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70e84049 MOS |
1 | /* |
2 | * Filename: ks0108.c | |
3 | * Version: 0.1.0 | |
4 | * Description: ks0108 LCD Controller driver | |
5 | * License: GPLv2 | |
6 | * Depends: parport | |
7 | * | |
450c622e | 8 | * Author: Copyright (C) Miguel Ojeda Sandonis |
70e84049 MOS |
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 | ||
42 | static unsigned int ks0108_port = CONFIG_KS0108_PORT; | |
43 | module_param(ks0108_port, uint, S_IRUGO); | |
44 | MODULE_PARM_DESC(ks0108_port, "Parallel port where the LCD is connected"); | |
45 | ||
46 | static unsigned int ks0108_delay = CONFIG_KS0108_DELAY; | |
47 | module_param(ks0108_delay, uint, S_IRUGO); | |
48 | MODULE_PARM_DESC(ks0108_delay, "Delay between each control writing (microseconds)"); | |
49 | ||
50 | /* | |
51 | * Device | |
52 | */ | |
53 | ||
54 | static struct parport *ks0108_parport; | |
55 | static 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 | ||
75 | void ks0108_writedata(unsigned char byte) | |
76 | { | |
77 | parport_write_data(ks0108_parport, byte); | |
78 | } | |
79 | ||
80 | void 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 | ||
86 | void 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 | ||
91 | void ks0108_startline(unsigned char startline) | |
92 | { | |
93 | ks0108_writedata(min(startline,(unsigned char)63) | bit(6) | bit(7)); | |
94 | } | |
95 | ||
96 | void ks0108_address(unsigned char address) | |
97 | { | |
98 | ks0108_writedata(min(address,(unsigned char)63) | bit(6)); | |
99 | } | |
100 | ||
101 | void ks0108_page(unsigned char page) | |
102 | { | |
103 | ks0108_writedata(min(page,(unsigned char)7) | bit(3) | bit(4) | bit(5) | bit(7)); | |
104 | } | |
105 | ||
106 | EXPORT_SYMBOL_GPL(ks0108_writedata); | |
107 | EXPORT_SYMBOL_GPL(ks0108_writecontrol); | |
108 | EXPORT_SYMBOL_GPL(ks0108_displaystate); | |
109 | EXPORT_SYMBOL_GPL(ks0108_startline); | |
110 | EXPORT_SYMBOL_GPL(ks0108_address); | |
111 | EXPORT_SYMBOL_GPL(ks0108_page); | |
112 | ||
34173a4a MO |
113 | /* |
114 | * Is the module inited? | |
115 | */ | |
116 | ||
117 | static unsigned char ks0108_inited; | |
118 | unsigned char ks0108_isinited(void) | |
119 | { | |
120 | return ks0108_inited; | |
121 | } | |
122 | EXPORT_SYMBOL_GPL(ks0108_isinited); | |
123 | ||
70e84049 MOS |
124 | /* |
125 | * Module Init & Exit | |
126 | */ | |
127 | ||
128 | static int __init ks0108_init(void) | |
129 | { | |
130 | int result; | |
131 | int ret = -EINVAL; | |
132 | ||
133 | ks0108_parport = parport_find_base(ks0108_port); | |
134 | if (ks0108_parport == NULL) { | |
135 | printk(KERN_ERR KS0108_NAME ": ERROR: " | |
136 | "parport didn't find %i port\n", ks0108_port); | |
137 | goto none; | |
138 | } | |
139 | ||
140 | ks0108_pardevice = parport_register_device(ks0108_parport, KS0108_NAME, | |
141 | NULL, NULL, NULL, PARPORT_DEV_EXCL, NULL); | |
142 | if (ks0108_pardevice == NULL) { | |
143 | printk(KERN_ERR KS0108_NAME ": ERROR: " | |
144 | "parport didn't register new device\n"); | |
145 | goto none; | |
146 | } | |
147 | ||
148 | result = parport_claim(ks0108_pardevice); | |
149 | if (result != 0) { | |
150 | printk(KERN_ERR KS0108_NAME ": ERROR: " | |
151 | "can't claim %i parport, maybe in use\n", ks0108_port); | |
152 | ret = result; | |
153 | goto registered; | |
154 | } | |
155 | ||
34173a4a | 156 | ks0108_inited = 1; |
70e84049 MOS |
157 | return 0; |
158 | ||
159 | registered: | |
160 | parport_unregister_device(ks0108_pardevice); | |
161 | ||
162 | none: | |
163 | return ret; | |
164 | } | |
165 | ||
166 | static void __exit ks0108_exit(void) | |
167 | { | |
168 | parport_release(ks0108_pardevice); | |
169 | parport_unregister_device(ks0108_pardevice); | |
170 | } | |
171 | ||
172 | module_init(ks0108_init); | |
173 | module_exit(ks0108_exit); | |
174 | ||
175 | MODULE_LICENSE("GPL v2"); | |
450c622e | 176 | MODULE_AUTHOR("Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>"); |
70e84049 MOS |
177 | MODULE_DESCRIPTION("ks0108 LCD Controller driver"); |
178 |