/*
 * Copyright (c) 2010, STMicroelectronics.
 * 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. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 * This file is part of the Contiki OS
 *
 */
/*---------------------------------------------------------------------------*/
/**
* \file
*					Machine dependent STM32W UART1 code.
* \author
*					Salvatore Pitrulli
* \version
*					0.1
* \since
*					03.04.2010
*/
/*---------------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
//#include <io.h>
//#include <signal.h>

#include "sys/energest.h"
#include "dev/uart1.h"
#include "dev/watchdog.h"

#include "lib/ringbuf.h"

#include "dev/leds.h"

static int (*uart1_input_handler)(unsigned char c);

static volatile uint8_t transmitting;

#ifdef UART1_CONF_TX_WITH_INTERRUPT
#define TX_WITH_INTERRUPT UART1_CONF_TX_WITH_INTERRUPT
#else /* UART1_CONF_TX_WITH_INTERRUPT */
#define TX_WITH_INTERRUPT 1
#endif /* UART1_CONF_TX_WITH_INTERRUPT */


#if TX_WITH_INTERRUPT

#ifdef UART1_CONF_TX_BUFSIZE
#define UART1_TX_BUFSIZE UART1_CONF_TX_BUFSIZE
#else /* UART1_CONF_TX_BUFSIZE */
#define UART1_TX_BUFSIZE 64
#endif /* UART1_CONF_TX_BUFSIZE */

static struct ringbuf txbuf;
static uint8_t txbuf_data[UART1_TX_BUFSIZE];
#endif /* TX_WITH_INTERRUPT */

/*---------------------------------------------------------------------------*/
//uint8_t
//uart1_active(void)
//{
//  return ((~ UTCTL1) & TXEPT) | transmitting;
//}
/*---------------------------------------------------------------------------*/
void
uart1_set_input(int (*input)(unsigned char c))
{
  uart1_input_handler = input;
}
/*---------------------------------------------------------------------------*/
void
uart1_writeb(unsigned char c)
{
  watchdog_periodic();
#if TX_WITH_INTERRUPT

  /* Put the outgoing byte on the transmission buffer. If the buffer
     is full, we just keep on trying to put the byte into the buffer
     until it is possible to put it there. */
  while(ringbuf_put(&txbuf, c) == 0);

  /* If there is no transmission going, we need to start it by putting
     the first byte into the UART. */
  if(transmitting == 0) {
    transmitting = 1; 
    SC1_DATA = ringbuf_get(&txbuf);
    INT_SC1FLAG = INT_SCTXFREE;
    INT_SC1CFG |= INT_SCTXFREE;
  }

#else /* TX_WITH_INTERRUPT */

  /* Loop until the transmission buffer is available. */
  while((INT_SC1FLAG & INT_SCTXFREE) == 0);

  /* Transmit the data. */
  SC1_DATA = c;
  
  INT_SC1FLAG = INT_SCTXFREE;
#endif /* TX_WITH_INTERRUPT */
}
/*---------------------------------------------------------------------------*/
#if ! WITH_UIP /* If WITH_UIP is defined, putchar() is defined by the SLIP driver */
#endif /* ! WITH_UIP */
/*---------------------------------------------------------------------------*/
/**
 * Initalize the RS232 port.
 *
 */
void
uart1_init(unsigned long ubr)
{
  
  GPIO_PBCFGL &= 0xF00F;
  GPIO_PBCFGL |= 0x0490;  
  
  uint16_t uartper = (uint32_t)24e6/(2*ubr);
  uint32_t rest = (uint32_t)24e6%(2*ubr);
  
  SC1_UARTFRAC = 0;
  
  if(rest > (2*ubr)/4 && rest < (3*2*ubr)/4){
    SC1_UARTFRAC = 1;           // + 0.5
  }
  else if(rest >= (3*2*ubr)/4){
    uartper++;                  // + 1
  }
  
  SC1_UARTPER = uartper;
  
  SC1_UARTCFG = SC_UART8BIT;
  
  SC1_MODE = SC1_MODE_UART;
  
  SC1_INTMODE = SC_RXVALLEVEL | SC_TXFREELEVEL; // Receive buffer has data interrupt mode and Transmit buffer free interrupt mode: Level triggered.
  
  INT_SC1CFG = INT_SCRXVAL; // Receive buffer has data interrupt enable

  transmitting = 0;
  
#if TX_WITH_INTERRUPT
  ringbuf_init(&txbuf, txbuf_data, sizeof(txbuf_data));  
#endif /* TX_WITH_INTERRUPT */ 
    
  
  INT_SC1FLAG = 0xFFFF;
  
  INT_CFGSET = INT_SC1;
}
/*---------------------------------------------------------------------------*/
void uart1_rx_interrupt(void);
void uart1_tx_interrupt(void);

void halSc1Isr(void)
{
  
  ENERGEST_ON(ENERGEST_TYPE_IRQ);
  
  if(INT_SC1FLAG & INT_SCRXVAL){
    uart1_rx_interrupt();
    INT_SC1FLAG = INT_SCRXVAL;    
  }
  #if TX_WITH_INTERRUPT
  else if(INT_SC1FLAG & INT_SCTXFREE){
    uart1_tx_interrupt();
    INT_SC1FLAG = INT_SCTXFREE;
  }  
  #endif /* TX_WITH_INTERRUPT */
  

  
  ENERGEST_OFF(ENERGEST_TYPE_IRQ);

}

void uart1_rx_interrupt(void)
{
  uint8_t c;  
  
  c = SC1_DATA;
  
  if(uart1_input_handler != NULL) {
    uart1_input_handler(c);
  }  

}
/*---------------------------------------------------------------------------*/
#if TX_WITH_INTERRUPT
void uart1_tx_interrupt(void)
{

  if(ringbuf_elements(&txbuf) == 0) {
    transmitting = 0;
    INT_SC1CFG &= ~INT_SCTXFREE;
  } else {
    SC1_DATA = ringbuf_get(&txbuf);
  }
  
}
#endif /* TX_WITH_INTERRUPT */
/*---------------------------------------------------------------------------*/
