lpc214x_serial.c

這是一個實時嵌入式作業系統 實作了MCS51 ARM等MCU

/****************************************************************************
 * lpc214x/lpc214x_serial.c
 *
 *   Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <[e-mail]>
 *
 * 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 name NuttX nor the names of its 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 OWNER 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.
 *
 ****************************************************************************/

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

#include <nuttx/config.h>
#include <sys/types.h>
#include <unistd.h>
#include <semaphore.h>
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include <nuttx/serial.h>
#include <arch/serial.h>

#include "up_arch.h"
#include "os_internal.h"
#include "up_internal.h"

#include "lpc214x_uart.h"

/****************************************************************************
 * Definitions
 ****************************************************************************/

#define BASE_BAUD 115200

/****************************************************************************
 * Private Types
 ****************************************************************************/

struct up_dev_s
{
  uint32  uartbase;  /* Base address of UART registers */
  uint32  baud;      /* Configured baud */
  ubyte   ier;       /* Saved IER value */
  ubyte   irq;       /* IRQ associated with this UART */
  ubyte   parity;    /* 0=none, 1=odd, 2=even */
  ubyte   bits;      /* Number of bits (7 or 8) */
  boolean stopbits2; /* TRUE: Configure with 2 stop bits instead of 1 */
};

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

static int     up_setup(struct uart_dev_s *dev);
static void    up_shutdown(struct uart_dev_s *dev);
static int     up_attach(struct uart_dev_s *dev);
static void    up_detach(struct uart_dev_s *dev);
static int     up_interrupt(int irq, void *context);
static int     up_ioctl(struct file *filep, int cmd, unsigned long arg);
static int     up_receive(struct uart_dev_s *dev, uint32 *status);
static void    up_rxint(struct uart_dev_s *dev, boolean enable);
static boolean up_rxavailable(struct uart_dev_s *dev);
static void    up_send(struct uart_dev_s *dev, int ch);
static void    up_txint(struct uart_dev_s *dev, boolean enable);
static boolean up_txready(struct uart_dev_s *dev);
static boolean up_txempty(struct uart_dev_s *dev);

/****************************************************************************
 * Private Variables
 ****************************************************************************/

struct uart_ops_s g_uart_ops =
{
  .setup          = up_setup,
  .shutdown       = up_shutdown,
  .attach         = up_attach,
  .detach         = up_detach,
  .ioctl          = up_ioctl,
  .receive        = up_receive,
  .rxint          = up_rxint,
  .rxavailable    = up_rxavailable,
  .send           = up_send,
  .txint          = up_txint,
  .txready        = up_txready,
  .txempty    = up_txempty,
};

/* I/O buffers */

static char g_uart0rxbuffer[CONFIG_UART0_RXBUFSIZE];
static char g_uart0txbuffer[CONFIG_UART0_TXBUFSIZE];
static char g_uart1rxbuffer[CONFIG_UART1_RXBUFSIZE];
static char g_uart1txbuffer[CONFIG_UART1_TXBUFSIZE];

/* This describes the state of the LPC214X uart0 port. */

static struct up_dev_s g_uart0priv =
{
  .uartbase       = LPC214X_UART0_BASE,
  .baud           = CONFIG_UART0_BAUD,
  .irq            = LPC214X_UART0_IRQ,
  .parity         = CONFIG_UART0_PARITY,
  .bits           = CONFIG_UART0_BITS,
  .stopbits2      = CONFIG_UART0_2STOP,
};

static uart_dev_t g_uart0port =
{
  .recv     =
  {
    .size   = CONFIG_UART0_RXBUFSIZE,
    .buffer = g_uart0rxbuffer,
  },
  .xmit     =
  {
    .size   = CONFIG_UART0_TXBUFSIZE,
    .buffer = g_uart0txbuffer,
  },
  .ops      = &g_uart_ops,
  .priv     = &g_uart0priv,
};

/* This describes the state of the LPC214X uart1 port. */

static struct up_dev_s g_uart1priv =
{
  .uartbase       = LPC214X_UART1_BASE,
  .baud           = CONFIG_UART1_BAUD,
  .irq            = LPC214X_UART1_IRQ,
  .parity         = CONFIG_UART1_PARITY,
  .bits           = CONFIG_UART1_BITS,
  .stopbits2      = CONFIG_UART1_2STOP,
};

static uart_dev_t g_uart1port =
{
  .recv     =
  {
    .size   = CONFIG_UART1_RXBUFSIZE,
    .buffer = g_uart1rxbuffer,
  },
  .xmit     =
  {
    .size   = CONFIG_UART1_TXBUFSIZE,
    .buffer = g_uart1txbuffer,
   },
  .ops      = &g_uart_ops,
  .priv     = &g_uart1priv,
};

/* Now, which one with be tty0/console and which tty1? */

#ifdef CONFIG_SERIAL_IRDA_CONSOLE
# define CONSOLE_DEV     g_uart1port
# define TTYS0_DEV       g_uart1port
# define TTYS1_DEV       g_uart0port
#else
# define CONSOLE_DEV     g_uart0port
# define TTYS0_DEV       g_uart0port
# define TTYS1_DEV       g_uart1port
#endif

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: up_serialin
 ****************************************************************************/

static inline ubyte up_serialin(struct up_dev_s *priv, int offset)
{
  return getreg16(priv->uartbase + offset);
}

/****************************************************************************
 * Name: up_serialout
 ****************************************************************************/

static inline void up_serialout(struct up_dev_s *priv, int offset, ubyte value)
{
  putreg16(value, priv->uartbase + offset);
}

/****************************************************************************
 * Name: up_disableuartint
 ****************************************************************************/

static inline void up_disableuartint(struct up_dev_s *priv, ubyte *ier)
{
  if (ier)
    {
      *ier = priv->ier & LPC214X_IER_ALLIE;
    }

  priv->ier &= ~LPC214X_IER_ALLIE;
  up_serialout(priv, LPC214X_UART_IER_OFFSET, priv->ier);
}

/****************************************************************************
 * Name: up_restoreuartint
 ****************************************************************************/

static inline void up_restoreuartint(struct up_dev_s *priv, ubyte ier)
{
  priv->ier |= ier & LPC214X_IER_ALLIE;
  up_serialout(priv, LPC214X_UART_IER_OFFSET, priv->ier);
}

/****************************************************************************
 * Name: up_waittxready
 ****************************************************************************/

static inline void up_waittxready(struct up_dev_s *priv)
{
  int tmp;

  /* Limit how long we will wait for the TX available condition */
  for (tmp = 1000 ; tmp > 0 ; tmp--)
    {
      /* Check if the tranmitter holding register (THR) is empty */
      if ((up_serialin(priv, LPC214X_UART_LSR_OFFSET) & LPC214X_LSR_THRE) != 0)
        {
          /* The THR is empty, return */
          break;
        }
    }
}

/****************************************************************************
 * Name: up_enablebreaks
 ****************************************************************************/

static inline void up_enablebreaks(struct up_dev_s *priv, boolean enable)
{
  ubyte lcr = up_serialin(priv, LPC214X_UART_LCR_OFFSET);
  if (enable)
    {
      lcr |= LPC214X_LCR_BREAK_ENABLE;
    }
  else
    {
      lcr &= ~LPC214X_LCR_BREAK_ENABLE;
    }
  up_serialout(priv, LPC214X_UART_LCR_OFFSET, lcr);
}

/****************************************************************************
 * Name: up_setup
 *
 * Description:
 *   Configure the UART baud, bits, parity, fifos, etc. This
 *   method is called the first time that the serial port is
 *   opened.
 *
 ****************************************************************************/

static int up_setup(struct uart_dev_s *dev)
{
#ifndef CONFIG_SUPPRESS_LPC214X_UART_CONFIG
  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
  uint16 baud;
  ubyte lcr;

  /* Clear fifos */

  up_serialout(priv, LPC214X_UART_FCR_OFFSET, (LPC214X_FCR_RX_FIFO_RESET|LPC214X_FCR_TX_FIFO_RESET));
 
  /* Set trigger */

  up_serialout(priv, LPC214X_UART_FCR_OFFSET, (LPC214X_FCR_FIFO_ENABLE|LPC214X_FCR_FIFO_TRIG14));

  /* Set up the IER */

  priv->ier = up_serialin(priv, LPC214X_UART_IER_OFFSET);

  /* Set up the LCR */

  lcr = 0;

  if (priv->bits == 7)
    {
      lcr |= LPC214X_LCR_CHAR_7;
    }
  else
    {
      lcr |= LPC214X_LCR_CHAR_8;
    }

  if (priv->stopbits2)
    {
      lcr |= LPC214X_LCR_STOP_2;
    }

  if (priv->parity == 1)
    {
      lcr |= LPC214X_LCR_PAR_ODD;
    }
  else if (priv->parity == 2)
    {
      lcr |= LPC214X_LCR_PAR_EVEN;
    }

  /* Enter DLAB=1 */

  up_serialout(priv, LPC214X_UART_LCR_OFFSET, (lcr | LPC214X_LCR_DLAB_ENABLE));

  /* Set the BAUD divisor */

  baud = UART_BAUD(priv->baud);
  up_serialout(priv, LPC214X_UART_DLM_OFFSET, baud >> 8);
  up_serialout(priv, LPC214X_UART_DLL_OFFSET, baud & 0xff);

  /* Clear DLAB */

 up_serialout(priv, LPC214X_UART_LCR_OFFSET, lcr);
#endif
  return OK;
}

/****************************************************************************
 * Name: up_shutdown
 *
 * Description:
 *   Disable the UART.  This method is called when the serial
 *   port is closed
 *
 ****************************************************************************/

static void up_shutdown(struct uart_dev_s *dev)
{
  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
  up_disableuartint(priv, NULL);
}

/****************************************************************************
 * Name: up_attach
 *
 * Description:
 *   Configure the UART to operation in interrupt driven mode.  This method is
 *   called when the serial port is opened.  Normally, this is just after the
 *   the setup() method is called, however, the serial console may operate in
 *   a non-interrupt driven mode during the boot phase.
 *
 *   RX and TX interrupts are not enabled when by the attach method (unless the
 *   hardware supports multiple levels of interrupt enabling).  The RX and TX
 *   interrupts are not enabled until the txint() and rxint() methods are called.
 *
 ****************************************************************************/

static int up_attach(struct uart_dev_s *dev)
{
  struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
  int ret;