00001 /* 00002 * Copyright Droids Corporation, Microb Technology, Eirbot (2005) 00003 * 00004 * This program is free software; you can redistribute it and/or modify 00005 * it under the terms of the GNU General Public License as published by 00006 * the Free Software Foundation; either version 2 of the License, or 00007 * (at your option) any later version. 00008 * 00009 * This program is distributed in the hope that it will be useful, 00010 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00012 * GNU General Public License for more details. 00013 * 00014 * You should have received a copy of the GNU General Public License 00015 * along with this program; if not, write to the Free Software 00016 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 00017 * 00018 * Revision : $Id: uart_send_nowait.c,v 1.2 2009-03-15 21:51:18 zer0 Exp $ 00019 * 00020 */ 00021 00022 /* Olivier MATZ, Droids-corp 2004 - 2009 */ 00023 00024 #include <uart.h> 00025 #include <uart_defs.h> 00026 #include <uart_private.h> 00027 00028 00029 /* send a char, or put it in the fifo if uart is not ready. Return -1 00030 * if fifo is full */ 00031 int uart_send_nowait(uint8_t num, char c) 00032 { 00033 uint8_t flags; 00034 00035 IRQ_LOCK(flags); 00036 00037 /* if uart intrp mode is disabled (note that we look rx */ 00038 /* intrp -- RXCIE is 0) */ 00039 if ( !(*uart_regs[num].ucsrb & (1 << RXCIE )) ) { 00040 /* we have to poll the status register before xmit */ 00041 if (*uart_regs[num].ucsra & (1<<UDRE)) { 00042 uart_set_udr(num, c); 00043 IRQ_UNLOCK(flags); 00044 return (int)c; 00045 } 00046 else { 00047 IRQ_UNLOCK(flags); 00048 return -1; 00049 } 00050 } 00051 00052 if (CIRBUF_IS_FULL(&g_tx_fifo[num])) { 00053 IRQ_UNLOCK(flags); 00054 return -1; 00055 } 00056 00057 /* uart is ready to send */ 00058 if (CIRBUF_IS_EMPTY(&g_tx_fifo[num]) && 00059 *uart_regs[num].ucsra & (1<<UDRE)) { 00060 uart_set_udr(num, c); 00061 sbi(*uart_regs[num].ucsrb, UDRIE); /* XXX */ 00062 } 00063 else { /* not ready, put char in fifo */ 00064 cirbuf_add_head(&g_tx_fifo[num], c); 00065 } 00066 00067 IRQ_UNLOCK(flags); 00068 return (int)c; 00069 }
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