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351f683b | 1 | // SPDX-License-Identifier: GPL-2.0 |
70e84049 MOS |
2 | /* |
3 | * Filename: ks0108.c | |
4 | * Version: 0.1.0 | |
5 | * Description: ks0108 LCD Controller driver | |
70e84049 MOS |
6 | * Depends: parport |
7 | * | |
450c622e | 8 | * Author: Copyright (C) Miguel Ojeda Sandonis |
70e84049 | 9 | * Date: 2006-10-31 |
70e84049 MOS |
10 | */ |
11 | ||
7faad1df SM |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
70e84049 MOS |
14 | #include <linux/init.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/fs.h> | |
19 | #include <linux/io.h> | |
20 | #include <linux/parport.h> | |
21 | #include <linux/uaccess.h> | |
22 | #include <linux/ks0108.h> | |
23 | ||
24 | #define KS0108_NAME "ks0108" | |
25 | ||
26 | /* | |
27 | * Module Parameters | |
28 | */ | |
29 | ||
30 | static unsigned int ks0108_port = CONFIG_KS0108_PORT; | |
31 | module_param(ks0108_port, uint, S_IRUGO); | |
32 | MODULE_PARM_DESC(ks0108_port, "Parallel port where the LCD is connected"); | |
33 | ||
34 | static unsigned int ks0108_delay = CONFIG_KS0108_DELAY; | |
35 | module_param(ks0108_delay, uint, S_IRUGO); | |
36 | MODULE_PARM_DESC(ks0108_delay, "Delay between each control writing (microseconds)"); | |
37 | ||
38 | /* | |
39 | * Device | |
40 | */ | |
41 | ||
42 | static struct parport *ks0108_parport; | |
43 | static struct pardevice *ks0108_pardevice; | |
44 | ||
45 | /* | |
46 | * ks0108 Exported Commands (don't lock) | |
47 | * | |
48 | * You _should_ lock in the top driver: This functions _should not_ | |
49 | * get race conditions in any way. Locking for each byte here would be | |
50 | * so slow and useless. | |
51 | * | |
52 | * There are not bit definitions because they are not flags, | |
53 | * just arbitrary combinations defined by the documentation for each | |
54 | * function in the ks0108 LCD controller. If you want to know what means | |
55 | * a specific combination, look at the function's name. | |
56 | * | |
57 | * The ks0108_writecontrol bits need to be reverted ^(0,1,3) because | |
58 | * the parallel port also revert them using a "not" logic gate. | |
59 | */ | |
60 | ||
61 | #define bit(n) (((unsigned char)1)<<(n)) | |
62 | ||
63 | void ks0108_writedata(unsigned char byte) | |
64 | { | |
65 | parport_write_data(ks0108_parport, byte); | |
66 | } | |
67 | ||
68 | void ks0108_writecontrol(unsigned char byte) | |
69 | { | |
70 | udelay(ks0108_delay); | |
71 | parport_write_control(ks0108_parport, byte ^ (bit(0) | bit(1) | bit(3))); | |
72 | } | |
73 | ||
74 | void ks0108_displaystate(unsigned char state) | |
75 | { | |
76 | ks0108_writedata((state ? bit(0) : 0) | bit(1) | bit(2) | bit(3) | bit(4) | bit(5)); | |
77 | } | |
78 | ||
79 | void ks0108_startline(unsigned char startline) | |
80 | { | |
c9efdbe6 SM |
81 | ks0108_writedata(min_t(unsigned char, startline, 63) | bit(6) | |
82 | bit(7)); | |
70e84049 MOS |
83 | } |
84 | ||
85 | void ks0108_address(unsigned char address) | |
86 | { | |
c9efdbe6 | 87 | ks0108_writedata(min_t(unsigned char, address, 63) | bit(6)); |
70e84049 MOS |
88 | } |
89 | ||
90 | void ks0108_page(unsigned char page) | |
91 | { | |
c9efdbe6 SM |
92 | ks0108_writedata(min_t(unsigned char, page, 7) | bit(3) | bit(4) | |
93 | bit(5) | bit(7)); | |
70e84049 MOS |
94 | } |
95 | ||
96 | EXPORT_SYMBOL_GPL(ks0108_writedata); | |
97 | EXPORT_SYMBOL_GPL(ks0108_writecontrol); | |
98 | EXPORT_SYMBOL_GPL(ks0108_displaystate); | |
99 | EXPORT_SYMBOL_GPL(ks0108_startline); | |
100 | EXPORT_SYMBOL_GPL(ks0108_address); | |
101 | EXPORT_SYMBOL_GPL(ks0108_page); | |
102 | ||
34173a4a MO |
103 | /* |
104 | * Is the module inited? | |
105 | */ | |
106 | ||
107 | static unsigned char ks0108_inited; | |
108 | unsigned char ks0108_isinited(void) | |
109 | { | |
110 | return ks0108_inited; | |
111 | } | |
112 | EXPORT_SYMBOL_GPL(ks0108_isinited); | |
113 | ||
4edd70c1 | 114 | static void ks0108_parport_attach(struct parport *port) |
70e84049 | 115 | { |
4edd70c1 | 116 | struct pardev_cb ks0108_cb; |
70e84049 | 117 | |
4edd70c1 SM |
118 | if (port->base != ks0108_port) |
119 | return; | |
70e84049 | 120 | |
4edd70c1 SM |
121 | memset(&ks0108_cb, 0, sizeof(ks0108_cb)); |
122 | ks0108_cb.flags = PARPORT_DEV_EXCL; | |
123 | ks0108_pardevice = parport_register_dev_model(port, KS0108_NAME, | |
124 | &ks0108_cb, 0); | |
125 | if (!ks0108_pardevice) { | |
7faad1df | 126 | pr_err("ERROR: parport didn't register new device\n"); |
4edd70c1 | 127 | return; |
70e84049 | 128 | } |
4edd70c1 SM |
129 | if (parport_claim(ks0108_pardevice)) { |
130 | pr_err("could not claim access to parport %i. Aborting.\n", | |
7faad1df | 131 | ks0108_port); |
4edd70c1 | 132 | goto err_unreg_device; |
70e84049 MOS |
133 | } |
134 | ||
92f26189 | 135 | ks0108_parport = port; |
34173a4a | 136 | ks0108_inited = 1; |
4edd70c1 | 137 | return; |
70e84049 | 138 | |
4edd70c1 | 139 | err_unreg_device: |
70e84049 | 140 | parport_unregister_device(ks0108_pardevice); |
4edd70c1 | 141 | ks0108_pardevice = NULL; |
70e84049 MOS |
142 | } |
143 | ||
4edd70c1 | 144 | static void ks0108_parport_detach(struct parport *port) |
70e84049 | 145 | { |
4edd70c1 SM |
146 | if (port->base != ks0108_port) |
147 | return; | |
148 | ||
149 | if (!ks0108_pardevice) { | |
150 | pr_err("%s: already unregistered.\n", KS0108_NAME); | |
151 | return; | |
152 | } | |
153 | ||
70e84049 MOS |
154 | parport_release(ks0108_pardevice); |
155 | parport_unregister_device(ks0108_pardevice); | |
4edd70c1 | 156 | ks0108_pardevice = NULL; |
92f26189 | 157 | ks0108_parport = NULL; |
4edd70c1 SM |
158 | } |
159 | ||
160 | /* | |
161 | * Module Init & Exit | |
162 | */ | |
163 | ||
164 | static struct parport_driver ks0108_parport_driver = { | |
165 | .name = "ks0108", | |
166 | .match_port = ks0108_parport_attach, | |
167 | .detach = ks0108_parport_detach, | |
168 | .devmodel = true, | |
169 | }; | |
170 | ||
171 | static int __init ks0108_init(void) | |
172 | { | |
173 | return parport_register_driver(&ks0108_parport_driver); | |
174 | } | |
175 | ||
176 | static void __exit ks0108_exit(void) | |
177 | { | |
178 | parport_unregister_driver(&ks0108_parport_driver); | |
70e84049 MOS |
179 | } |
180 | ||
181 | module_init(ks0108_init); | |
182 | module_exit(ks0108_exit); | |
183 | ||
184 | MODULE_LICENSE("GPL v2"); | |
450c622e | 185 | MODULE_AUTHOR("Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>"); |
70e84049 MOS |
186 | MODULE_DESCRIPTION("ks0108 LCD Controller driver"); |
187 |