#include <stdio.h>
#include <string.h>
#include <malloc.h>
#include <usb.h>
#include <ftdi.h>
#include <math.h>

#define IDBYTE 0x74

// USB interface

#define return_message(...) do { fprintf(stderr, __VA_ARGS__); return; } while(0)
#define retval_message(retval, ...) do { fprintf(stderr, __VA_ARGS__); return retval; } while(0)

#define USB_VENDOR 0x8482
#define USB_DEVICE 0x1003

#define TSTEP 50000

int hw_write_byte(struct ftdi_context *ctx, unsigned char val)
{
	if(ftdi_write_data(ctx, (void *)&val, 1)<1)
		retval_message(1, "Error: write failed\n");
	return 0;
}

int hw_write_bytes(struct ftdi_context *ctx, unsigned char *val, int n)
{
	if(ftdi_write_data(ctx, (void *)val, n)<n)
		retval_message(1, "Error: write-N failed\n");
	return 0;
}

int hw_read_byte(struct ftdi_context *ctx, unsigned char *val, int timeout)
{
	int res, tvl = (timeout>=0);
	while(1) {
		if((res=ftdi_read_data(ctx, val, 1))==1)
			return 0;
		if(res<0)
			retval_message(1, "Error: read failed: %s\n", ctx->error_str);
		if(timeout>0)
			usleep(TSTEP);
		if(tvl) {
			timeout -= TSTEP;
			if(timeout<=0)
				return -1;
		}
	}
}

struct ftdi_context *hw_open_board(char *serial)
{
	struct ftdi_context *ctx = calloc(1, sizeof(struct ftdi_context));
	ftdi_init(ctx);
	if(ftdi_usb_open_desc(ctx, USB_VENDOR, USB_DEVICE, NULL, serial))
		retval_message(NULL, "Error: opening device %s failed\n", serial?serial:"<ANY>");
	ftdi_usb_purge_buffers(ctx);
	return ctx;
}

void hw_close_board(struct ftdi_context *ctx)
{
	ftdi_deinit(ctx);
}

void write_byte(unsigned char val, unsigned char *buf, int *ptr)
{
    int i;
    for(i=7; i>=0; i--) {
	buf[(*ptr)++] = 0x00|(((val>>i)&1)<<1);
	buf[(*ptr)++] = 0x01|(((val>>i)&1)<<1);
    }
}

#define INDEX 0x00
#define DATA 0x02

void write_reg(struct ftdi_context *ctx, unsigned short index, unsigned short data)
{
    unsigned char buf[1024];
    int ptr = 0;
    buf[ptr++] = 0x00;
    write_byte(IDBYTE|INDEX, buf, &ptr);
    write_byte(index>>8, buf, &ptr);
    write_byte(index, buf, &ptr);
    buf[ptr++] = 0x04;
    buf[ptr++] = 0x00;
    write_byte(IDBYTE|DATA, buf, &ptr);
    write_byte(data>>8, buf, &ptr);
    write_byte(data, buf, &ptr);
    buf[ptr++] = 0x04;
    hw_write_bytes(ctx, buf, ptr);
}

unsigned short initcode[] = {
    0x00, 0x0001,

    0xFFFF, 20,

    0x08, 0x0303,
    0x02, 0x0500,
    0x01, 0x010B,
    0x0B, 0x4001,
    0x30, 0x0000,
    0x31, 0x0000,
    0x32, 0x0000,
    0x33, 0x0401,
    0x34, 0x0707,
    0x35, 0x0707,
    0x36, 0x0707,
    0x37, 0x0104,
    0x38, 0x0004,
    0x39, 0x0004,
    0x41, 0x0280,
    0x42, 0x8300,
    0x43, 0x9F9F,
    0x11, 0x0001,
    0x12, 0x0008,
    0x13, 0x100E,
    0x10, 0x0044,
    0x12, 0x0018,
    0x40, 0x0000,
    0x41, 0x0000,
    0x42, 0x5F00,

    0xFFFF, 40,

    0x13, 0x300C,

    0xFFFF, 60,

    0x10, 0x4340,

    0xFFFF, 100,

    0x21, 0x0004,
    0x44, 0x8304,
    0x45, 0x7F00,
    0x07, 0x0205,

    0xFFFF, 40,

    0x07, 0x0227,

    0xFFFF, 1,

    0x03, 0x1030,
    0x0D, 0x3336,
    0x07, 0x1237,

    0xFFFF, 0xFFFF,
};

int main(int argc, char *argv[])
{
    struct ftdi_context *usb;
    int i, x, y, r, g, b;
    float a, c, w;
    unsigned char buf[4096];
    int ptr;

    usb = hw_open_board(NULL);
    if(!usb)
	return 1;

    ftdi_set_bitmode(usb, 0x07, BITMODE_BITBANG);
    ftdi_set_baudrate(usb, 230400);

    for(i=0; ; i+=2) {
	if(initcode[i] == 0xFFFF) {
	    if(initcode[i+1] == 0xFFFF)
		break;
	    usleep(initcode[i+1]*1000);
	} else
	    write_reg(usb, initcode[i], initcode[i+1]);
    }

    write_reg(usb, 0x44, 0x7F00);
    write_reg(usb, 0x45, 0x5F00);
    write_reg(usb, 0x21, 0x0000);
    write_reg(usb, 0x23, 0x0000);
    write_reg(usb, 0x24, 0x0000);

    ptr = 0;
    buf[ptr++] = 0x00;
    write_byte(IDBYTE|INDEX, buf, &ptr);
    write_byte(0x00, buf, &ptr);
    write_byte(0x22, buf, &ptr);
    buf[ptr++] = 0x04;
    buf[ptr++] = 0x00;
    write_byte(IDBYTE|DATA, buf, &ptr);
    hw_write_bytes(usb, buf, ptr);
    ptr = 0;

    for(y=0; y<96; y++)
	for(x=0; x<128; x++) {
	    a = (y/48.0f)*3.14159f;
	    w = x/127.0f;
	    c = (w<0.5f)?w:(1.0f-w);
	    r = (int)(31.0f*w+31.0f*c*cos(a));
	    g = (int)(63.0f*w+63.0f*c*cos(a+2*3.14159f/3.0f));
	    b = (int)(31.0f*w+31.0f*c*cos(a+4*3.14159f/3.0f));
	    write_byte((r<<3)|(g>>3), buf, &ptr);
	    write_byte((g<<5)|b, buf, &ptr);
	    if(ptr>=4080) {
		hw_write_bytes(usb, buf, ptr);
		ptr = 0;
	    }
	}
    buf[ptr++] = 0x04;
    hw_write_bytes(usb, buf, ptr);

    hw_close_board(usb);
    return 0;
}