drivers/macintosh/ans-lcd.c

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