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Miguel Ojeda Sandonis70e84042007-02-10 01:44:32 -08001/*
2 * Filename: ks0108.c
3 * Version: 0.1.0
4 * Description: ks0108 LCD Controller driver
5 * License: GPLv2
6 * Depends: parport
7 *
8 * Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
9 * Date: 2006-10-31
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 */
25
26#include <linux/init.h>
27#include <linux/module.h>
28#include <linux/kernel.h>
29#include <linux/delay.h>
30#include <linux/fs.h>
31#include <linux/io.h>
32#include <linux/parport.h>
33#include <linux/uaccess.h>
34#include <linux/ks0108.h>
35
36#define KS0108_NAME "ks0108"
37
38/*
39 * Module Parameters
40 */
41
42static unsigned int ks0108_port = CONFIG_KS0108_PORT;
43module_param(ks0108_port, uint, S_IRUGO);
44MODULE_PARM_DESC(ks0108_port, "Parallel port where the LCD is connected");
45
46static unsigned int ks0108_delay = CONFIG_KS0108_DELAY;
47module_param(ks0108_delay, uint, S_IRUGO);
48MODULE_PARM_DESC(ks0108_delay, "Delay between each control writing (microseconds)");
49
50/*
51 * Device
52 */
53
54static struct parport *ks0108_parport;
55static struct pardevice *ks0108_pardevice;
56
57/*
58 * ks0108 Exported Commands (don't lock)
59 *
60 * You _should_ lock in the top driver: This functions _should not_
61 * get race conditions in any way. Locking for each byte here would be
62 * so slow and useless.
63 *
64 * There are not bit definitions because they are not flags,
65 * just arbitrary combinations defined by the documentation for each
66 * function in the ks0108 LCD controller. If you want to know what means
67 * a specific combination, look at the function's name.
68 *
69 * The ks0108_writecontrol bits need to be reverted ^(0,1,3) because
70 * the parallel port also revert them using a "not" logic gate.
71 */
72
73#define bit(n) (((unsigned char)1)<<(n))
74
75void ks0108_writedata(unsigned char byte)
76{
77 parport_write_data(ks0108_parport, byte);
78}
79
80void ks0108_writecontrol(unsigned char byte)
81{
82 udelay(ks0108_delay);
83 parport_write_control(ks0108_parport, byte ^ (bit(0) | bit(1) | bit(3)));
84}
85
86void ks0108_displaystate(unsigned char state)
87{
88 ks0108_writedata((state ? bit(0) : 0) | bit(1) | bit(2) | bit(3) | bit(4) | bit(5));
89}
90
91void ks0108_startline(unsigned char startline)
92{
93 ks0108_writedata(min(startline,(unsigned char)63) | bit(6) | bit(7));
94}
95
96void ks0108_address(unsigned char address)
97{
98 ks0108_writedata(min(address,(unsigned char)63) | bit(6));
99}
100
101void ks0108_page(unsigned char page)
102{
103 ks0108_writedata(min(page,(unsigned char)7) | bit(3) | bit(4) | bit(5) | bit(7));
104}
105
106EXPORT_SYMBOL_GPL(ks0108_writedata);
107EXPORT_SYMBOL_GPL(ks0108_writecontrol);
108EXPORT_SYMBOL_GPL(ks0108_displaystate);
109EXPORT_SYMBOL_GPL(ks0108_startline);
110EXPORT_SYMBOL_GPL(ks0108_address);
111EXPORT_SYMBOL_GPL(ks0108_page);
112
113/*
114 * Module Init & Exit
115 */
116
117static int __init ks0108_init(void)
118{
119 int result;
120 int ret = -EINVAL;
121
122 ks0108_parport = parport_find_base(ks0108_port);
123 if (ks0108_parport == NULL) {
124 printk(KERN_ERR KS0108_NAME ": ERROR: "
125 "parport didn't find %i port\n", ks0108_port);
126 goto none;
127 }
128
129 ks0108_pardevice = parport_register_device(ks0108_parport, KS0108_NAME,
130 NULL, NULL, NULL, PARPORT_DEV_EXCL, NULL);
131 if (ks0108_pardevice == NULL) {
132 printk(KERN_ERR KS0108_NAME ": ERROR: "
133 "parport didn't register new device\n");
134 goto none;
135 }
136
137 result = parport_claim(ks0108_pardevice);
138 if (result != 0) {
139 printk(KERN_ERR KS0108_NAME ": ERROR: "
140 "can't claim %i parport, maybe in use\n", ks0108_port);
141 ret = result;
142 goto registered;
143 }
144
145 return 0;
146
147registered:
148 parport_unregister_device(ks0108_pardevice);
149
150none:
151 return ret;
152}
153
154static void __exit ks0108_exit(void)
155{
156 parport_release(ks0108_pardevice);
157 parport_unregister_device(ks0108_pardevice);
158}
159
160module_init(ks0108_init);
161module_exit(ks0108_exit);
162
163MODULE_LICENSE("GPL v2");
164MODULE_AUTHOR("Miguel Ojeda Sandonis <maxextreme@gmail.com>");
165MODULE_DESCRIPTION("ks0108 LCD Controller driver");
166