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
lcdkp_attach_subr(struct lcdkp_chip * sc)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
lcdkp_scankey(struct lcdkp_chip * sc)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
lcdkp_readkey(struct lcdkp_chip * sc,u_int8_t * result)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
lcdkp_scan(struct lcdkp_chip * sc,u_int8_t * b)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
lcdkp_poll(struct lcdkp_chip * sc)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