incubator-nuttx/drivers/sercomm/console.c

/****************************************************************************
 * drivers/sercomm/console.c
 * Driver for NuttX Console
 *
 * (C) 2010 by Harald Welte <laforge@gnumonks.org>
 * (C) 2011 Stefan Richter <ichgeh@l--putt.de>
 *
 * This source code is derivated from Osmocom-BB project and was
 * relicensed as BSD with permission from original authors.
 *
 * 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.
 *
 **************************************************************************/

#include <nuttx/config.h>
#include <nuttx/arch.h>
#include <nuttx/fs/fs.h>
#include <nuttx/serial/serial.h>

#include <errno.h>
#include <debug.h>
#include <string.h>

#include "uart.h"
#include <nuttx/sercomm/sercomm.h>

/* stubs to make serial driver happy */

void sercomm_recvchars(void *a) { }
void sercomm_xmitchars(void *a) { }

/* Stubs to make memory allocator happy */

void cons_puts(void *foo){}
void delay_ms(int ms){}

/************************************************************************************
 * Fileops Prototypes and Structures
 ************************************************************************************/

typedef FAR struct file    file_t;

static ssize_t sc_console_read(file_t *filep, FAR char *buffer, size_t buflen);
static ssize_t sc_console_write(file_t *filep, FAR const char *buffer, size_t buflen);
static int     sc_console_ioctl(file_t *filep, int cmd, unsigned long arg);
#ifndef CONFIG_DISABLE_POLL
static int     sc_console_poll(file_t *filep, FAR struct pollfd *fds, bool setup);
#endif

static const struct file_operations g_sercom_console_ops =
{
  0,      /* open, always opened */
  0,      /* close, stays open */
  sc_console_read,  /* read */
  sc_console_write,  /* write */
  0,      /* seek, not supported */
  sc_console_ioctl,  /* ioctl */
#ifndef CONFIG_DISABLE_POLL
  sc_console_poll    /* poll */
#endif
};

static FAR uart_dev_t *readdev = NULL;
static struct msgb *recvmsg = NULL;

/****************************************************************************
 * Helper functions
 ****************************************************************************/

static void recv_cb(uint8_t dlci, struct msgb *msg)
{
  sem_post(&readdev->recvsem);
  recvmsg = msg;
}

/****************************************************************************
 * Fileops
 ****************************************************************************/

/* XXX: recvmsg is overwritten when multiple msg arrive! */
static ssize_t sc_console_read(file_t *filep, FAR char *buffer, size_t buflen)
{
  size_t len;
  struct msgb *tmp;

  /* Wait until data is received */

  while (recvmsg == NULL)
    {
      sem_wait(&readdev->recvsem);
    }

  len = recvmsg->len > buflen ? buflen : recvmsg->len;
  memcpy(buffer, msgb_get(recvmsg, len), len);

  if (recvmsg->len == 0)
    {
      /* prevent inconsistent msg by first invalidating it, then free it */

      tmp = recvmsg;
      recvmsg = NULL;
      msgb_free(tmp);
    }

  return len;
}

/* XXX: redirect to old Osmocom-BB comm/sercomm_cons.c -> 2 buffers */

extern int sercomm_puts(const char *s);

static ssize_t sc_console_write(file_t *filep, FAR const char *buffer, size_t buflen)
{
  char dstbuf[32];
  int cnt;

  if (buflen >= 31)
    {
      cnt = 31;
    }
  else
    {
      cnt = buflen;
    }

  memcpy(dstbuf, buffer, cnt);
  dstbuf[cnt] = '\0';

  /* print part of our buffer */

  sercomm_puts(dstbuf);

  /* wait a little bit to get data transfered */

  up_mdelay(1);

  return cnt;
}

/* Forward ioctl to uart driver */

static int sc_console_ioctl(struct file *filep, int cmd, unsigned long arg)
{
  FAR struct inode *inode = filep->f_inode;
  FAR uart_dev_t   *dev   = inode->i_private;

  return dev->ops->ioctl(filep, cmd, arg);
}

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

/* Use sercomm on uart driver, register console driver */

int sercomm_register(FAR const char *path, FAR uart_dev_t *dev)
{
  /* XXX: initialize MODEMUART to be used for sercomm*/

  uart_init(SERCOMM_UART_NR, 1);
  uart_baudrate(SERCOMM_UART_NR, UART_115200);
  readdev = dev;
  sercomm_register_rx_cb(SC_DLCI_LOADER, &recv_cb);

  sem_init(&dev->xmit.sem, 0, 1);
  sem_init(&dev->recv.sem, 0, 1);
  sem_init(&dev->closesem, 0, 1);
  sem_init(&dev->xmitsem,  0, 0);
  sem_init(&dev->recvsem,  0, 0);
#ifndef CONFIG_DISABLE_POLL
  sem_init(&dev->pollsem,  0, 1);
#endif

  dbg("Registering %s\n", path);
  return register_driver(path, &g_sercom_console_ops, 0666, NULL);
}