linux/drivers/parisc/led.c
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   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 2001-2005 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 * Changes:
  19 *      - Audit copy_from_user in led_proc_write.
  20 *                                Daniele Bellucci <bellucda@tiscali.it>
  21 *      - Switch from using a tasklet to a work queue, so the led_LCD_driver
  22 *              can sleep.
  23 *                                David Pye <dmp@davidmpye.dyndns.org>
  24 */
  25
  26#include <linux/module.h>
  27#include <linux/stddef.h>       /* for offsetof() */
  28#include <linux/init.h>
  29#include <linux/types.h>
  30#include <linux/ioport.h>
  31#include <linux/utsname.h>
  32#include <linux/capability.h>
  33#include <linux/delay.h>
  34#include <linux/netdevice.h>
  35#include <linux/inetdevice.h>
  36#include <linux/in.h>
  37#include <linux/interrupt.h>
  38#include <linux/kernel_stat.h>
  39#include <linux/reboot.h>
  40#include <linux/proc_fs.h>
  41#include <linux/ctype.h>
  42#include <linux/blkdev.h>
  43#include <linux/workqueue.h>
  44#include <linux/rcupdate.h>
  45#include <asm/io.h>
  46#include <asm/processor.h>
  47#include <asm/hardware.h>
  48#include <asm/param.h>          /* HZ */
  49#include <asm/led.h>
  50#include <asm/pdc.h>
  51#include <asm/uaccess.h>
  52
  53/* The control of the LEDs and LCDs on PARISC-machines have to be done 
  54   completely in software. The necessary calculations are done in a work queue
  55   task which is scheduled regularly, and since the calculations may consume a 
  56   relatively large amount of CPU time, some of the calculations can be 
  57   turned off with the following variables (controlled via procfs) */
  58
  59static int led_type __read_mostly = -1;
  60static unsigned char lastleds;  /* LED state from most recent update */
  61static unsigned int led_heartbeat __read_mostly = 1;
  62static unsigned int led_diskio    __read_mostly = 1;
  63static unsigned int led_lanrxtx   __read_mostly = 1;
  64static char lcd_text[32]          __read_mostly;
  65static char lcd_text_default[32]  __read_mostly;
  66
  67
  68static struct workqueue_struct *led_wq;
  69static void led_work_func(struct work_struct *);
  70static DECLARE_DELAYED_WORK(led_task, led_work_func);
  71
  72#if 0
  73#define DPRINTK(x)      printk x
  74#else
  75#define DPRINTK(x)
  76#endif
  77
  78struct lcd_block {
  79        unsigned char command;  /* stores the command byte      */
  80        unsigned char on;       /* value for turning LED on     */
  81        unsigned char off;      /* value for turning LED off    */
  82};
  83
  84/* Structure returned by PDC_RETURN_CHASSIS_INFO */
  85/* NOTE: we use unsigned long:16 two times, since the following member 
  86   lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */
  87struct pdc_chassis_lcd_info_ret_block {
  88        unsigned long model:16;         /* DISPLAY_MODEL_XXXX */
  89        unsigned long lcd_width:16;     /* width of the LCD in chars (DISPLAY_MODEL_LCD only) */
  90        unsigned long lcd_cmd_reg_addr; /* ptr to LCD cmd-register & data ptr for LED */
  91        unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */
  92        unsigned int min_cmd_delay;     /* delay in uS after cmd-write (LCD only) */
  93        unsigned char reset_cmd1;       /* command #1 for writing LCD string (LCD only) */
  94        unsigned char reset_cmd2;       /* command #2 for writing LCD string (LCD only) */
  95        unsigned char act_enable;       /* 0 = no activity (LCD only) */
  96        struct lcd_block heartbeat;
  97        struct lcd_block disk_io;
  98        struct lcd_block lan_rcv;
  99        struct lcd_block lan_tx;
 100        char _pad;
 101};
 102
 103
 104/* LCD_CMD and LCD_DATA for KittyHawk machines */
 105#define KITTYHAWK_LCD_CMD  F_EXTEND(0xf0190000UL) /* 64bit-ready */
 106#define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1)
 107
 108/* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's 
 109 * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
 110static struct pdc_chassis_lcd_info_ret_block
 111lcd_info __attribute__((aligned(8))) __read_mostly =
 112{
 113        .model =                DISPLAY_MODEL_LCD,
 114        .lcd_width =            16,
 115        .lcd_cmd_reg_addr =     KITTYHAWK_LCD_CMD,
 116        .lcd_data_reg_addr =    KITTYHAWK_LCD_DATA,
 117        .min_cmd_delay =        40,
 118        .reset_cmd1 =           0x80,
 119        .reset_cmd2 =           0xc0,
 120};
 121
 122
 123/* direct access to some of the lcd_info variables */
 124#define LCD_CMD_REG     lcd_info.lcd_cmd_reg_addr        
 125#define LCD_DATA_REG    lcd_info.lcd_data_reg_addr       
 126#define LED_DATA_REG    lcd_info.lcd_cmd_reg_addr       /* LASI & ASP only */
 127
 128#define LED_HASLCD 1
 129#define LED_NOLCD  0
 130
 131/* The workqueue must be created at init-time */
 132static int start_task(void) 
 133{       
 134        /* Display the default text now */
 135        if (led_type == LED_HASLCD) lcd_print( lcd_text_default );
 136
 137        /* Create the work queue and queue the LED task */
 138        led_wq = create_singlethread_workqueue("led_wq");       
 139        queue_delayed_work(led_wq, &led_task, 0);
 140
 141        return 0;
 142}
 143
 144device_initcall(start_task);
 145
 146/* ptr to LCD/LED-specific function */
 147static void (*led_func_ptr) (unsigned char) __read_mostly;
 148
 149#ifdef CONFIG_PROC_FS
 150static int led_proc_read(char *page, char **start, off_t off, int count, 
 151        int *eof, void *data)
 152{
 153        char *out = page;
 154        int len;
 155
 156        switch ((long)data)
 157        {
 158        case LED_NOLCD:
 159                out += sprintf(out, "Heartbeat: %d\n", led_heartbeat);
 160                out += sprintf(out, "Disk IO: %d\n", led_diskio);
 161                out += sprintf(out, "LAN Rx/Tx: %d\n", led_lanrxtx);
 162                break;
 163        case LED_HASLCD:
 164                out += sprintf(out, "%s\n", lcd_text);
 165                break;
 166        default:
 167                *eof = 1;
 168                return 0;
 169        }
 170
 171        len = out - page - off;
 172        if (len < count) {
 173                *eof = 1;
 174                if (len <= 0) return 0;
 175        } else {
 176                len = count;
 177        }
 178        *start = page + off;
 179        return len;
 180}
 181
 182static int led_proc_write(struct file *file, const char *buf, 
 183        unsigned long count, void *data)
 184{
 185        char *cur, lbuf[count + 1];
 186        int d;
 187
 188        if (!capable(CAP_SYS_ADMIN))
 189                return -EACCES;
 190
 191        memset(lbuf, 0, count + 1);
 192
 193        if (copy_from_user(lbuf, buf, count))
 194                return -EFAULT;
 195
 196        cur = lbuf;
 197
 198        switch ((long)data)
 199        {
 200        case LED_NOLCD:
 201                d = *cur++ - '0';
 202                if (d != 0 && d != 1) goto parse_error;
 203                led_heartbeat = d;
 204
 205                if (*cur++ != ' ') goto parse_error;
 206
 207                d = *cur++ - '0';
 208                if (d != 0 && d != 1) goto parse_error;
 209                led_diskio = d;
 210
 211                if (*cur++ != ' ') goto parse_error;
 212
 213                d = *cur++ - '0';
 214                if (d != 0 && d != 1) goto parse_error;
 215                led_lanrxtx = d;
 216
 217                break;
 218        case LED_HASLCD:
 219                if (*cur && cur[strlen(cur)-1] == '\n')
 220                        cur[strlen(cur)-1] = 0;
 221                if (*cur == 0) 
 222                        cur = lcd_text_default;
 223                lcd_print(cur);
 224                break;
 225        default:
 226                return 0;
 227        }
 228        
 229        return count;
 230
 231parse_error:
 232        if ((long)data == LED_NOLCD)
 233                printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n");
 234        return -EINVAL;
 235}
 236
 237static int __init led_create_procfs(void)
 238{
 239        struct proc_dir_entry *proc_pdc_root = NULL;
 240        struct proc_dir_entry *ent;
 241
 242        if (led_type == -1) return -1;
 243
 244        proc_pdc_root = proc_mkdir("pdc", 0);
 245        if (!proc_pdc_root) return -1;
 246        proc_pdc_root->owner = THIS_MODULE;
 247        ent = create_proc_entry("led", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
 248        if (!ent) return -1;
 249        ent->data = (void *)LED_NOLCD; /* LED */
 250        ent->read_proc = led_proc_read;
 251        ent->write_proc = led_proc_write;
 252        ent->owner = THIS_MODULE;
 253
 254        if (led_type == LED_HASLCD)
 255        {
 256                ent = create_proc_entry("lcd", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
 257                if (!ent) return -1;
 258                ent->data = (void *)LED_HASLCD; /* LCD */
 259                ent->read_proc = led_proc_read;
 260                ent->write_proc = led_proc_write;
 261                ent->owner = THIS_MODULE;
 262        }
 263
 264        return 0;
 265}
 266#endif
 267
 268/*
 269   ** 
 270   ** led_ASP_driver()
 271   ** 
 272 */
 273#define LED_DATA        0x01    /* data to shift (0:on 1:off) */
 274#define LED_STROBE      0x02    /* strobe to clock data */
 275static void led_ASP_driver(unsigned char leds)
 276{
 277        int i;
 278
 279        leds = ~leds;
 280        for (i = 0; i < 8; i++) {
 281                unsigned char value;
 282                value = (leds & 0x80) >> 7;
 283                gsc_writeb( value,               LED_DATA_REG );
 284                gsc_writeb( value | LED_STROBE,  LED_DATA_REG );
 285                leds <<= 1;
 286        }
 287}
 288
 289
 290/*
 291   ** 
 292   ** led_LASI_driver()
 293   ** 
 294 */
 295static void led_LASI_driver(unsigned char leds)
 296{
 297        leds = ~leds;
 298        gsc_writeb( leds, LED_DATA_REG );
 299}
 300
 301
 302/*
 303   ** 
 304   ** led_LCD_driver()
 305   **   
 306 */
 307static void led_LCD_driver(unsigned char leds)
 308{
 309        static int i;
 310        static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
 311                LED_LAN_RCV, LED_LAN_TX };
 312        
 313        static struct lcd_block * blockp[4] = {
 314                &lcd_info.heartbeat,
 315                &lcd_info.disk_io,
 316                &lcd_info.lan_rcv,
 317                &lcd_info.lan_tx
 318        };
 319
 320        /* Convert min_cmd_delay to milliseconds */
 321        unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000);
 322        
 323        for (i=0; i<4; ++i) 
 324        {
 325                if ((leds & mask[i]) != (lastleds & mask[i])) 
 326                {
 327                        gsc_writeb( blockp[i]->command, LCD_CMD_REG );
 328                        msleep(msec_cmd_delay);
 329                        
 330                        gsc_writeb( leds & mask[i] ? blockp[i]->on : 
 331                                        blockp[i]->off, LCD_DATA_REG );
 332                        msleep(msec_cmd_delay);
 333                }
 334        }
 335}
 336
 337
 338/*
 339   ** 
 340   ** led_get_net_activity()
 341   ** 
 342   ** calculate if there was TX- or RX-throughput on the network interfaces
 343   ** (analog to dev_get_info() from net/core/dev.c)
 344   **   
 345 */
 346static __inline__ int led_get_net_activity(void)
 347{ 
 348#ifndef CONFIG_NET
 349        return 0;
 350#else
 351        static unsigned long rx_total_last, tx_total_last;
 352        unsigned long rx_total, tx_total;
 353        struct net_device *dev;
 354        int retval;
 355
 356        rx_total = tx_total = 0;
 357        
 358        /* we are running as a workqueue task, so locking dev_base 
 359         * for reading should be OK */
 360        read_lock(&dev_base_lock);
 361        rcu_read_lock();
 362        for_each_netdev(&init_net, dev) {
 363            struct net_device_stats *stats;
 364            struct in_device *in_dev = __in_dev_get_rcu(dev);
 365            if (!in_dev || !in_dev->ifa_list)
 366                continue;
 367            if (ipv4_is_loopback(in_dev->ifa_list->ifa_local))
 368                continue;
 369            stats = dev->get_stats(dev);
 370            rx_total += stats->rx_packets;
 371            tx_total += stats->tx_packets;
 372        }
 373        rcu_read_unlock();
 374        read_unlock(&dev_base_lock);
 375
 376        retval = 0;
 377
 378        if (rx_total != rx_total_last) {
 379                rx_total_last = rx_total;
 380                retval |= LED_LAN_RCV;
 381        }
 382
 383        if (tx_total != tx_total_last) {
 384                tx_total_last = tx_total;
 385                retval |= LED_LAN_TX;
 386        }
 387
 388        return retval;
 389#endif
 390}
 391
 392
 393/*
 394   ** 
 395   ** led_get_diskio_activity()
 396   ** 
 397   ** calculate if there was disk-io in the system
 398   **   
 399 */
 400static __inline__ int led_get_diskio_activity(void)
 401{       
 402        static unsigned long last_pgpgin, last_pgpgout;
 403        unsigned long events[NR_VM_EVENT_ITEMS];
 404        int changed;
 405
 406        all_vm_events(events);
 407
 408        /* Just use a very simple calculation here. Do not care about overflow,
 409           since we only want to know if there was activity or not. */
 410        changed = (events[PGPGIN] != last_pgpgin) ||
 411                  (events[PGPGOUT] != last_pgpgout);
 412        last_pgpgin  = events[PGPGIN];
 413        last_pgpgout = events[PGPGOUT];
 414
 415        return (changed ? LED_DISK_IO : 0);
 416}
 417
 418
 419
 420/*
 421   ** led_work_func()
 422   ** 
 423   ** manages when and which chassis LCD/LED gets updated
 424
 425    TODO:
 426    - display load average (older machines like 715/64 have 4 "free" LED's for that)
 427    - optimizations
 428 */
 429
 430#define HEARTBEAT_LEN (HZ*10/100)
 431#define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
 432#define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
 433
 434#define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
 435
 436static void led_work_func (struct work_struct *unused)
 437{
 438        static unsigned long last_jiffies;
 439        static unsigned long count_HZ; /* counter in range 0..HZ */
 440        unsigned char currentleds = 0; /* stores current value of the LEDs */
 441
 442        /* exit if not initialized */
 443        if (!led_func_ptr)
 444            return;
 445
 446        /* increment the heartbeat timekeeper */
 447        count_HZ += jiffies - last_jiffies;
 448        last_jiffies = jiffies;
 449        if (count_HZ >= HZ)
 450            count_HZ = 0;
 451
 452        if (likely(led_heartbeat))
 453        {
 454                /* flash heartbeat-LED like a real heart
 455                 * (2 x short then a long delay)
 456                 */
 457                if (count_HZ < HEARTBEAT_LEN || 
 458                                (count_HZ >= HEARTBEAT_2ND_RANGE_START &&
 459                                count_HZ < HEARTBEAT_2ND_RANGE_END)) 
 460                        currentleds |= LED_HEARTBEAT;
 461        }
 462
 463        if (likely(led_lanrxtx))  currentleds |= led_get_net_activity();
 464        if (likely(led_diskio))   currentleds |= led_get_diskio_activity();
 465
 466        /* blink all LEDs twice a second if we got an Oops (HPMC) */
 467        if (unlikely(oops_in_progress)) 
 468                currentleds = (count_HZ<=(HZ/2)) ? 0 : 0xff;
 469
 470        if (currentleds != lastleds)
 471        {
 472                led_func_ptr(currentleds);      /* Update the LCD/LEDs */
 473                lastleds = currentleds;
 474        }
 475
 476        queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
 477}
 478
 479/*
 480   ** led_halt()
 481   ** 
 482   ** called by the reboot notifier chain at shutdown and stops all
 483   ** LED/LCD activities.
 484   ** 
 485 */
 486
 487static int led_halt(struct notifier_block *, unsigned long, void *);
 488
 489static struct notifier_block led_notifier = {
 490        .notifier_call = led_halt,
 491};
 492static int notifier_disabled = 0;
 493
 494static int led_halt(struct notifier_block *nb, unsigned long event, void *buf) 
 495{
 496        char *txt;
 497
 498        if (notifier_disabled)
 499                return NOTIFY_OK;
 500
 501        notifier_disabled = 1;
 502        switch (event) {
 503        case SYS_RESTART:       txt = "SYSTEM RESTART";
 504                                break;
 505        case SYS_HALT:          txt = "SYSTEM HALT";
 506                                break;
 507        case SYS_POWER_OFF:     txt = "SYSTEM POWER OFF";
 508                                break;
 509        default:                return NOTIFY_DONE;
 510        }
 511        
 512        /* Cancel the work item and delete the queue */
 513        if (led_wq) {
 514                cancel_rearming_delayed_workqueue(led_wq, &led_task);
 515                destroy_workqueue(led_wq);
 516                led_wq = NULL;
 517        }
 518 
 519        if (lcd_info.model == DISPLAY_MODEL_LCD)
 520                lcd_print(txt);
 521        else
 522                if (led_func_ptr)
 523                        led_func_ptr(0xff); /* turn all LEDs ON */
 524        
 525        return NOTIFY_OK;
 526}
 527
 528/*
 529   ** register_led_driver()
 530   ** 
 531   ** registers an external LED or LCD for usage by this driver.
 532   ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
 533   ** 
 534 */
 535
 536int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
 537{
 538        static int initialized;
 539        
 540        if (initialized || !data_reg)
 541                return 1;
 542        
 543        lcd_info.model = model;         /* store the values */
 544        LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
 545
 546        switch (lcd_info.model) {
 547        case DISPLAY_MODEL_LCD:
 548                LCD_DATA_REG = data_reg;
 549                printk(KERN_INFO "LCD display at %lx,%lx registered\n", 
 550                        LCD_CMD_REG , LCD_DATA_REG);
 551                led_func_ptr = led_LCD_driver;
 552                led_type = LED_HASLCD;
 553                break;
 554
 555        case DISPLAY_MODEL_LASI:
 556                LED_DATA_REG = data_reg;
 557                led_func_ptr = led_LASI_driver;
 558                printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
 559                led_type = LED_NOLCD;
 560                break;
 561
 562        case DISPLAY_MODEL_OLD_ASP:
 563                LED_DATA_REG = data_reg;
 564                led_func_ptr = led_ASP_driver;
 565                printk(KERN_INFO "LED (ASP-style) display at %lx registered\n", 
 566                    LED_DATA_REG);
 567                led_type = LED_NOLCD;
 568                break;
 569
 570        default:
 571                printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
 572                       __func__, lcd_info.model);
 573                return 1;
 574        }
 575        
 576        /* mark the LCD/LED driver now as initialized and 
 577         * register to the reboot notifier chain */
 578        initialized++;
 579        register_reboot_notifier(&led_notifier);
 580
 581        /* Ensure the work is queued */
 582        if (led_wq) {
 583                queue_delayed_work(led_wq, &led_task, 0);
 584        }
 585
 586        return 0;
 587}
 588
 589/*
 590   ** register_led_regions()
 591   ** 
 592   ** register_led_regions() registers the LCD/LED regions for /procfs.
 593   ** At bootup - where the initialisation of the LCD/LED normally happens - 
 594   ** not all internal structures of request_region() are properly set up,
 595   ** so that we delay the led-registration until after busdevices_init() 
 596   ** has been executed.
 597   **
 598 */
 599
 600void __init register_led_regions(void)
 601{
 602        switch (lcd_info.model) {
 603        case DISPLAY_MODEL_LCD:
 604                request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
 605                request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
 606                break;
 607        case DISPLAY_MODEL_LASI:
 608        case DISPLAY_MODEL_OLD_ASP:
 609                request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
 610                break;
 611        }
 612}
 613
 614
 615/*
 616   ** 
 617   ** lcd_print()
 618   ** 
 619   ** Displays the given string on the LCD-Display of newer machines.
 620   ** lcd_print() disables/enables the timer-based led work queue to
 621   ** avoid a race condition while writing the CMD/DATA register pair.
 622   **
 623 */
 624int lcd_print( const char *str )
 625{
 626        int i;
 627
 628        if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
 629            return 0;
 630        
 631        /* temporarily disable the led work task */
 632        if (led_wq)
 633                cancel_rearming_delayed_workqueue(led_wq, &led_task);
 634
 635        /* copy display string to buffer for procfs */
 636        strlcpy(lcd_text, str, sizeof(lcd_text));
 637
 638        /* Set LCD Cursor to 1st character */
 639        gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
 640        udelay(lcd_info.min_cmd_delay);
 641
 642        /* Print the string */
 643        for (i=0; i < lcd_info.lcd_width; i++) {
 644            if (str && *str)
 645                gsc_writeb(*str++, LCD_DATA_REG);
 646            else
 647                gsc_writeb(' ', LCD_DATA_REG);
 648            udelay(lcd_info.min_cmd_delay);
 649        }
 650        
 651        /* re-queue the work */
 652        if (led_wq) {
 653                queue_delayed_work(led_wq, &led_task, 0);
 654        }
 655
 656        return lcd_info.lcd_width;
 657}
 658
 659/*
 660   ** led_init()
 661   ** 
 662   ** led_init() is called very early in the bootup-process from setup.c 
 663   ** and asks the PDC for an usable chassis LCD or LED.
 664   ** If the PDC doesn't return any info, then the LED
 665   ** is detected by lasi.c or asp.c and registered with the
 666   ** above functions lasi_led_init() or asp_led_init().
 667   ** KittyHawk machines have often a buggy PDC, so that
 668   ** we explicitly check for those machines here.
 669 */
 670
 671int __init led_init(void)
 672{
 673        struct pdc_chassis_info chassis_info;
 674        int ret;
 675
 676        snprintf(lcd_text_default, sizeof(lcd_text_default),
 677                "Linux %s", init_utsname()->release);
 678
 679        /* Work around the buggy PDC of KittyHawk-machines */
 680        switch (CPU_HVERSION) {
 681        case 0x580:             /* KittyHawk DC2-100 (K100) */
 682        case 0x581:             /* KittyHawk DC3-120 (K210) */
 683        case 0x582:             /* KittyHawk DC3 100 (K400) */
 684        case 0x583:             /* KittyHawk DC3 120 (K410) */
 685        case 0x58B:             /* KittyHawk DC2 100 (K200) */
 686                printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
 687                                "LED detection skipped.\n", __FILE__, CPU_HVERSION);
 688                goto found;     /* use the preinitialized values of lcd_info */
 689        }
 690
 691        /* initialize the struct, so that we can check for valid return values */
 692        lcd_info.model = DISPLAY_MODEL_NONE;
 693        chassis_info.actcnt = chassis_info.maxcnt = 0;
 694
 695        ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
 696        if (ret == PDC_OK) {
 697                DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
 698                         "lcd_width=%d, cmd_delay=%u,\n"
 699                         "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
 700                         __FILE__, lcd_info.model,
 701                         (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
 702                          (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
 703                         lcd_info.lcd_width, lcd_info.min_cmd_delay,
 704                         __FILE__, sizeof(lcd_info), 
 705                         chassis_info.actcnt, chassis_info.maxcnt));
 706                DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
 707                        __FILE__, lcd_info.lcd_cmd_reg_addr, 
 708                        lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,  
 709                        lcd_info.reset_cmd2, lcd_info.act_enable ));
 710        
 711                /* check the results. Some machines have a buggy PDC */
 712                if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
 713                        goto not_found;
 714
 715                switch (lcd_info.model) {
 716                case DISPLAY_MODEL_LCD:         /* LCD display */
 717                        if (chassis_info.actcnt < 
 718                                offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
 719                                goto not_found;
 720                        if (!lcd_info.act_enable) {
 721                                DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
 722                                goto not_found;
 723                        }
 724                        break;
 725
 726                case DISPLAY_MODEL_NONE:        /* no LED or LCD available */
 727                        printk(KERN_INFO "PDC reported no LCD or LED.\n");
 728                        goto not_found;
 729
 730                case DISPLAY_MODEL_LASI:        /* Lasi style 8 bit LED display */
 731                        if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
 732                                goto not_found;
 733                        break;
 734
 735                default:
 736                        printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
 737                               lcd_info.model);
 738                        goto not_found;
 739                } /* switch() */
 740
 741found:
 742                /* register the LCD/LED driver */
 743                register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
 744                return 0;
 745
 746        } else { /* if() */
 747                DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
 748        }
 749
 750not_found:
 751        lcd_info.model = DISPLAY_MODEL_NONE;
 752        return 1;
 753}
 754
 755static void __exit led_exit(void)
 756{
 757        unregister_reboot_notifier(&led_notifier);
 758        return;
 759}
 760
 761#ifdef CONFIG_PROC_FS
 762module_init(led_create_procfs)
 763#endif
 764