/*
 * This file is part of the sigrok project.
 *
 * Copyright (C) 2010 Sven Peter <sven@fail0verflow.com>
 * Copyright (C) 2010 Haxx Enterprises <bushing@gmail.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 *  THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <libusb.h>
#include <stdio.h>
#include <sigrok-internal.h>
#include "gl_usb.h"

#define CTRL_IN		(LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN | \
			 LIBUSB_RECIPIENT_INTERFACE)
#define CTRL_OUT	(LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_OUT | \
			 LIBUSB_RECIPIENT_INTERFACE)

const int PACKET_CTRL_LEN = 2;
const int PACKET_INT_LEN = 2;
const int PACKET_BULK_LEN = 64;
const int INTERFACE = 0;
const int ENDPOINT_INT_IN = 0x81;	/* Endpoint 0x81 address for IN */
const int ENDPOINT_INT_OUT = 0x01;	/* Endpoint 1 address for OUT */
const int ENDPOINT_BULK_IN = 0x81;	/* Endpoint 0x81 address for IN */
const int ENDPOINT_BULK_OUT = 0x02;	/* Endpoint 1 address for OUT */
const int TIMEOUT = 5000;		/* Timeout in ms */

enum {
	REQ_READBULK = 0x82,
	REQ_WRITEADDR,
	REQ_READDATA,
	REQ_WRITEDATA,
};

static struct libusb_device_handle *g_devh = NULL;

int gl_write_address(libusb_device_handle *devh, unsigned int address)
{
	unsigned char packet[8] = { address & 0xFF };
	int ret;

	ret = libusb_control_transfer(devh, CTRL_OUT, 0xc, REQ_WRITEADDR,
					 0, packet, 1, TIMEOUT);
	if (ret != 1)
		sr_err("%s: libusb_control_transfer returned %d\n",
		       __func__, ret);
	return ret;
}

int gl_write_data(libusb_device_handle *devh, unsigned int val)
{
	unsigned char packet[8] = { val & 0xFF };
	int ret;

	ret = libusb_control_transfer(devh, CTRL_OUT, 0xc, REQ_WRITEDATA,
				      0, packet, 1, TIMEOUT);
	if (ret != 1)
		sr_err("%s: libusb_control_transfer returned %d\n",
		       __func__, ret);
	return ret;
}

int gl_read_data(libusb_device_handle *devh)
{
	unsigned char packet[8] = { 0 };
	int ret;

	ret = libusb_control_transfer(devh, CTRL_IN, 0xc, REQ_READDATA,
				      0, packet, 1, TIMEOUT);
	if (ret != 1)
		sr_err("%s: libusb_control_transfer returned %d, val=%hhx\n",
		       __func__, ret, packet[0]);
	return (ret == 1) ? packet[0] : ret;
}

int gl_read_bulk(libusb_device_handle *devh, void *buffer, unsigned int size)
{
	unsigned char packet[8] =
	    { 0, 0, 0, 0, size & 0xff, (size & 0xff00) >> 8,
	      (size & 0xff0000) >> 16, (size & 0xff000000) >> 24 };
	int ret, transferred = 0;

	ret = libusb_control_transfer(devh, CTRL_OUT, 0x4, REQ_READBULK,
				      0, packet, 8, TIMEOUT);
	if (ret != 8)
		sr_err("%s: libusb_control_transfer returned %d\n",
		       __func__, ret);

	ret = libusb_bulk_transfer(devh, ENDPOINT_BULK_IN, buffer, size,
				   &transferred, TIMEOUT);
	if (ret < 0)
		sr_err("Bulk read error %d\n", ret);
	return transferred;
}

int gl_reg_write(libusb_device_handle *devh, unsigned int reg,
		 unsigned int val)
{
	int ret;

	ret = gl_write_address(devh, reg);
	if (ret < 0)
		return ret;
	ret = gl_write_data(devh, val);
	return ret;
}

int gl_reg_read(libusb_device_handle *devh, unsigned int reg)
{
	int ret;

	ret = gl_write_address(devh, reg);
	if (ret < 0)
		return ret;
	ret = gl_read_data(devh);
	return ret;
}

int gl_open(int vid)
{
	int ret;
	struct libusb_device **devs;
	struct libusb_device *dev;
	size_t i = 0;
	struct libusb_device_descriptor desc;

	ret = libusb_init(NULL);
	if (ret < 0)
		return GL_ELIBUSB;

	if (libusb_get_device_list(NULL, &devs) < 0) {
		ret = GL_EOPEN;
		goto gl_open_error;
	}

	while ((dev = devs[i++]) != NULL) {
		if (libusb_get_device_descriptor(dev, &desc) < 0)
			break;

		if (desc.idVendor == vid) {
			if (libusb_open(dev, &g_devh) < 0)
				g_devh = NULL;
			break;
		}
	}

	libusb_free_device_list(devs, 1);

	if (!g_devh) {
		ret = GL_EOPEN;
		goto gl_open_error;
	}

	ret = libusb_set_configuration(g_devh, 1);
	if (ret < 0) {
		ret = GL_ESETCONFIG;
		goto gl_open_error;
	}

	ret = libusb_claim_interface(g_devh, 0);
	if (ret < 0) {
		ret = GL_ECLAIM;
		goto gl_open_error;
	}

	return GL_OK;

gl_open_error:
	gl_close();
	return ret;
}

int gl_close(void)
{
	if (g_devh) {
		libusb_release_interface(g_devh, 0);
		libusb_reset_device(g_devh);
		libusb_close(g_devh);
	}
	libusb_exit(NULL);

	return 0;
}