alienfx.h

#include <stdio.h>
#include <stdlib.h>
#include <libusb-1.0/libusb.h>

#define __alienfx__ 1

#define ALIENWARE_VENDID   0x187c // Dell Alienware
// XXX use lsusb to determine your device_id
// #define ALIENWARE_PRODID   0x0514 // M11XR1
// #define ALIENWARE_PRODID   0x0515 // M11XR2
// #define ALIENWARE_PRODID   0x0516 // M11XR25
#define ALIENWARE_PRODID   0x0522 // M11XR3
// #define ALIENWARE_PRODID   0x0521 // M14XR1
// #define ALIENWARE_PRODID   0x0512 // M15X
// #define ALIENWARE_PRODID   0x0512 // M17X
// #define ALIENWARE_PRODID   0x0520 // M17XR3
// #define ALIENWARE_PRODID   0x0518 // M18XR2
// #define ALIENWARE_PRODID   0x0513 // AURORA
// #define ALIENWARE_PRODID   0x0511 // AREA51

#define OK                 0
#define LIBUSB_INIT_ERR   -1
#define LIBUSB_OPEN_ERR   -2
#define LIBUSB_SIZE_ERR   -3
#define LIBUSB_WRITE_ERR  -4
#define LIBUSB_READ_ERR   -5

#define SEND_REQUEST_TYPE  0x21
#define SEND_REQUEST       0x09
#define SEND_VALUE         0x202
#define SEND_INDEX         0x00
#define SEND_DATA_SIZE     9

#define READ_REQUEST_TYPE  0xa1
#define READ_REQUEST       0x01
#define READ_VALUE         0x101
#define READ_INDEX         0x0
#define READ_DATA_SIZE     8

#define _DEBUG 0

int InitDevice(libusb_device_handle **usbhandle, unsigned short idVendor, unsigned short idProduct)
{
    if( 0 == libusb_init(NULL) ) {
        *usbhandle = libusb_open_device_with_vid_pid(NULL, idVendor, idProduct);

        if( *usbhandle == NULL ) {
            fprintf(stderr, "AlienFX device not found\n");
            libusb_exit(NULL);
            return LIBUSB_OPEN_ERR;
        }

        if( libusb_kernel_driver_active(*usbhandle, 0) ) {
            libusb_detach_kernel_driver(*usbhandle, 0);
        }

        if( libusb_claim_interface(*usbhandle, 0) < 0 ) {
            fprintf(stderr, "Interface error\n");
            libusb_exit(NULL);
            return LIBUSB_OPEN_ERR;
        }

#if _DEBUG
        fprintf(stdout, "device opened\n");
#endif
        return OK;
    } else {
        return LIBUSB_INIT_ERR;
    }
}

int usbwrite(libusb_device_handle *usbhandle, unsigned char *data, unsigned short len)
{
    unsigned short retval;
    if( len != SEND_DATA_SIZE )
        return LIBUSB_SIZE_ERR;

#if _DEBUG
    fprintf(stderr,"write > ");
    for( unsigned short i = 0; i < SEND_DATA_SIZE; i++ )
        fprintf(stderr, "%02x ", 0xff & ((unsigned short)data[i]));
    fprintf(stderr, "\n");
#endif

    retval = libusb_control_transfer(usbhandle,
                    SEND_REQUEST_TYPE,
                    SEND_REQUEST,
                    SEND_VALUE,
                    SEND_INDEX,
                    data,
                    SEND_DATA_SIZE,
                    0);
    if( retval != SEND_DATA_SIZE )
        return LIBUSB_WRITE_ERR;

    usleep(8000);

    return OK;
}

int usbread(libusb_device_handle *usbhandle, char *data, unsigned int len)
{
    unsigned char buf[READ_DATA_SIZE];
    unsigned short readbytes;

    if( len != READ_DATA_SIZE )
        return LIBUSB_SIZE_ERR;

    readbytes = libusb_control_transfer(usbhandle,
                READ_REQUEST_TYPE,
                READ_REQUEST,
                READ_VALUE,
                READ_INDEX,
                buf,
                READ_DATA_SIZE,
                0);
    if (readbytes != READ_DATA_SIZE)
        return LIBUSB_READ_ERR;

#if _DEBUG
    fprintf(stdout,"read < ");
#endif
    for( unsigned short i = 0; i < READ_DATA_SIZE; i++ ) {
        data[i] = buf[i];
#if _DEBUG
        fprintf(stdout, "%02x ", 0xff & ((unsigned int)data[i]));
#endif
    }
#if _DEBUG
    fprintf(stdout, "\n");
#endif

    return OK;
}

void afx_kbd(short r, short g, short b)
{
    char rply[8];

    unsigned char keys[6][9]={
        {0x02,0x07,0x04,0x00,0x00,0x00,0x00,0x00,0x00}, // RST
        {0x02,0x03,0x00,0x00,0x00,0x01,0xff,0xf0,0x00}, // keyboard
        {0x02,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00}, // END
        {0x02,0x05,0x00,0x00,0x00,0x00,0x00,0x00,0x00}, // PGE
        {0x02,0x07,0x04,0x00,0x00,0x00,0x00,0x00,0x00}, // RST
        {0x02,0x06,0x00,0x00,0x00,0x00,0x00,0x00,0x00}  // CHK
    };
    libusb_device_handle *usbhandle;

    unsigned short retval = InitDevice(&usbhandle, ALIENWARE_VENDID, ALIENWARE_PRODID);

    if( retval == OK ) {
        usbread(usbhandle, rply, 8);
    } else {
#if _DEBUG
        fprintf(stderr, "Unable to open the AlienFX device\n");
#endif
        return;
    }

#if _DEBUG
    fprintf(stdout, "Changing the keyboard AlienFX color to rgb(%d, %d, %d)\n", r, g, b);
#endif

    // Convert colors from 8 to 3 bits
    r /= 32;
    g /= 32;
    b /= 32;

    unsigned short a = ( r + g + b ) / 3;

    keys[1][6] = ((r << 4) & 0xf0) | g; // R|G
    keys[1][7] = ((b << 4) & 0xf0) | a; // B|A

    for( unsigned short i = 0; i < 5; i++ )
        usbwrite(usbhandle, keys[i], 9);

    // Mutex_lock
    while( rply[0] != 0x11 ) {
        usbwrite(usbhandle, keys[5], 9); // CHK
        usbread(usbhandle, rply, 8);
    }

    libusb_attach_kernel_driver(usbhandle, 0);
    libusb_close(usbhandle);
    libusb_exit(NULL);
}