1 /* ------------------------------------------------------------------------- */
2 /* i2c-elv.c i2c-hw access for philips style parallel port adapters */
3 /* ------------------------------------------------------------------------- */
4 /* Copyright (C) 1995-2000 Simon G. Vogl
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
19 /* ------------------------------------------------------------------------- */
20
21 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
22 Frodo Looijaard <frodol@dds.nl> */
23
24 /* $Id: i2c-elv.c,v 1.16 2000/01/18 23:54:07 frodo Exp $ */
25
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/delay.h>
29 #include <linux/malloc.h>
30 #include <linux/version.h>
31 #include <linux/init.h>
32
33 #include <asm/uaccess.h>
34
35 #include <linux/ioport.h>
36 #include <asm/io.h>
37 #include <linux/errno.h>
38 #include <linux/i2c.h>
39 #include <linux/i2c-algo-bit.h>
40
41 #define DEFAULT_BASE 0x378
42 static int base=0;
43 static unsigned char PortData = 0;
44
45 /* ----- global defines ----------------------------------------------- */
46 #define DEB(x) /* should be reasonable open, close &c. */
47 #define DEB2(x) /* low level debugging - very slow */
48 #define DEBE(x) x /* error messages */
49 #define DEBINIT(x) x /* detection status messages */
50
51 /* --- Convenience defines for the parallel port: */
52 #define BASE (unsigned int)(data)
53 #define DATA BASE /* Centronics data port */
54 #define STAT (BASE+1) /* Centronics status port */
55 #define CTRL (BASE+2) /* Centronics control port */
56
57
58 /* ----- local functions ---------------------------------------------- */
59
60
61 static void bit_elv_setscl(void *data, int state)
62 {
63 if (state) {
64 PortData &= 0xfe;
65 } else {
66 PortData |=1;
67 }
68 outb(PortData, DATA);
69 }
70
71 static void bit_elv_setsda(void *data, int state)
72 {
73 if (state) {
74 PortData &=0xfd;
75 } else {
76 PortData |=2;
77 }
78 outb(PortData, DATA);
79 }
80
81 static int bit_elv_getscl(void *data)
82 {
83 return ( 0 == ( (inb_p(STAT)) & 0x08 ) );
84 }
85
86 static int bit_elv_getsda(void *data)
87 {
88 return ( 0 == ( (inb_p(STAT)) & 0x40 ) );
89 }
90
91 static int bit_elv_init(void)
92 {
93 if (check_region(base,(base == 0x3bc)? 3 : 8) < 0 ) {
94 return -ENODEV;
95 } else {
96 /* test for ELV adap. */
97 if (inb(base+1) & 0x80) { /* BUSY should be high */
98 DEBINIT(printk("i2c-elv.o: Busy was low.\n"));
99 return -ENODEV;
100 } else {
101 outb(0x0c,base+2); /* SLCT auf low */
102 udelay(400);
103 if ( !(inb(base+1) && 0x10) ) {
104 outb(0x04,base+2);
105 DEBINIT(printk("i2c-elv.o: Select was high.\n"));
106 return -ENODEV;
107 }
108 }
109 request_region(base,(base == 0x3bc)? 3 : 8,
110 "i2c (ELV adapter)");
111 PortData = 0;
112 bit_elv_setsda((void*)base,1);
113 bit_elv_setscl((void*)base,1);
114 }
115 return 0;
116 }
117
118 static void bit_elv_exit(void)
119 {
120 release_region( base , (base == 0x3bc)? 3 : 8 );
121 }
122
123 static int bit_elv_reg(struct i2c_client *client)
124 {
125 return 0;
126 }
127
128 static int bit_elv_unreg(struct i2c_client *client)
129 {
130 return 0;
131 }
132
133 static void bit_elv_inc_use(struct i2c_adapter *adap)
134 {
135 #ifdef MODULE
136 MOD_INC_USE_COUNT;
137 #endif
138 }
139
140 static void bit_elv_dec_use(struct i2c_adapter *adap)
141 {
142 #ifdef MODULE
143 MOD_DEC_USE_COUNT;
144 #endif
145 }
146
147 /* ------------------------------------------------------------------------
148 * Encapsulate the above functions in the correct operations structure.
149 * This is only done when more than one hardware adapter is supported.
150 */
151 static struct i2c_algo_bit_data bit_elv_data = {
152 NULL,
153 bit_elv_setsda,
154 bit_elv_setscl,
155 bit_elv_getsda,
156 bit_elv_getscl,
157 80, 80, 100, /* waits, timeout */
158 };
159
160 static struct i2c_adapter bit_elv_ops = {
161 "ELV Parallel port adaptor",
162 I2C_HW_B_ELV,
163 NULL,
164 &bit_elv_data,
165 bit_elv_inc_use,
166 bit_elv_dec_use,
167 bit_elv_reg,
168 bit_elv_unreg,
169 };
170
171 int __init i2c_bitelv_init(void)
172 {
173 printk("i2c-elv.o: i2c ELV parallel port adapter module\n");
174 if (base==0) {
175 /* probe some values */
176 base=DEFAULT_BASE;
177 bit_elv_data.data=(void*)DEFAULT_BASE;
178 if (bit_elv_init()==0) {
179 if(i2c_bit_add_bus(&bit_elv_ops) < 0)
180 return -ENODEV;
181 } else {
182 return -ENODEV;
183 }
184 } else {
185 bit_elv_ops.data=(void*)base;
186 if (bit_elv_init()==0) {
187 if(i2c_bit_add_bus(&bit_elv_ops) < 0)
188 return -ENODEV;
189 } else {
190 return -ENODEV;
191 }
192 }
193 printk("i2c-elv.o: found device at %#x.\n",base);
194 return 0;
195 }
196
197
198 EXPORT_NO_SYMBOLS;
199
200 #ifdef MODULE
201 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
202 MODULE_DESCRIPTION("I2C-Bus adapter routines for ELV parallel port adapter")
203 ;
204
205 MODULE_PARM(base, "i");
206
207 int init_module(void)
208 {
209 return i2c_bitelv_init();
210 }
211
212 void cleanup_module(void)
213 {
214 i2c_bit_del_bus(&bit_elv_ops);
215 bit_elv_exit();
216 }
217
218 #endif
219
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