usr/src/psm/promif/ieee1275/sun4/prom_heartbeat.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <sys/promif.h>
  27 #include <sys/promimpl.h>
  28
  29 /*
  30  * Provide 10 millisecond heartbeat for the PROM. A client that has taken over
  31  * the trap table and clock interrupts, but is not quite ready to take over the
  32  * function of polling the input-device for an abort sequence (L1/A or BREAK)
  33  * may use this function to instruct the PROM to poll the keyboard. If used,
  34  * this function should be called every 10 milliseconds.
  35  */
  36 int
  37 prom_heartbeat(int msecs)
  38 {
  39         cell_t ci[5];
  40
  41         ci[0] = p1275_ptr2cell("SUNW,heartbeat");       /* Service name */
  42         ci[1] = (cell_t)1;                              /* #argument cells */
  43         ci[2] = (cell_t)1;                              /* #result cells */
  44         ci[3] = p1275_int2cell(msecs);                  /* Arg1: msecs */
  45         ci[4] = (cell_t)0;                              /* Prime the result */
  46
  47         promif_preprom();
  48         (void) p1275_cif_handler(&ci);
  49         promif_postprom();
  50
  51         return (p1275_cell2int(ci[4]));                 /* Res1: abort-flag */
  52 }