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      1 /* $NetBSD: lcdkp_subr.c,v 1.7 2011/05/14 02:58:27 rmind 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 1.7 2011/05/14 02:58:27 rmind 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 
     62 	sc->sc_flags = 0x0;
     63 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_NONE);
     64 }
     65 
     66 /*
     67  * Scan whether input is pending, don't block if not.
     68  */
     69 int
     70 lcdkp_scankey(struct lcdkp_chip *sc)
     71 {
     72 	int ret;
     73 
     74 	if ((sc->sc_knum == 0) || (sc->sc_kpad == NULL))
     75 		return 0;
     76 
     77 	mutex_enter(&sc->sc_lock);
     78 	if (!(sc->sc_flags & LCDKP_HAS_BUF)) {
     79 		u_int8_t b;
     80 		if (lcdkp_scan(sc, &b) != 0) {
     81 			sc->sc_buf = b;
     82 			sc->sc_flags |= LCDKP_HAS_BUF;
     83 		}
     84 	}
     85 	ret = (sc->sc_flags & LCDKP_HAS_BUF);
     86 	mutex_exit(&sc->sc_lock);
     87 
     88 	return ret;
     89 }
     90 
     91 /*
     92  * Read new key code, block if needed.
     93  */
     94 int
     95 lcdkp_readkey(struct lcdkp_chip *sc, u_int8_t *result)
     96 {
     97 	int error;
     98 
     99 	if ((sc->sc_knum == 0) || (sc->sc_kpad == NULL))
    100 		return EIO;
    101 
    102 	mutex_enter(&sc->sc_lock);
    103 	if ( (error = lcdkp_poll(sc)) == 0) {
    104 		*result = sc->sc_buf;
    105 		sc->sc_flags &= ~LCDKP_HAS_BUF;
    106 	}
    107 	mutex_exit(&sc->sc_lock);
    108 
    109 	return 0;
    110 }
    111 
    112 /*
    113  * Scan the keypad and translate the input.
    114  */
    115 static u_char
    116 lcdkp_scan(struct lcdkp_chip *sc, u_int8_t *b)
    117 {
    118 	u_int8_t i;
    119 	u_int8_t c;
    120 
    121 	c = lcdkp_dr_read(sc);
    122 	for (i = 0; i < sc->sc_knum; i++) {
    123 		if (sc->sc_kpad[i].x_keycode == c) {
    124 			*b = sc->sc_kpad[i].x_outcode;
    125 			return 1;
    126 		}
    127 	}
    128 	return 0;
    129 }
    130 
    131 /*
    132  * Block until input is available.
    133  */
    134 static int
    135 lcdkp_poll(struct lcdkp_chip *sc)
    136 {
    137 	int error;
    138 	uint8_t b;
    139 
    140 	KASSERT(mutex_owned(&sc->sc_lock));
    141 
    142 	if (sc->sc_flags & LCDKP_HAS_BUF) {
    143 		return 0;
    144 	}
    145 	while (lcdkp_scan(sc, &b) == 0) {
    146 		error = mtsleep((void*)sc, PRIBIO | PCATCH, "kppoll",
    147 		    HD_POLL_RATE, &sc->sc_lock);
    148 		if (error != 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 	return 0;
    157 }
    158