drivers/parisc/led.c

   1 /*
   2  *    Chassis LCD/LED driver for HP-PARISC workstations
   3  *
   4  *      (c) Copyright 2000 Red Hat Software
   5  *      (c) Copyright 2000 Helge Deller <hdeller@redhat.com>
   6  *      (c) Copyright 2001-2003 Helge Deller <deller@gmx.de>
   7  *      (c) Copyright 2001 Randolph Chung <tausq@debian.org>
   8  *
   9  *      This program is free software; you can redistribute it and/or modify
  10  *      it under the terms of the GNU General Public License as published by
  11  *      the Free Software Foundation; either version 2 of the License, or
  12  *      (at your option) any later version.
  13  *
  14  * TODO:
  15  *      - speed-up calculations with inlined assembler
  16  *      - interface to write to second row of LCD from /proc (if technically possible)
  17  */
  18
  19 #include <linux/config.h>
  20 #include <linux/module.h>
  21 #include <linux/stddef.h>       /* for offsetof() */
  22 #include <linux/init.h>
  23 #include <linux/types.h>
  24 #include <linux/ioport.h>
  25 #include <linux/version.h>
  26 #include <linux/delay.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/inetdevice.h>
  29 #include <linux/in.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/kernel_stat.h>
  32 #include <linux/reboot.h>
  33 #include <linux/proc_fs.h>
  34 #include <linux/ctype.h>
  35 #include <linux/blkdev.h>
  36 #include <asm/io.h>
  37 #include <asm/processor.h>
  38 #include <asm/hardware.h>
  39 #include <asm/param.h>          /* HZ */
  40 #include <asm/led.h>
  41 #include <asm/pdc.h>
  42 #include <asm/uaccess.h>
  43
  44 /* The control of the LEDs and LCDs on PARISC-machines have to be done
  45    completely in software. The necessary calculations are done in a tasklet
  46    which is scheduled at every timer interrupt and since the calculations
  47    may consume relatively much CPU-time some of the calculations can be
  48    turned off with the following variables (controlled via procfs) */
  49
  50 static int led_type = -1;
  51 static int led_heartbeat = 1;
  52 static int led_diskio = 1;
  53 static int led_lanrxtx = 1;
  54 static char lcd_text[32];
  55
  56 #if 0
  57 #define DPRINTK(x)      printk x
  58 #else
  59 #define DPRINTK(x)
  60 #endif
  61
  62
  63 struct lcd_block {
  64         unsigned char command;  /* stores the command byte      */
  65         unsigned char on;       /* value for turning LED on     */
  66         unsigned char off;      /* value for turning LED off    */
  67 };
  68
  69 /* Structure returned by PDC_RETURN_CHASSIS_INFO */
  70 /* NOTE: we use unsigned long:16 two times, since the following member
  71    lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */
  72 struct pdc_chassis_lcd_info_ret_block {
  73         unsigned long model:16;         /* DISPLAY_MODEL_XXXX */
  74         unsigned long lcd_width:16;     /* width of the LCD in chars (DISPLAY_MODEL_LCD only) */
  75         char *lcd_cmd_reg_addr;         /* ptr to LCD cmd-register & data ptr for LED */
  76         char *lcd_data_reg_addr;        /* ptr to LCD data-register (LCD only) */
  77         unsigned int min_cmd_delay;     /* delay in uS after cmd-write (LCD only) */
  78         unsigned char reset_cmd1;       /* command #1 for writing LCD string (LCD only) */
  79         unsigned char reset_cmd2;       /* command #2 for writing LCD string (LCD only) */
  80         unsigned char act_enable;       /* 0 = no activity (LCD only) */
  81         struct lcd_block heartbeat;
  82         struct lcd_block disk_io;
  83         struct lcd_block lan_rcv;
  84         struct lcd_block lan_tx;
  85         char _pad;
  86 };
  87
  88
  89 /* LCD_CMD and LCD_DATA for KittyHawk machines */
  90 #define KITTYHAWK_LCD_CMD  (0xfffffffff0190000UL) /* 64bit-ready */
  91 #define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1)
  92
  93 /* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's
  94  * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
  95 static struct pdc_chassis_lcd_info_ret_block
  96 lcd_info __attribute__((aligned(8))) =
  97 {
  98         .model =                DISPLAY_MODEL_LCD,
  99         .lcd_width =            16,
 100         .lcd_cmd_reg_addr =     (char *) KITTYHAWK_LCD_CMD,
 101         .lcd_data_reg_addr =    (char *) KITTYHAWK_LCD_DATA,
 102         .min_cmd_delay =        40,
 103         .reset_cmd1 =           0x80,
 104         .reset_cmd2 =           0xc0,
 105 };
 106
 107
 108 /* direct access to some of the lcd_info variables */
 109 #define LCD_CMD_REG     lcd_info.lcd_cmd_reg_addr
 110 #define LCD_DATA_REG    lcd_info.lcd_data_reg_addr
 111 #define LED_DATA_REG    lcd_info.lcd_cmd_reg_addr       /* LASI & ASP only */
 112
 113
 114 /* ptr to LCD/LED-specific function */
 115 static void (*led_func_ptr) (unsigned char);
 116
 117 #define LED_HASLCD 1
 118 #define LED_NOLCD  0
 119 #ifdef CONFIG_PROC_FS
 120 static int led_proc_read(char *page, char **start, off_t off, int count,
 121         int *eof, void *data)
 122 {
 123         char *out = page;
 124         int len;
 125
 126         switch ((long)data)
 127         {
 128         case LED_NOLCD:
 129                 out += sprintf(out, "Heartbeat: %d\n", led_heartbeat);
 130                 out += sprintf(out, "Disk IO: %d\n", led_diskio);
 131                 out += sprintf(out, "LAN Rx/Tx: %d\n", led_lanrxtx);
 132                 break;
 133         case LED_HASLCD:
 134                 out += sprintf(out, "%s\n", lcd_text);
 135                 break;
 136         default:
 137                 *eof = 1;
 138                 return 0;
 139         }
 140
 141         len = out - page - off;
 142         if (len < count) {
 143                 *eof = 1;
 144                 if (len <= 0) return 0;
 145         } else {
 146                 len = count;
 147         }
 148         *start = page + off;
 149         return len;
 150 }
 151
 152 static int led_proc_write(struct file *file, const char *buf,
 153         unsigned long count, void *data)
 154 {
 155         char *cur, lbuf[count];
 156         int d;
 157
 158         if (!capable(CAP_SYS_ADMIN))
 159                 return -EACCES;
 160
 161         memset(lbuf, 0, count);
 162
 163         copy_from_user(lbuf, buf, count);
 164         cur = lbuf;
 165
 166         /* skip initial spaces */
 167         while (*cur && isspace(*cur))
 168         {
 169                 cur++;
 170         }
 171
 172         switch ((long)data)
 173         {
 174         case LED_NOLCD:
 175                 d = *cur++ - '0';
 176                 if (d != 0 && d != 1) goto parse_error;
 177                 led_heartbeat = d;
 178
 179                 if (*cur++ != ' ') goto parse_error;
 180
 181                 d = *cur++ - '0';
 182                 if (d != 0 && d != 1) goto parse_error;
 183                 led_diskio = d;
 184
 185                 if (*cur++ != ' ') goto parse_error;
 186
 187                 d = *cur++ - '0';
 188                 if (d != 0 && d != 1) goto parse_error;
 189                 led_lanrxtx = d;
 190
 191                 break;
 192         case LED_HASLCD:
 193                 if (*cur == 0)
 194                 {
 195                         /* reset to default */
 196                         lcd_print("Linux " UTS_RELEASE);
 197                 }
 198                 else
 199                 {
 200                         /* chop off trailing \n.. if the user gives multiple
 201                          * \n then it's all their fault.. */
 202                         if (*cur && cur[strlen(cur)-1] == '\n')
 203                                 cur[strlen(cur)-1] = 0;
 204                         lcd_print(cur);
 205                 }
 206                 break;
 207         default:
 208                 return 0;
 209         }
 210
 211         return count;
 212
 213 parse_error:
 214         if ((long)data == LED_NOLCD)
 215                 printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n");
 216         return -EINVAL;
 217 }
 218
 219 static int __init led_create_procfs(void)
 220 {
 221         struct proc_dir_entry *proc_pdc_root = NULL;
 222         struct proc_dir_entry *ent;
 223
 224         if (led_type == -1) return -1;
 225
 226         proc_pdc_root = proc_mkdir("pdc", 0);
 227         if (!proc_pdc_root) return -1;
 228         proc_pdc_root->owner = THIS_MODULE;
 229         ent = create_proc_entry("led", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
 230         if (!ent) return -1;
 231         ent->nlink = 1;
 232         ent->data = (void *)LED_NOLCD; /* LED */
 233         ent->read_proc = led_proc_read;
 234         ent->write_proc = led_proc_write;
 235         ent->owner = THIS_MODULE;
 236
 237         if (led_type == LED_HASLCD)
 238         {
 239                 ent = create_proc_entry("lcd", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
 240                 if (!ent) return -1;
 241                 ent->nlink = 1;
 242                 ent->data = (void *)LED_HASLCD; /* LCD */
 243                 ent->read_proc = led_proc_read;
 244                 ent->write_proc = led_proc_write;
 245                 ent->owner = THIS_MODULE;
 246         }
 247
 248         return 0;
 249 }
 250 #endif
 251
 252 /*
 253    **
 254    ** led_ASP_driver()
 255    **
 256  */
 257 #define LED_DATA        0x01    /* data to shift (0:on 1:off) */
 258 #define LED_STROBE      0x02    /* strobe to clock data */
 259 static void led_ASP_driver(unsigned char leds)
 260 {
 261         int i;
 262
 263         leds = ~leds;
 264         for (i = 0; i < 8; i++) {
 265                 unsigned char value;
 266                 value = (leds & 0x80) >> 7;
 267                 gsc_writeb( value,               LED_DATA_REG );
 268                 gsc_writeb( value | LED_STROBE,  LED_DATA_REG );
 269                 leds <<= 1;
 270         }
 271 }
 272
 273
 274 /*
 275    **
 276    ** led_LASI_driver()
 277    **
 278  */
 279 static void led_LASI_driver(unsigned char leds)
 280 {
 281         leds = ~leds;
 282         gsc_writeb( leds, LED_DATA_REG );
 283 }
 284
 285
 286 /*
 287    **
 288    ** led_LCD_driver()
 289    **
 290    ** The logic of the LCD driver is, that we write at every scheduled call
 291    ** only to one of LCD_CMD_REG _or_ LCD_DATA_REG - registers.
 292    ** That way we don't need to let this tasklet busywait for min_cmd_delay
 293    ** milliseconds.
 294    **
 295    ** TODO: check the value of "min_cmd_delay" against the value of HZ.
 296    **
 297  */
 298 static void led_LCD_driver(unsigned char leds)
 299 {
 300         static int last_index;  /* 0:heartbeat, 1:disk, 2:lan_in, 3:lan_out */
 301         static int last_was_cmd;/* 0: CMD was written last, 1: DATA was last */
 302         struct lcd_block *block_ptr;
 303         int value;
 304
 305         switch (last_index) {
 306             case 0:     block_ptr = &lcd_info.heartbeat;
 307                         value = leds & LED_HEARTBEAT;
 308                         break;
 309             case 1:     block_ptr = &lcd_info.disk_io;
 310                         value = leds & LED_DISK_IO;
 311                         break;
 312             case 2:     block_ptr = &lcd_info.lan_rcv;
 313                         value = leds & LED_LAN_RCV;
 314                         break;
 315             case 3:     block_ptr = &lcd_info.lan_tx;
 316                         value = leds & LED_LAN_TX;
 317                         break;
 318             default:    /* should never happen: */
 319                         return;
 320         }
 321
 322         if (last_was_cmd) {
 323             /* write the value to the LCD data port */
 324             gsc_writeb( value ? block_ptr->on : block_ptr->off, LCD_DATA_REG );
 325         } else {
 326             /* write the command-byte to the LCD command register */
 327             gsc_writeb( block_ptr->command, LCD_CMD_REG );
 328         }
 329
 330         /* now update the vars for the next interrupt iteration */
 331         if (++last_was_cmd == 2) { /* switch between cmd & data */
 332             last_was_cmd = 0;
 333             if (++last_index == 4)
 334                 last_index = 0;  /* switch back to heartbeat index */
 335         }
 336 }
 337
 338
 339 /*
 340    **
 341    ** led_get_net_activity()
 342    **
 343    ** calculate if there was TX- or RX-troughput on the network interfaces
 344    ** (analog to dev_get_info() from net/core/dev.c)
 345    **
 346  */
 347 static __inline__ int led_get_net_activity(void)
 348 {
 349 #ifndef CONFIG_NET
 350         return 0;
 351 #else
 352         static unsigned long rx_total_last, tx_total_last;
 353         unsigned long rx_total, tx_total;
 354         struct net_device *dev;
 355         int retval;
 356
 357         rx_total = tx_total = 0;
 358
 359         /* we are running as tasklet, so locking dev_base
 360          * for reading should be OK */
 361         read_lock(&dev_base_lock);
 362         for (dev = dev_base; dev; dev = dev->next) {
 363             struct net_device_stats *stats;
 364             struct in_device *in_dev = __in_dev_get(dev);
 365             if (!in_dev || !in_dev->ifa_list)
 366                 continue;
 367             if (LOOPBACK(in_dev->ifa_list->ifa_local))
 368                 continue;
 369             if (!dev->get_stats)
 370                 continue;
 371             stats = dev->get_stats(dev);
 372             rx_total += stats->rx_packets;
 373             tx_total += stats->tx_packets;
 374         }
 375         read_unlock(&dev_base_lock);
 376
 377         retval = 0;
 378
 379         if (rx_total != rx_total_last) {
 380                 rx_total_last = rx_total;
 381                 retval |= LED_LAN_RCV;
 382         }
 383
 384         if (tx_total != tx_total_last) {
 385                 tx_total_last = tx_total;
 386                 retval |= LED_LAN_TX;
 387         }
 388
 389         return retval;
 390 #endif
 391 }
 392
 393
 394 /*
 395    **
 396    ** led_get_diskio_activity()
 397    **
 398    ** calculate if there was disk-io in the system
 399    **
 400  */
 401 static __inline__ int led_get_diskio_activity(void)
 402 {
 403         static unsigned long last_pgpgin, last_pgpgout;
 404         struct page_state pgstat;
 405         int changed;
 406
 407         get_full_page_state(&pgstat); /* get no of sectors in & out */
 408
 409         /* Just use a very simple calculation here. Do not care about overflow,
 410            since we only want to know if there was activity or not. */
 411         changed = (pgstat.pgpgin != last_pgpgin) || (pgstat.pgpgout != last_pgpgout);
 412         last_pgpgin  = pgstat.pgpgin;
 413         last_pgpgout = pgstat.pgpgout;
 414
 415         return (changed ? LED_DISK_IO : 0);
 416 }
 417
 418
 419
 420 /*
 421    ** led_tasklet_func()
 422    **
 423    ** is scheduled at every timer interrupt from time.c and
 424    ** updates the chassis LCD/LED
 425
 426     TODO:
 427     - display load average (older machines like 715/64 have 4 "free" LED's for that)
 428     - optimizations
 429  */
 430
 431 #define HEARTBEAT_LEN (HZ*6/100)
 432 #define HEARTBEAT_2ND_RANGE_START (HZ*22/100)
 433 #define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
 434
 435 #if HZ==100
 436  #define NORMALIZED_COUNT(count) (count)
 437 #else
 438  #warning "Untested situation HZ != 100 !!"
 439  #define NORMALIZED_COUNT(count) (count/(HZ/100))
 440 #endif
 441
 442 static void led_tasklet_func(unsigned long unused)
 443 {
 444         static unsigned char lastleds;
 445         unsigned char currentleds; /* stores current value of the LEDs */
 446         static unsigned long count; /* static incremented value, not wrapped */
 447         static unsigned long count_HZ; /* counter in range 0..HZ */
 448
 449         /* exit if not initialized */
 450         if (!led_func_ptr)
 451             return;
 452
 453         /* increment the local counters */
 454         ++count;
 455         if (++count_HZ == HZ)
 456             count_HZ = 0;
 457
 458         currentleds = lastleds;
 459
 460         if (led_heartbeat)
 461         {
 462                 /* flash heartbeat-LED like a real heart (2 x short then a long delay) */
 463                 if (count_HZ<HEARTBEAT_LEN ||
 464                     (count_HZ>=HEARTBEAT_2ND_RANGE_START && count_HZ<HEARTBEAT_2ND_RANGE_END))
 465                     currentleds |= LED_HEARTBEAT;
 466                 else
 467                     currentleds &= ~LED_HEARTBEAT;
 468         }
 469
 470         /* look for network activity and flash LEDs respectively */
 471         if (led_lanrxtx && ((NORMALIZED_COUNT(count)+(8/2)) & 7) == 0)
 472         {
 473                 currentleds &= ~(LED_LAN_RCV | LED_LAN_TX);
 474                 currentleds |= led_get_net_activity();
 475         }
 476
 477         /* avoid to calculate diskio-stats at same irq  as netio-stats */
 478         if (led_diskio && (NORMALIZED_COUNT(count) & 7) == 0)
 479         {
 480                 currentleds &= ~LED_DISK_IO;
 481                 currentleds |= led_get_diskio_activity();
 482         }
 483
 484         /* blink all LEDs twice a second if we got an Oops (HPMC) */
 485         if (oops_in_progress) {
 486                 currentleds = (count_HZ<=(HZ/2)) ? 0 : 0xff;
 487         }
 488
 489         /* update the LCD/LEDs */
 490         if (currentleds != lastleds) {
 491             led_func_ptr(currentleds);
 492             lastleds = currentleds;
 493         }
 494 }
 495
 496 /* main led tasklet struct (scheduled from time.c) */
 497 DECLARE_TASKLET_DISABLED(led_tasklet, led_tasklet_func, 0);
 498
 499
 500 /*
 501    ** led_halt()
 502    **
 503    ** called by the reboot notifier chain at shutdown and stops all
 504    ** LED/LCD activities.
 505    **
 506  */
 507
 508 static int led_halt(struct notifier_block *, unsigned long, void *);
 509
 510 static struct notifier_block led_notifier = {
 511         .notifier_call = led_halt,
 512 };
 513
 514 static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
 515 {
 516         char *txt;
 517
 518         switch (event) {
 519         case SYS_RESTART:       txt = "SYSTEM RESTART";
 520                                 break;
 521         case SYS_HALT:          txt = "SYSTEM HALT";
 522                                 break;
 523         case SYS_POWER_OFF:     txt = "SYSTEM POWER OFF";
 524                                 break;
 525         default:                return NOTIFY_DONE;
 526         }
 527
 528         /* completely stop the LED/LCD tasklet */
 529         tasklet_disable(&led_tasklet);
 530
 531         if (lcd_info.model == DISPLAY_MODEL_LCD)
 532                 lcd_print(txt);
 533         else
 534                 if (led_func_ptr)
 535                         led_func_ptr(0xff); /* turn all LEDs ON */
 536
 537         unregister_reboot_notifier(&led_notifier);
 538         return NOTIFY_OK;
 539 }
 540
 541 /*
 542    ** register_led_driver()
 543    **
 544    ** registers an external LED or LCD for usage by this driver.
 545    ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
 546    **
 547  */
 548
 549 int __init register_led_driver(int model, char *cmd_reg, char *data_reg)
 550 {
 551         static int initialized;
 552
 553         if (initialized || !data_reg)
 554             return 1;
 555
 556         lcd_info.model = model;         /* store the values */
 557         LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? NULL : cmd_reg;
 558
 559         switch (lcd_info.model) {
 560         case DISPLAY_MODEL_LCD:
 561                 LCD_DATA_REG = data_reg;
 562                 printk(KERN_INFO "LCD display at %p,%p registered\n",
 563                         LCD_CMD_REG , LCD_DATA_REG);
 564                 led_func_ptr = led_LCD_driver;
 565                 lcd_print( "Linux " UTS_RELEASE );
 566                 led_type = LED_HASLCD;
 567                 break;
 568
 569         case DISPLAY_MODEL_LASI:
 570                 LED_DATA_REG = data_reg;
 571                 led_func_ptr = led_LASI_driver;
 572                 printk(KERN_INFO "LED display at %p registered\n", LED_DATA_REG);
 573                 led_type = LED_NOLCD;
 574                 break;
 575
 576         case DISPLAY_MODEL_OLD_ASP:
 577                 LED_DATA_REG = data_reg;
 578                 led_func_ptr = led_ASP_driver;
 579                 printk(KERN_INFO "LED (ASP-style) display at %p registered\n",
 580                     LED_DATA_REG);
 581                 led_type = LED_NOLCD;
 582                 break;
 583
 584         default:
 585                 printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
 586                        __FUNCTION__, lcd_info.model);
 587                 return 1;
 588         }
 589
 590         /* mark the LCD/LED driver now as initialized and
 591          * register to the reboot notifier chain */
 592         initialized++;
 593         register_reboot_notifier(&led_notifier);
 594
 595         /* start the led tasklet for the first time */
 596         tasklet_enable(&led_tasklet);
 597
 598         return 0;
 599 }
 600
 601 /*
 602    ** register_led_regions()
 603    **
 604    ** register_led_regions() registers the LCD/LED regions for /procfs.
 605    ** At bootup - where the initialisation of the LCD/LED normally happens -
 606    ** not all internal structures of request_region() are properly set up,
 607    ** so that we delay the led-registration until after busdevices_init()
 608    ** has been executed.
 609    **
 610  */
 611
 612 void __init register_led_regions(void)
 613 {
 614         switch (lcd_info.model) {
 615         case DISPLAY_MODEL_LCD:
 616                 request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
 617                 request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
 618                 break;
 619         case DISPLAY_MODEL_LASI:
 620         case DISPLAY_MODEL_OLD_ASP:
 621                 request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
 622                 break;
 623         }
 624 }
 625
 626
 627 /*
 628    **
 629    ** lcd_print()
 630    **
 631    ** Displays the given string on the LCD-Display of newer machines.
 632    ** lcd_print() disables the timer-based led tasklet during its
 633    ** execution and enables it afterwards again.
 634    **
 635  */
 636 int lcd_print( char *str )
 637 {
 638         int i;
 639
 640         if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
 641             return 0;
 642
 643         /* temporarily disable the led tasklet */
 644         tasklet_disable(&led_tasklet);
 645
 646         /* copy display string to buffer for procfs */
 647         strlcpy(lcd_text, str, sizeof(lcd_text));
 648
 649         /* Set LCD Cursor to 1st character */
 650         gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
 651         udelay(lcd_info.min_cmd_delay);
 652
 653         /* Print the string */
 654         for (i=0; i < lcd_info.lcd_width; i++) {
 655             if (str && *str)
 656                 gsc_writeb(*str++, LCD_DATA_REG);
 657             else
 658                 gsc_writeb(' ', LCD_DATA_REG);
 659             udelay(lcd_info.min_cmd_delay);
 660         }
 661
 662         /* re-enable the led tasklet */
 663         tasklet_enable(&led_tasklet);
 664
 665         return lcd_info.lcd_width;
 666 }
 667
 668 /*
 669    ** led_init()
 670    **
 671    ** led_init() is called very early in the bootup-process from setup.c
 672    ** and asks the PDC for an usable chassis LCD or LED.
 673    ** If the PDC doesn't return any info, then the LED
 674    ** is detected by lasi.c or asp.c and registered with the
 675    ** above functions lasi_led_init() or asp_led_init().
 676    ** KittyHawk machines have often a buggy PDC, so that
 677    ** we explicitly check for those machines here.
 678  */
 679
 680 int __init led_init(void)
 681 {
 682         struct pdc_chassis_info chassis_info;
 683         int ret;
 684
 685         /* Work around the buggy PDC of KittyHawk-machines */
 686         switch (CPU_HVERSION) {
 687         case 0x580:             /* KittyHawk DC2-100 (K100) */
 688         case 0x581:             /* KittyHawk DC3-120 (K210) */
 689         case 0x582:             /* KittyHawk DC3 100 (K400) */
 690         case 0x583:             /* KittyHawk DC3 120 (K410) */
 691         case 0x58B:             /* KittyHawk DC2 100 (K200) */
 692                 printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
 693                                 "LED detection skipped.\n", __FILE__, CPU_HVERSION);
 694                 goto found;     /* use the preinitialized values of lcd_info */
 695         }
 696
 697         /* initialize the struct, so that we can check for valid return values */
 698         lcd_info.model = DISPLAY_MODEL_NONE;
 699         chassis_info.actcnt = chassis_info.maxcnt = 0;
 700
 701         if ((ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info))) == PDC_OK) {
 702                 DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
 703                          "lcd_width=%d, cmd_delay=%u,\n"
 704                          "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
 705                          __FILE__, lcd_info.model,
 706                          (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
 707                           (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
 708                          lcd_info.lcd_width, lcd_info.min_cmd_delay,
 709                          __FILE__, sizeof(lcd_info),
 710                          chassis_info.actcnt, chassis_info.maxcnt));
 711                 DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
 712                         __FILE__, lcd_info.lcd_cmd_reg_addr,
 713                         lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
 714                         lcd_info.reset_cmd2, lcd_info.act_enable ));
 715
 716                 /* check the results. Some machines have a buggy PDC */
 717                 if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
 718                         goto not_found;
 719
 720                 switch (lcd_info.model) {
 721                 case DISPLAY_MODEL_LCD:         /* LCD display */
 722                         if (chassis_info.actcnt <
 723                                 offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
 724                                 goto not_found;
 725                         if (!lcd_info.act_enable) {
 726                                 DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
 727                                 goto not_found;
 728                         }
 729                         break;
 730
 731                 case DISPLAY_MODEL_NONE:        /* no LED or LCD available */
 732                         printk(KERN_INFO "PDC reported no LCD or LED.\n");
 733                         goto not_found;
 734
 735                 case DISPLAY_MODEL_LASI:        /* Lasi style 8 bit LED display */
 736                         if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
 737                                 goto not_found;
 738                         break;
 739
 740                 default:
 741                         printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
 742                                lcd_info.model);
 743                         goto not_found;
 744                 } /* switch() */
 745
 746 found:
 747                 /* register the LCD/LED driver */
 748                 register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
 749                 return 0;
 750
 751         } else { /* if() */
 752                 DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
 753         }
 754
 755 not_found:
 756         lcd_info.model = DISPLAY_MODEL_NONE;
 757         return 1;
 758 }
 759
 760 #ifdef CONFIG_PROC_FS
 761 module_init(led_create_procfs)
 762 #endif