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 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 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), error_code ? GFP_ATOMIC : GFP_KERNEL); TRACE_M("add_msg - kmalloc %p", pMsg); if (pMsg == NULL) { return; } spin_lock_irqsave(&pClient->lock, flags); 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++; } spin_unlock_irqrestore(&pClient->lock, 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_pid(pClient->pid, SIGIO, 1); } }
static void on_timeout(unsigned long priv) { struct r3964_info *pInfo = (void *)priv; 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 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 invalid char"); pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY; mod_timer(&pInfo->tmr, jiffies + 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; mod_timer(&pInfo->tmr, jiffies + 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; mod_timer(&pInfo->tmr, jiffies + 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; mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ); } else { on_receive_block(pInfo); } } else { pInfo->last_rx = c; char_to_buf: pInfo->rx_buf[pInfo->rx_position++] = c; mod_timer(&pInfo->tmr, jiffies + 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 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->nRetry++; mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC); } 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); del_timer_sync(&pInfo->tmr); 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 %p", 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); }