drivers/char/briq_panel.c

   1 /*
   2  * Drivers for the Total Impact PPC based computer "BRIQ"
   3  * by Dr. Karsten Jeppesen
   4  *
   5  */
   6
   7 #include <linux/module.h>
   8
   9 #include <linux/smp_lock.h>
  10 #include <linux/types.h>
  11 #include <linux/errno.h>
  12 #include <linux/tty.h>
  13 #include <linux/timer.h>
  14 #include <linux/kernel.h>
  15 #include <linux/wait.h>
  16 #include <linux/string.h>
  17 #include <linux/ioport.h>
  18 #include <linux/delay.h>
  19 #include <linux/miscdevice.h>
  20 #include <linux/fs.h>
  21 #include <linux/mm.h>
  22 #include <linux/init.h>
  23
  24 #include <asm/uaccess.h>
  25 #include <asm/io.h>
  26 #include <asm/prom.h>
  27
  28 #define         BRIQ_PANEL_MINOR        156
  29 #define         BRIQ_PANEL_VFD_IOPORT   0x0390
  30 #define         BRIQ_PANEL_LED_IOPORT   0x0398
  31 #define         BRIQ_PANEL_VER          "1.1 (04/20/2002)"
  32 #define         BRIQ_PANEL_MSG0         "Loading Linux"
  33
  34 static int              vfd_is_open;
  35 static unsigned char    vfd[40];
  36 static int              vfd_cursor;
  37 static unsigned char    ledpb, led;
  38
  39 static void update_vfd(void)
  40 {
  41         int     i;
  42
  43         /* cursor home */
  44         outb(0x02, BRIQ_PANEL_VFD_IOPORT);
  45         for (i=0; i<20; i++)
  46                 outb(vfd[i], BRIQ_PANEL_VFD_IOPORT + 1);
  47
  48         /* cursor to next line */
  49         outb(0xc0, BRIQ_PANEL_VFD_IOPORT);
  50         for (i=20; i<40; i++)
  51                 outb(vfd[i], BRIQ_PANEL_VFD_IOPORT + 1);
  52
  53 }
  54
  55 static void set_led(char state)
  56 {
  57         if (state == 'R')
  58                 led = 0x01;
  59         else if (state == 'G')
  60                 led = 0x02;
  61         else if (state == 'Y')
  62                 led = 0x03;
  63         else if (state == 'X')
  64                 led = 0x00;
  65         outb(led, BRIQ_PANEL_LED_IOPORT);
  66 }
  67
  68 static int briq_panel_open(struct inode *ino, struct file *filep)
  69 {
  70         lock_kernel();
  71         /* enforce single access, vfd_is_open is protected by BKL */
  72         if (vfd_is_open) {
  73                 unlock_kernel();
  74                 return -EBUSY;
  75         }
  76         vfd_is_open = 1;
  77
  78         unlock_kernel();
  79         return 0;
  80 }
  81
  82 static int briq_panel_release(struct inode *ino, struct file *filep)
  83 {
  84         if (!vfd_is_open)
  85                 return -ENODEV;
  86
  87         vfd_is_open = 0;
  88
  89         return 0;
  90 }
  91
  92 static ssize_t briq_panel_read(struct file *file, char __user *buf, size_t count,
  93                          loff_t *ppos)
  94 {
  95         unsigned short c;
  96         unsigned char cp;
  97
  98         if (!vfd_is_open)
  99                 return -ENODEV;
 100
 101         c = (inb(BRIQ_PANEL_LED_IOPORT) & 0x000c) | (ledpb & 0x0003);
 102         set_led(' ');
 103         /* upper button released */
 104         if ((!(ledpb & 0x0004)) && (c & 0x0004)) {
 105                 cp = ' ';
 106                 ledpb = c;
 107                 if (copy_to_user(buf, &cp, 1))
 108                         return -EFAULT;
 109                 return 1;
 110         }
 111         /* lower button released */
 112         else if ((!(ledpb & 0x0008)) && (c & 0x0008)) {
 113                 cp = '\r';
 114                 ledpb = c;
 115                 if (copy_to_user(buf, &cp, 1))
 116                         return -EFAULT;
 117                 return 1;
 118         } else {
 119                 ledpb = c;
 120                 return 0;
 121         }
 122 }
 123
 124 static void scroll_vfd( void )
 125 {
 126         int     i;
 127
 128         for (i=0; i<20; i++) {
 129                 vfd[i] = vfd[i+20];
 130                 vfd[i+20] = ' ';
 131         }
 132         vfd_cursor = 20;
 133 }
 134
 135 static ssize_t briq_panel_write(struct file *file, const char __user *buf, size_t len,
 136                           loff_t *ppos)
 137 {
 138         size_t indx = len;
 139         int i, esc = 0;
 140
 141         if (!vfd_is_open)
 142                 return -EBUSY;
 143
 144         for (;;) {
 145                 char c;
 146                 if (!indx)
 147                         break;
 148                 if (get_user(c, buf))
 149                         return -EFAULT;
 150                 if (esc) {
 151                         set_led(c);
 152                         esc = 0;
 153                 } else if (c == 27) {
 154                         esc = 1;
 155                 } else if (c == 12) {
 156                         /* do a form feed */
 157                         for (i=0; i<40; i++)
 158                                 vfd[i] = ' ';
 159                         vfd_cursor = 0;
 160                 } else if (c == 10) {
 161                         if (vfd_cursor < 20)
 162                                 vfd_cursor = 20;
 163                         else if (vfd_cursor < 40)
 164                                 vfd_cursor = 40;
 165                         else if (vfd_cursor < 60)
 166                                 vfd_cursor = 60;
 167                         if (vfd_cursor > 59)
 168                                 scroll_vfd();
 169                 } else {
 170                         /* just a character */
 171                         if (vfd_cursor > 39)
 172                                 scroll_vfd();
 173                         vfd[vfd_cursor++] = c;
 174                 }
 175                 indx--;
 176                 buf++;
 177         }
 178         update_vfd();
 179
 180         return len;
 181 }
 182
 183 static const struct file_operations briq_panel_fops = {
 184         .owner          = THIS_MODULE,
 185         .read           = briq_panel_read,
 186         .write          = briq_panel_write,
 187         .open           = briq_panel_open,
 188         .release        = briq_panel_release,
 189 };
 190
 191 static struct miscdevice briq_panel_miscdev = {
 192         BRIQ_PANEL_MINOR,
 193         "briq_panel",
 194         &briq_panel_fops
 195 };
 196
 197 static int __init briq_panel_init(void)
 198 {
 199         struct device_node *root = of_find_node_by_path("/");
 200         const char *machine;
 201         int i;
 202
 203         machine = of_get_property(root, "model", NULL);
 204         if (!machine || strncmp(machine, "TotalImpact,BRIQ-1", 18) != 0) {
 205                 of_node_put(root);
 206                 return -ENODEV;
 207         }
 208         of_node_put(root);
 209
 210         printk(KERN_INFO
 211                 "briq_panel: v%s Dr. Karsten Jeppesen (kj@totalimpact.com)\n",
 212                 BRIQ_PANEL_VER);
 213
 214         if (!request_region(BRIQ_PANEL_VFD_IOPORT, 4, "BRIQ Front Panel"))
 215                 return -EBUSY;
 216
 217         if (!request_region(BRIQ_PANEL_LED_IOPORT, 2, "BRIQ Front Panel")) {
 218                 release_region(BRIQ_PANEL_VFD_IOPORT, 4);
 219                 return -EBUSY;
 220         }
 221         ledpb = inb(BRIQ_PANEL_LED_IOPORT) & 0x000c;
 222
 223         if (misc_register(&briq_panel_miscdev) < 0) {
 224                 release_region(BRIQ_PANEL_VFD_IOPORT, 4);
 225                 release_region(BRIQ_PANEL_LED_IOPORT, 2);
 226                 return -EBUSY;
 227         }
 228
 229         outb(0x38, BRIQ_PANEL_VFD_IOPORT);      /* Function set */
 230         outb(0x01, BRIQ_PANEL_VFD_IOPORT);      /* Clear display */
 231         outb(0x0c, BRIQ_PANEL_VFD_IOPORT);      /* Display on */
 232         outb(0x06, BRIQ_PANEL_VFD_IOPORT);      /* Entry normal */
 233         for (i=0; i<40; i++)
 234                 vfd[i]=' ';
 235 #ifndef MODULE
 236         vfd[0] = 'L';
 237         vfd[1] = 'o';
 238         vfd[2] = 'a';
 239         vfd[3] = 'd';
 240         vfd[4] = 'i';
 241         vfd[5] = 'n';
 242         vfd[6] = 'g';
 243         vfd[7] = ' ';
 244         vfd[8] = '.';
 245         vfd[9] = '.';
 246         vfd[10] = '.';
 247 #endif /* !MODULE */
 248
 249         update_vfd();
 250
 251         return 0;
 252 }
 253
 254 static void __exit briq_panel_exit(void)
 255 {
 256         misc_deregister(&briq_panel_miscdev);
 257         release_region(BRIQ_PANEL_VFD_IOPORT, 4);
 258         release_region(BRIQ_PANEL_LED_IOPORT, 2);
 259 }
 260
 261 module_init(briq_panel_init);
 262 module_exit(briq_panel_exit);
 263
 264 MODULE_LICENSE("GPL");
 265 MODULE_AUTHOR("Karsten Jeppesen <karsten@jeppesens.com>");
 266 MODULE_DESCRIPTION("Driver for the Total Impact briQ front panel");