libfprint/libfprint/drivers/aes4000.c

/*
 * AuthenTec AES4000 driver for libfprint
 * Copyright (C) 2007 Daniel Drake <dsd@gentoo.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#define FP_COMPONENT "aes4000"

#include <errno.h>

#include <glib.h>
#include <usb.h>

#include <fp_internal.h>

#define CTRL_TIMEOUT	1000
#define EP_IN			(1 | USB_ENDPOINT_IN)
#define EP_OUT			(2 | USB_ENDPOINT_OUT)
#define DATA_BUFLEN		0x1259
#define NR_SUBARRAYS	6
#define SUBARRAY_LEN	768

static int write_reg(struct fp_img_dev *dev, unsigned char reg,
	unsigned char value)
{
	unsigned char data[] = { reg, value };
	int r;

	fp_dbg("%02x=%02x", reg, value);
	r = usb_bulk_write(dev->udev, EP_OUT, data, sizeof(data), CTRL_TIMEOUT);
	if (r < 0) {
		fp_err("bulk write error %d", r);
		return r;
	} else if (r < sizeof(data)) {
		fp_err("unexpected short write %d/%d", r, sizeof(data));
		return -EIO;
	}

	return 0;
}

static void process_subarray(unsigned char *src, unsigned char *dst)
{
	int col, row;
	int offset = -1;

	for (col = 95; col >= 0; col--) {
		for (row = 15; row >= 0; row -= 2) {
			unsigned char val = src[++offset];
			dst[(row * 96) + col] = (val & 0x7) * 36;
			dst[((row - 1) * 96) + col] = ((val & 0x70) >> 4) * 36;
		}
	}
}

static const struct aes4000_regwrite {
	unsigned char reg;
	unsigned char value;
} init_reqs[] = {
	/* master reset */
	{ 0x80, 0x01 },
	{ 0x80, 0x00 },

	{ 0x81, 0x00 },
	{ 0x80, 0x00 },

	/* scan reset */
	{ 0x80, 0x02 },
	{ 0x80, 0x00 },

	/* disable register buffering */
	{ 0x80, 0x04 },
	{ 0x80, 0x00 },

	{ 0x81, 0x00 },
	/* windows driver reads registers now (81 02) */
	{ 0x80, 0x00 },
	{ 0x81, 0x00 },

	/* set excitation bias current: 2mhz drive ring frequency,
	 * 4V drive ring voltage, 16.5mA excitation bias */
	{ 0x82, 0x04 },

	/* continuously sample drive ring for finger detection,
	 * 62.50ms debounce delay */
	{ 0x83, 0x13 },

	{ 0x84, 0x07 }, /* set calibration resistance to 12 kiloohms */
	{ 0x85, 0x3d }, /* set calibration capacitance */
	{ 0x86, 0x03 }, /* detect drive voltage */
	{ 0x87, 0x01 }, /* set detection frequency to 125khz */
	{ 0x88, 0x02 }, /* set column scan period */
	{ 0x89, 0x02 }, /* set measure drive */
	{ 0x8a, 0x33 }, /* set measure frequency and sense amplifier bias */
	{ 0x8b, 0x33 }, /* set matrix pattern */
	{ 0x8c, 0x0f }, /* set demodulation phase 1 */
	{ 0x8d, 0x04 }, /* set demodulation phase 2 */
	{ 0x8e, 0x23 }, /* set sensor gain */
	{ 0x8f, 0x07 }, /* set image parameters */
	{ 0x90, 0x00 }, /* carrier offset null */
	{ 0x91, 0x1c }, /* set A/D reference high */
	{ 0x92, 0x08 }, /* set A/D reference low */
	{ 0x93, 0x00 }, /* set start row to 0 */
	{ 0x94, 0x05 }, /* set end row to 5 */
	{ 0x95, 0x00 }, /* set start column to 0 */
	{ 0x96, 0x18 }, /* set end column to 24*4=96 */
	{ 0x97, 0x04 }, /* data format and thresholds */
	{ 0x98, 0x28 }, /* image data control */
	{ 0x99, 0x00 }, /* disable general purpose outputs */
	{ 0x9a, 0x0b }, /* set initial scan state */
	{ 0x9b, 0x00 }, /* clear challenge word bits */
	{ 0x9c, 0x00 }, /* clear challenge word bits */
	{ 0x9d, 0x09 }, /* set some challenge word bits */
	{ 0x9e, 0x53 }, /* clear challenge word bits */
	{ 0x9f, 0x6b }, /* set some challenge word bits */

	{ 0x80, 0x00 },
	{ 0x81, 0x00 },
	{ 0x81, 0x04 },
	{ 0x81, 0x00 },
};

static int capture(struct fp_img_dev *dev, gboolean unconditional,
	struct fp_img **ret)
{
	int i;
	int r;
	struct fp_img *img;
	unsigned char *data;
	unsigned char *ptr;

	for (i = 0; i < ARRAY_SIZE(init_reqs); i++) {
		r = write_reg(dev, init_reqs[i].reg, init_reqs[i].value);
		if (r < 0)
			return r;
	}

	img = fpi_img_new_for_imgdev(dev);
	data = g_malloc(DATA_BUFLEN);
	ptr = data;

	/* See the timeout explanation in the uru4000 driver for the reasoning
	 * behind this silly loop. */
retry:
	r = usb_bulk_read(dev->udev, EP_IN, data, DATA_BUFLEN, 1000);
	if (r == -ETIMEDOUT)
		goto retry;

	if (r < 0) {
		fp_err("data read failed, error %d", r);
		goto err;
	} else if (r < DATA_BUFLEN) {
		fp_err("short data read (%d)", r);
		r = -EIO;
		goto err;
	}

	for (i = NR_SUBARRAYS - 1; i >= 0; i--) {
		fp_dbg("subarray header byte %02x", *ptr);
		ptr++;
		process_subarray(ptr, img->data + (i * 96 * 16));
		ptr += SUBARRAY_LEN;
	}

	img->flags = FP_IMG_COLORS_INVERTED;
	*ret = img;
	g_free(data);
	return 0;
err:
	g_free(data);
	g_free(img);
	return r;
}

static int dev_init(struct fp_img_dev *dev, unsigned long driver_data)
{
	int r;

	r = usb_claim_interface(dev->udev, 0);
	if (r < 0) {
		fp_err("could not claim interface 0");
		return r;
	}

	return 0;
}

static void dev_exit(struct fp_img_dev *dev)
{
	usb_release_interface(dev->udev, 0);
}

static const struct usb_id id_table[] = {
	{ .vendor = 0x08ff, .product = 0x5501 },
	{ 0, 0, 0, },
};

struct fp_img_driver aes4000_driver = {
	.driver = {
		.id = 3,
		.name = FP_COMPONENT,
		.full_name = "AuthenTec AES4000",
		.id_table = id_table,
	},
	.flags = 0,
	.img_height = 96,
	.img_width = 96,
	.enlarge_factor = 3,

	/* temporarily lowered until image quality improves */
	.bz3_threshold = 9,

	.init = dev_init,
	.exit = dev_exit,
	.capture = capture,
};