xref: /netbsd-src/sys/dev/ic/lcdkp_subr.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /* $NetBSD: lcdkp_subr.c,v 1.2 2003/01/20 01:50:31 soren 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 1.2 2003/01/20 01:50:31 soren 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 <machine/intr.h>
46 #include <machine/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