File: /usr/src/linux/drivers/i2c/i2c-velleman.c
1 /* ------------------------------------------------------------------------- */
2 /* i2c-velleman.c i2c-hw access for Velleman K9000 adapters */
3 /* ------------------------------------------------------------------------- */
4 /* Copyright (C) 1995-96, 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 /* $Id: i2c-velleman.c,v 1.19 2000/01/24 02:06:33 mds Exp $ */
22
23 #include <linux/kernel.h>
24 #include <linux/ioport.h>
25 #include <linux/module.h>
26 #include <linux/init.h>
27 #include <linux/string.h> /* for 2.0 kernels to get NULL */
28 #include <asm/errno.h> /* for 2.0 kernels to get ENODEV */
29 #include <asm/io.h>
30
31 #include <linux/i2c.h>
32 #include <linux/i2c-algo-bit.h>
33
34 /* ----- global defines ----------------------------------------------- */
35 #define DEB(x) /* should be reasonable open, close &c. */
36 #define DEB2(x) /* low level debugging - very slow */
37 #define DEBE(x) x /* error messages */
38
39 /* Pin Port Inverted name */
40 #define I2C_SDA 0x02 /* ctrl bit 1 (inv) */
41 #define I2C_SCL 0x08 /* ctrl bit 3 (inv) */
42
43 #define I2C_SDAIN 0x10 /* stat bit 4 */
44 #define I2C_SCLIN 0x08 /* ctrl bit 3 (inv)(reads own output)*/
45
46 #define I2C_DMASK 0xfd
47 #define I2C_CMASK 0xf7
48
49
50 /* --- Convenience defines for the parallel port: */
51 #define BASE (unsigned int)(data)
52 #define DATA BASE /* Centronics data port */
53 #define STAT (BASE+1) /* Centronics status port */
54 #define CTRL (BASE+2) /* Centronics control port */
55
56 #define DEFAULT_BASE 0x378
57 static int base=0;
58
59 /* ----- local functions --------------------------------------------------- */
60
61 static void bit_velle_setscl(void *data, int state)
62 {
63 if (state) {
64 outb(inb(CTRL) & I2C_CMASK, CTRL);
65 } else {
66 outb(inb(CTRL) | I2C_SCL, CTRL);
67 }
68
69 }
70
71 static void bit_velle_setsda(void *data, int state)
72 {
73 if (state) {
74 outb(inb(CTRL) & I2C_DMASK , CTRL);
75 } else {
76 outb(inb(CTRL) | I2C_SDA, CTRL);
77 }
78
79 }
80
81 static int bit_velle_getscl(void *data)
82 {
83 return ( 0 == ( (inb(CTRL)) & I2C_SCLIN ) );
84 }
85
86 static int bit_velle_getsda(void *data)
87 {
88 return ( 0 != ( (inb(STAT)) & I2C_SDAIN ) );
89 }
90
91 static int bit_velle_init(void)
92 {
93 if (check_region(base,(base == 0x3bc)? 3 : 8) < 0 ) {
94 DEBE(printk("i2c-velleman.o: Port %#x already in use.\n",
95 base));
96 return -ENODEV;
97 } else {
98 request_region(base, (base == 0x3bc)? 3 : 8,
99 "i2c (Vellemann adapter)");
100 bit_velle_setsda((void*)base,1);
101 bit_velle_setscl((void*)base,1);
102 }
103 return 0;
104 }
105
106 static void bit_velle_exit(void)
107 {
108 release_region( base , (base == 0x3bc)? 3 : 8 );
109 }
110
111
112 static int bit_velle_reg(struct i2c_client *client)
113 {
114 return 0;
115 }
116
117 static int bit_velle_unreg(struct i2c_client *client)
118 {
119 return 0;
120 }
121
122 static void bit_velle_inc_use(struct i2c_adapter *adap)
123 {
124 #ifdef MODULE
125 MOD_INC_USE_COUNT;
126 #endif
127 }
128
129 static void bit_velle_dec_use(struct i2c_adapter *adap)
130 {
131 #ifdef MODULE
132 MOD_DEC_USE_COUNT;
133 #endif
134 }
135
136 /* ------------------------------------------------------------------------
137 * Encapsulate the above functions in the correct operations structure.
138 * This is only done when more than one hardware adapter is supported.
139 */
140
141 static struct i2c_algo_bit_data bit_velle_data = {
142 NULL,
143 bit_velle_setsda,
144 bit_velle_setscl,
145 bit_velle_getsda,
146 bit_velle_getscl,
147 10, 10, 100, /* waits, timeout */
148 };
149
150 static struct i2c_adapter bit_velle_ops = {
151 "Velleman K8000",
152 I2C_HW_B_VELLE,
153 NULL,
154 &bit_velle_data,
155 bit_velle_inc_use,
156 bit_velle_dec_use,
157 bit_velle_reg,
158 bit_velle_unreg,
159 };
160
161 int __init i2c_bitvelle_init(void)
162 {
163 printk("i2c-velleman.o: i2c Velleman K8000 adapter module\n");
164 if (base==0) {
165 /* probe some values */
166 base=DEFAULT_BASE;
167 bit_velle_data.data=(void*)DEFAULT_BASE;
168 if (bit_velle_init()==0) {
169 if(i2c_bit_add_bus(&bit_velle_ops) < 0)
170 return -ENODEV;
171 } else {
172 return -ENODEV;
173 }
174 } else {
175 bit_velle_data.data=(void*)base;
176 if (bit_velle_init()==0) {
177 if(i2c_bit_add_bus(&bit_velle_ops) < 0)
178 return -ENODEV;
179 } else {
180 return -ENODEV;
181 }
182 }
183 printk("i2c-velleman.o: found device at %#x.\n",base);
184 return 0;
185 }
186
187 EXPORT_NO_SYMBOLS;
188
189 #ifdef MODULE
190 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
191 MODULE_DESCRIPTION("I2C-Bus adapter routines for Velleman K8000 adapter");
192
193 MODULE_PARM(base, "i");
194
195 int init_module(void)
196 {
197 return i2c_bitvelle_init();
198 }
199
200 void cleanup_module(void)
201 {
202 i2c_bit_del_bus(&bit_velle_ops);
203 bit_velle_exit();
204 }
205
206 #endif
207