n_r3964.c

linux和2410结合开发 用他可以生成2410所需的zImage文件

         return;
      }

      save_flags(flags);
      cli();

      pMsg->msg_id = msg_id;
      pMsg->arg    = arg;
      pMsg->error_code = error_code;
      pMsg->block  = pBlock;
      pMsg->next   = NULL;
      
      if(pClient->last_msg==NULL)
      {
         pClient->first_msg=pClient->last_msg=pMsg;
      }
      else
      {
         pClient->last_msg->next = pMsg;
         pClient->last_msg=pMsg;
      }

      pClient->msg_count++;

      if(pBlock!=NULL)
      {
         pBlock->locks++;
      }
      restore_flags(flags);
   }
   else
   {
      if((pClient->last_msg->msg_id == R3964_MSG_ACK)
		 && (pClient->last_msg->error_code==R3964_OVERFLOW))
      {
         pClient->last_msg->arg++;
		 TRACE_PE("add_msg - inc prev OVERFLOW-msg");
      }
      else
      {
         msg_id = R3964_MSG_ACK;
         arg = 0;
		 error_code = R3964_OVERFLOW;
         pBlock = NULL;
		 TRACE_PE("add_msg - queue OVERFLOW-msg");
         goto queue_the_message;
      }
   }
   /* Send SIGIO signal to client process: */
   if(pClient->sig_flags & R3964_USE_SIGIO)
   {
      kill_proc(pClient->pid, SIGIO, 1);
   }
}

static struct r3964_message *remove_msg(struct r3964_info *pInfo,
                       struct r3964_client_info *pClient)
{
   struct r3964_message *pMsg=NULL;
   unsigned long flags;

   if(pClient->first_msg)
   {
      save_flags(flags);
      cli();

      pMsg = pClient->first_msg;
      pClient->first_msg = pMsg->next;
      if(pClient->first_msg==NULL)
      {
         pClient->last_msg = NULL;
      }
      
      pClient->msg_count--;
      if(pMsg->block)
      {
        remove_client_block(pInfo, pClient);
        pClient->next_block_to_read = pMsg->block;
      }
      restore_flags(flags);
   }
   return pMsg;
}

static void remove_client_block(struct r3964_info *pInfo, 
                struct r3964_client_info *pClient)
{
    struct r3964_block_header *block;

    TRACE_PS("remove_client_block PID %d", pClient->pid);

    block=pClient->next_block_to_read;
    if(block)
    {
        block->locks--;
        if(block->locks==0)
        {
            remove_from_rx_queue(pInfo, block);
        }
    }
    pClient->next_block_to_read = NULL;
}


/*************************************************************
 * Line discipline routines
 *************************************************************/

static int r3964_open(struct tty_struct *tty)
{
   struct r3964_info *pInfo;
   
   MOD_INC_USE_COUNT;

   TRACE_L("open");
   TRACE_L("tty=%x, PID=%d, disc_data=%x", 
          (int)tty, current->pid, (int)tty->disc_data);
   
   pInfo=kmalloc(sizeof(struct r3964_info), GFP_KERNEL); 
   TRACE_M("r3964_open - info kmalloc %x",(int)pInfo);

   if(!pInfo)
   {
      printk(KERN_ERR "r3964: failed to alloc info structure\n");
      return -ENOMEM;
   }

   pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
   TRACE_M("r3964_open - rx_buf kmalloc %x",(int)pInfo->rx_buf);

   if(!pInfo->rx_buf)
   {
      printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
      kfree(pInfo);
      TRACE_M("r3964_open - info kfree %x",(int)pInfo);
      return -ENOMEM;
   }
   
   pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
   TRACE_M("r3964_open - tx_buf kmalloc %x",(int)pInfo->tx_buf);

   if(!pInfo->tx_buf)
   {
      printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
      kfree(pInfo->rx_buf);
      TRACE_M("r3964_open - rx_buf kfree %x",(int)pInfo->rx_buf);
      kfree(pInfo);
      TRACE_M("r3964_open - info kfree %x",(int)pInfo);
      return -ENOMEM;
   }

   pInfo->tty = tty;
   init_waitqueue_head (&pInfo->read_wait);
   pInfo->priority = R3964_MASTER;
   pInfo->rx_first = pInfo->rx_last = NULL;
   pInfo->tx_first = pInfo->tx_last = NULL;
   pInfo->rx_position = 0;
   pInfo->tx_position = 0;
   pInfo->last_rx = 0;
   pInfo->blocks_in_rx_queue = 0;
   pInfo->firstClient=NULL;
   pInfo->state=R3964_IDLE;
   pInfo->flags = R3964_DEBUG;
   pInfo->count_down = 0;
   pInfo->nRetry = 0;
   
   tty->disc_data = pInfo;

   /*
    * Add 'on_timer' to timer task queue
    * (will be called from timer bh)
    */
   INIT_LIST_HEAD(&pInfo->bh_1.list);
   pInfo->bh_1.sync = 0;
   pInfo->bh_1.routine = &on_timer_1;
   pInfo->bh_1.data = pInfo;
   
   INIT_LIST_HEAD(&pInfo->bh_2.list);
   pInfo->bh_2.sync = 0;
   pInfo->bh_2.routine = &on_timer_2;
   pInfo->bh_2.data = pInfo;

   queue_task(&pInfo->bh_1, &tq_timer);

   return 0;
}

static void r3964_close(struct tty_struct *tty)
{
   struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
   struct r3964_client_info *pClient, *pNext;
   struct r3964_message *pMsg;
   struct r3964_block_header *pHeader, *pNextHeader;
   unsigned long flags;

   TRACE_L("close");

    /*
     * Make sure that our task queue isn't activated.  If it
     * is, take it out of the linked list.
     */
    spin_lock_irqsave(&tqueue_lock, flags);
    if (pInfo->bh_1.sync)
    	list_del(&pInfo->bh_1.list);
    if (pInfo->bh_2.sync)
    	list_del(&pInfo->bh_2.list);
    spin_unlock_irqrestore(&tqueue_lock, flags);

   /* Remove client-structs and message queues: */
    pClient=pInfo->firstClient;
    while(pClient)
    {
       pNext=pClient->next;
       while(pClient->msg_count)
       {
          pMsg=remove_msg(pInfo, pClient);
          if(pMsg)
          {
             kfree(pMsg);
             TRACE_M("r3964_close - msg kfree %x",(int)pMsg);
          }
       }
       kfree(pClient);
       TRACE_M("r3964_close - client kfree %x",(int)pClient);
       pClient=pNext;
    }
    /* Remove jobs from tx_queue: */
	save_flags(flags);
        cli();
	pHeader=pInfo->tx_first;
	pInfo->tx_first=pInfo->tx_last=NULL;
	restore_flags(flags);
	
    while(pHeader)
	{
	   pNextHeader=pHeader->next;
	   kfree(pHeader);
	   pHeader=pNextHeader;
	}

    /* Free buffers: */
    wake_up_interruptible(&pInfo->read_wait);
    kfree(pInfo->rx_buf);
    TRACE_M("r3964_close - rx_buf kfree %x",(int)pInfo->rx_buf);
    kfree(pInfo->tx_buf);
    TRACE_M("r3964_close - tx_buf kfree %x",(int)pInfo->tx_buf);
    kfree(pInfo);
    TRACE_M("r3964_close - info kfree %x",(int)pInfo);

    MOD_DEC_USE_COUNT;
}

static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
			  unsigned char *buf, size_t nr)
{
   struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
   struct r3964_client_info *pClient;
   struct r3964_message *pMsg;
   struct r3964_client_message theMsg;
   DECLARE_WAITQUEUE (wait, current);
   
   int pid = current->pid;
   int count;
   
   TRACE_L("read()");
 
   pClient=findClient(pInfo, pid);
   if(pClient)
   {
      pMsg = remove_msg(pInfo, pClient);
      if(pMsg==NULL)
      {
		 /* no messages available. */
         if (file->f_flags & O_NONBLOCK)
		 {
            return -EAGAIN;
		 }
         /* block until there is a message: */
         add_wait_queue(&pInfo->read_wait, &wait);
repeat:
         current->state = TASK_INTERRUPTIBLE;
         pMsg = remove_msg(pInfo, pClient);
	 if (!pMsg && !signal_pending(current))
		 {
            schedule();
            goto repeat;
         }
         current->state = TASK_RUNNING;
         remove_wait_queue(&pInfo->read_wait, &wait);
      }
      
      /* If we still haven't got a message, we must have been signalled */

      if (!pMsg) return -EINTR;

      /* deliver msg to client process: */
      theMsg.msg_id = pMsg->msg_id;
      theMsg.arg    = pMsg->arg;
      theMsg.error_code = pMsg->error_code;
      count = sizeof(struct r3964_client_message);

      kfree(pMsg);
      TRACE_M("r3964_read - msg kfree %x",(int)pMsg);

      if (copy_to_user(buf,&theMsg, count))
	return -EFAULT;

      TRACE_PS("read - return %d", count);
      return count;
   }
   return -EPERM;
}

static ssize_t r3964_write(struct tty_struct * tty, struct file * file,
			   const unsigned char *data, size_t count)
{
   struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
   struct r3964_block_header *pHeader;
   struct r3964_client_info *pClient;
   unsigned char *new_data;
   int status;
   int pid;
   
   TRACE_L("write request, %d characters", count);
/* 
 * Verify the pointers 
 */

   if(!pInfo)
      return -EIO;

   status = verify_area (VERIFY_READ, data, count);
   if (status != 0) 
   {
      return status;
   }

/*
 * Ensure that the caller does not wish to send too much.
 */
   if (count > R3964_MTU) 
   {
      if (pInfo->flags & R3964_DEBUG)
      {
         TRACE_L (KERN_WARNING
                 "r3964_write: truncating user packet "
                 "from %u to mtu %d", count, R3964_MTU);
      }
      count = R3964_MTU;
   }
/*
 * Allocate a buffer for the data and fetch it from the user space.
 */
   new_data = kmalloc (count+sizeof(struct r3964_block_header), GFP_KERNEL);
   TRACE_M("r3964_write - kmalloc %x",(int)new_data);
   if (new_data == NULL) {
      if (pInfo->flags & R3964_DEBUG)
      {
         printk (KERN_ERR
               "r3964_write: no memory\n");
      }
      return -ENOSPC;
   }
   
   pHeader = (struct r3964_block_header *)new_data;
   pHeader->data = new_data + sizeof(struct r3964_block_header);
   pHeader->length = count;
   pHeader->locks = 0;
   pHeader->owner = NULL;
   
   pid=current->pid;
   
   pClient=findClient(pInfo, pid);
   if(pClient)
   {
      pHeader->owner = pClient;
   }

   copy_from_user (pHeader->data, data, count); /* We already verified this */

   if(pInfo->flags & R3964_DEBUG)
   {
      dump_block(pHeader->data, count);
   }

/*
 * Add buffer to transmit-queue:
 */
   add_tx_queue(pInfo, pHeader);
   trigger_transmit(pInfo);
   
   return 0;
}

static int r3964_ioctl(struct tty_struct * tty, struct file * file,
               unsigned int cmd, unsigned long arg)
{
   struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
   if(pInfo==NULL)
      return -EINVAL;
   switch(cmd)
   {
      case R3964_ENABLE_SIGNALS:
         return enable_signals(pInfo, current->pid, arg);
      case R3964_SETPRIORITY:
         if(arg<R3964_MASTER || arg>R3964_SLAVE)
            return -EINVAL;
         pInfo->priority = arg & 0xff;
         return 0;
      case R3964_USE_BCC:
             if(arg)
            pInfo->flags |= R3964_BCC;
         else
            pInfo->flags &= ~R3964_BCC;
         return 0;
      case R3964_READ_TELEGRAM:
         return read_telegram(pInfo, current->pid, (unsigned char *)arg);
      default:
         return -ENOIOCTLCMD;
   }
}

static void r3964_set_termios(struct tty_struct *tty, struct termios * old)
{
   TRACE_L("set_termios");
}

/* Called without the kernel lock held - fine */
static unsigned int r3964_poll(struct tty_struct * tty, struct file * file,
		      struct poll_table_struct *wait)
{
   struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
   int pid=current->pid;
   struct r3964_client_info *pClient;
   struct r3964_message *pMsg=NULL;
   unsigned long flags;
   int result = POLLOUT;

   TRACE_L("POLL");

   pClient=findClient(pInfo,pid);
   if(pClient)
     {
       poll_wait(file, &pInfo->read_wait, wait);
       save_flags(flags);
       cli();
       pMsg=pClient->first_msg;
       restore_flags(flags);
       if(pMsg)
	   result |= POLLIN | POLLRDNORM;
     }
   else
     {
       result = -EINVAL;
     }
   return result;
}

static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
                              char *fp, int count)
{
   struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
    const unsigned char *p;
    char *f, flags = 0;
    int i;

    for (i=count, p = cp, f = fp; i; i--, p++) {
        if (f)
            flags = *f++;
        if(flags==TTY_NORMAL)
        {
            receive_char(pInfo, *p);
        }
        else
        {
            receive_error(pInfo, flags);
        }
        
    }
}

static int r3964_receive_room(struct tty_struct *tty)
{
   TRACE_L("receive_room");
   return -1;
}


MODULE_LICENSE("GPL");

EXPORT_NO_SYMBOLS;