ih_twi.c

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00001 /*
00002  * Copyright (C) 2001-2005 by egnite Software GmbH. All rights reserved.
00003  *
00004  * Redistribution and use in source and binary forms, with or without
00005  * modification, are permitted provided that the following conditions
00006  * are met:
00007  *
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 3. Neither the name of the copyright holders nor the names of
00014  *    contributors may be used to endorse or promote products derived
00015  *    from this software without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY EGNITE SOFTWARE GMBH AND CONTRIBUTORS
00018  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00019  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00020  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL EGNITE
00021  * SOFTWARE GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00022  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00023  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
00024  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
00025  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00026  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
00027  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00028  * SUCH DAMAGE.
00029  *
00030  * For additional information see http://www.ethernut.de/
00031  *
00032  */
00033 
00073 #include <dev/irqreg.h>
00074 
00079 
00080 #if defined(SIG_2WIRE_SERIAL) || defined(iv_TWI)
00081 
00082 static int AvrTwiIrqCtl(int cmd, void *param);
00083 
00084 IRQ_HANDLER sig_2WIRE_SERIAL = {
00085 #ifdef NUT_PERFMON
00086     0,                          /* Interrupt counter, ir_count. */
00087 #endif
00088     NULL,                       /* Passed argument, ir_arg. */
00089     NULL,                       /* Handler subroutine, ir_handler. */
00090     AvrTwiIrqCtl                /* Interrupt control, ir_ctl. */
00091 };
00092 
00108 static int AvrTwiIrqCtl(int cmd, void *param)
00109 {
00110     int rc = 0;
00111     u_int *ival = (u_int *) param;
00112     int enabled = bit_is_set(TWCR, TWIE);
00113     u_char bval;
00114 
00115     /* Disable interrupt. */
00116     cbi(TWCR, TWIE);
00117 
00118     switch (cmd) {
00119     case NUT_IRQCTL_INIT:
00120         enabled = 0;
00121     case NUT_IRQCTL_CLEAR:
00122         /* Clear any pending interrupt. */
00123         if (bit_is_set(SPSR, SPIF)) {
00124             bval = inb(SPDR);
00125         }
00126         break;
00127     case NUT_IRQCTL_STATUS:
00128         if (bit_is_set(TWCR, TWINT)) {
00129             *ival = 1;
00130         } else {
00131             *ival = 0;
00132         }
00133         if (enabled) {
00134             *ival |= 0x80;
00135         }
00136         break;
00137     case NUT_IRQCTL_ENABLE:
00138         enabled = 1;
00139         break;
00140     case NUT_IRQCTL_DISABLE:
00141         enabled = 0;
00142         break;
00143     case NUT_IRQCTL_GETPRIO:
00144         *ival = 16;
00145         break;
00146 #ifdef NUT_PERFMON
00147     case NUT_IRQCTL_GETCOUNT:
00148         *ival = (u_int) sig_2WIRE_SERIAL.ir_count;
00149         sig_2WIRE_SERIAL.ir_count = 0;
00150         break;
00151 #endif
00152     default:
00153         rc = -1;
00154         break;
00155     }
00156 
00157     /* Enable interrupt. */
00158     if (enabled) {
00159         sbi(TWCR, TWIE);
00160     }
00161     return rc;
00162 }
00163 
00167 #ifdef __IMAGECRAFT__
00168 #pragma interrupt_handler SIG_2WIRE_SERIAL:iv_TWI
00169 #endif
00170 NUTSIGNAL(SIG_2WIRE_SERIAL, sig_2WIRE_SERIAL)
00171 #endif
00172 

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