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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/*
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