drivers/parisc/led.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *    Chassis LCD/LED driver for HP-PARISC workstations
   4  *
   5  *      (c) Copyright 2000 Red Hat Software
   6  *      (c) Copyright 2000 Helge Deller <hdeller@redhat.com>
   7  *      (c) Copyright 2001-2009 Helge Deller <deller@gmx.de>
   8  *      (c) Copyright 2001 Randolph Chung <tausq@debian.org>
   9  *
  10  * TODO:
  11  *      - speed-up calculations with inlined assembler
  12  *      - interface to write to second row of LCD from /proc (if technically possible)
  13  *
  14  * Changes:
  15  *      - Audit copy_from_user in led_proc_write.
  16  *                                Daniele Bellucci <bellucda@tiscali.it>
  17  *      - Switch from using a tasklet to a work queue, so the led_LCD_driver
  18  *              can sleep.
  19  *                                David Pye <dmp@davidmpye.dyndns.org>
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/stddef.h>       /* for offsetof() */
  24 #include <linux/init.h>
  25 #include <linux/types.h>
  26 #include <linux/ioport.h>
  27 #include <linux/utsname.h>
  28 #include <linux/capability.h>
  29 #include <linux/delay.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/inetdevice.h>
  32 #include <linux/in.h>
  33 #include <linux/interrupt.h>
  34 #include <linux/kernel_stat.h>
  35 #include <linux/reboot.h>
  36 #include <linux/proc_fs.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/ctype.h>
  39 #include <linux/blkdev.h>
  40 #include <linux/workqueue.h>
  41 #include <linux/rcupdate.h>
  42 #include <asm/io.h>
  43 #include <asm/processor.h>
  44 #include <asm/hardware.h>
  45 #include <asm/param.h>          /* HZ */
  46 #include <asm/led.h>
  47 #include <asm/pdc.h>
  48 #include <linux/uaccess.h>
  49
  50 /* The control of the LEDs and LCDs on PARISC-machines have to be done
  51    completely in software. The necessary calculations are done in a work queue
  52    task which is scheduled regularly, and since the calculations may consume a
  53    relatively large amount of CPU time, some of the calculations can be
  54    turned off with the following variables (controlled via procfs) */
  55
  56 static int led_type __read_mostly = -1;
  57 static unsigned char lastleds;  /* LED state from most recent update */
  58 static unsigned int led_heartbeat __read_mostly = 1;
  59 static unsigned int led_diskio    __read_mostly = 1;
  60 static unsigned int led_lanrxtx   __read_mostly = 1;
  61 static char lcd_text[32]          __read_mostly;
  62 static char lcd_text_default[32]  __read_mostly;
  63 static int  lcd_no_led_support    __read_mostly = 0; /* KittyHawk doesn't support LED on its LCD */
  64
  65
  66 static struct workqueue_struct *led_wq;
  67 static void led_work_func(struct work_struct *);
  68 static DECLARE_DELAYED_WORK(led_task, led_work_func);
  69
  70 #if 0
  71 #define DPRINTK(x)      printk x
  72 #else
  73 #define DPRINTK(x)
  74 #endif
  75
  76 struct lcd_block {
  77         unsigned char command;  /* stores the command byte      */
  78         unsigned char on;       /* value for turning LED on     */
  79         unsigned char off;      /* value for turning LED off    */
  80 };
  81
  82 /* Structure returned by PDC_RETURN_CHASSIS_INFO */
  83 /* NOTE: we use unsigned long:16 two times, since the following member
  84    lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */
  85 struct pdc_chassis_lcd_info_ret_block {
  86         unsigned long model:16;         /* DISPLAY_MODEL_XXXX */
  87         unsigned long lcd_width:16;     /* width of the LCD in chars (DISPLAY_MODEL_LCD only) */
  88         unsigned long lcd_cmd_reg_addr; /* ptr to LCD cmd-register & data ptr for LED */
  89         unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */
  90         unsigned int min_cmd_delay;     /* delay in uS after cmd-write (LCD only) */
  91         unsigned char reset_cmd1;       /* command #1 for writing LCD string (LCD only) */
  92         unsigned char reset_cmd2;       /* command #2 for writing LCD string (LCD only) */
  93         unsigned char act_enable;       /* 0 = no activity (LCD only) */
  94         struct lcd_block heartbeat;
  95         struct lcd_block disk_io;
  96         struct lcd_block lan_rcv;
  97         struct lcd_block lan_tx;
  98         char _pad;
  99 };
 100
 101
 102 /* LCD_CMD and LCD_DATA for KittyHawk machines */
 103 #define KITTYHAWK_LCD_CMD  F_EXTEND(0xf0190000UL) /* 64bit-ready */
 104 #define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1)
 105
 106 /* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's
 107  * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
 108 static struct pdc_chassis_lcd_info_ret_block
 109 lcd_info __attribute__((aligned(8))) __read_mostly =
 110 {
 111         .model =                DISPLAY_MODEL_LCD,
 112         .lcd_width =            16,
 113         .lcd_cmd_reg_addr =     KITTYHAWK_LCD_CMD,
 114         .lcd_data_reg_addr =    KITTYHAWK_LCD_DATA,
 115         .min_cmd_delay =        80,
 116         .reset_cmd1 =           0x80,
 117         .reset_cmd2 =           0xc0,
 118 };
 119
 120
 121 /* direct access to some of the lcd_info variables */
 122 #define LCD_CMD_REG     lcd_info.lcd_cmd_reg_addr
 123 #define LCD_DATA_REG    lcd_info.lcd_data_reg_addr
 124 #define LED_DATA_REG    lcd_info.lcd_cmd_reg_addr       /* LASI & ASP only */
 125
 126 #define LED_HASLCD 1
 127 #define LED_NOLCD  0
 128
 129 /* The workqueue must be created at init-time */
 130 static int start_task(void)
 131 {
 132         /* Display the default text now */
 133         if (led_type == LED_HASLCD) lcd_print( lcd_text_default );
 134
 135         /* KittyHawk has no LED support on its LCD */
 136         if (lcd_no_led_support) return 0;
 137
 138         /* Create the work queue and queue the LED task */
 139         led_wq = create_singlethread_workqueue("led_wq");
 140         queue_delayed_work(led_wq, &led_task, 0);
 141
 142         return 0;
 143 }
 144
 145 device_initcall(start_task);
 146
 147 /* ptr to LCD/LED-specific function */
 148 static void (*led_func_ptr) (unsigned char) __read_mostly;
 149
 150 #ifdef CONFIG_PROC_FS
 151 static int led_proc_show(struct seq_file *m, void *v)
 152 {
 153         switch ((long)m->private)
 154         {
 155         case LED_NOLCD:
 156                 seq_printf(m, "Heartbeat: %d\n", led_heartbeat);
 157                 seq_printf(m, "Disk IO: %d\n", led_diskio);
 158                 seq_printf(m, "LAN Rx/Tx: %d\n", led_lanrxtx);
 159                 break;
 160         case LED_HASLCD:
 161                 seq_printf(m, "%s\n", lcd_text);
 162                 break;
 163         default:
 164                 return 0;
 165         }
 166         return 0;
 167 }
 168
 169 static int led_proc_open(struct inode *inode, struct file *file)
 170 {
 171         return single_open(file, led_proc_show, PDE_DATA(inode));
 172 }
 173
 174
 175 static ssize_t led_proc_write(struct file *file, const char __user *buf,
 176         size_t count, loff_t *pos)
 177 {
 178         void *data = PDE_DATA(file_inode(file));
 179         char *cur, lbuf[32];
 180         int d;
 181
 182         if (!capable(CAP_SYS_ADMIN))
 183                 return -EACCES;
 184
 185         if (count >= sizeof(lbuf))
 186                 count = sizeof(lbuf)-1;
 187
 188         if (copy_from_user(lbuf, buf, count))
 189                 return -EFAULT;
 190         lbuf[count] = 0;
 191
 192         cur = lbuf;
 193
 194         switch ((long)data)
 195         {
 196         case LED_NOLCD:
 197                 d = *cur++ - '0';
 198                 if (d != 0 && d != 1) goto parse_error;
 199                 led_heartbeat = d;
 200
 201                 if (*cur++ != ' ') goto parse_error;
 202
 203                 d = *cur++ - '0';
 204                 if (d != 0 && d != 1) goto parse_error;
 205                 led_diskio = d;
 206
 207                 if (*cur++ != ' ') goto parse_error;
 208
 209                 d = *cur++ - '0';
 210                 if (d != 0 && d != 1) goto parse_error;
 211                 led_lanrxtx = d;
 212
 213                 break;
 214         case LED_HASLCD:
 215                 if (*cur && cur[strlen(cur)-1] == '\n')
 216                         cur[strlen(cur)-1] = 0;
 217                 if (*cur == 0)
 218                         cur = lcd_text_default;
 219                 lcd_print(cur);
 220                 break;
 221         default:
 222                 return 0;
 223         }
 224
 225         return count;
 226
 227 parse_error:
 228         if ((long)data == LED_NOLCD)
 229                 printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n");
 230         return -EINVAL;
 231 }
 232
 233 static const struct proc_ops led_proc_ops = {
 234         .proc_open      = led_proc_open,
 235         .proc_read      = seq_read,
 236         .proc_lseek     = seq_lseek,
 237         .proc_release   = single_release,
 238         .proc_write     = led_proc_write,
 239 };
 240
 241 static int __init led_create_procfs(void)
 242 {
 243         struct proc_dir_entry *proc_pdc_root = NULL;
 244         struct proc_dir_entry *ent;
 245
 246         if (led_type == -1) return -1;
 247
 248         proc_pdc_root = proc_mkdir("pdc", NULL);
 249         if (!proc_pdc_root) return -1;
 250
 251         if (!lcd_no_led_support)
 252         {
 253                 ent = proc_create_data("led", S_IRUGO|S_IWUSR, proc_pdc_root,
 254                                         &led_proc_ops, (void *)LED_NOLCD); /* LED */
 255                 if (!ent) return -1;
 256         }
 257
 258         if (led_type == LED_HASLCD)
 259         {
 260                 ent = proc_create_data("lcd", S_IRUGO|S_IWUSR, proc_pdc_root,
 261                                         &led_proc_ops, (void *)LED_HASLCD); /* LCD */
 262                 if (!ent) return -1;
 263         }
 264
 265         return 0;
 266 }
 267 #endif
 268
 269 /*
 270    **
 271    ** led_ASP_driver()
 272    **
 273  */
 274 #define LED_DATA        0x01    /* data to shift (0:on 1:off) */
 275 #define LED_STROBE      0x02    /* strobe to clock data */
 276 static void led_ASP_driver(unsigned char leds)
 277 {
 278         int i;
 279
 280         leds = ~leds;
 281         for (i = 0; i < 8; i++) {
 282                 unsigned char value;
 283                 value = (leds & 0x80) >> 7;
 284                 gsc_writeb( value,               LED_DATA_REG );
 285                 gsc_writeb( value | LED_STROBE,  LED_DATA_REG );
 286                 leds <<= 1;
 287         }
 288 }
 289
 290
 291 /*
 292    **
 293    ** led_LASI_driver()
 294    **
 295  */
 296 static void led_LASI_driver(unsigned char leds)
 297 {
 298         leds = ~leds;
 299         gsc_writeb( leds, LED_DATA_REG );
 300 }
 301
 302
 303 /*
 304    **
 305    ** led_LCD_driver()
 306    **
 307  */
 308 static void led_LCD_driver(unsigned char leds)
 309 {
 310         static int i;
 311         static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
 312                 LED_LAN_RCV, LED_LAN_TX };
 313
 314         static struct lcd_block * blockp[4] = {
 315                 &lcd_info.heartbeat,
 316                 &lcd_info.disk_io,
 317                 &lcd_info.lan_rcv,
 318                 &lcd_info.lan_tx
 319         };
 320
 321         /* Convert min_cmd_delay to milliseconds */
 322         unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000);
 323
 324         for (i=0; i<4; ++i)
 325         {
 326                 if ((leds & mask[i]) != (lastleds & mask[i]))
 327                 {
 328                         gsc_writeb( blockp[i]->command, LCD_CMD_REG );
 329                         msleep(msec_cmd_delay);
 330
 331                         gsc_writeb( leds & mask[i] ? blockp[i]->on :
 332                                         blockp[i]->off, LCD_DATA_REG );
 333                         msleep(msec_cmd_delay);
 334                 }
 335         }
 336 }
 337
 338
 339 /*
 340    **
 341    ** led_get_net_activity()
 342    **
 343    ** calculate if there was TX- or RX-throughput 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 u64 rx_total_last, tx_total_last;
 353         u64 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 a workqueue task, so we can use an RCU lookup */
 360         rcu_read_lock();
 361         for_each_netdev_rcu(&init_net, dev) {
 362             const struct rtnl_link_stats64 *stats;
 363             struct rtnl_link_stats64 temp;
 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, &temp);
 370             rx_total += stats->rx_packets;
 371             tx_total += stats->tx_packets;
 372         }
 373         rcu_read_unlock();
 374
 375         retval = 0;
 376
 377         if (rx_total != rx_total_last) {
 378                 rx_total_last = rx_total;
 379                 retval |= LED_LAN_RCV;
 380         }
 381
 382         if (tx_total != tx_total_last) {
 383                 tx_total_last = tx_total;
 384                 retval |= LED_LAN_TX;
 385         }
 386
 387         return retval;
 388 #endif
 389 }
 390
 391
 392 /*
 393    **
 394    ** led_get_diskio_activity()
 395    **
 396    ** calculate if there was disk-io in the system
 397    **
 398  */
 399 static __inline__ int led_get_diskio_activity(void)
 400 {
 401         static unsigned long last_pgpgin, last_pgpgout;
 402         unsigned long events[NR_VM_EVENT_ITEMS];
 403         int changed;
 404
 405         all_vm_events(events);
 406
 407         /* Just use a very simple calculation here. Do not care about overflow,
 408            since we only want to know if there was activity or not. */
 409         changed = (events[PGPGIN] != last_pgpgin) ||
 410                   (events[PGPGOUT] != last_pgpgout);
 411         last_pgpgin  = events[PGPGIN];
 412         last_pgpgout = events[PGPGOUT];
 413
 414         return (changed ? LED_DISK_IO : 0);
 415 }
 416
 417
 418
 419 /*
 420    ** led_work_func()
 421    **
 422    ** manages when and which chassis LCD/LED gets updated
 423
 424     TODO:
 425     - display load average (older machines like 715/64 have 4 "free" LED's for that)
 426     - optimizations
 427  */
 428
 429 #define HEARTBEAT_LEN (HZ*10/100)
 430 #define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
 431 #define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
 432
 433 #define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
 434
 435 static void led_work_func (struct work_struct *unused)
 436 {
 437         static unsigned long last_jiffies;
 438         static unsigned long count_HZ; /* counter in range 0..HZ */
 439         unsigned char currentleds = 0; /* stores current value of the LEDs */
 440
 441         /* exit if not initialized */
 442         if (!led_func_ptr)
 443             return;
 444
 445         /* increment the heartbeat timekeeper */
 446         count_HZ += jiffies - last_jiffies;
 447         last_jiffies = jiffies;
 448         if (count_HZ >= HZ)
 449             count_HZ = 0;
 450
 451         if (likely(led_heartbeat))
 452         {
 453                 /* flash heartbeat-LED like a real heart
 454                  * (2 x short then a long delay)
 455                  */
 456                 if (count_HZ < HEARTBEAT_LEN ||
 457                                 (count_HZ >= HEARTBEAT_2ND_RANGE_START &&
 458                                 count_HZ < HEARTBEAT_2ND_RANGE_END))
 459                         currentleds |= LED_HEARTBEAT;
 460         }
 461
 462         if (likely(led_lanrxtx))  currentleds |= led_get_net_activity();
 463         if (likely(led_diskio))   currentleds |= led_get_diskio_activity();
 464
 465         /* blink LEDs if we got an Oops (HPMC) */
 466         if (unlikely(oops_in_progress)) {
 467                 if (boot_cpu_data.cpu_type >= pcxl2) {
 468                         /* newer machines don't have loadavg. LEDs, so we
 469                          * let all LEDs blink twice per second instead */
 470                         currentleds = (count_HZ <= (HZ/2)) ? 0 : 0xff;
 471                 } else {
 472                         /* old machines: blink loadavg. LEDs twice per second */
 473                         if (count_HZ <= (HZ/2))
 474                                 currentleds &= ~(LED4|LED5|LED6|LED7);
 475                         else
 476                                 currentleds |= (LED4|LED5|LED6|LED7);
 477                 }
 478         }
 479
 480         if (currentleds != lastleds)
 481         {
 482                 led_func_ptr(currentleds);      /* Update the LCD/LEDs */
 483                 lastleds = currentleds;
 484         }
 485
 486         queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
 487 }
 488
 489 /*
 490    ** led_halt()
 491    **
 492    ** called by the reboot notifier chain at shutdown and stops all
 493    ** LED/LCD activities.
 494    **
 495  */
 496
 497 static int led_halt(struct notifier_block *, unsigned long, void *);
 498
 499 static struct notifier_block led_notifier = {
 500         .notifier_call = led_halt,
 501 };
 502 static int notifier_disabled = 0;
 503
 504 static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
 505 {
 506         char *txt;
 507
 508         if (notifier_disabled)
 509                 return NOTIFY_OK;
 510
 511         notifier_disabled = 1;
 512         switch (event) {
 513         case SYS_RESTART:       txt = "SYSTEM RESTART";
 514                                 break;
 515         case SYS_HALT:          txt = "SYSTEM HALT";
 516                                 break;
 517         case SYS_POWER_OFF:     txt = "SYSTEM POWER OFF";
 518                                 break;
 519         default:                return NOTIFY_DONE;
 520         }
 521
 522         /* Cancel the work item and delete the queue */
 523         if (led_wq) {
 524                 cancel_delayed_work_sync(&led_task);
 525                 destroy_workqueue(led_wq);
 526                 led_wq = NULL;
 527         }
 528
 529         if (lcd_info.model == DISPLAY_MODEL_LCD)
 530                 lcd_print(txt);
 531         else
 532                 if (led_func_ptr)
 533                         led_func_ptr(0xff); /* turn all LEDs ON */
 534
 535         return NOTIFY_OK;
 536 }
 537
 538 /*
 539    ** register_led_driver()
 540    **
 541    ** registers an external LED or LCD for usage by this driver.
 542    ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
 543    **
 544  */
 545
 546 int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
 547 {
 548         static int initialized;
 549
 550         if (initialized || !data_reg)
 551                 return 1;
 552
 553         lcd_info.model = model;         /* store the values */
 554         LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
 555
 556         switch (lcd_info.model) {
 557         case DISPLAY_MODEL_LCD:
 558                 LCD_DATA_REG = data_reg;
 559                 printk(KERN_INFO "LCD display at %lx,%lx registered\n",
 560                         LCD_CMD_REG , LCD_DATA_REG);
 561                 led_func_ptr = led_LCD_driver;
 562                 led_type = LED_HASLCD;
 563                 break;
 564
 565         case DISPLAY_MODEL_LASI:
 566                 /* Skip to register LED in QEMU */
 567                 if (running_on_qemu)
 568                         return 1;
 569                 LED_DATA_REG = data_reg;
 570                 led_func_ptr = led_LASI_driver;
 571                 printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
 572                 led_type = LED_NOLCD;
 573                 break;
 574
 575         case DISPLAY_MODEL_OLD_ASP:
 576                 LED_DATA_REG = data_reg;
 577                 led_func_ptr = led_ASP_driver;
 578                 printk(KERN_INFO "LED (ASP-style) display at %lx registered\n",
 579                     LED_DATA_REG);
 580                 led_type = LED_NOLCD;
 581                 break;
 582
 583         default:
 584                 printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
 585                        __func__, lcd_info.model);
 586                 return 1;
 587         }
 588
 589         /* mark the LCD/LED driver now as initialized and
 590          * register to the reboot notifier chain */
 591         initialized++;
 592         register_reboot_notifier(&led_notifier);
 593
 594         /* Ensure the work is queued */
 595         if (led_wq) {
 596                 queue_delayed_work(led_wq, &led_task, 0);
 597         }
 598
 599         return 0;
 600 }
 601
 602 /*
 603    ** register_led_regions()
 604    **
 605    ** register_led_regions() registers the LCD/LED regions for /procfs.
 606    ** At bootup - where the initialisation of the LCD/LED normally happens -
 607    ** not all internal structures of request_region() are properly set up,
 608    ** so that we delay the led-registration until after busdevices_init()
 609    ** has been executed.
 610    **
 611  */
 612
 613 void __init register_led_regions(void)
 614 {
 615         switch (lcd_info.model) {
 616         case DISPLAY_MODEL_LCD:
 617                 request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
 618                 request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
 619                 break;
 620         case DISPLAY_MODEL_LASI:
 621         case DISPLAY_MODEL_OLD_ASP:
 622                 request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
 623                 break;
 624         }
 625 }
 626
 627
 628 /*
 629    **
 630    ** lcd_print()
 631    **
 632    ** Displays the given string on the LCD-Display of newer machines.
 633    ** lcd_print() disables/enables the timer-based led work queue to
 634    ** avoid a race condition while writing the CMD/DATA register pair.
 635    **
 636  */
 637 int lcd_print( const char *str )
 638 {
 639         int i;
 640
 641         if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
 642             return 0;
 643
 644         /* temporarily disable the led work task */
 645         if (led_wq)
 646                 cancel_delayed_work_sync(&led_task);
 647
 648         /* copy display string to buffer for procfs */
 649         strlcpy(lcd_text, str, sizeof(lcd_text));
 650
 651         /* Set LCD Cursor to 1st character */
 652         gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
 653         udelay(lcd_info.min_cmd_delay);
 654
 655         /* Print the string */
 656         for (i=0; i < lcd_info.lcd_width; i++) {
 657             if (str && *str)
 658                 gsc_writeb(*str++, LCD_DATA_REG);
 659             else
 660                 gsc_writeb(' ', LCD_DATA_REG);
 661             udelay(lcd_info.min_cmd_delay);
 662         }
 663
 664         /* re-queue the work */
 665         if (led_wq) {
 666                 queue_delayed_work(led_wq, &led_task, 0);
 667         }
 668
 669         return lcd_info.lcd_width;
 670 }
 671
 672 /*
 673    ** led_init()
 674    **
 675    ** led_init() is called very early in the bootup-process from setup.c
 676    ** and asks the PDC for an usable chassis LCD or LED.
 677    ** If the PDC doesn't return any info, then the LED
 678    ** is detected by lasi.c or asp.c and registered with the
 679    ** above functions lasi_led_init() or asp_led_init().
 680    ** KittyHawk machines have often a buggy PDC, so that
 681    ** we explicitly check for those machines here.
 682  */
 683
 684 int __init led_init(void)
 685 {
 686         struct pdc_chassis_info chassis_info;
 687         int ret;
 688
 689         snprintf(lcd_text_default, sizeof(lcd_text_default),
 690                 "Linux %s", init_utsname()->release);
 691
 692         /* Work around the buggy PDC of KittyHawk-machines */
 693         switch (CPU_HVERSION) {
 694         case 0x580:             /* KittyHawk DC2-100 (K100) */
 695         case 0x581:             /* KittyHawk DC3-120 (K210) */
 696         case 0x582:             /* KittyHawk DC3 100 (K400) */
 697         case 0x583:             /* KittyHawk DC3 120 (K410) */
 698         case 0x58B:             /* KittyHawk DC2 100 (K200) */
 699                 printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
 700                                 "LED detection skipped.\n", __FILE__, CPU_HVERSION);
 701                 lcd_no_led_support = 1;
 702                 goto found;     /* use the preinitialized values of lcd_info */
 703         }
 704
 705         /* initialize the struct, so that we can check for valid return values */
 706         lcd_info.model = DISPLAY_MODEL_NONE;
 707         chassis_info.actcnt = chassis_info.maxcnt = 0;
 708
 709         ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
 710         if (ret == PDC_OK) {
 711                 DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
 712                          "lcd_width=%d, cmd_delay=%u,\n"
 713                          "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
 714                          __FILE__, lcd_info.model,
 715                          (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
 716                           (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
 717                          lcd_info.lcd_width, lcd_info.min_cmd_delay,
 718                          __FILE__, sizeof(lcd_info),
 719                          chassis_info.actcnt, chassis_info.maxcnt));
 720                 DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
 721                         __FILE__, lcd_info.lcd_cmd_reg_addr,
 722                         lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
 723                         lcd_info.reset_cmd2, lcd_info.act_enable ));
 724
 725                 /* check the results. Some machines have a buggy PDC */
 726                 if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
 727                         goto not_found;
 728
 729                 switch (lcd_info.model) {
 730                 case DISPLAY_MODEL_LCD:         /* LCD display */
 731                         if (chassis_info.actcnt <
 732                                 offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
 733                                 goto not_found;
 734                         if (!lcd_info.act_enable) {
 735                                 DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
 736                                 goto not_found;
 737                         }
 738                         break;
 739
 740                 case DISPLAY_MODEL_NONE:        /* no LED or LCD available */
 741                         printk(KERN_INFO "PDC reported no LCD or LED.\n");
 742                         goto not_found;
 743
 744                 case DISPLAY_MODEL_LASI:        /* Lasi style 8 bit LED display */
 745                         if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
 746                                 goto not_found;
 747                         break;
 748
 749                 default:
 750                         printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
 751                                lcd_info.model);
 752                         goto not_found;
 753                 } /* switch() */
 754
 755 found:
 756                 /* register the LCD/LED driver */
 757                 register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
 758                 return 0;
 759
 760         } else { /* if() */
 761                 DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
 762         }
 763
 764 not_found:
 765         lcd_info.model = DISPLAY_MODEL_NONE;
 766         return 1;
 767 }
 768
 769 static void __exit led_exit(void)
 770 {
 771         unregister_reboot_notifier(&led_notifier);
 772         return;
 773 }
 774
 775 #ifdef CONFIG_PROC_FS
 776 module_init(led_create_procfs)
 777 #endif