/*
 * TCP/IP controlled VPI JTAG Interface.
 * Based on Julius Baxter's work on jp_vpi.c
 *
 * Copyright (C) 2012 Franck Jullien, <franck.jullien@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:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the names of the copyright holders nor the names of any
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 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 <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <arpa/inet.h>

#include <vpi_user.h>

// Calling bind with port 0 will return a socket bound to an unused port.
#define RSP_SERVER_PORT	0
#define	XFERT_MAX_SIZE	512

const char * cmd_to_string[] = {"CMD_RESET",
				"CMD_TMS_SEQ",
				"CMD_SCAN_CHAIN"};

struct vpi_cmd {
	int cmd;
	unsigned char buffer_out[XFERT_MAX_SIZE];
	unsigned char buffer_in[XFERT_MAX_SIZE];
	int length;
	int nb_bits;
};

int listenfd = 0;
int connfd = 0;

int init_jtag_server(int port)
{
	struct sockaddr_in serv_addr;
	int flags;

	listenfd = socket(AF_INET, SOCK_STREAM, 0);
	memset(&serv_addr, '0', sizeof(serv_addr));

	serv_addr.sin_family = AF_INET;
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	serv_addr.sin_port = htons(port);

	bind(listenfd, (struct sockaddr*)&serv_addr, sizeof(serv_addr));

	listen(listenfd, 10);

	socklen_t socklen = sizeof(serv_addr);
	if (getsockname(listenfd, (struct sockaddr *)&serv_addr, &socklen) == -1) {
		perror("init_jtag_server");
                fflush(stderr);
		exit(1);
	} else {
		printf("Listening on port %d\n", ntohs(serv_addr.sin_port));
                fflush(stdout);
	}

	printf("Waiting for client connection...");
        fflush(stdout);
	connfd = accept(listenfd, (struct sockaddr*)NULL, NULL);
	printf("ok\n");
        fflush(stdout);

	flags = fcntl(listenfd, F_GETFL, 0);
	fcntl(listenfd, F_SETFL, flags | O_NONBLOCK);

	return 0;
}

// See if there's anything on the FIFO for us

void check_for_command(char *userdata)
{
	vpiHandle systfref, args_iter, argh;
	struct t_vpi_value argval;
	struct vpi_cmd vpi;
	int nb;
	int loaded_words = 0;

	(void)userdata;

	// Get the command from TCP server
	if(!connfd)
	  init_jtag_server(RSP_SERVER_PORT);
	nb = read(connfd, &vpi, sizeof(struct vpi_cmd));

	if (((nb < 0) && (errno == EAGAIN)) || (nb == 0)) {
		// Nothing in the fifo this time, let's return
		return;
	} else {
		if (nb < 0) {
			// some sort of error
			perror("check_for_command");
			exit(1);
		}
	}

/************* vpi.cmd to VPI ******************************/

	// Obtain a handle to the argument list
	systfref = vpi_handle(vpiSysTfCall, NULL);
	// Now call iterate with the vpiArgument parameter
	args_iter = vpi_iterate(vpiArgument, systfref);
	// get a handle on the variable passed to the function
	argh = vpi_scan(args_iter);
	// now store the command value back in the sim
	argval.format = vpiIntVal;
	// Now set the command value
	vpi_get_value(argh, &argval);

	argval.value.integer = (uint32_t)vpi.cmd;

	// And vpi_put_value() it back into the sim
	vpi_put_value(argh, &argval, NULL, vpiNoDelay);

/************* vpi.length to VPI ******************************/

	// now get a handle on the next object (memory array)
	argh = vpi_scan(args_iter);
	// now store the command value back in the sim
	argval.format = vpiIntVal;
	// Now set the command value
	vpi_get_value(argh, &argval);

	argval.value.integer = (uint32_t)vpi.length;

	// And vpi_put_value() it back into the sim
	vpi_put_value(argh, &argval, NULL, vpiNoDelay);

/************* vpi.nb_bits to VPI ******************************/

	// now get a handle on the next object (memory array)
	argh = vpi_scan(args_iter);
	// now store the command value back in the sim
	argval.format = vpiIntVal;
	// Now set the command value
	vpi_get_value(argh, &argval);

	argval.value.integer = (uint32_t)vpi.nb_bits;

	// And vpi_put_value() it back into the sim
	vpi_put_value(argh, &argval, NULL, vpiNoDelay);

/*****************vpi.buffer_out to VPI ********/

	// now get a handle on the next object (memory array)
	argh = vpi_scan(args_iter);
	vpiHandle array_word;

	// Loop to load the words
	while (loaded_words < vpi.length) {
		// now get a handle on the current word we want in the array that was passed to us
		array_word = vpi_handle_by_index(argh, loaded_words);

		if (array_word != NULL) {
			argval.value.integer = (uint32_t)vpi.buffer_out[loaded_words];
			// And vpi_put_value() it back into the sim
			vpi_put_value(array_word, &argval, NULL, vpiNoDelay);
		} else
			return;

		loaded_words++;
	}

/*******************************************/

	// Cleanup and return
	vpi_free_object(args_iter);
}

void send_result_to_server(char *userdata)
{
	vpiHandle systfref, args_iter, argh;
	struct t_vpi_value argval;
	ssize_t n;
	struct vpi_cmd vpi;

	int32_t length;
	int sent_words;

	vpiHandle array_word;

	(void)userdata;

	// Now setup the handles to verilog objects and check things
	// Obtain a handle to the argument list
	systfref = vpi_handle(vpiSysTfCall, NULL);

	// Now call iterate with the vpiArgument parameter
	args_iter = vpi_iterate(vpiArgument, systfref);

	// get a handle on the length variable
	argh = vpi_scan(args_iter);

	argval.format = vpiIntVal;

	// get the value for the length object
	vpi_get_value(argh, &argval);

	// now set length
	length = argval.value.integer;

	// now get a handle on the next object (memory array)
	argh = vpi_scan(args_iter);

	// check we got passed a memory (array of regs)
	if (!((vpi_get(vpiType, argh) == vpiMemory)
#ifdef MODELSIM_VPI
	|| (vpi_get(vpiType, argh) == vpiRegArray)
#endif
#ifdef VCS_VPI
        || (vpi_get(vpiType, argh) == vpiRegArray)
#endif
	)) {
		vpi_printf("jtag_vpi: ERROR: did not pass a memory to get_command_block_data\n");
		vpi_printf("jtag_vpi: ERROR: was passed type %d\n", (int)vpi_get(vpiType, argh));
		return;
	}

	// check the memory we're writing into is big enough
	if (vpi_get(vpiSize, argh) < length ) {
		vpi_printf("jtag_vpi: ERROR: buffer passed to get_command_block_data too small. size is %d words, needs to be %d\n",
		vpi_get(vpiSize, argh), length);
		return;
	}

	// Loop to load the words
	sent_words = 0;
	while (sent_words < length) {
		// Get a handle on the current word we want in the array that was passed to us
		array_word = vpi_handle_by_index(argh, sent_words);

		if (array_word != NULL) {
			vpi_get_value(array_word, &argval);
			vpi.buffer_in[sent_words] = (uint32_t) argval.value.integer;
		} else
			return;

		sent_words++;
	}

	n = write(connfd, &vpi, sizeof(struct vpi_cmd));
	if (n < (ssize_t)sizeof(struct vpi_cmd))
		vpi_printf("jtag_vpi: ERROR: error during write to server\n");

	// Cleanup and return
	vpi_free_object(args_iter);
}

void register_check_for_command(void)
{
	s_vpi_systf_data data = {
		vpiSysTask,
		0,
		"$check_for_command",
		(void *)check_for_command,
		0,
		0,
		0
	};

	vpi_register_systf(&data);
}

void register_send_result_to_server(void)
{
	s_vpi_systf_data data = {
		vpiSysTask,
		0,
		"$send_result_to_server",
		(void *)send_result_to_server,
		0,
		0,
		0
	};

	vpi_register_systf(&data);
}

void sim_reset_callback(void)
{
  // nothing to do!
}

void setup_reset_callbacks(void)
{
	// here we setup and install callbacks for
	// the setup and management of connections to
	// the simulator upon simulation start and
	// reset

	static s_vpi_time time_s = {vpiScaledRealTime, 0, 0, 0};
	static s_vpi_value value_s = {.format = vpiBinStrVal};

	static s_cb_data cb_data_s = {
		cbEndOfReset, // or start of simulation - initing socket fds etc
		(void *)sim_reset_callback,
		NULL,
		&time_s,
		&value_s,
		0,
		NULL
	};

	cb_data_s.obj = NULL;  /* trigger object */

	cb_data_s.user_data = NULL;

	// actual call to register the callback
	vpi_register_cb(&cb_data_s);
}

void sim_endofcompile_callback(void)
{

}

void setup_endofcompile_callbacks(void)
{
	// here we setup and install callbacks for
	// simulation finish

	static s_vpi_time time_s = {vpiScaledRealTime, 0, 0, 0};
	static s_vpi_value value_s = {.format = vpiBinStrVal};

	static s_cb_data cb_data_s = {
		cbEndOfCompile, // end of compile
		(void *)sim_endofcompile_callback,
		NULL,
		&time_s,
		&value_s,
		0,
		NULL
	};

	cb_data_s.obj = NULL;  /* trigger object */

	cb_data_s.user_data = NULL;

	// actual call to register the callback
	vpi_register_cb(&cb_data_s);
}

void sim_finish_callback(void)
{
	if(connfd)
		printf("Closing RSP server\n");
	close(connfd);
	close(listenfd);
}

void setup_finish_callbacks(void)
{
	// here we setup and install callbacks for
	// simulation finish

	static s_vpi_time time_s = {vpiScaledRealTime, 0, 0, 0};
	static s_vpi_value value_s = {.format = vpiBinStrVal};

	static s_cb_data cb_data_s = {
		cbEndOfSimulation, // end of simulation
		(void *)sim_finish_callback,
		NULL,
		&time_s,
		&value_s,
		0,
		NULL
	};

	cb_data_s.obj = NULL;  /* trigger object */
	cb_data_s.user_data = NULL;

	// actual call to register the callback
	vpi_register_cb(&cb_data_s);
}

#ifndef VCS_VPI
// Register the new system task here
void (*vlog_startup_routines[])(void) = {
#ifdef CDS_VPI
	// this installs a callback on simulator reset - something which
	// icarus does not do, so we only do it for cadence currently
	setup_reset_callbacks,
#endif
	setup_endofcompile_callbacks,
	setup_finish_callbacks,
	register_check_for_command,
	register_send_result_to_server,
	0  // last entry must be 0
};

// Entry point for testing development of the vpi functions
int main(int argc, char *argv[])
{
	(void)argc;
	(void)argv;

	return 0;
}
#endif