usb_gadgetfs_event_type { + GADGETFS_NOP = 0, + + GADGETFS_CONNECT, + GADGETFS_DISCONNECT, + GADGETFS_SETUP, + GADGETFS_SUSPEND, + // and likely more ! +}; + +struct usb_gadgetfs_event { + enum usb_gadgetfs_event_type type; + union { + // NOP, DISCONNECT, SUSPEND: nothing + // ... some hardware can't report disconnection + + // CONNECT: just the speed + enum usb_device_speed speed; + + // SETUP: packet; DATA phase i/o precedes next event + // (setup.bmRequestType & USB_DIR_IN) flags direction + // ... includes SET_CONFIGURATION, SET_INTERFACE + struct usb_ctrlrequest setup; + } u; +}; + + +/* endpoint ioctls */ + +/* 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 GADGETFS_FIFO_STATUS _IO('g',1) + +/* discards any unclaimed data in the fifo. */ +#define GADGETFS_FIFO_FLUSH _IO('g',2) + +/* resets endpoint halt+toggle; used to implement set_interface. + * some hardware (like pxa2xx) can't support this. + */ +#define GADGETFS_CLEAR_HALT _IO('g',3) + + |