sys/dev/ic/lcdkp_subr.c

   1 /* $NetBSD: lcdkp_subr.c,v 1.5 2007/10/19 11:59:54 ad Exp $ */
   2
   3 /*
   4  * Copyright (c) 2002 Dennis I. Chernoivanov
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * Subroutines for simple one-port keypad.
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __KERNEL_RCSID(0, "$NetBSD: lcdkp_subr.c,v 1.5 2007/10/19 11:59:54 ad Exp $");
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/proc.h>
  40 #include <sys/conf.h>
  41 #include <sys/kernel.h>
  42 #include <sys/types.h>
  43
  44 #include <machine/autoconf.h>
  45 #include <sys/intr.h>
  46 #include <sys/bus.h>
  47
  48 #include <dev/ic/lcdkp_subr.h>
  49
  50 #define HD_POLL_RATE    (hz / 10)
  51
  52 static int    lcdkp_poll(struct lcdkp_chip *);
  53 static u_char lcdkp_scan(struct lcdkp_chip *, u_int8_t *);
  54
  55 /*
  56  * Initialization.
  57  */
  58 void
  59 lcdkp_attach_subr(struct lcdkp_chip *sc)
  60 {
  61         sc->sc_flags = 0x0;
  62         lcdkp_lock_init(sc);
  63 }
  64
  65 /*
  66  * Scan whether input is pending, don't block if not.
  67  */
  68 int
  69 lcdkp_scankey(struct lcdkp_chip *sc)
  70 {
  71         int ret;
  72
  73         if ((sc->sc_knum == 0) || (sc->sc_kpad == NULL))
  74                 return 0;
  75
  76         lcdkp_lock(sc);
  77         if (!(sc->sc_flags & LCDKP_HAS_BUF)) {
  78                 u_int8_t b;
  79                 if (lcdkp_scan(sc, &b) != 0) {
  80                         sc->sc_buf = b;
  81                         sc->sc_flags |= LCDKP_HAS_BUF;
  82                 }
  83         }
  84         ret = (sc->sc_flags & LCDKP_HAS_BUF);
  85         lcdkp_unlock(sc);
  86
  87         return ret;
  88 }
  89
  90 /*
  91  * Read new key code, block if needed.
  92  */
  93 int
  94 lcdkp_readkey(struct lcdkp_chip *sc, u_int8_t *result)
  95 {
  96         int error;
  97
  98         if ((sc->sc_knum == 0) || (sc->sc_kpad == NULL))
  99                 return EIO;
 100
 101         lcdkp_lock(sc);
 102         if ( (error = lcdkp_poll(sc)) == 0) {
 103                 *result = sc->sc_buf;
 104                 sc->sc_flags &= ~LCDKP_HAS_BUF;
 105         }
 106         lcdkp_unlock(sc);
 107
 108         return 0;
 109 }
 110
 111 /*
 112  * Scan the keypad and translate the input.
 113  */
 114 static u_char
 115 lcdkp_scan(struct lcdkp_chip *sc, u_int8_t *b)
 116 {
 117         u_int8_t i;
 118         u_int8_t c;
 119
 120         c = lcdkp_dr_read(sc);
 121         for (i = 0; i < sc->sc_knum; i++) {
 122                 if (sc->sc_kpad[i].x_keycode == c) {
 123                         *b = sc->sc_kpad[i].x_outcode;
 124                         return 1;
 125                 }
 126         }
 127         return 0;
 128 }
 129
 130 /*
 131  * Block until input is available.
 132  */
 133 static int
 134 lcdkp_poll(struct lcdkp_chip *sc)
 135 {
 136         if (!(sc->sc_flags & LCDKP_HAS_BUF)) {
 137                 u_int8_t b;
 138                 while(lcdkp_scan(sc, &b) == 0) {
 139                         int err = ltsleep((void*)sc, PRIBIO | PCATCH, "kppoll",
 140                                         HD_POLL_RATE, lcdkp_lockaddr(sc));
 141                         if (err != EWOULDBLOCK) {
 142                                 if (lcdkp_scan(sc, &b) != 0)
 143                                         break;
 144                                 return EINTR;
 145                         }
 146                 }
 147                 sc->sc_buf = b;
 148                 sc->sc_flags |= LCDKP_HAS_BUF;
 149         }
 150         return 0;
 151 }