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lcdkp_subr.c revision 1.6 
      1 /* $NetBSD: lcdkp_subr.c,v 1.6 2009/03/14 15:36:17 dsl 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 1.6 2009/03/14 15:36:17 dsl 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 }
    152