keyboard/qmk/lib/vusb/examples/hid-mouse/firmware/main.c

/* Name: main.c
 * Project: hid-mouse, a very simple HID example
 * Author: Christian Starkjohann
 * Creation Date: 2008-04-07
 * Tabsize: 4
 * Copyright: (c) 2008 by OBJECTIVE DEVELOPMENT Software GmbH
 * License: GNU GPL v2 (see License.txt), GNU GPL v3 or proprietary (CommercialLicense.txt)
 */

/*
This example should run on most AVRs with only little changes. No special
hardware resources except INT0 are used. You may have to change usbconfig.h for
different I/O pins for USB. Please note that USB D+ must be the INT0 pin, or
at least be connected to INT0 as well.

We use VID/PID 0x046D/0xC00E which is taken from a Logitech mouse. Don't
publish any hardware using these IDs! This is for demonstration only!
*/

#include <avr/io.h>
#include <avr/wdt.h>
#include <avr/interrupt.h>  /* for sei() */
#include <util/delay.h>     /* for _delay_ms() */

#include <avr/pgmspace.h>   /* required by usbdrv.h */
#include "usbdrv.h"
#include "oddebug.h"        /* This is also an example for using debug macros */

/* ------------------------------------------------------------------------- */
/* ----------------------------- USB interface ----------------------------- */
/* ------------------------------------------------------------------------- */

PROGMEM const char usbHidReportDescriptor[52] = { /* USB report descriptor, size must match usbconfig.h */
    0x05, 0x01,                    // USAGE_PAGE (Generic Desktop)
    0x09, 0x02,                    // USAGE (Mouse)
    0xa1, 0x01,                    // COLLECTION (Application)
    0x09, 0x01,                    //   USAGE (Pointer)
    0xA1, 0x00,                    //   COLLECTION (Physical)
    0x05, 0x09,                    //     USAGE_PAGE (Button)
    0x19, 0x01,                    //     USAGE_MINIMUM
    0x29, 0x03,                    //     USAGE_MAXIMUM
    0x15, 0x00,                    //     LOGICAL_MINIMUM (0)
    0x25, 0x01,                    //     LOGICAL_MAXIMUM (1)
    0x95, 0x03,                    //     REPORT_COUNT (3)
    0x75, 0x01,                    //     REPORT_SIZE (1)
    0x81, 0x02,                    //     INPUT (Data,Var,Abs)
    0x95, 0x01,                    //     REPORT_COUNT (1)
    0x75, 0x05,                    //     REPORT_SIZE (5)
    0x81, 0x03,                    //     INPUT (Const,Var,Abs)
    0x05, 0x01,                    //     USAGE_PAGE (Generic Desktop)
    0x09, 0x30,                    //     USAGE (X)
    0x09, 0x31,                    //     USAGE (Y)
    0x09, 0x38,                    //     USAGE (Wheel)
    0x15, 0x81,                    //     LOGICAL_MINIMUM (-127)
    0x25, 0x7F,                    //     LOGICAL_MAXIMUM (127)
    0x75, 0x08,                    //     REPORT_SIZE (8)
    0x95, 0x03,                    //     REPORT_COUNT (3)
    0x81, 0x06,                    //     INPUT (Data,Var,Rel)
    0xC0,                          //   END_COLLECTION
    0xC0,                          // END COLLECTION
};
/* This is the same report descriptor as seen in a Logitech mouse. The data
 * described by this descriptor consists of 4 bytes:
 *      .  .  .  .  . B2 B1 B0 .... one byte with mouse button states
 *     X7 X6 X5 X4 X3 X2 X1 X0 .... 8 bit signed relative coordinate x
 *     Y7 Y6 Y5 Y4 Y3 Y2 Y1 Y0 .... 8 bit signed relative coordinate y
 *     W7 W6 W5 W4 W3 W2 W1 W0 .... 8 bit signed relative coordinate wheel
 */
typedef struct{
    uchar   buttonMask;
    char    dx;
    char    dy;
    char    dWheel;
}report_t;

static report_t reportBuffer;
static int      sinus = 7 << 6, cosinus = 0;
static uchar    idleRate;   /* repeat rate for keyboards, never used for mice */


/* The following function advances sin/cos by a fixed angle
 * and stores the difference to the previous coordinates in the report
 * descriptor.
 * The algorithm is the simulation of a second order differential equation.
 */
static void advanceCircleByFixedAngle(void)
{
char    d;

#define DIVIDE_BY_64(val)  (val + (val > 0 ? 32 : -32)) >> 6    /* rounding divide */
    reportBuffer.dx = d = DIVIDE_BY_64(cosinus);
    sinus += d;
    reportBuffer.dy = d = DIVIDE_BY_64(sinus);
    cosinus -= d;
}

/* ------------------------------------------------------------------------- */

usbMsgLen_t usbFunctionSetup(uchar data[8])
{
usbRequest_t    *rq = (void *)data;

    /* The following requests are never used. But since they are required by
     * the specification, we implement them in this example.
     */
    if((rq->bmRequestType & USBRQ_TYPE_MASK) == USBRQ_TYPE_CLASS){    /* class request type */
        DBG1(0x50, &rq->bRequest, 1);   /* debug output: print our request */
        if(rq->bRequest == USBRQ_HID_GET_REPORT){  /* wValue: ReportType (highbyte), ReportID (lowbyte) */
            /* we only have one report type, so don't look at wValue */
            usbMsgPtr = (void *)&reportBuffer;
            return sizeof(reportBuffer);
        }else if(rq->bRequest == USBRQ_HID_GET_IDLE){
            usbMsgPtr = &idleRate;
            return 1;
        }else if(rq->bRequest == USBRQ_HID_SET_IDLE){
            idleRate = rq->wValue.bytes[1];
        }
    }else{
        /* no vendor specific requests implemented */
    }
    return 0;   /* default for not implemented requests: return no data back to host */
}

/* ------------------------------------------------------------------------- */

int __attribute__((noreturn)) main(void)
{
uchar   i;

    wdt_enable(WDTO_1S);
    /* If you don't use the watchdog, replace the call above with a wdt_disable().
     * On newer devices, the status of the watchdog (on/off, period) is PRESERVED
     * OVER RESET!
     */
    /* RESET status: all port bits are inputs without pull-up.
     * That's the way we need D+ and D-. Therefore we don't need any
     * additional hardware initialization.
     */
    odDebugInit();
    DBG1(0x00, 0, 0);       /* debug output: main starts */
    usbInit();
    usbDeviceDisconnect();  /* enforce re-enumeration, do this while interrupts are disabled! */
    i = 0;
    while(--i){             /* fake USB disconnect for > 250 ms */
        wdt_reset();
        _delay_ms(1);
    }
    usbDeviceConnect();
    sei();
    DBG1(0x01, 0, 0);       /* debug output: main loop starts */
    for(;;){                /* main event loop */
        DBG1(0x02, 0, 0);   /* debug output: main loop iterates */
        wdt_reset();
        usbPoll();
        if(usbInterruptIsReady()){
            /* called after every poll of the interrupt endpoint */
            advanceCircleByFixedAngle();
            DBG1(0x03, 0, 0);   /* debug output: interrupt report prepared */
            usbSetInterrupt((void *)&reportBuffer, sizeof(reportBuffer));
        }
    }
}

/* ------------------------------------------------------------------------- */