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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Filename: ks0108.c
4 * Version: 0.1.0
5 * Description: ks0108 LCD Controller driver
6 * Depends: parport
7 *
8 * Author: Copyright (C) Miguel Ojeda <ojeda@kernel.org>
9 * Date: 2006-10-31
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/init.h>
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/delay.h>
18#include <linux/parport.h>
19#include <linux/ks0108.h>
20
21#define KS0108_NAME "ks0108"
22
23/*
24 * Module Parameters
25 */
26
27static unsigned int ks0108_port = CONFIG_KS0108_PORT;
28module_param(ks0108_port, uint, 0444);
29MODULE_PARM_DESC(ks0108_port, "Parallel port where the LCD is connected");
30
31static unsigned int ks0108_delay = CONFIG_KS0108_DELAY;
32module_param(ks0108_delay, uint, 0444);
33MODULE_PARM_DESC(ks0108_delay, "Delay between each control writing (microseconds)");
34
35/*
36 * Device
37 */
38
39static struct parport *ks0108_parport;
40static struct pardevice *ks0108_pardevice;
41
42/*
43 * ks0108 Exported Commands (don't lock)
44 *
45 * You _should_ lock in the top driver: This functions _should not_
46 * get race conditions in any way. Locking for each byte here would be
47 * so slow and useless.
48 *
49 * There are not bit definitions because they are not flags,
50 * just arbitrary combinations defined by the documentation for each
51 * function in the ks0108 LCD controller. If you want to know what means
52 * a specific combination, look at the function's name.
53 *
54 * The ks0108_writecontrol bits need to be reverted ^(0,1,3) because
55 * the parallel port also revert them using a "not" logic gate.
56 */
57
58#define bit(n) (((unsigned char)1)<<(n))
59
60void ks0108_writedata(unsigned char byte)
61{
62 parport_write_data(ks0108_parport, byte);
63}
64
65void ks0108_writecontrol(unsigned char byte)
66{
67 udelay(ks0108_delay);
68 parport_write_control(ks0108_parport, byte ^ (bit(0) | bit(1) | bit(3)));
69}
70
71void ks0108_displaystate(unsigned char state)
72{
73 ks0108_writedata((state ? bit(0) : 0) | bit(1) | bit(2) | bit(3) | bit(4) | bit(5));
74}
75
76void ks0108_startline(unsigned char startline)
77{
78 ks0108_writedata(min_t(unsigned char, startline, 63) | bit(6) |
79 bit(7));
80}
81
82void ks0108_address(unsigned char address)
83{
84 ks0108_writedata(min_t(unsigned char, address, 63) | bit(6));
85}
86
87void ks0108_page(unsigned char page)
88{
89 ks0108_writedata(min_t(unsigned char, page, 7) | bit(3) | bit(4) |
90 bit(5) | bit(7));
91}
92
93EXPORT_SYMBOL_GPL(ks0108_writedata);
94EXPORT_SYMBOL_GPL(ks0108_writecontrol);
95EXPORT_SYMBOL_GPL(ks0108_displaystate);
96EXPORT_SYMBOL_GPL(ks0108_startline);
97EXPORT_SYMBOL_GPL(ks0108_address);
98EXPORT_SYMBOL_GPL(ks0108_page);
99
100/*
101 * Is the module inited?
102 */
103
104static unsigned char ks0108_inited;
105unsigned char ks0108_isinited(void)
106{
107 return ks0108_inited;
108}
109EXPORT_SYMBOL_GPL(ks0108_isinited);
110
111static void ks0108_parport_attach(struct parport *port)
112{
113 struct pardev_cb ks0108_cb;
114
115 if (port->base != ks0108_port)
116 return;
117
118 memset(&ks0108_cb, 0, sizeof(ks0108_cb));
119 ks0108_cb.flags = PARPORT_DEV_EXCL;
120 ks0108_pardevice = parport_register_dev_model(port, KS0108_NAME,
121 &ks0108_cb, 0);
122 if (!ks0108_pardevice) {
123 pr_err("ERROR: parport didn't register new device\n");
124 return;
125 }
126 if (parport_claim(ks0108_pardevice)) {
127 pr_err("could not claim access to parport %i. Aborting.\n",
128 ks0108_port);
129 goto err_unreg_device;
130 }
131
132 ks0108_parport = port;
133 ks0108_inited = 1;
134 return;
135
136err_unreg_device:
137 parport_unregister_device(ks0108_pardevice);
138 ks0108_pardevice = NULL;
139}
140
141static void ks0108_parport_detach(struct parport *port)
142{
143 if (port->base != ks0108_port)
144 return;
145
146 if (!ks0108_pardevice) {
147 pr_err("%s: already unregistered.\n", KS0108_NAME);
148 return;
149 }
150
151 parport_release(ks0108_pardevice);
152 parport_unregister_device(ks0108_pardevice);
153 ks0108_pardevice = NULL;
154 ks0108_parport = NULL;
155}
156
157/*
158 * Module Init & Exit
159 */
160
161static struct parport_driver ks0108_parport_driver = {
162 .name = "ks0108",
163 .match_port = ks0108_parport_attach,
164 .detach = ks0108_parport_detach,
165 .devmodel = true,
166};
167module_parport_driver(ks0108_parport_driver);
168
169MODULE_LICENSE("GPL v2");
170MODULE_AUTHOR("Miguel Ojeda <ojeda@kernel.org>");
171MODULE_DESCRIPTION("ks0108 LCD Controller driver");
172
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Filename: ks0108.c
4 * Version: 0.1.0
5 * Description: ks0108 LCD Controller driver
6 * Depends: parport
7 *
8 * Author: Copyright (C) Miguel Ojeda <ojeda@kernel.org>
9 * Date: 2006-10-31
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
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
30static unsigned int ks0108_port = CONFIG_KS0108_PORT;
31module_param(ks0108_port, uint, S_IRUGO);
32MODULE_PARM_DESC(ks0108_port, "Parallel port where the LCD is connected");
33
34static unsigned int ks0108_delay = CONFIG_KS0108_DELAY;
35module_param(ks0108_delay, uint, S_IRUGO);
36MODULE_PARM_DESC(ks0108_delay, "Delay between each control writing (microseconds)");
37
38/*
39 * Device
40 */
41
42static struct parport *ks0108_parport;
43static 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
63void ks0108_writedata(unsigned char byte)
64{
65 parport_write_data(ks0108_parport, byte);
66}
67
68void 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
74void 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
79void ks0108_startline(unsigned char startline)
80{
81 ks0108_writedata(min_t(unsigned char, startline, 63) | bit(6) |
82 bit(7));
83}
84
85void ks0108_address(unsigned char address)
86{
87 ks0108_writedata(min_t(unsigned char, address, 63) | bit(6));
88}
89
90void ks0108_page(unsigned char page)
91{
92 ks0108_writedata(min_t(unsigned char, page, 7) | bit(3) | bit(4) |
93 bit(5) | bit(7));
94}
95
96EXPORT_SYMBOL_GPL(ks0108_writedata);
97EXPORT_SYMBOL_GPL(ks0108_writecontrol);
98EXPORT_SYMBOL_GPL(ks0108_displaystate);
99EXPORT_SYMBOL_GPL(ks0108_startline);
100EXPORT_SYMBOL_GPL(ks0108_address);
101EXPORT_SYMBOL_GPL(ks0108_page);
102
103/*
104 * Is the module inited?
105 */
106
107static unsigned char ks0108_inited;
108unsigned char ks0108_isinited(void)
109{
110 return ks0108_inited;
111}
112EXPORT_SYMBOL_GPL(ks0108_isinited);
113
114static void ks0108_parport_attach(struct parport *port)
115{
116 struct pardev_cb ks0108_cb;
117
118 if (port->base != ks0108_port)
119 return;
120
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) {
126 pr_err("ERROR: parport didn't register new device\n");
127 return;
128 }
129 if (parport_claim(ks0108_pardevice)) {
130 pr_err("could not claim access to parport %i. Aborting.\n",
131 ks0108_port);
132 goto err_unreg_device;
133 }
134
135 ks0108_parport = port;
136 ks0108_inited = 1;
137 return;
138
139err_unreg_device:
140 parport_unregister_device(ks0108_pardevice);
141 ks0108_pardevice = NULL;
142}
143
144static void ks0108_parport_detach(struct parport *port)
145{
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
154 parport_release(ks0108_pardevice);
155 parport_unregister_device(ks0108_pardevice);
156 ks0108_pardevice = NULL;
157 ks0108_parport = NULL;
158}
159
160/*
161 * Module Init & Exit
162 */
163
164static 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
171static int __init ks0108_init(void)
172{
173 return parport_register_driver(&ks0108_parport_driver);
174}
175
176static void __exit ks0108_exit(void)
177{
178 parport_unregister_driver(&ks0108_parport_driver);
179}
180
181module_init(ks0108_init);
182module_exit(ks0108_exit);
183
184MODULE_LICENSE("GPL v2");
185MODULE_AUTHOR("Miguel Ojeda <ojeda@kernel.org>");
186MODULE_DESCRIPTION("ks0108 LCD Controller driver");
187