/*- * Copyright (c) 1997 Kazutaka YOKOTA (yokota@zodiac.mech.utsunomiya-u.ac.jp) * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $Id: probe_keyboard.c,v 1.13 1997/06/09 05:10:55 bde Exp $ */ #include #include #include #include #include "boot.h" #define PROBE_MAXRETRY 5 #define PROBE_MAXWAIT 400 #define IO_DUMMY 0x84 /* 7 microsec delay necessary for some keyboard controllers */ static void delay7(void) { /* * I know this is broken, but no timer is avaiable yet at this stage... * See also comments in `delay1ms()' in `io.c'. */ inb(IO_DUMMY); inb(IO_DUMMY); inb(IO_DUMMY); inb(IO_DUMMY); inb(IO_DUMMY); inb(IO_DUMMY); } /* * Perform a simple test on the keyboard; issue the ECHO command and see * if the right answer is returned. We don't do anything as drastic as * full keyboard reset; it will be too troublesome and take too much time. */ int probe_keyboard(void) { int retry = PROBE_MAXRETRY; int wait; int i; while (--retry >= 0) { /* flush any noise */ while (inb(IO_KBD + KBD_STATUS_PORT) & KBDS_ANY_BUFFER_FULL) { delay7(); inb(IO_KBD + KBD_DATA_PORT); delay1ms(); } /* wait until the controller can accept a command */ for (wait = PROBE_MAXWAIT; wait > 0; --wait) { if (((i = inb(IO_KBD + KBD_STATUS_PORT)) & (KBDS_INPUT_BUFFER_FULL | KBDS_ANY_BUFFER_FULL)) == 0) break; if (i & KBDS_ANY_BUFFER_FULL) { delay7(); inb(IO_KBD + KBD_DATA_PORT); } delay1ms(); } if (wait <= 0) continue; /* send the ECHO command */ outb(IO_KBD + KBD_DATA_PORT, KBDC_ECHO); /* wait for a response */ for (wait = PROBE_MAXWAIT; wait > 0; --wait) { if (inb(IO_KBD + KBD_STATUS_PORT) & KBDS_ANY_BUFFER_FULL) break; delay1ms(); } if (wait <= 0) continue; delay7(); i = inb(IO_KBD + KBD_DATA_PORT); #ifdef PROBE_KBD_BEBUG printf("probe_keyboard: got 0x%x.\n", i); #endif if (i == KBD_ECHO) { /* got the right answer */ return (0); } } return (1); }