Loading...
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/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