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/types.h>
  10 #include <linux/errno.h>
  11 #include <linux/tty.h>
  12 #include <linux/timer.h>
  13 #include <linux/kernel.h>
  14 #include <linux/wait.h>
  15 #include <linux/string.h>
  16 #include <linux/slab.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         /* enforce single access */
  71         if (vfd_is_open)
  72                 return -EBUSY;
  73         vfd_is_open = 1;
  74
  75         return 0;
  76 }
  77
  78 static int briq_panel_release(struct inode *ino, struct file *filep)
  79 {
  80         if (!vfd_is_open)
  81                 return -ENODEV;
  82
  83         vfd_is_open = 0;
  84
  85         return 0;
  86 }
  87
  88 static ssize_t briq_panel_read(struct file *file, char __user *buf, size_t count,
  89                          loff_t *ppos)
  90 {
  91         unsigned short c;
  92         unsigned char cp;
  93
  94 #if 0   /*  Can't seek (pread) on this device  */
  95         if (ppos != &file->f_pos)
  96                 return -ESPIPE;
  97 #endif
  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 0   /*  Can't seek (pwrite) on this device  */
 143         if (ppos != &file->f_pos)
 144                 return -ESPIPE;
 145 #endif
 146
 147         if (!vfd_is_open)
 148                 return -EBUSY;
 149
 150         for (;;) {
 151                 char c;
 152                 if (!indx)
 153                         break;
 154                 if (get_user(c, buf))
 155                         return -EFAULT;
 156                 if (esc) {
 157                         set_led(c);
 158                         esc = 0;
 159                 } else if (c == 27) {
 160                         esc = 1;
 161                 } else if (c == 12) {
 162                         /* do a form feed */
 163                         for (i=0; i<40; i++)
 164                                 vfd[i] = ' ';
 165                         vfd_cursor = 0;
 166                 } else if (c == 10) {
 167                         if (vfd_cursor < 20)
 168                                 vfd_cursor = 20;
 169                         else if (vfd_cursor < 40)
 170                                 vfd_cursor = 40;
 171                         else if (vfd_cursor < 60)
 172                                 vfd_cursor = 60;
 173                         if (vfd_cursor > 59)
 174                                 scroll_vfd();
 175                 } else {
 176                         /* just a character */
 177                         if (vfd_cursor > 39)
 178                                 scroll_vfd();
 179                         vfd[vfd_cursor++] = c;
 180                 }
 181                 indx--;
 182                 buf++;
 183         }
 184         update_vfd();
 185
 186         return len;
 187 }
 188
 189 static const struct file_operations briq_panel_fops = {
 190         .owner          = THIS_MODULE,
 191         .read           = briq_panel_read,
 192         .write          = briq_panel_write,
 193         .open           = briq_panel_open,
 194         .release        = briq_panel_release,
 195 };
 196
 197 static struct miscdevice briq_panel_miscdev = {
 198         BRIQ_PANEL_MINOR,
 199         "briq_panel",
 200         &briq_panel_fops
 201 };
 202
 203 static int __init briq_panel_init(void)
 204 {
 205         struct device_node *root = of_find_node_by_path("/");
 206         const char *machine;
 207         int i;
 208
 209         machine = get_property(root, "model", NULL);
 210         if (!machine || strncmp(machine, "TotalImpact,BRIQ-1", 18) != 0) {
 211                 of_node_put(root);
 212                 return -ENODEV;
 213         }
 214         of_node_put(root);
 215
 216         printk(KERN_INFO
 217                 "briq_panel: v%s Dr. Karsten Jeppesen (kj@totalimpact.com)\n",
 218                 BRIQ_PANEL_VER);
 219
 220         if (!request_region(BRIQ_PANEL_VFD_IOPORT, 4, "BRIQ Front Panel"))
 221                 return -EBUSY;
 222
 223         if (!request_region(BRIQ_PANEL_LED_IOPORT, 2, "BRIQ Front Panel")) {
 224                 release_region(BRIQ_PANEL_VFD_IOPORT, 4);
 225                 return -EBUSY;
 226         }
 227         ledpb = inb(BRIQ_PANEL_LED_IOPORT) & 0x000c;
 228
 229         if (misc_register(&briq_panel_miscdev) < 0) {
 230                 release_region(BRIQ_PANEL_VFD_IOPORT, 4);
 231                 release_region(BRIQ_PANEL_LED_IOPORT, 2);
 232                 return -EBUSY;
 233         }
 234
 235         outb(0x38, BRIQ_PANEL_VFD_IOPORT);      /* Function set */
 236         outb(0x01, BRIQ_PANEL_VFD_IOPORT);      /* Clear display */
 237         outb(0x0c, BRIQ_PANEL_VFD_IOPORT);      /* Display on */
 238         outb(0x06, BRIQ_PANEL_VFD_IOPORT);      /* Entry normal */
 239         for (i=0; i<40; i++)
 240                 vfd[i]=' ';
 241 #ifndef MODULE
 242         vfd[0] = 'L';
 243         vfd[1] = 'o';
 244         vfd[2] = 'a';
 245         vfd[3] = 'd';
 246         vfd[4] = 'i';
 247         vfd[5] = 'n';
 248         vfd[6] = 'g';
 249         vfd[7] = ' ';
 250         vfd[8] = '.';
 251         vfd[9] = '.';
 252         vfd[10] = '.';
 253 #endif /* !MODULE */
 254
 255         update_vfd();
 256
 257         return 0;
 258 }
 259
 260 static void __exit briq_panel_exit(void)
 261 {
 262         misc_deregister(&briq_panel_miscdev);
 263         release_region(BRIQ_PANEL_VFD_IOPORT, 4);
 264         release_region(BRIQ_PANEL_LED_IOPORT, 2);
 265 }
 266
 267 module_init(briq_panel_init);
 268 module_exit(briq_panel_exit);
 269
 270 MODULE_LICENSE("GPL");
 271 MODULE_AUTHOR("Karsten Jeppesen <karsten@jeppesens.com>");
 272 MODULE_DESCRIPTION("Driver for the Total Impact briQ front panel");