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 2001-2009 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/seq_file.h>
  42 #include <linux/ctype.h>
  43 #include <linux/blkdev.h>
  44 #include <linux/workqueue.h>
  45 #include <linux/rcupdate.h>
  46 #include <asm/io.h>
  47 #include <asm/processor.h>
  48 #include <asm/hardware.h>
  49 #include <asm/param.h>          /* HZ */
  50 #include <asm/led.h>
  51 #include <asm/pdc.h>
  52 #include <linux/uaccess.h>
  53
  54 /* The control of the LEDs and LCDs on PARISC-machines have to be done
  55    completely in software. The necessary calculations are done in a work queue
  56    task which is scheduled regularly, and since the calculations may consume a
  57    relatively large amount of CPU time, some of the calculations can be
  58    turned off with the following variables (controlled via procfs) */
  59
  60 static int led_type __read_mostly = -1;
  61 static unsigned char lastleds;  /* LED state from most recent update */
  62 static unsigned int led_heartbeat __read_mostly = 1;
  63 static unsigned int led_diskio    __read_mostly = 1;
  64 static unsigned int led_lanrxtx   __read_mostly = 1;
  65 static char lcd_text[32]          __read_mostly;
  66 static char lcd_text_default[32]  __read_mostly;
  67 static int  lcd_no_led_support    __read_mostly = 0; /* KittyHawk doesn't support LED on its LCD */
  68
  69
  70 static struct workqueue_struct *led_wq;
  71 static void led_work_func(struct work_struct *);
  72 static DECLARE_DELAYED_WORK(led_task, led_work_func);
  73
  74 #if 0
  75 #define DPRINTK(x)      printk x
  76 #else
  77 #define DPRINTK(x)
  78 #endif
  79
  80 struct lcd_block {
  81         unsigned char command;  /* stores the command byte      */
  82         unsigned char on;       /* value for turning LED on     */
  83         unsigned char off;      /* value for turning LED off    */
  84 };
  85
  86 /* Structure returned by PDC_RETURN_CHASSIS_INFO */
  87 /* NOTE: we use unsigned long:16 two times, since the following member
  88    lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */
  89 struct pdc_chassis_lcd_info_ret_block {
  90         unsigned long model:16;         /* DISPLAY_MODEL_XXXX */
  91         unsigned long lcd_width:16;     /* width of the LCD in chars (DISPLAY_MODEL_LCD only) */
  92         unsigned long lcd_cmd_reg_addr; /* ptr to LCD cmd-register & data ptr for LED */
  93         unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */
  94         unsigned int min_cmd_delay;     /* delay in uS after cmd-write (LCD only) */
  95         unsigned char reset_cmd1;       /* command #1 for writing LCD string (LCD only) */
  96         unsigned char reset_cmd2;       /* command #2 for writing LCD string (LCD only) */
  97         unsigned char act_enable;       /* 0 = no activity (LCD only) */
  98         struct lcd_block heartbeat;
  99         struct lcd_block disk_io;
 100         struct lcd_block lan_rcv;
 101         struct lcd_block lan_tx;
 102         char _pad;
 103 };
 104
 105
 106 /* LCD_CMD and LCD_DATA for KittyHawk machines */
 107 #define KITTYHAWK_LCD_CMD  F_EXTEND(0xf0190000UL) /* 64bit-ready */
 108 #define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1)
 109
 110 /* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's
 111  * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
 112 static struct pdc_chassis_lcd_info_ret_block
 113 lcd_info __attribute__((aligned(8))) __read_mostly =
 114 {
 115         .model =                DISPLAY_MODEL_LCD,
 116         .lcd_width =            16,
 117         .lcd_cmd_reg_addr =     KITTYHAWK_LCD_CMD,
 118         .lcd_data_reg_addr =    KITTYHAWK_LCD_DATA,
 119         .min_cmd_delay =        80,
 120         .reset_cmd1 =           0x80,
 121         .reset_cmd2 =           0xc0,
 122 };
 123
 124
 125 /* direct access to some of the lcd_info variables */
 126 #define LCD_CMD_REG     lcd_info.lcd_cmd_reg_addr
 127 #define LCD_DATA_REG    lcd_info.lcd_data_reg_addr
 128 #define LED_DATA_REG    lcd_info.lcd_cmd_reg_addr       /* LASI & ASP only */
 129
 130 #define LED_HASLCD 1
 131 #define LED_NOLCD  0
 132
 133 /* The workqueue must be created at init-time */
 134 static int start_task(void)
 135 {
 136         /* Display the default text now */
 137         if (led_type == LED_HASLCD) lcd_print( lcd_text_default );
 138
 139         /* KittyHawk has no LED support on its LCD */
 140         if (lcd_no_led_support) return 0;
 141
 142         /* Create the work queue and queue the LED task */
 143         led_wq = create_singlethread_workqueue("led_wq");
 144         queue_delayed_work(led_wq, &led_task, 0);
 145
 146         return 0;
 147 }
 148
 149 device_initcall(start_task);
 150
 151 /* ptr to LCD/LED-specific function */
 152 static void (*led_func_ptr) (unsigned char) __read_mostly;
 153
 154 #ifdef CONFIG_PROC_FS
 155 static int led_proc_show(struct seq_file *m, void *v)
 156 {
 157         switch ((long)m->private)
 158         {
 159         case LED_NOLCD:
 160                 seq_printf(m, "Heartbeat: %d\n", led_heartbeat);
 161                 seq_printf(m, "Disk IO: %d\n", led_diskio);
 162                 seq_printf(m, "LAN Rx/Tx: %d\n", led_lanrxtx);
 163                 break;
 164         case LED_HASLCD:
 165                 seq_printf(m, "%s\n", lcd_text);
 166                 break;
 167         default:
 168                 return 0;
 169         }
 170         return 0;
 171 }
 172
 173 static int led_proc_open(struct inode *inode, struct file *file)
 174 {
 175         return single_open(file, led_proc_show, PDE_DATA(inode));
 176 }
 177
 178
 179 static ssize_t led_proc_write(struct file *file, const char __user *buf,
 180         size_t count, loff_t *pos)
 181 {
 182         void *data = PDE_DATA(file_inode(file));
 183         char *cur, lbuf[32];
 184         int d;
 185
 186         if (!capable(CAP_SYS_ADMIN))
 187                 return -EACCES;
 188
 189         if (count >= sizeof(lbuf))
 190                 count = sizeof(lbuf)-1;
 191
 192         if (copy_from_user(lbuf, buf, count))
 193                 return -EFAULT;
 194         lbuf[count] = 0;
 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
 231 parse_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
 237 static const struct file_operations led_proc_fops = {
 238         .owner          = THIS_MODULE,
 239         .open           = led_proc_open,
 240         .read           = seq_read,
 241         .llseek         = seq_lseek,
 242         .release        = single_release,
 243         .write          = led_proc_write,
 244 };
 245
 246 static int __init led_create_procfs(void)
 247 {
 248         struct proc_dir_entry *proc_pdc_root = NULL;
 249         struct proc_dir_entry *ent;
 250
 251         if (led_type == -1) return -1;
 252
 253         proc_pdc_root = proc_mkdir("pdc", NULL);
 254         if (!proc_pdc_root) return -1;
 255
 256         if (!lcd_no_led_support)
 257         {
 258                 ent = proc_create_data("led", S_IRUGO|S_IWUSR, proc_pdc_root,
 259                                         &led_proc_fops, (void *)LED_NOLCD); /* LED */
 260                 if (!ent) return -1;
 261         }
 262
 263         if (led_type == LED_HASLCD)
 264         {
 265                 ent = proc_create_data("lcd", S_IRUGO|S_IWUSR, proc_pdc_root,
 266                                         &led_proc_fops, (void *)LED_HASLCD); /* LCD */
 267                 if (!ent) return -1;
 268         }
 269
 270         return 0;
 271 }
 272 #endif
 273
 274 /*
 275    **
 276    ** led_ASP_driver()
 277    **
 278  */
 279 #define LED_DATA        0x01    /* data to shift (0:on 1:off) */
 280 #define LED_STROBE      0x02    /* strobe to clock data */
 281 static void led_ASP_driver(unsigned char leds)
 282 {
 283         int i;
 284
 285         leds = ~leds;
 286         for (i = 0; i < 8; i++) {
 287                 unsigned char value;
 288                 value = (leds & 0x80) >> 7;
 289                 gsc_writeb( value,               LED_DATA_REG );
 290                 gsc_writeb( value | LED_STROBE,  LED_DATA_REG );
 291                 leds <<= 1;
 292         }
 293 }
 294
 295
 296 /*
 297    **
 298    ** led_LASI_driver()
 299    **
 300  */
 301 static void led_LASI_driver(unsigned char leds)
 302 {
 303         leds = ~leds;
 304         gsc_writeb( leds, LED_DATA_REG );
 305 }
 306
 307
 308 /*
 309    **
 310    ** led_LCD_driver()
 311    **
 312  */
 313 static void led_LCD_driver(unsigned char leds)
 314 {
 315         static int i;
 316         static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
 317                 LED_LAN_RCV, LED_LAN_TX };
 318
 319         static struct lcd_block * blockp[4] = {
 320                 &lcd_info.heartbeat,
 321                 &lcd_info.disk_io,
 322                 &lcd_info.lan_rcv,
 323                 &lcd_info.lan_tx
 324         };
 325
 326         /* Convert min_cmd_delay to milliseconds */
 327         unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000);
 328
 329         for (i=0; i<4; ++i)
 330         {
 331                 if ((leds & mask[i]) != (lastleds & mask[i]))
 332                 {
 333                         gsc_writeb( blockp[i]->command, LCD_CMD_REG );
 334                         msleep(msec_cmd_delay);
 335
 336                         gsc_writeb( leds & mask[i] ? blockp[i]->on :
 337                                         blockp[i]->off, LCD_DATA_REG );
 338                         msleep(msec_cmd_delay);
 339                 }
 340         }
 341 }
 342
 343
 344 /*
 345    **
 346    ** led_get_net_activity()
 347    **
 348    ** calculate if there was TX- or RX-throughput on the network interfaces
 349    ** (analog to dev_get_info() from net/core/dev.c)
 350    **
 351  */
 352 static __inline__ int led_get_net_activity(void)
 353 {
 354 #ifndef CONFIG_NET
 355         return 0;
 356 #else
 357         static u64 rx_total_last, tx_total_last;
 358         u64 rx_total, tx_total;
 359         struct net_device *dev;
 360         int retval;
 361
 362         rx_total = tx_total = 0;
 363
 364         /* we are running as a workqueue task, so we can use an RCU lookup */
 365         rcu_read_lock();
 366         for_each_netdev_rcu(&init_net, dev) {
 367             const struct rtnl_link_stats64 *stats;
 368             struct rtnl_link_stats64 temp;
 369             struct in_device *in_dev = __in_dev_get_rcu(dev);
 370             if (!in_dev || !in_dev->ifa_list)
 371                 continue;
 372             if (ipv4_is_loopback(in_dev->ifa_list->ifa_local))
 373                 continue;
 374             stats = dev_get_stats(dev, &temp);
 375             rx_total += stats->rx_packets;
 376             tx_total += stats->tx_packets;
 377         }
 378         rcu_read_unlock();
 379
 380         retval = 0;
 381
 382         if (rx_total != rx_total_last) {
 383                 rx_total_last = rx_total;
 384                 retval |= LED_LAN_RCV;
 385         }
 386
 387         if (tx_total != tx_total_last) {
 388                 tx_total_last = tx_total;
 389                 retval |= LED_LAN_TX;
 390         }
 391
 392         return retval;
 393 #endif
 394 }
 395
 396
 397 /*
 398    **
 399    ** led_get_diskio_activity()
 400    **
 401    ** calculate if there was disk-io in the system
 402    **
 403  */
 404 static __inline__ int led_get_diskio_activity(void)
 405 {
 406         static unsigned long last_pgpgin, last_pgpgout;
 407         unsigned long events[NR_VM_EVENT_ITEMS];
 408         int changed;
 409
 410         all_vm_events(events);
 411
 412         /* Just use a very simple calculation here. Do not care about overflow,
 413            since we only want to know if there was activity or not. */
 414         changed = (events[PGPGIN] != last_pgpgin) ||
 415                   (events[PGPGOUT] != last_pgpgout);
 416         last_pgpgin  = events[PGPGIN];
 417         last_pgpgout = events[PGPGOUT];
 418
 419         return (changed ? LED_DISK_IO : 0);
 420 }
 421
 422
 423
 424 /*
 425    ** led_work_func()
 426    **
 427    ** manages when and which chassis LCD/LED gets updated
 428
 429     TODO:
 430     - display load average (older machines like 715/64 have 4 "free" LED's for that)
 431     - optimizations
 432  */
 433
 434 #define HEARTBEAT_LEN (HZ*10/100)
 435 #define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
 436 #define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
 437
 438 #define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
 439
 440 static void led_work_func (struct work_struct *unused)
 441 {
 442         static unsigned long last_jiffies;
 443         static unsigned long count_HZ; /* counter in range 0..HZ */
 444         unsigned char currentleds = 0; /* stores current value of the LEDs */
 445
 446         /* exit if not initialized */
 447         if (!led_func_ptr)
 448             return;
 449
 450         /* increment the heartbeat timekeeper */
 451         count_HZ += jiffies - last_jiffies;
 452         last_jiffies = jiffies;
 453         if (count_HZ >= HZ)
 454             count_HZ = 0;
 455
 456         if (likely(led_heartbeat))
 457         {
 458                 /* flash heartbeat-LED like a real heart
 459                  * (2 x short then a long delay)
 460                  */
 461                 if (count_HZ < HEARTBEAT_LEN ||
 462                                 (count_HZ >= HEARTBEAT_2ND_RANGE_START &&
 463                                 count_HZ < HEARTBEAT_2ND_RANGE_END))
 464                         currentleds |= LED_HEARTBEAT;
 465         }
 466
 467         if (likely(led_lanrxtx))  currentleds |= led_get_net_activity();
 468         if (likely(led_diskio))   currentleds |= led_get_diskio_activity();
 469
 470         /* blink LEDs if we got an Oops (HPMC) */
 471         if (unlikely(oops_in_progress)) {
 472                 if (boot_cpu_data.cpu_type >= pcxl2) {
 473                         /* newer machines don't have loadavg. LEDs, so we
 474                          * let all LEDs blink twice per second instead */
 475                         currentleds = (count_HZ <= (HZ/2)) ? 0 : 0xff;
 476                 } else {
 477                         /* old machines: blink loadavg. LEDs twice per second */
 478                         if (count_HZ <= (HZ/2))
 479                                 currentleds &= ~(LED4|LED5|LED6|LED7);
 480                         else
 481                                 currentleds |= (LED4|LED5|LED6|LED7);
 482                 }
 483         }
 484
 485         if (currentleds != lastleds)
 486         {
 487                 led_func_ptr(currentleds);      /* Update the LCD/LEDs */
 488                 lastleds = currentleds;
 489         }
 490
 491         queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
 492 }
 493
 494 /*
 495    ** led_halt()
 496    **
 497    ** called by the reboot notifier chain at shutdown and stops all
 498    ** LED/LCD activities.
 499    **
 500  */
 501
 502 static int led_halt(struct notifier_block *, unsigned long, void *);
 503
 504 static struct notifier_block led_notifier = {
 505         .notifier_call = led_halt,
 506 };
 507 static int notifier_disabled = 0;
 508
 509 static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
 510 {
 511         char *txt;
 512
 513         if (notifier_disabled)
 514                 return NOTIFY_OK;
 515
 516         notifier_disabled = 1;
 517         switch (event) {
 518         case SYS_RESTART:       txt = "SYSTEM RESTART";
 519                                 break;
 520         case SYS_HALT:          txt = "SYSTEM HALT";
 521                                 break;
 522         case SYS_POWER_OFF:     txt = "SYSTEM POWER OFF";
 523                                 break;
 524         default:                return NOTIFY_DONE;
 525         }
 526
 527         /* Cancel the work item and delete the queue */
 528         if (led_wq) {
 529                 cancel_delayed_work_sync(&led_task);
 530                 destroy_workqueue(led_wq);
 531                 led_wq = NULL;
 532         }
 533
 534         if (lcd_info.model == DISPLAY_MODEL_LCD)
 535                 lcd_print(txt);
 536         else
 537                 if (led_func_ptr)
 538                         led_func_ptr(0xff); /* turn all LEDs ON */
 539
 540         return NOTIFY_OK;
 541 }
 542
 543 /*
 544    ** register_led_driver()
 545    **
 546    ** registers an external LED or LCD for usage by this driver.
 547    ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
 548    **
 549  */
 550
 551 int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
 552 {
 553         static int initialized;
 554
 555         if (initialized || !data_reg)
 556                 return 1;
 557
 558         lcd_info.model = model;         /* store the values */
 559         LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
 560
 561         switch (lcd_info.model) {
 562         case DISPLAY_MODEL_LCD:
 563                 LCD_DATA_REG = data_reg;
 564                 printk(KERN_INFO "LCD display at %lx,%lx registered\n",
 565                         LCD_CMD_REG , LCD_DATA_REG);
 566                 led_func_ptr = led_LCD_driver;
 567                 led_type = LED_HASLCD;
 568                 break;
 569
 570         case DISPLAY_MODEL_LASI:
 571                 /* Skip to register LED in QEMU */
 572                 if (running_on_qemu)
 573                         return 1;
 574                 LED_DATA_REG = data_reg;
 575                 led_func_ptr = led_LASI_driver;
 576                 printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
 577                 led_type = LED_NOLCD;
 578                 break;
 579
 580         case DISPLAY_MODEL_OLD_ASP:
 581                 LED_DATA_REG = data_reg;
 582                 led_func_ptr = led_ASP_driver;
 583                 printk(KERN_INFO "LED (ASP-style) display at %lx registered\n",
 584                     LED_DATA_REG);
 585                 led_type = LED_NOLCD;
 586                 break;
 587
 588         default:
 589                 printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
 590                        __func__, lcd_info.model);
 591                 return 1;
 592         }
 593
 594         /* mark the LCD/LED driver now as initialized and
 595          * register to the reboot notifier chain */
 596         initialized++;
 597         register_reboot_notifier(&led_notifier);
 598
 599         /* Ensure the work is queued */
 600         if (led_wq) {
 601                 queue_delayed_work(led_wq, &led_task, 0);
 602         }
 603
 604         return 0;
 605 }
 606
 607 /*
 608    ** register_led_regions()
 609    **
 610    ** register_led_regions() registers the LCD/LED regions for /procfs.
 611    ** At bootup - where the initialisation of the LCD/LED normally happens -
 612    ** not all internal structures of request_region() are properly set up,
 613    ** so that we delay the led-registration until after busdevices_init()
 614    ** has been executed.
 615    **
 616  */
 617
 618 void __init register_led_regions(void)
 619 {
 620         switch (lcd_info.model) {
 621         case DISPLAY_MODEL_LCD:
 622                 request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
 623                 request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
 624                 break;
 625         case DISPLAY_MODEL_LASI:
 626         case DISPLAY_MODEL_OLD_ASP:
 627                 request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
 628                 break;
 629         }
 630 }
 631
 632
 633 /*
 634    **
 635    ** lcd_print()
 636    **
 637    ** Displays the given string on the LCD-Display of newer machines.
 638    ** lcd_print() disables/enables the timer-based led work queue to
 639    ** avoid a race condition while writing the CMD/DATA register pair.
 640    **
 641  */
 642 int lcd_print( const char *str )
 643 {
 644         int i;
 645
 646         if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
 647             return 0;
 648
 649         /* temporarily disable the led work task */
 650         if (led_wq)
 651                 cancel_delayed_work_sync(&led_task);
 652
 653         /* copy display string to buffer for procfs */
 654         strlcpy(lcd_text, str, sizeof(lcd_text));
 655
 656         /* Set LCD Cursor to 1st character */
 657         gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
 658         udelay(lcd_info.min_cmd_delay);
 659
 660         /* Print the string */
 661         for (i=0; i < lcd_info.lcd_width; i++) {
 662             if (str && *str)
 663                 gsc_writeb(*str++, LCD_DATA_REG);
 664             else
 665                 gsc_writeb(' ', LCD_DATA_REG);
 666             udelay(lcd_info.min_cmd_delay);
 667         }
 668
 669         /* re-queue the work */
 670         if (led_wq) {
 671                 queue_delayed_work(led_wq, &led_task, 0);
 672         }
 673
 674         return lcd_info.lcd_width;
 675 }
 676
 677 /*
 678    ** led_init()
 679    **
 680    ** led_init() is called very early in the bootup-process from setup.c
 681    ** and asks the PDC for an usable chassis LCD or LED.
 682    ** If the PDC doesn't return any info, then the LED
 683    ** is detected by lasi.c or asp.c and registered with the
 684    ** above functions lasi_led_init() or asp_led_init().
 685    ** KittyHawk machines have often a buggy PDC, so that
 686    ** we explicitly check for those machines here.
 687  */
 688
 689 int __init led_init(void)
 690 {
 691         struct pdc_chassis_info chassis_info;
 692         int ret;
 693
 694         snprintf(lcd_text_default, sizeof(lcd_text_default),
 695                 "Linux %s", init_utsname()->release);
 696
 697         /* Work around the buggy PDC of KittyHawk-machines */
 698         switch (CPU_HVERSION) {
 699         case 0x580:             /* KittyHawk DC2-100 (K100) */
 700         case 0x581:             /* KittyHawk DC3-120 (K210) */
 701         case 0x582:             /* KittyHawk DC3 100 (K400) */
 702         case 0x583:             /* KittyHawk DC3 120 (K410) */
 703         case 0x58B:             /* KittyHawk DC2 100 (K200) */
 704                 printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
 705                                 "LED detection skipped.\n", __FILE__, CPU_HVERSION);
 706                 lcd_no_led_support = 1;
 707                 goto found;     /* use the preinitialized values of lcd_info */
 708         }
 709
 710         /* initialize the struct, so that we can check for valid return values */
 711         lcd_info.model = DISPLAY_MODEL_NONE;
 712         chassis_info.actcnt = chassis_info.maxcnt = 0;
 713
 714         ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
 715         if (ret == PDC_OK) {
 716                 DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
 717                          "lcd_width=%d, cmd_delay=%u,\n"
 718                          "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
 719                          __FILE__, lcd_info.model,
 720                          (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
 721                           (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
 722                          lcd_info.lcd_width, lcd_info.min_cmd_delay,
 723                          __FILE__, sizeof(lcd_info),
 724                          chassis_info.actcnt, chassis_info.maxcnt));
 725                 DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
 726                         __FILE__, lcd_info.lcd_cmd_reg_addr,
 727                         lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
 728                         lcd_info.reset_cmd2, lcd_info.act_enable ));
 729
 730                 /* check the results. Some machines have a buggy PDC */
 731                 if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
 732                         goto not_found;
 733
 734                 switch (lcd_info.model) {
 735                 case DISPLAY_MODEL_LCD:         /* LCD display */
 736                         if (chassis_info.actcnt <
 737                                 offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
 738                                 goto not_found;
 739                         if (!lcd_info.act_enable) {
 740                                 DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
 741                                 goto not_found;
 742                         }
 743                         break;
 744
 745                 case DISPLAY_MODEL_NONE:        /* no LED or LCD available */
 746                         printk(KERN_INFO "PDC reported no LCD or LED.\n");
 747                         goto not_found;
 748
 749                 case DISPLAY_MODEL_LASI:        /* Lasi style 8 bit LED display */
 750                         if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
 751                                 goto not_found;
 752                         break;
 753
 754                 default:
 755                         printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
 756                                lcd_info.model);
 757                         goto not_found;
 758                 } /* switch() */
 759
 760 found:
 761                 /* register the LCD/LED driver */
 762                 register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
 763                 return 0;
 764
 765         } else { /* if() */
 766                 DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
 767         }
 768
 769 not_found:
 770         lcd_info.model = DISPLAY_MODEL_NONE;
 771         return 1;
 772 }
 773
 774 static void __exit led_exit(void)
 775 {
 776         unregister_reboot_notifier(&led_notifier);
 777         return;
 778 }
 779
 780 #ifdef CONFIG_PROC_FS
 781 module_init(led_create_procfs)
 782 #endif