/*
 * 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"

extern struct usb_device *find_cp2102_device();
char *device_selector;

process_cmdline(argc, argv)
	char **argv;
{
	int c;
	extern int optind;
	extern char *optarg;

	while ((c = getopt(argc, argv, "d:")) != EOF) {
		switch (c) {
		case 'd':
			device_selector = optarg;
			continue;
		default:
		usage:
			fprintf(stderr, "usage: %s [-d device-selector]\n",
				argv[0]);
			exit(1);
		}
	}
	if (argc != optind)
		goto usage;
}

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

	process_cmdline(argc, argv);
	dev = find_cp2102_device(device_selector);
	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,
			     REG_PART_NUMBER, 0, (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);
}