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 2001-2009 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 <asm/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
  60static int led_type __read_mostly = -1;
  61static unsigned char lastleds;  /* LED state from most recent update */
  62static unsigned int led_heartbeat __read_mostly = 1;
  63static unsigned int led_diskio    __read_mostly = 1;
  64static unsigned int led_lanrxtx   __read_mostly = 1;
  65static char lcd_text[32]          __read_mostly;
  66static char lcd_text_default[32]  __read_mostly;
  67static int  lcd_no_led_support    __read_mostly = 0; /* KittyHawk doesn't support LED on its LCD */
  68
  69
  70static struct workqueue_struct *led_wq;
  71static void led_work_func(struct work_struct *);
  72static 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
  80struct 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 */
  89struct 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. */
 112static struct pdc_chassis_lcd_info_ret_block
 113lcd_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 */
 134static 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
 149device_initcall(start_task);
 150
 151/* ptr to LCD/LED-specific function */
 152static void (*led_func_ptr) (unsigned char) __read_mostly;
 153
 154#ifdef CONFIG_PROC_FS
 155static 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
 173static int led_proc_open(struct inode *inode, struct file *file)
 174{
 175        return single_open(file, led_proc_show, PDE(inode)->data);
 176}
 177
 178
 179static ssize_t led_proc_write(struct file *file, const char *buf,
 180        size_t count, loff_t *pos)
 181{
 182        void *data = PDE(file->f_path.dentry->d_inode)->data;
 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
 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 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
 246static 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", 0);
 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 */
 281static 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 */
 301static 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 */
 313static 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 */
 352static __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 */
 404static __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
 440static 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
 502static int led_halt(struct notifier_block *, unsigned long, void *);
 503
 504static struct notifier_block led_notifier = {
 505        .notifier_call = led_halt,
 506};
 507static int notifier_disabled = 0;
 508
 509static 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
 551int __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                LED_DATA_REG = data_reg;
 572                led_func_ptr = led_LASI_driver;
 573                printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
 574                led_type = LED_NOLCD;
 575                break;
 576
 577        case DISPLAY_MODEL_OLD_ASP:
 578                LED_DATA_REG = data_reg;
 579                led_func_ptr = led_ASP_driver;
 580                printk(KERN_INFO "LED (ASP-style) display at %lx registered\n", 
 581                    LED_DATA_REG);
 582                led_type = LED_NOLCD;
 583                break;
 584
 585        default:
 586                printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
 587                       __func__, lcd_info.model);
 588                return 1;
 589        }
 590        
 591        /* mark the LCD/LED driver now as initialized and 
 592         * register to the reboot notifier chain */
 593        initialized++;
 594        register_reboot_notifier(&led_notifier);
 595
 596        /* Ensure the work is queued */
 597        if (led_wq) {
 598                queue_delayed_work(led_wq, &led_task, 0);
 599        }
 600
 601        return 0;
 602}
 603
 604/*
 605   ** register_led_regions()
 606   ** 
 607   ** register_led_regions() registers the LCD/LED regions for /procfs.
 608   ** At bootup - where the initialisation of the LCD/LED normally happens - 
 609   ** not all internal structures of request_region() are properly set up,
 610   ** so that we delay the led-registration until after busdevices_init() 
 611   ** has been executed.
 612   **
 613 */
 614
 615void __init register_led_regions(void)
 616{
 617        switch (lcd_info.model) {
 618        case DISPLAY_MODEL_LCD:
 619                request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
 620                request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
 621                break;
 622        case DISPLAY_MODEL_LASI:
 623        case DISPLAY_MODEL_OLD_ASP:
 624                request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
 625                break;
 626        }
 627}
 628
 629
 630/*
 631   ** 
 632   ** lcd_print()
 633   ** 
 634   ** Displays the given string on the LCD-Display of newer machines.
 635   ** lcd_print() disables/enables the timer-based led work queue to
 636   ** avoid a race condition while writing the CMD/DATA register pair.
 637   **
 638 */
 639int lcd_print( const char *str )
 640{
 641        int i;
 642
 643        if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
 644            return 0;
 645        
 646        /* temporarily disable the led work task */
 647        if (led_wq)
 648                cancel_delayed_work_sync(&led_task);
 649
 650        /* copy display string to buffer for procfs */
 651        strlcpy(lcd_text, str, sizeof(lcd_text));
 652
 653        /* Set LCD Cursor to 1st character */
 654        gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
 655        udelay(lcd_info.min_cmd_delay);
 656
 657        /* Print the string */
 658        for (i=0; i < lcd_info.lcd_width; i++) {
 659            if (str && *str)
 660                gsc_writeb(*str++, LCD_DATA_REG);
 661            else
 662                gsc_writeb(' ', LCD_DATA_REG);
 663            udelay(lcd_info.min_cmd_delay);
 664        }
 665        
 666        /* re-queue the work */
 667        if (led_wq) {
 668                queue_delayed_work(led_wq, &led_task, 0);
 669        }
 670
 671        return lcd_info.lcd_width;
 672}
 673
 674/*
 675   ** led_init()
 676   ** 
 677   ** led_init() is called very early in the bootup-process from setup.c 
 678   ** and asks the PDC for an usable chassis LCD or LED.
 679   ** If the PDC doesn't return any info, then the LED
 680   ** is detected by lasi.c or asp.c and registered with the
 681   ** above functions lasi_led_init() or asp_led_init().
 682   ** KittyHawk machines have often a buggy PDC, so that
 683   ** we explicitly check for those machines here.
 684 */
 685
 686int __init led_init(void)
 687{
 688        struct pdc_chassis_info chassis_info;
 689        int ret;
 690
 691        snprintf(lcd_text_default, sizeof(lcd_text_default),
 692                "Linux %s", init_utsname()->release);
 693
 694        /* Work around the buggy PDC of KittyHawk-machines */
 695        switch (CPU_HVERSION) {
 696        case 0x580:             /* KittyHawk DC2-100 (K100) */
 697        case 0x581:             /* KittyHawk DC3-120 (K210) */
 698        case 0x582:             /* KittyHawk DC3 100 (K400) */
 699        case 0x583:             /* KittyHawk DC3 120 (K410) */
 700        case 0x58B:             /* KittyHawk DC2 100 (K200) */
 701                printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
 702                                "LED detection skipped.\n", __FILE__, CPU_HVERSION);
 703                lcd_no_led_support = 1;
 704                goto found;     /* use the preinitialized values of lcd_info */
 705        }
 706
 707        /* initialize the struct, so that we can check for valid return values */
 708        lcd_info.model = DISPLAY_MODEL_NONE;
 709        chassis_info.actcnt = chassis_info.maxcnt = 0;
 710
 711        ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
 712        if (ret == PDC_OK) {
 713                DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
 714                         "lcd_width=%d, cmd_delay=%u,\n"
 715                         "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
 716                         __FILE__, lcd_info.model,
 717                         (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
 718                          (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
 719                         lcd_info.lcd_width, lcd_info.min_cmd_delay,
 720                         __FILE__, sizeof(lcd_info), 
 721                         chassis_info.actcnt, chassis_info.maxcnt));
 722                DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
 723                        __FILE__, lcd_info.lcd_cmd_reg_addr, 
 724                        lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,  
 725                        lcd_info.reset_cmd2, lcd_info.act_enable ));
 726        
 727                /* check the results. Some machines have a buggy PDC */
 728                if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
 729                        goto not_found;
 730
 731                switch (lcd_info.model) {
 732                case DISPLAY_MODEL_LCD:         /* LCD display */
 733                        if (chassis_info.actcnt < 
 734                                offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
 735                                goto not_found;
 736                        if (!lcd_info.act_enable) {
 737                                DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
 738                                goto not_found;
 739                        }
 740                        break;
 741
 742                case DISPLAY_MODEL_NONE:        /* no LED or LCD available */
 743                        printk(KERN_INFO "PDC reported no LCD or LED.\n");
 744                        goto not_found;
 745
 746                case DISPLAY_MODEL_LASI:        /* Lasi style 8 bit LED display */
 747                        if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
 748                                goto not_found;
 749                        break;
 750
 751                default:
 752                        printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
 753                               lcd_info.model);
 754                        goto not_found;
 755                } /* switch() */
 756
 757found:
 758                /* register the LCD/LED driver */
 759                register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
 760                return 0;
 761
 762        } else { /* if() */
 763                DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
 764        }
 765
 766not_found:
 767        lcd_info.model = DISPLAY_MODEL_NONE;
 768        return 1;
 769}
 770
 771static void __exit led_exit(void)
 772{
 773        unregister_reboot_notifier(&led_notifier);
 774        return;
 775}
 776
 777#ifdef CONFIG_PROC_FS
 778module_init(led_create_procfs)
 779#endif
 780
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