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lcdkp_subr.c revision 1.5 
      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(sc)
     60 	struct lcdkp_chip *sc;
     61 {
     62 	sc->sc_flags = 0x0;
     63 	lcdkp_lock_init(sc);
     64 }
     65 
     66 /*
     67  * Scan whether input is pending, don't block if not.
     68  */
     69 int
     70 lcdkp_scankey(sc)
     71 	struct lcdkp_chip *sc;
     72 {
     73 	int ret;
     74 
     75 	if ((sc->sc_knum == 0) || (sc->sc_kpad == NULL))
     76 		return 0;
     77 
     78 	lcdkp_lock(sc);
     79 	if (!(sc->sc_flags & LCDKP_HAS_BUF)) {
     80 		u_int8_t b;
     81 		if (lcdkp_scan(sc, &b) != 0) {
     82 			sc->sc_buf = b;
     83 			sc->sc_flags |= LCDKP_HAS_BUF;
     84 		}
     85 	}
     86 	ret = (sc->sc_flags & LCDKP_HAS_BUF);
     87 	lcdkp_unlock(sc);
     88 
     89 	return ret;
     90 }
     91 
     92 /*
     93  * Read new key code, block if needed.
     94  */
     95 int
     96 lcdkp_readkey(sc, result)
     97 	struct lcdkp_chip *sc;
     98 	u_int8_t *result;
     99 {
    100 	int error;
    101 
    102 	if ((sc->sc_knum == 0) || (sc->sc_kpad == NULL))
    103 		return EIO;
    104 
    105 	lcdkp_lock(sc);
    106 	if ( (error = lcdkp_poll(sc)) == 0) {
    107 		*result = sc->sc_buf;
    108 		sc->sc_flags &= ~LCDKP_HAS_BUF;
    109 	}
    110 	lcdkp_unlock(sc);
    111 
    112 	return 0;
    113 }
    114 
    115 /*
    116  * Scan the keypad and translate the input.
    117  */
    118 static u_char
    119 lcdkp_scan(sc, b)
    120 	struct lcdkp_chip *sc;
    121 	u_int8_t *b;
    122 {
    123 	u_int8_t i;
    124 	u_int8_t c;
    125 
    126 	c = lcdkp_dr_read(sc);
    127 	for (i = 0; i < sc->sc_knum; i++) {
    128 		if (sc->sc_kpad[i].x_keycode == c) {
    129 			*b = sc->sc_kpad[i].x_outcode;
    130 			return 1;
    131 		}
    132 	}
    133 	return 0;
    134 }
    135 
    136 /*
    137  * Block until input is available.
    138  */
    139 static int
    140 lcdkp_poll(sc)
    141 	struct lcdkp_chip *sc;
    142 {
    143 	if (!(sc->sc_flags & LCDKP_HAS_BUF)) {
    144 		u_int8_t b;
    145 		while(lcdkp_scan(sc, &b) == 0) {
    146 			int err = ltsleep((void*)sc, PRIBIO | PCATCH, "kppoll",
    147 					HD_POLL_RATE, lcdkp_lockaddr(sc));
    148 			if (err != EWOULDBLOCK) {
    149 				if (lcdkp_scan(sc, &b) != 0)
    150 					break;
    151 				return EINTR;
    152 			}
    153 		}
    154 		sc->sc_buf = b;
    155 		sc->sc_flags |= LCDKP_HAS_BUF;
    156 	}
    157 	return 0;
    158 }
    159