/*
 * This program locates a presumed-CP2102 device via libusb and reads its
 * vendor-specific part number register, seeking to distinguish between
 * the original CP2102 and the later CP2102N.
 */

#include <sys/types.h>
#include <string.h>
#include <strings.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <usb.h>
#include "../libuwrap/find_dev.h"
#include "cp210x_defs.h"

main(argc, argv)
	char **argv;
{
	struct usb_device *dev;
	usb_dev_handle *usbh;
	u_char partno;
	int rc;

	if (argc != 2) {
		fprintf(stderr, "usage: %s device-selector\n", argv[0]);
		exit(1);
	}
	dev = find_usbdev_by_desc_string(argv[1]);
	if (!dev) {
		fprintf(stderr, "error: specified USB device not found\n");
		exit(1);
	}
	usbh = usb_open(dev);
	if (!usbh) {
		fprintf(stderr, "error: usb_open() failed\n");
		exit(1);
	}
	rc = usb_control_msg(usbh, DEVICE_IN_REQTYPE, CP210x_CONFIG, 0,
			     REG_PART_NUMBER, (char *) &partno, 1,
			     USB_READ_TIMEOUT);
	if (rc != 1) {
		fprintf(stderr,
		"REG_PART_NUMBER read error: usb_control_msg() returned %d\n",
			rc);
		exit(1);
	}
	usb_close(usbh);
	printf("0x%02X\n", partno);
	exit(0);
}