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
26 static unsigned long anslcd_short_delay = 80;
27 static unsigned long anslcd_long_delay = 3280;
28 static volatile unsigned char __iomem *anslcd_ptr;
29 static DEFINE_MUTEX(anslcd_mutex);
30
31 #undef DEBUG
32
33 static void
anslcd_write_byte_ctrl(unsigned char c)34 anslcd_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
49 static void
anslcd_write_byte_data(unsigned char c)50 anslcd_write_byte_data ( unsigned char c )
51 {
52 out_8(anslcd_ptr + ANSLCD_DATA_IX, c);
53 udelay(anslcd_short_delay);
54 }
55
56 static ssize_t
anslcd_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)57 anslcd_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
82 static long
anslcd_ioctl(struct file * file,unsigned int cmd,unsigned long arg)83 anslcd_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
131 static int
anslcd_open(struct inode * inode,struct file * file)132 anslcd_open( struct inode * inode, struct file * file )
133 {
134 return 0;
135 }
136
137 const struct file_operations anslcd_fops = {
138 .write = anslcd_write,
139 .unlocked_ioctl = anslcd_ioctl,
140 .open = anslcd_open,
141 .llseek = default_llseek,
142 };
143
144 static struct miscdevice anslcd_dev = {
145 LCD_MINOR,
146 "anslcd",
147 &anslcd_fops
148 };
149
150 static const char anslcd_logo[] __initconst =
151 "********************" /* Line #1 */
152 "* LINUX! *" /* Line #3 */
153 "* Welcome to *" /* Line #2 */
154 "********************"; /* Line #4 */
155
156 static int __init
anslcd_init(void)157 anslcd_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
196 static void __exit
anslcd_exit(void)197 anslcd_exit(void)
198 {
199 misc_deregister(&anslcd_dev);
200 iounmap(anslcd_ptr);
201 }
202
203 module_init(anslcd_init);
204 module_exit(anslcd_exit);
205 MODULE_LICENSE("GPL v2");
206