from usbh_hid.h:209
typedef struct _HID_Process
{
uint8_t OutPipe;
uint8_t InPipe;
USBH_HID_StateTypeDef state;
uint8_t OutEp;
uint8_t InEp;
HID_CtlStateTypeDef ctl_state;
FIFO_TypeDef fifo;
uint8_t *pData;
uint16_t length;
uint8_t ep_addr;
uint16_t poll;
uint32_t timer;
uint8_t DataReady;
HID_DescTypeDef HID_Desc;
USBH_StatusTypeDef(* Init)(USBH_HandleTypeDef *phost);
}
HID_HandleTypeDef;