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