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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 Sandonis
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 Sandonis <miguel.ojeda.sandonis@gmail.com>");
186MODULE_DESCRIPTION("ks0108 LCD Controller driver");
187
1/*
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
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 * Is the module inited?
115 */
116
117static unsigned char ks0108_inited;
118unsigned char ks0108_isinited(void)
119{
120 return ks0108_inited;
121}
122EXPORT_SYMBOL_GPL(ks0108_isinited);
123
124/*
125 * Module Init & Exit
126 */
127
128static 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
156 ks0108_inited = 1;
157 return 0;
158
159registered:
160 parport_unregister_device(ks0108_pardevice);
161
162none:
163 return ret;
164}
165
166static void __exit ks0108_exit(void)
167{
168 parport_release(ks0108_pardevice);
169 parport_unregister_device(ks0108_pardevice);
170}
171
172module_init(ks0108_init);
173module_exit(ks0108_exit);
174
175MODULE_LICENSE("GPL v2");
176MODULE_AUTHOR("Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>");
177MODULE_DESCRIPTION("ks0108 LCD Controller driver");
178