xref: /openbmc/linux/drivers/macintosh/ans-lcd.c (revision 545e4006)
1 /*
2  * /dev/lcd driver for Apple Network Servers.
3  */
4 
5 #include <linux/types.h>
6 #include <linux/smp_lock.h>
7 #include <linux/errno.h>
8 #include <linux/kernel.h>
9 #include <linux/miscdevice.h>
10 #include <linux/fcntl.h>
11 #include <linux/init.h>
12 #include <linux/delay.h>
13 #include <linux/fs.h>
14 
15 #include <asm/uaccess.h>
16 #include <asm/sections.h>
17 #include <asm/prom.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 
30 #undef DEBUG
31 
32 static void
33 anslcd_write_byte_ctrl ( unsigned char c )
34 {
35 #ifdef DEBUG
36 	printk(KERN_DEBUG "LCD: CTRL byte: %02x\n",c);
37 #endif
38 	out_8(anslcd_ptr + ANSLCD_CTRL_IX, c);
39 	switch(c) {
40 		case 1:
41 		case 2:
42 		case 3:
43 			udelay(anslcd_long_delay); break;
44 		default: udelay(anslcd_short_delay);
45 	}
46 }
47 
48 static void
49 anslcd_write_byte_data ( unsigned char c )
50 {
51 	out_8(anslcd_ptr + ANSLCD_DATA_IX, c);
52 	udelay(anslcd_short_delay);
53 }
54 
55 static ssize_t
56 anslcd_write( struct file * file, const char __user * buf,
57 				size_t count, loff_t *ppos )
58 {
59 	const char __user *p = buf;
60 	int i;
61 
62 #ifdef DEBUG
63 	printk(KERN_DEBUG "LCD: write\n");
64 #endif
65 
66 	if (!access_ok(VERIFY_READ, buf, count))
67 		return -EFAULT;
68 	for ( i = *ppos; count > 0; ++i, ++p, --count )
69 	{
70 		char c;
71 		__get_user(c, p);
72 		anslcd_write_byte_data( c );
73 	}
74 	*ppos = i;
75 	return p - buf;
76 }
77 
78 static int
79 anslcd_ioctl( struct inode * inode, struct file * file,
80 				unsigned int cmd, unsigned long arg )
81 {
82 	char ch, __user *temp;
83 
84 #ifdef DEBUG
85 	printk(KERN_DEBUG "LCD: ioctl(%d,%d)\n",cmd,arg);
86 #endif
87 
88 	switch ( cmd )
89 	{
90 	case ANSLCD_CLEAR:
91 		anslcd_write_byte_ctrl ( 0x38 );
92 		anslcd_write_byte_ctrl ( 0x0f );
93 		anslcd_write_byte_ctrl ( 0x06 );
94 		anslcd_write_byte_ctrl ( 0x01 );
95 		anslcd_write_byte_ctrl ( 0x02 );
96 		return 0;
97 	case ANSLCD_SENDCTRL:
98 		temp = (char __user *) arg;
99 		__get_user(ch, temp);
100 		for (; ch; temp++) { /* FIXME: This is ugly, but should work, as a \0 byte is not a valid command code */
101 			anslcd_write_byte_ctrl ( ch );
102 			__get_user(ch, temp);
103 		}
104 		return 0;
105 	case ANSLCD_SETSHORTDELAY:
106 		if (!capable(CAP_SYS_ADMIN))
107 			return -EACCES;
108 		anslcd_short_delay=arg;
109 		return 0;
110 	case ANSLCD_SETLONGDELAY:
111 		if (!capable(CAP_SYS_ADMIN))
112 			return -EACCES;
113 		anslcd_long_delay=arg;
114 		return 0;
115 	default:
116 		return -EINVAL;
117 	}
118 }
119 
120 static int
121 anslcd_open( struct inode * inode, struct file * file )
122 {
123 	cycle_kernel_lock();
124 	return 0;
125 }
126 
127 const struct file_operations anslcd_fops = {
128 	.write	= anslcd_write,
129 	.ioctl	= anslcd_ioctl,
130 	.open	= anslcd_open,
131 };
132 
133 static struct miscdevice anslcd_dev = {
134 	ANSLCD_MINOR,
135 	"anslcd",
136 	&anslcd_fops
137 };
138 
139 const char anslcd_logo[] =	"********************"  /* Line #1 */
140 				"*      LINUX!      *"  /* Line #3 */
141 				"*    Welcome to    *"  /* Line #2 */
142 				"********************"; /* Line #4 */
143 
144 static int __init
145 anslcd_init(void)
146 {
147 	int a;
148 	int retval;
149 	struct device_node* node;
150 
151 	node = of_find_node_by_name(NULL, "lcd");
152 	if (!node || !node->parent || strcmp(node->parent->name, "gc")) {
153 		of_node_put(node);
154 		return -ENODEV;
155 	}
156 	of_node_put(node);
157 
158 	anslcd_ptr = ioremap(ANSLCD_ADDR, 0x20);
159 
160 	retval = misc_register(&anslcd_dev);
161 	if(retval < 0){
162 		printk(KERN_INFO "LCD: misc_register failed\n");
163 		iounmap(anslcd_ptr);
164 		return retval;
165 	}
166 
167 #ifdef DEBUG
168 	printk(KERN_DEBUG "LCD: init\n");
169 #endif
170 
171 	anslcd_write_byte_ctrl ( 0x38 );
172 	anslcd_write_byte_ctrl ( 0x0c );
173 	anslcd_write_byte_ctrl ( 0x06 );
174 	anslcd_write_byte_ctrl ( 0x01 );
175 	anslcd_write_byte_ctrl ( 0x02 );
176 	for(a=0;a<80;a++) {
177 		anslcd_write_byte_data(anslcd_logo[a]);
178 	}
179 	return 0;
180 }
181 
182 static void __exit
183 anslcd_exit(void)
184 {
185 	misc_deregister(&anslcd_dev);
186 	iounmap(anslcd_ptr);
187 }
188 
189 module_init(anslcd_init);
190 module_exit(anslcd_exit);
191