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