n_r3964.c

linux和2410结合开发 用他可以生成2410所需的zImage文件

      restore_flags(flags);
   }
}

static void retry_transmit(struct r3964_info *pInfo)
{
   if(pInfo->nRetry<R3964_MAX_RETRIES)
   {
      TRACE_PE("transmission failed. Retry #%d", 
             pInfo->nRetry);
      pInfo->bcc = 0;
      put_char(pInfo, STX);
      flush(pInfo);
      pInfo->state = R3964_TX_REQUEST;
      pInfo->count_down = R3964_TO_QVZ;
      pInfo->nRetry++;
   }
   else
   {
      TRACE_PE("transmission failed after %d retries", 
             R3964_MAX_RETRIES);

      remove_from_tx_queue(pInfo, R3964_TX_FAIL);
      
      put_char(pInfo, NAK);
      flush(pInfo);
      pInfo->state = R3964_IDLE;

      trigger_transmit(pInfo);
   }
}


static void transmit_block(struct r3964_info *pInfo)
{
   struct tty_struct *tty = pInfo->tty;
   struct r3964_block_header *pBlock = pInfo->tx_first;
   int room=0;

   if((tty==NULL) || (pBlock==NULL))
   {
      return;
   }

   if(tty->driver.write_room)
      room=tty->driver.write_room(tty);

   TRACE_PS("transmit_block %x, room %d, length %d", 
          (int)pBlock, room, pBlock->length);
   
   while(pInfo->tx_position < pBlock->length)
   {
      if(room<2)
         break;
 
      if(pBlock->data[pInfo->tx_position]==DLE)
      {
         /* send additional DLE char: */
         put_char(pInfo, DLE);
      }
      put_char(pInfo, pBlock->data[pInfo->tx_position++]);
      
      room--;
   }

   if((pInfo->tx_position == pBlock->length) && (room>=3))
   {
      put_char(pInfo, DLE);
      put_char(pInfo, ETX);
      if(pInfo->flags & R3964_BCC)
      {
         put_char(pInfo, pInfo->bcc);
      }
      pInfo->state = R3964_WAIT_FOR_TX_ACK;
      pInfo->count_down = R3964_TO_QVZ;
   }
   flush(pInfo);
}

static void on_receive_block(struct r3964_info *pInfo)
{
   unsigned int length;
   struct r3964_client_info *pClient;
   struct r3964_block_header *pBlock;
   
   length=pInfo->rx_position;

   /* compare byte checksum characters: */
   if(pInfo->flags & R3964_BCC)
   {
      if(pInfo->bcc!=pInfo->last_rx)
      {
         TRACE_PE("checksum error - got %x but expected %x",
                pInfo->last_rx, pInfo->bcc);
         pInfo->flags |= R3964_CHECKSUM;
      }
   }

   /* check for errors (parity, overrun,...): */
   if(pInfo->flags & R3964_ERROR)
   {
      TRACE_PE("on_receive_block - transmission failed error %x",
             pInfo->flags & R3964_ERROR);
      
      put_char(pInfo, NAK);
      flush(pInfo);
      if(pInfo->nRetry<R3964_MAX_RETRIES)
      {
         pInfo->state=R3964_WAIT_FOR_RX_REPEAT;
         pInfo->count_down = R3964_TO_RX_PANIC;
         pInfo->nRetry++;
      }
      else
      {
         TRACE_PE("on_receive_block - failed after max retries");
         pInfo->state=R3964_IDLE;
      }
      return;
   }

   
   /* received block; submit DLE: */
   put_char(pInfo, DLE);
   flush(pInfo);
   pInfo->count_down=0;
   TRACE_PS(" rx success: got %d chars", length);

   /* prepare struct r3964_block_header: */
   pBlock = kmalloc(length+sizeof(struct r3964_block_header), GFP_KERNEL);
   TRACE_M("on_receive_block - kmalloc %x",(int)pBlock);

   if(pBlock==NULL)
      return;

   pBlock->length = length;
   pBlock->data   = ((unsigned char*)pBlock)+sizeof(struct r3964_block_header);
   pBlock->locks  = 0;
   pBlock->next   = NULL;
   pBlock->owner  = NULL;

   memcpy(pBlock->data, pInfo->rx_buf, length);

   /* queue block into rx_queue: */
   add_rx_queue(pInfo, pBlock);

   /* notify attached client processes: */
   for(pClient=pInfo->firstClient; pClient; pClient=pClient->next)
   {
      if(pClient->sig_flags & R3964_SIG_DATA)
      {
         add_msg(pClient, R3964_MSG_DATA, length, R3964_OK, pBlock);
      }
   }
   wake_up_interruptible (&pInfo->read_wait);
   
   pInfo->state = R3964_IDLE;

   trigger_transmit(pInfo);
}


static void receive_char(struct r3964_info *pInfo, const unsigned char c)
{
   switch(pInfo->state)
   {
      case R3964_TX_REQUEST:
         if(c==DLE)
         {
            TRACE_PS("TX_REQUEST - got DLE");

            pInfo->state = R3964_TRANSMITTING;
            pInfo->tx_position = 0;
            
            transmit_block(pInfo);
         }
         else if(c==STX)
         {
            if(pInfo->nRetry==0)
            {
               TRACE_PE("TX_REQUEST - init conflict");
               if(pInfo->priority == R3964_SLAVE)
               {
                  goto start_receiving;
               }
            } 
            else 
            {
               TRACE_PE("TX_REQUEST - secondary init conflict!?"
                        " Switching to SLAVE mode for next rx.");
               goto start_receiving;
            }
         }
         else
         {
            TRACE_PE("TX_REQUEST - char != DLE: %x", c);
            retry_transmit(pInfo);
         }
         break;
      case R3964_TRANSMITTING:
         if(c==NAK)
         {
            TRACE_PE("TRANSMITTING - got NAK");
            retry_transmit(pInfo);
         }
         else
         {
            TRACE_PE("TRANSMITTING - got illegal char");
 
            pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
            pInfo->count_down = R3964_TO_ZVZ;
         }
         break;
      case R3964_WAIT_FOR_TX_ACK:
         if(c==DLE)
         {
            TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
            remove_from_tx_queue(pInfo, R3964_OK);
            
            pInfo->state = R3964_IDLE;
            trigger_transmit(pInfo);
         }
         else
         {
            retry_transmit(pInfo);
         }
         break;
      case R3964_WAIT_FOR_RX_REPEAT:
         /* FALLTROUGH */
      case R3964_IDLE:
         if(c==STX)
         {
            /* Prevent rx_queue from overflow: */
            if(pInfo->blocks_in_rx_queue >= R3964_MAX_BLOCKS_IN_RX_QUEUE)
            {
               TRACE_PE("IDLE - got STX but no space in rx_queue!");
               pInfo->state=R3964_WAIT_FOR_RX_BUF;
               pInfo->count_down = R3964_TO_NO_BUF;
               break;
            }
start_receiving:
            /* Ok, start receiving: */
            TRACE_PS("IDLE - got STX");
            pInfo->rx_position = 0;
            pInfo->last_rx = 0;
            pInfo->flags &= ~R3964_ERROR;
            pInfo->state=R3964_RECEIVING;
            pInfo->count_down = R3964_TO_ZVZ;
            pInfo->nRetry = 0;
            put_char(pInfo, DLE);
            flush(pInfo);
            pInfo->bcc = 0;
         }
         break;
      case R3964_RECEIVING:
         if(pInfo->rx_position < RX_BUF_SIZE)
         {
            pInfo->bcc ^= c;
            
            if(c==DLE)
            {
               if(pInfo->last_rx==DLE)
               {
                  pInfo->last_rx = 0;
                  goto char_to_buf;
               }
               pInfo->last_rx = DLE;
               break;
            } 
            else if((c==ETX) && (pInfo->last_rx==DLE))
            {
               if(pInfo->flags & R3964_BCC)
               {
                  pInfo->state = R3964_WAIT_FOR_BCC;
                  pInfo->count_down = R3964_TO_ZVZ;
               }
               else 
               {
                  on_receive_block(pInfo);
               }
            }
            else
            {
               pInfo->last_rx = c;
char_to_buf:
               pInfo->rx_buf[pInfo->rx_position++] = c;
               pInfo->count_down = R3964_TO_ZVZ;
            }
         }
        /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */ 
         break;
      case R3964_WAIT_FOR_BCC:
         pInfo->last_rx = c;
         on_receive_block(pInfo);
         break;
   }
}

static void receive_error(struct r3964_info *pInfo, const char flag)
{
    switch (flag) 
    {
    case TTY_NORMAL:
        break;
    case TTY_BREAK:
        TRACE_PE("received break")
        pInfo->flags |= R3964_BREAK;
        break;
    case TTY_PARITY:
        TRACE_PE("parity error")
        pInfo->flags |= R3964_PARITY;
        break;
    case TTY_FRAME:
        TRACE_PE("frame error")
        pInfo->flags |= R3964_FRAME;
        break;
    case TTY_OVERRUN:
        TRACE_PE("frame overrun")
        pInfo->flags |= R3964_OVERRUN;
        break;
    default:
        TRACE_PE("receive_error - unknown flag %d", flag);
        pInfo->flags |= R3964_UNKNOWN;
        break;
    }
}

static void on_timeout(struct r3964_info *pInfo)
{
   switch(pInfo->state)
   {
      case R3964_TX_REQUEST:
         TRACE_PE("TX_REQUEST - timeout");
         retry_transmit(pInfo);
         break;
      case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
         put_char(pInfo, NAK);
         flush(pInfo);
         retry_transmit(pInfo);
         break;
      case R3964_WAIT_FOR_TX_ACK:
         TRACE_PE("WAIT_FOR_TX_ACK - timeout");
         retry_transmit(pInfo);
         break;
      case R3964_WAIT_FOR_RX_BUF:
         TRACE_PE("WAIT_FOR_RX_BUF - timeout");
         put_char(pInfo, NAK);
         flush(pInfo);
         pInfo->state=R3964_IDLE;
         break;
      case R3964_RECEIVING:
         TRACE_PE("RECEIVING - timeout after %d chars", 
                  pInfo->rx_position);
         put_char(pInfo, NAK);
         flush(pInfo);
         pInfo->state=R3964_IDLE;
         break;
      case R3964_WAIT_FOR_RX_REPEAT:
         TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
         pInfo->state=R3964_IDLE;
         break;
      case R3964_WAIT_FOR_BCC:
         TRACE_PE("WAIT_FOR_BCC - timeout");
         put_char(pInfo, NAK);
         flush(pInfo);
         pInfo->state=R3964_IDLE;
         break;
   }
}

static struct r3964_client_info *findClient(
  struct r3964_info *pInfo, pid_t pid)
{
   struct r3964_client_info *pClient;
   
   for(pClient=pInfo->firstClient; pClient; pClient=pClient->next)
   {
      if(pClient->pid == pid)
      {
         return pClient;
      }
   }
   return NULL;
}

static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg)
{
   struct r3964_client_info *pClient;
   struct r3964_client_info **ppClient;
   struct r3964_message *pMsg;
   
   if((arg & R3964_SIG_ALL)==0)
   {
      /* Remove client from client list */
      for(ppClient=&pInfo->firstClient; *ppClient; ppClient=&(*ppClient)->next)
      {
         pClient = *ppClient;
         
         if(pClient->pid == pid)
         {
            TRACE_PS("removing client %d from client list", pid);
            *ppClient = pClient->next;
            while(pClient->msg_count)
            {
               pMsg=remove_msg(pInfo, pClient);
               if(pMsg)
               {
                  kfree(pMsg);
                  TRACE_M("enable_signals - msg kfree %x",(int)pMsg);
               }
            }
            kfree(pClient);
            TRACE_M("enable_signals - kfree %x",(int)pClient);
            return 0;
         }
      }
      return -EINVAL;
   }
   else
   {
      pClient=findClient(pInfo, pid);
      if(pClient)
      {
         /* update signal options */
         pClient->sig_flags=arg;
      } 
      else 
      {
         /* add client to client list */
         pClient=kmalloc(sizeof(struct r3964_client_info), GFP_KERNEL);
         TRACE_M("enable_signals - kmalloc %x",(int)pClient);
         if(pClient==NULL)
            return -ENOMEM;

         TRACE_PS("add client %d to client list", pid);
         pClient->sig_flags=arg;
         pClient->pid = pid;
         pClient->next=pInfo->firstClient;
         pClient->first_msg = NULL;
         pClient->last_msg = NULL;
         pClient->next_block_to_read = NULL;
         pClient->msg_count = 0;
         pInfo->firstClient=pClient;
      }
   }

   return 0;
}

static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char *buf)
{
    struct r3964_client_info *pClient;
    struct r3964_block_header *block;

    if(!buf)
    {
        return -EINVAL;
    }

    pClient=findClient(pInfo,pid);
    if(pClient==NULL)
    {
       return -EINVAL;
    }
    
    block=pClient->next_block_to_read;
    if(!block)
    {
       return 0;
    }
    else
    {
      if (copy_to_user (buf, block->data, block->length))
	return -EFAULT;

       remove_client_block(pInfo, pClient);
       return block->length;
    }

    return -EINVAL;
}

static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
             int error_code, struct r3964_block_header *pBlock)
{
   struct r3964_message *pMsg;
   unsigned long flags;
   
   if(pClient->msg_count<R3964_MAX_MSG_COUNT-1)
   {
queue_the_message:

      pMsg = kmalloc(sizeof(struct r3964_message), GFP_KERNEL);
      TRACE_M("add_msg - kmalloc %x",(int)pMsg);
      if(pMsg==NULL) {