/****************************************************************************
 * arch/risc-v/src/fe310/fe310_lowputc.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <stdint.h>

#include <arch/board/board.h>

#include "riscv_internal.h"
#include "riscv_arch.h"

#include "fe310_config.h"
#include "hardware/fe310_memorymap.h"
#include "hardware/fe310_uart.h"
#include "fe310_clockconfig.h"
#include "fe310.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/* Select UART parameters for the selected console */

#ifdef HAVE_SERIAL_CONSOLE
#  if defined(CONFIG_UART0_SERIAL_CONSOLE)
#    define FE310_CONSOLE_BASE        FE310_UART0_BASE
#    define FE310_CONSOLE_BAUD        CONFIG_UART0_BAUD
#    define FE310_CONSOLE_BITS        CONFIG_UART0_BITS
#    define FE310_CONSOLE_PARITY      CONFIG_UART0_PARITY
#    define FE310_CONSOLE_2STOP       CONFIG_UART0_2STOP
#    define FE310_CONSOLE_TX          GPIO_UART0_TX
#    define FE310_CONSOLE_RX          GPIO_UART0_RX
#    define HAVE_UART
#  elif defined(CONFIG_UART1_SERIAL_CONSOLE)
#    define FE310_CONSOLE_BASE        FE310_UART1_BASE
#    define FE310_CONSOLE_BAUD        CONFIG_UART1_BAUD
#    define FE310_CONSOLE_BITS        CONFIG_UART1_BITS
#    define FE310_CONSOLE_PARITY      CONFIG_UART1_PARITY
#    define FE310_CONSOLE_2STOP       CONFIG_UART1_2STOP
#    define FE310_CONSOLE_TX          GPIO_UART1_TX
#    define FE310_CONSOLE_RX          GPIO_UART1_RX
#    define HAVE_UART
#  endif
#endif /* HAVE_CONSOLE */

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: riscv_lowputc
 *
 * Description:
 *   Output one byte on the serial console
 *
 ****************************************************************************/

void riscv_lowputc(char ch)
{
#ifdef HAVE_SERIAL_CONSOLE
  /* Wait until the TX data register is empty */

  while ((getreg32(FE310_CONSOLE_BASE + UART_TXDATA_OFFSET) & UART_TX_FULL))
    ;

  /* Then send the character */

  putreg32((uint32_t)ch, FE310_CONSOLE_BASE + UART_TXDATA_OFFSET);

#endif /* HAVE_CONSOLE */
}

/****************************************************************************
 * Name: fe310_lowsetup
 *
 * Description:
 *   This performs basic initialization of the UART used for the serial
 *   console.  Its purpose is to get the console output available as soon
 *   as possible.
 *
 ****************************************************************************/

void fe310_lowsetup(void)
{
#if defined(HAVE_UART)

  /* Enable and configure the selected console device */

#if defined(HAVE_SERIAL_CONSOLE) && !defined(CONFIG_SUPPRESS_UART_CONFIG)

  /* Configure the UART Baud Rate */

  uint32_t hfclk = fe310_get_hfclk();
  uint32_t div;

  div  = hfclk / 1152; /* NOTE: To avoid a bug with debugger */
  div /= 100;
  div -= 1;

  putreg32(div, FE310_CONSOLE_BASE + UART_DIV_OFFSET);

  /* Enable TX */

  putreg32(1, FE310_CONSOLE_BASE + UART_TXCTL_OFFSET);
#endif /* HAVE_SERIAL_CONSOLE && !CONFIG_SUPPRESS_UART_CONFIG */
#endif /* HAVE_UART */
}