Writing a USB driver for an HID class device

//*****************************************************************************
//
// usb_host_mouse.c - An example using that supports a mouse.
//
// Copyright (c) 2013-2014 Texas Instruments Incorporated.  All rights reserved.
// Software License Agreement
// 
// Texas Instruments (TI) is supplying this software for use solely and
// exclusively on TI's microcontroller products. The software is owned by
// TI and/or its suppliers, and is protected under applicable copyright
// laws. You may not combine this software with "viral" open-source
// software in order to form a larger program.
// 
// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
// DAMAGES, FOR ANY REASON WHATSOEVER.
// 
// This is part of revision 2.1.0.12573 of the EK-TM4C1294XL Firmware Package.
//
//*****************************************************************************

#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include "inc/hw_memmap.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/sysctl.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "usblib/usblib.h"
#include "usblib/usbhid.h"
#include "usblib/host/usbhost.h"
#include "usblib/host/usbhhid.h"
#include "usblib/host/usbhhidmouse.h"
#include "drivers/pinout.h"
#include "utils/uartstdio.h"

//*****************************************************************************
//
//! \addtogroup example_list
//! <h1>USB Host mouse example(usb_host_mouse)</h1>
//!
//! This example application demonstrates how to support a USB mouse using
//! the EK-TM4C129X evaluation kit.  This application supports only a
//! standard mouse HID device.
//!
//! UART0, connected to the Virtual Serial Port and running at 115,200, 8-N-1,
//! is used to display messages from this application.
//!
//!
//
//*****************************************************************************


//*****************************************************************************
//
// The size of the host controller's memory pool in bytes.
//
//*****************************************************************************
#define HCD_MEMORY_SIZE         128

//*****************************************************************************
//
// Structure to hold the status of the attached mouse.
//
//*****************************************************************************
typedef struct
{
    //
    // Holds if there is a device connected to this port.
    //
    bool bConnected;

    //
    // Holds if the mouse state has been updated.
    //
    bool bUpdate;

    //
    // The instance data for the device if bConnected is true.
    //
    uint32_t ui32Instance;

    //
    // The mouse button state.
    //
    uint32_t ui32Buttons;

    //
    // The mouse X position.
    //
    int32_t i32XPos;

    //
    // The mouse Y position.
    //
    int32_t i32YPos;
}
tMouseStatus;

//*****************************************************************************
//
// The global application status structure.
//
//*****************************************************************************
tMouseStatus g_sStatus;

//*****************************************************************************
//
// The memory pool to provide to the Host controller driver.
//
//*****************************************************************************
uint8_t g_pui8HCDPool[HCD_MEMORY_SIZE * MAX_USB_DEVICES];

//*****************************************************************************
//
// Declare the USB Events driver interface.
//
//*****************************************************************************
DECLARE_EVENT_DRIVER(g_sUSBEventDriver, 0, 0, USBHCDEvents);

//*****************************************************************************
//
// The global that holds all of the host drivers in use in the application.
// In this case, only the HID class is loaded.
//
//*****************************************************************************
static tUSBHostClassDriver const * const g_ppHostClassDrivers[] =
{
    &g_sUSBHIDClassDriver,
    &g_sUSBEventDriver
};

//*****************************************************************************
//
// This global holds the number of class drivers in the g_ppHostClassDrivers
// list.
//
//*****************************************************************************
static const uint32_t g_ui32NumHostClassDrivers =
                  sizeof(g_ppHostClassDrivers) / sizeof(tUSBHostClassDriver *);

//*****************************************************************************
//
// The global value used to store the mouse instance value.
//
//*****************************************************************************
static tUSBHMouse *g_psMouse;
static tHIDInstance *g_psDLP;

// some buf
#define DLPBUFSIZE 100
uint8_t DLPbuf[DLPBUFSIZE];

//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif

//*****************************************************************************
//
// This enumerated type is used to hold the states of the mouse.
//
//*****************************************************************************
enum
{
    //
    // No device is present.
    //
    eStateNoDevice,

    //
    // Mouse has been detected and needs to be initialized in the main loop.
    //
    eStateMouseInit,

    //
    // Mouse is connected and waiting for events.
    //
    eStateMouseConnected,
}
g_iMouseState;

//*****************************************************************************
//
// This is the callback from the USB HID mouse handler.
//
// pvCBData is ignored by this function.
// ui32Event is one of the valid events for a mouse device.
// ui32MsgParam is defined by the event that occurs.
// pvMsgData is a pointer to data that is defined by the event that
// occurs.
//
// This function will be called to inform the application when a mouse has
// been plugged in or removed and any time a mouse movement or button pressed
// has occurred.
//
// This function will return 0.
//
//*****************************************************************************
void
MouseCallback(tUSBHMouse *psMouse, uint32_t ui32Event, uint32_t ui32MsgParam,
              void *pvMsgData)
{
    //
    // Start with the assumption that the data on the serial port will need
    // updating.
    //
    g_sStatus.bUpdate = true;

    switch(ui32Event)
    {
        //
        // New mouse detected.
        //
        case USB_EVENT_CONNECTED:
        {
            //
            // Proceed to the eStateMouseInit state so that the main loop
            // can finish initializing the mouse since USBHMouseInit() cannot
            // be called from within a callback.
            //
            g_iMouseState = eStateMouseInit;

            //
            // Indicate that the mouse has been detected.
            //
            UARTprintf("\nMouse Connected\n");

            break;
        }

        //
        // Mouse has been unplugged.
        //
        case USB_EVENT_DISCONNECTED:
        {
            //
            // Change the state so that the main loop knows that a device is no
            // longer present.
            //
            g_iMouseState = eStateNoDevice;

            //
            // Need to clear out any held buttons.
            //
            g_sStatus.ui32Buttons = 0;

            //
            // Indicate that the device was disconnected.
            //
            UARTprintf("\nMouse disconnected\n");

            //
            // There shouldn't be any updates from a disconnected mouse.
            //
            g_sStatus.bUpdate = false;

            break;
        }

        //
        // New button press detected.
        //
        case USBH_EVENT_HID_MS_PRESS:
        {
            //
            // Save the new button that was pressed.
            //
            g_sStatus.ui32Buttons |= ui32MsgParam;

            break;
        }

        //
        // A button was released on a HID mouse.
        //
        case USBH_EVENT_HID_MS_REL:
        {
            //
            // Remove the button from the pressed state.
            //
            g_sStatus.ui32Buttons &= ~ui32MsgParam;

            break;
        }

        //
        // The HID mouse detected movement in the X direction.
        //
        case USBH_EVENT_HID_MS_X:
        {
            //
            // Update the cursor X position.
            //
            g_sStatus.i32XPos += (int8_t) ui32MsgParam;

            break;
        }

        //
        // The HID mouse detected movement in the Y direction.
        //
        case USBH_EVENT_HID_MS_Y:
        {
            //
            // Update the cursor Y position.
            //
            g_sStatus.i32YPos += (int8_t) ui32MsgParam;

            break;
        }
        default:
        {
            //
            // This was an event that we don't recognize, so there is no reason
            // to update the UART output.
            //
            g_sStatus.bUpdate = false;

            break;
        }
    }

    //
    // If we have an update for the UART, send it now.
    //
    if(g_sStatus.bUpdate == true)
    {
        //
        // Print an update to the UART showing the current mouse position and
        // the state of all three buttons.
        //
        UARTprintf("\rPos: %d, %d  Buttons: %d%d%d    ",
                   g_sStatus.i32XPos, g_sStatus.i32YPos,
                   g_sStatus.ui32Buttons & 1,
                   (g_sStatus.ui32Buttons & 2) >> 1,
                   (g_sStatus.ui32Buttons & 4) >> 2);
    }
}

// this is analogous to USBHMouseInit()
// atm we are using a generic HID instance struct/pointer - TODO implement a DLPInstance struct akin to Mouse struct
uint32_t
USBHDLPInit(tHIDInstance *psDLPInstance)
{
	UARTprintf("USBHDLPInit()\n");

    //
    // Set the initial rate to only update on mouse state changes.
    //
    USBHHIDSetIdle(psDLPInstance, 0, 0);

    //
    // Read out the Report Descriptor from the mouse and parse it for
    // the format of the reports coming back from the mouse.
    //
    USBHHIDGetReportDescriptor(psDLPInstance,
    		DLPbuf,
    		DLPBUFSIZE);

    //
    // Set the DLP to boot protocol.
    //
    USBHHIDSetProtocol(psDLPInstance, 0);

    return(0);
}

uint32_t
DLPCallback(void *vp, uint32_t ui32Event, uint32_t ui32MsgParam,
              void *pvMsgData)
{
	UARTprintf("DLPCallback()\n");

	if (ui32Event == USB_EVENT_CONNECTED)
	{
		UARTprintf("Connected\n");
		USBHDLPInit(g_psDLP);
	}
	else if (ui32Event == USB_EVENT_DISCONNECTED)
	{
		UARTprintf("Disconnected\n");
	}
	return 0;
}

//*****************************************************************************
//
// The main routine for handling the USB mouse.
//
//*****************************************************************************
void
MouseMain(void)
{
    switch(g_iMouseState)
    {
        //
        // This state is entered when they mouse is first detected.
        //
        case eStateMouseInit:
        {
            //
            // Initialized the newly connected mouse.
            //
            USBHMouseInit(g_psMouse);

            //
            // Proceed to the mouse connected state.
            //
            g_iMouseState = eStateMouseConnected;

            break;
        }
        case eStateMouseConnected:
        {
            //
            // Nothing is currently done on mouse connect.
            //
            break;
        }
        default:
        {
            break;
        }
    }
}

//*****************************************************************************
//
// This is the generic callback from host stack.
//
// pvData is actually a pointer to a tEventInfo structure.
//
// This function will be called to inform the application when a USB event has
// occurred that is outside those related to the mouse device.  At this
// point this is used to detect unsupported devices being inserted and removed.
// It is also used to inform the application when a power fault has occurred.
// This function is required when the g_USBGenericEventDriver is included in
// the host controller driver array that is passed in to the
// USBHCDRegisterDrivers() function.
//
//*****************************************************************************
void
USBHCDEvents(void *pvData)
{
    tEventInfo *pEventInfo;

    //
    // Cast this pointer to its actual type.
    //
    pEventInfo = (tEventInfo *)pvData;

    UARTprintf("event: %d, inst: %d\n", pEventInfo->ui32Event, pEventInfo->ui32Instance);
    switch(pEventInfo->ui32Event)
    {
        case USB_EVENT_UNKNOWN_CONNECTED:
        case USB_EVENT_CONNECTED:
        {
            //
            // Save the device instance data.
            //
            g_sStatus.ui32Instance = pEventInfo->ui32Instance;
            g_sStatus.bConnected = true;

            UARTprintf("connected\n");
            break;
        }
        //
        // A device has been unplugged.
        //
        case USB_EVENT_DISCONNECTED:
        {
            //
            // Device is no longer connected.
            //
            g_sStatus.bConnected = false;
            UARTprintf("disconnected\n");
            break;
        }
        default:
        {
            break;
        }
    }
}

//*****************************************************************************
//
// The main application loop.
//
//*****************************************************************************
int
main(void)
{
    uint32_t ui32SysClock, ui32PLLRate;

    //
    // Set the application to run at 120 MHz with a PLL frequency of 480 MHz.
    //
    ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
                                           SYSCTL_OSC_MAIN | SYSCTL_USE_PLL |
                                           SYSCTL_CFG_VCO_480), 120000000);

    //
    // Set the part pin out appropriately for this device.
    //
    PinoutSet(false, true);

    //
    // Configure UART0 for 115,200 baud serial data output.
    //
    UARTStdioConfig(0, 115200, ui32SysClock);

    //
    // Print a welcome message
    //
    UARTprintf("\033[2J\033[H");
    UARTprintf("USB Host Mouse Example\n");
    UARTprintf("Waiting for device....\n");

    //
    // Save the PLL rate used by this application.
    //
    ui32PLLRate = 480000000;

    //
    // Initialize the connection status.
    //
    g_sStatus.bConnected = false;
    g_sStatus.ui32Buttons = 0;

    //
    // Enable Clocking to the USB controller.
    //
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_USB0);

    //
    // Enable Interrupts
    //
    ROM_IntMasterEnable();

    //
    // Initialize the USB stack mode and pass in a mode callback.
    //
    USBStackModeSet(0, eUSBModeHost, 0);

    //
    // Register the host class drivers.
    //
    USBHCDRegisterDrivers(0, g_ppHostClassDrivers, g_ui32NumHostClassDrivers);

    //
    // Open an instance of the mouse driver.  The mouse does not need
    // to be present at this time, this just save a place for it and allows
    // the applications to be notified when a mouse is present.
    //
    //g_psMouse = USBHMouseOpen(MouseCallback, 0, 0);
    g_psDLP   = USBHHIDOpen(eUSBHHIDClassVendor, DLPCallback, (void *)g_psDLP);
    if (g_psDLP == 0)
    {
    	UARTprintf("USBHHIDOpen error!\n");
    }

    //
    // Initialize the power configuration. This sets the power enable signal
    // to be active high and does not enable the power fault.
    //
    USBHCDPowerConfigInit(0, USBHCD_VBUS_AUTO_HIGH | USBHCD_VBUS_FILTER);

    //
    // Tell the USB library the CPU clock and the PLL frequency.  This is a
    // new requirement for TM4C129 devices.
    //
    USBHCDFeatureSet(0, USBLIB_FEATURE_CPUCLK, &ui32SysClock);
    USBHCDFeatureSet(0, USBLIB_FEATURE_USBPLL, &ui32PLLRate);

    //
    // Initialize the USB controller for Host mode.
    //
    USBHCDInit(0, g_pui8HCDPool, sizeof(g_pui8HCDPool));

    //
    // The main loop for the application.
    //
    while(1)
    {
        //
        // Call the USB library to let non-interrupt code run.
        //
        USBHCDMain();

        //
        // Call the mouse and mass storage main routines.
        //
        //MouseMain();


    }
}