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205 lines · 4.0 KiB

1// SPDX-License-Identifier: GPL-2.0
2/*
3 * /dev/lcd driver for Apple Network Servers.
4 */
5
6#include <linux/types.h>
7#include <linux/errno.h>
8#include <linux/kernel.h>
9#include <linux/miscdevice.h>
10#include <linux/fcntl.h>
11#include <linux/module.h>
12#include <linux/delay.h>
13#include <linux/fs.h>
14#include <linux/of.h>
15
16#include <linux/uaccess.h>
17#include <asm/sections.h>
18#include <asm/io.h>
19
20#include "ans-lcd.h"
21
22#define ANSLCD_ADDR 0xf301c000
23#define ANSLCD_CTRL_IX 0x00
24#define ANSLCD_DATA_IX 0x10
25
26static unsigned long anslcd_short_delay = 80;
27static unsigned long anslcd_long_delay = 3280;
28static volatile unsigned char __iomem *anslcd_ptr;
29static DEFINE_MUTEX(anslcd_mutex);
30
31#undef DEBUG
32
33static void
34anslcd_write_byte_ctrl ( unsigned char c )
35{
36#ifdef DEBUG
37 printk(KERN_DEBUG "LCD: CTRL byte: %02x\n",c);
38#endif
39 out_8(anslcd_ptr + ANSLCD_CTRL_IX, c);
40 switch(c) {
41 case 1:
42 case 2:
43 case 3:
44 udelay(anslcd_long_delay); break;
45 default: udelay(anslcd_short_delay);
46 }
47}
48
49static void
50anslcd_write_byte_data ( unsigned char c )
51{
52 out_8(anslcd_ptr + ANSLCD_DATA_IX, c);
53 udelay(anslcd_short_delay);
54}
55
56static ssize_t
57anslcd_write( struct file * file, const char __user * buf,
58 size_t count, loff_t *ppos )
59{
60 const char __user *p = buf;
61 int i;
62
63#ifdef DEBUG
64 printk(KERN_DEBUG "LCD: write\n");
65#endif
66
67 if (!access_ok(buf, count))
68 return -EFAULT;
69
70 mutex_lock(&anslcd_mutex);
71 for ( i = *ppos; count > 0; ++i, ++p, --count )
72 {
73 char c;
74 __get_user(c, p);
75 anslcd_write_byte_data( c );
76 }
77 mutex_unlock(&anslcd_mutex);
78 *ppos = i;
79 return p - buf;
80}
81
82static long
83anslcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
84{
85 char ch, __user *temp;
86 long ret = 0;
87
88#ifdef DEBUG
89 printk(KERN_DEBUG "LCD: ioctl(%d,%d)\n",cmd,arg);
90#endif
91
92 mutex_lock(&anslcd_mutex);
93
94 switch ( cmd )
95 {
96 case ANSLCD_CLEAR:
97 anslcd_write_byte_ctrl ( 0x38 );
98 anslcd_write_byte_ctrl ( 0x0f );
99 anslcd_write_byte_ctrl ( 0x06 );
100 anslcd_write_byte_ctrl ( 0x01 );
101 anslcd_write_byte_ctrl ( 0x02 );
102 break;
103 case ANSLCD_SENDCTRL:
104 temp = (char __user *) arg;
105 __get_user(ch, temp);
106 for (; ch; temp++) { /* FIXME: This is ugly, but should work, as a \0 byte is not a valid command code */
107 anslcd_write_byte_ctrl ( ch );
108 __get_user(ch, temp);
109 }
110 break;
111 case ANSLCD_SETSHORTDELAY:
112 if (!capable(CAP_SYS_ADMIN))
113 ret =-EACCES;
114 else
115 anslcd_short_delay=arg;
116 break;
117 case ANSLCD_SETLONGDELAY:
118 if (!capable(CAP_SYS_ADMIN))
119 ret = -EACCES;
120 else
121 anslcd_long_delay=arg;
122 break;
123 default:
124 ret = -EINVAL;
125 }
126
127 mutex_unlock(&anslcd_mutex);
128 return ret;
129}
130
131static int
132anslcd_open( struct inode * inode, struct file * file )
133{
134 return 0;
135}
136
137const struct file_operations anslcd_fops = {
138 .write = anslcd_write,
139 .unlocked_ioctl = anslcd_ioctl,
140 .open = anslcd_open,
141 .llseek = default_llseek,
142};
143
144static struct miscdevice anslcd_dev = {
145 LCD_MINOR,
146 "anslcd",
147 &anslcd_fops
148};
149
150static const char anslcd_logo[] __initconst =
151 "********************" /* Line #1 */
152 "* LINUX! *" /* Line #3 */
153 "* Welcome to *" /* Line #2 */
154 "********************"; /* Line #4 */
155
156static int __init
157anslcd_init(void)
158{
159 int a;
160 int retval;
161 struct device_node* node;
162
163 node = of_find_node_by_name(NULL, "lcd");
164 if (!node || !of_node_name_eq(node->parent, "gc")) {
165 of_node_put(node);
166 return -ENODEV;
167 }
168 of_node_put(node);
169
170 anslcd_ptr = ioremap(ANSLCD_ADDR, 0x20);
171
172 retval = misc_register(&anslcd_dev);
173 if(retval < 0){
174 printk(KERN_INFO "LCD: misc_register failed\n");
175 iounmap(anslcd_ptr);
176 return retval;
177 }
178
179#ifdef DEBUG
180 printk(KERN_DEBUG "LCD: init\n");
181#endif
182
183 mutex_lock(&anslcd_mutex);
184 anslcd_write_byte_ctrl ( 0x38 );
185 anslcd_write_byte_ctrl ( 0x0c );
186 anslcd_write_byte_ctrl ( 0x06 );
187 anslcd_write_byte_ctrl ( 0x01 );
188 anslcd_write_byte_ctrl ( 0x02 );
189 for(a=0;a<80;a++) {
190 anslcd_write_byte_data(anslcd_logo[a]);
191 }
192 mutex_unlock(&anslcd_mutex);
193 return 0;
194}
195
196static void __exit
197anslcd_exit(void)
198{
199 misc_deregister(&anslcd_dev);
200 iounmap(anslcd_ptr);
201}
202
203module_init(anslcd_init);
204module_exit(anslcd_exit);
205MODULE_LICENSE("GPL v2");