/*
 * uart.c - UART Rx and Tx functions
 *
 * Copyright (C) 2008 Hugo Villeneuve <hugo@hugovil.com>
 *
 * Based on TI DaVinci Flash and Boot Utilities, original copyright follows:
 *   Copyright 2008 Texas Instruments, Inc. <www.ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include "common.h"
#include "davinci.h"
#include "uart.h"
#include "util.h"
#include "crc.h"

/* Symbol from linker script */
extern uint32_t __DDR_FREE; /* Start of free DDR memory region. */

/* Receive data from UART */
static int
uart_recv_bytes(size_t count, uint8_t *dest, const uint8_t timeout)
{
	uint32_t i, status = 0;
	uint32_t timerStatus = 1;

	for (i = 0; i < count; i++) {
		/* Enable timer one time */
		timer0_start(SYSTEM_CLK_HZ * timeout);
		do {
			status = (UART0->LSR)&(0x01);
			timerStatus = timer0_status();
		} while (!status && timerStatus);

		if (timerStatus == 0) {
			host_msg("UART_TIMEOUT");
			return E_TIMEOUT;
		}

		/* Receive byte */
		dest[i] = (UART0->RBR) & 0xFF;

		/* Check status for errors */
		if ((UART0->LSR & 0x1C) != 0) {
			host_msg("UART_RXERR");
			return E_FAIL;
		}
	}
	return E_PASS;
}

/* Send bytes with optional null terminating character. */
static void
uart_send_bytes(char *string)
{
	uint32_t status = 0;
	int32_t i, count;
	uint32_t timerStatus = 1;

	count = strlen(string);

	for (i = 0; i < count; i++) {
		/* Enable Timer one time */
		timer0_start(SYSTEM_CLK_HZ * 5);
		do {
			status = (UART0->LSR)&(0x20);
			timerStatus = timer0_status();
		} while (!status && timerStatus);

		if (timerStatus == 0)
			return; /* E_TIMEOUT */

		/* Send byte */
		(UART0->THR) = string[i];
	}
}

/* Check if the given string is received via UART */
static int
uart_check_string(char *string, int include_null, const uint8_t timeout)
{
	int i, count;

	count = strlen(string);
	if (include_null != false)
		count++;

	for (i = 0; i < count; i++) {
		uint8_t recv;

		/* Get one byte */
		if (uart_recv_bytes(1, &recv, timeout) != E_PASS)
			return E_FAIL;

		if (recv != string[i])
			return E_FAIL;
	}
	return E_PASS;
}

/* Receive a uint32 value in HEX form (8 bytes) */
static int
uart_recv_hex_uint32(uint32_t *data, const uint8_t timeout)
{
	int k;
	uint8_t recv[8];
	uint32_t temp;
	int shift;
	const int num_ascii_char = 8;

	/* Get 8 bytes from UART */
	if (uart_recv_bytes(num_ascii_char, recv, timeout) != E_PASS)
		return E_FAIL;

	*data = 0;

	/* Converting ascii to Hex */
	for (k = 0, shift = 28; k < num_ascii_char; k++, shift -= 4) {
		temp = recv[k] - 48;

		if (temp > 22) /* Lower case a,b,c,d,e,f */
			temp -= 39;
		else if (temp > 9) /* Upper case A,B,C,D,E,F */
			temp -= 7;

		*data |= temp << shift;
	}
	return E_PASS;
}

/* Send line feed (\n) to UART. */
void
uart_send_lf(void)
{
	uart_send_bytes("\r\n");
}

/* Send a string to UART, without line feed. */
void
uart_send_str(char *string)
{
	uart_send_bytes(string);
}

/* Send a string to UART, with line feed. */
void
uart_send_str_lf(char *string)
{
	uart_send_bytes(string);
	uart_send_lf();
}

void
uart_send_hexnum(uint32_t value, int digits)
{
	char seq[9];
	uint32_t i, shift;
	uint8_t temp;

	for (i = 0; i < digits; i++) {
		shift = ((digits - 1) - i) * 4;
		temp = (value >> shift) & 0x0F;
		if (temp > 9)
			temp += 7;
		seq[i] = temp + 48;
	}
	seq[digits] = 0;

	uart_send_str("0x");
	uart_send_bytes(seq);
}

int
uart_get_cmd(uint32_t *boot_cmd)
{
	return uart_get_cmd_timeout(boot_cmd, 5);
}

int
uart_get_cmd_timeout(uint32_t *boot_cmd, uint8_t timeout)
{
	if (uart_check_string("    CMD", true, timeout) != E_PASS)
		return E_FAIL;

	if (uart_recv_hex_uint32(boot_cmd, timeout) != E_PASS)
		return E_FAIL;

	return E_PASS;
}

uint32_t
uart_get_prog(struct uart_ack_header_t *uart_ack_header)
{
	uint32_t error;
	uint32_t recv_crc, computed_crc;
	uint8_t *ddr_free = (uint8_t *) &__DDR_FREE;

	uart_ack_header->recv_buffer = ddr_free;

	/* Send ACK command */
	error = uart_check_string("    ACK", true, 5);
	if (error != E_PASS)
		return E_FAIL;

	/* Get the ACK header elements */
	error =  uart_recv_hex_uint32(&uart_ack_header->magic, 5);
	error |= uart_recv_hex_uint32(&recv_crc, 5);
	error |= uart_recv_hex_uint32(&uart_ack_header->size, 5);
	error |= uart_recv_hex_uint32(&uart_ack_header->entry_point, 5);
	error |= uart_check_string("0000", false, 5);
	if (error != E_PASS)
		return E_FAIL;

	uart_send_str("Magic = ");
	uart_send_hexnum(uart_ack_header->magic, 8);
	uart_send_str(", CRC = ");
	uart_send_hexnum(recv_crc, 8);
	uart_send_str(", Entry = ");
	uart_send_hexnum(uart_ack_header->entry_point, 8);
	uart_send_str(", Size = ");
	uart_send_hexnum(uart_ack_header->size, 8);
	uart_send_lf();

	/* Verify that the file size is appropriate */
	if ((uart_ack_header->size == 0) ||
	    (uart_ack_header->size > MAX_IMAGE_SIZE)) {
		host_msg("BADCNT");
		return E_FAIL;
	}

	/* Send BEGIN command */
	host_msg("BEGIN");

	/* Receive the data over UART */
	if (uart_recv_bytes(uart_ack_header->size,
			    uart_ack_header->recv_buffer, 5)
	    != E_PASS) {
		return E_FAIL;
	}

	/* Return first DONE when all data arrives */
	host_msg("DONE");

	computed_crc = crc32_dv_compute(uart_ack_header->recv_buffer,
					uart_ack_header->size);
	if (computed_crc != recv_crc) {
		host_msg("BADCRC");
		return E_FAIL;
	}

	/* Return DONE when all data is validated */
	host_msg("DONE");

	return E_PASS;
}