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 |
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 |
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 |
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(lock: &anslcd_mutex); |
78 | *ppos = i; |
79 | return p - buf; |
80 | } |
81 | |
82 | static long |
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 ( c: 0x38 ); |
98 | anslcd_write_byte_ctrl ( c: 0x0f ); |
99 | anslcd_write_byte_ctrl ( c: 0x06 ); |
100 | anslcd_write_byte_ctrl ( c: 0x01 ); |
101 | anslcd_write_byte_ctrl ( c: 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 ( c: 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(lock: &anslcd_mutex); |
128 | return ret; |
129 | } |
130 | |
131 | static int |
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 |
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, name: "lcd" ); |
164 | if (!node || !of_node_name_eq(np: node->parent, name: "gc" )) { |
165 | of_node_put(node); |
166 | return -ENODEV; |
167 | } |
168 | of_node_put(node); |
169 | |
170 | anslcd_ptr = ioremap(ANSLCD_ADDR, size: 0x20); |
171 | |
172 | retval = misc_register(misc: &anslcd_dev); |
173 | if(retval < 0){ |
174 | printk(KERN_INFO "LCD: misc_register failed\n" ); |
175 | iounmap(addr: 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 ( c: 0x38 ); |
185 | anslcd_write_byte_ctrl ( c: 0x0c ); |
186 | anslcd_write_byte_ctrl ( c: 0x06 ); |
187 | anslcd_write_byte_ctrl ( c: 0x01 ); |
188 | anslcd_write_byte_ctrl ( c: 0x02 ); |
189 | for(a=0;a<80;a++) { |
190 | anslcd_write_byte_data(c: anslcd_logo[a]); |
191 | } |
192 | mutex_unlock(lock: &anslcd_mutex); |
193 | return 0; |
194 | } |
195 | |
196 | static void __exit |
197 | anslcd_exit(void) |
198 | { |
199 | misc_deregister(misc: &anslcd_dev); |
200 | iounmap(addr: anslcd_ptr); |
201 | } |
202 | |
203 | module_init(anslcd_init); |
204 | module_exit(anslcd_exit); |
205 | MODULE_LICENSE("GPL v2" ); |
206 | |