xref: /openbmc/linux/drivers/parisc/led.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 
59 static int led_type __read_mostly = -1;
60 static unsigned char lastleds;	/* LED state from most recent update */
61 static unsigned int led_heartbeat __read_mostly = 1;
62 static unsigned int led_diskio    __read_mostly = 1;
63 static unsigned int led_lanrxtx   __read_mostly = 1;
64 static char lcd_text[32]          __read_mostly;
65 static char lcd_text_default[32]  __read_mostly;
66 
67 
68 static struct workqueue_struct *led_wq;
69 static void led_work_func(struct work_struct *);
70 static DECLARE_DELAYED_WORK(led_task, led_work_func);
71 
72 #if 0
73 #define DPRINTK(x)	printk x
74 #else
75 #define DPRINTK(x)
76 #endif
77 
78 struct lcd_block {
79 	unsigned char command;	/* stores the command byte      */
80 	unsigned char on;	/* value for turning LED on     */
81 	unsigned char off;	/* value for turning LED off    */
82 };
83 
84 /* Structure returned by PDC_RETURN_CHASSIS_INFO */
85 /* NOTE: we use unsigned long:16 two times, since the following member
86    lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */
87 struct pdc_chassis_lcd_info_ret_block {
88 	unsigned long model:16;		/* DISPLAY_MODEL_XXXX */
89 	unsigned long lcd_width:16;	/* width of the LCD in chars (DISPLAY_MODEL_LCD only) */
90 	unsigned long lcd_cmd_reg_addr;	/* ptr to LCD cmd-register & data ptr for LED */
91 	unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */
92 	unsigned int min_cmd_delay;	/* delay in uS after cmd-write (LCD only) */
93 	unsigned char reset_cmd1;	/* command #1 for writing LCD string (LCD only) */
94 	unsigned char reset_cmd2;	/* command #2 for writing LCD string (LCD only) */
95 	unsigned char act_enable;	/* 0 = no activity (LCD only) */
96 	struct lcd_block heartbeat;
97 	struct lcd_block disk_io;
98 	struct lcd_block lan_rcv;
99 	struct lcd_block lan_tx;
100 	char _pad;
101 };
102 
103 
104 /* LCD_CMD and LCD_DATA for KittyHawk machines */
105 #define KITTYHAWK_LCD_CMD  F_EXTEND(0xf0190000UL) /* 64bit-ready */
106 #define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1)
107 
108 /* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's
109  * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
110 static struct pdc_chassis_lcd_info_ret_block
111 lcd_info __attribute__((aligned(8))) __read_mostly =
112 {
113 	.model =		DISPLAY_MODEL_LCD,
114 	.lcd_width =		16,
115 	.lcd_cmd_reg_addr =	KITTYHAWK_LCD_CMD,
116 	.lcd_data_reg_addr =	KITTYHAWK_LCD_DATA,
117 	.min_cmd_delay =	40,
118 	.reset_cmd1 =		0x80,
119 	.reset_cmd2 =		0xc0,
120 };
121 
122 
123 /* direct access to some of the lcd_info variables */
124 #define LCD_CMD_REG	lcd_info.lcd_cmd_reg_addr
125 #define LCD_DATA_REG	lcd_info.lcd_data_reg_addr
126 #define LED_DATA_REG	lcd_info.lcd_cmd_reg_addr	/* LASI & ASP only */
127 
128 #define LED_HASLCD 1
129 #define LED_NOLCD  0
130 
131 /* The workqueue must be created at init-time */
132 static int start_task(void)
133 {
134 	/* Display the default text now */
135 	if (led_type == LED_HASLCD) lcd_print( lcd_text_default );
136 
137 	/* Create the work queue and queue the LED task */
138 	led_wq = create_singlethread_workqueue("led_wq");
139 	queue_delayed_work(led_wq, &led_task, 0);
140 
141 	return 0;
142 }
143 
144 device_initcall(start_task);
145 
146 /* ptr to LCD/LED-specific function */
147 static void (*led_func_ptr) (unsigned char) __read_mostly;
148 
149 #ifdef CONFIG_PROC_FS
150 static int led_proc_read(char *page, char **start, off_t off, int count,
151 	int *eof, void *data)
152 {
153 	char *out = page;
154 	int len;
155 
156 	switch ((long)data)
157 	{
158 	case LED_NOLCD:
159 		out += sprintf(out, "Heartbeat: %d\n", led_heartbeat);
160 		out += sprintf(out, "Disk IO: %d\n", led_diskio);
161 		out += sprintf(out, "LAN Rx/Tx: %d\n", led_lanrxtx);
162 		break;
163 	case LED_HASLCD:
164 		out += sprintf(out, "%s\n", lcd_text);
165 		break;
166 	default:
167 		*eof = 1;
168 		return 0;
169 	}
170 
171 	len = out - page - off;
172 	if (len < count) {
173 		*eof = 1;
174 		if (len <= 0) return 0;
175 	} else {
176 		len = count;
177 	}
178 	*start = page + off;
179 	return len;
180 }
181 
182 static int led_proc_write(struct file *file, const char *buf,
183 	unsigned long count, void *data)
184 {
185 	char *cur, lbuf[count + 1];
186 	int d;
187 
188 	if (!capable(CAP_SYS_ADMIN))
189 		return -EACCES;
190 
191 	memset(lbuf, 0, count + 1);
192 
193 	if (copy_from_user(lbuf, buf, count))
194 		return -EFAULT;
195 
196 	cur = lbuf;
197 
198 	/* skip initial spaces */
199 	while (*cur && isspace(*cur))
200 	{
201 		cur++;
202 	}
203 
204 	switch ((long)data)
205 	{
206 	case LED_NOLCD:
207 		d = *cur++ - '0';
208 		if (d != 0 && d != 1) goto parse_error;
209 		led_heartbeat = d;
210 
211 		if (*cur++ != ' ') goto parse_error;
212 
213 		d = *cur++ - '0';
214 		if (d != 0 && d != 1) goto parse_error;
215 		led_diskio = d;
216 
217 		if (*cur++ != ' ') goto parse_error;
218 
219 		d = *cur++ - '0';
220 		if (d != 0 && d != 1) goto parse_error;
221 		led_lanrxtx = d;
222 
223 		break;
224 	case LED_HASLCD:
225 		if (*cur && cur[strlen(cur)-1] == '\n')
226 			cur[strlen(cur)-1] = 0;
227 		if (*cur == 0)
228 			cur = lcd_text_default;
229 		lcd_print(cur);
230 		break;
231 	default:
232 		return 0;
233 	}
234 
235 	return count;
236 
237 parse_error:
238 	if ((long)data == LED_NOLCD)
239 		printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n");
240 	return -EINVAL;
241 }
242 
243 static int __init led_create_procfs(void)
244 {
245 	struct proc_dir_entry *proc_pdc_root = NULL;
246 	struct proc_dir_entry *ent;
247 
248 	if (led_type == -1) return -1;
249 
250 	proc_pdc_root = proc_mkdir("pdc", 0);
251 	if (!proc_pdc_root) return -1;
252 	proc_pdc_root->owner = THIS_MODULE;
253 	ent = create_proc_entry("led", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
254 	if (!ent) return -1;
255 	ent->data = (void *)LED_NOLCD; /* LED */
256 	ent->read_proc = led_proc_read;
257 	ent->write_proc = led_proc_write;
258 	ent->owner = THIS_MODULE;
259 
260 	if (led_type == LED_HASLCD)
261 	{
262 		ent = create_proc_entry("lcd", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
263 		if (!ent) return -1;
264 		ent->data = (void *)LED_HASLCD; /* LCD */
265 		ent->read_proc = led_proc_read;
266 		ent->write_proc = led_proc_write;
267 		ent->owner = THIS_MODULE;
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 unsigned long rx_total_last, tx_total_last;
358 	unsigned long 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 locking dev_base
365 	 * for reading should be OK */
366 	read_lock(&dev_base_lock);
367 	rcu_read_lock();
368 	for_each_netdev(dev) {
369 	    struct net_device_stats *stats;
370 	    struct in_device *in_dev = __in_dev_get_rcu(dev);
371 	    if (!in_dev || !in_dev->ifa_list)
372 		continue;
373 	    if (LOOPBACK(in_dev->ifa_list->ifa_local))
374 		continue;
375 	    stats = dev->get_stats(dev);
376 	    rx_total += stats->rx_packets;
377 	    tx_total += stats->tx_packets;
378 	}
379 	rcu_read_unlock();
380 	read_unlock(&dev_base_lock);
381 
382 	retval = 0;
383 
384 	if (rx_total != rx_total_last) {
385 		rx_total_last = rx_total;
386 		retval |= LED_LAN_RCV;
387 	}
388 
389 	if (tx_total != tx_total_last) {
390 		tx_total_last = tx_total;
391 		retval |= LED_LAN_TX;
392 	}
393 
394 	return retval;
395 #endif
396 }
397 
398 
399 /*
400    **
401    ** led_get_diskio_activity()
402    **
403    ** calculate if there was disk-io in the system
404    **
405  */
406 static __inline__ int led_get_diskio_activity(void)
407 {
408 	static unsigned long last_pgpgin, last_pgpgout;
409 	unsigned long events[NR_VM_EVENT_ITEMS];
410 	int changed;
411 
412 	all_vm_events(events);
413 
414 	/* Just use a very simple calculation here. Do not care about overflow,
415 	   since we only want to know if there was activity or not. */
416 	changed = (events[PGPGIN] != last_pgpgin) ||
417 		  (events[PGPGOUT] != last_pgpgout);
418 	last_pgpgin  = events[PGPGIN];
419 	last_pgpgout = events[PGPGOUT];
420 
421 	return (changed ? LED_DISK_IO : 0);
422 }
423 
424 
425 
426 /*
427    ** led_work_func()
428    **
429    ** manages when and which chassis LCD/LED gets updated
430 
431     TODO:
432     - display load average (older machines like 715/64 have 4 "free" LED's for that)
433     - optimizations
434  */
435 
436 #define HEARTBEAT_LEN (HZ*10/100)
437 #define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
438 #define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
439 
440 #define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
441 
442 static void led_work_func (struct work_struct *unused)
443 {
444 	static unsigned long last_jiffies;
445 	static unsigned long count_HZ; /* counter in range 0..HZ */
446 	unsigned char currentleds = 0; /* stores current value of the LEDs */
447 
448 	/* exit if not initialized */
449 	if (!led_func_ptr)
450 	    return;
451 
452 	/* increment the heartbeat timekeeper */
453 	count_HZ += jiffies - last_jiffies;
454 	last_jiffies = jiffies;
455 	if (count_HZ >= HZ)
456 	    count_HZ = 0;
457 
458 	if (likely(led_heartbeat))
459 	{
460 		/* flash heartbeat-LED like a real heart
461 		 * (2 x short then a long delay)
462 		 */
463 		if (count_HZ < HEARTBEAT_LEN ||
464 				(count_HZ >= HEARTBEAT_2ND_RANGE_START &&
465 				count_HZ < HEARTBEAT_2ND_RANGE_END))
466 			currentleds |= LED_HEARTBEAT;
467 	}
468 
469 	if (likely(led_lanrxtx))  currentleds |= led_get_net_activity();
470 	if (likely(led_diskio))   currentleds |= led_get_diskio_activity();
471 
472 	/* blink all LEDs twice a second if we got an Oops (HPMC) */
473 	if (unlikely(oops_in_progress))
474 		currentleds = (count_HZ<=(HZ/2)) ? 0 : 0xff;
475 
476 	if (currentleds != lastleds)
477 	{
478 		led_func_ptr(currentleds);	/* Update the LCD/LEDs */
479 		lastleds = currentleds;
480 	}
481 
482 	queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
483 }
484 
485 /*
486    ** led_halt()
487    **
488    ** called by the reboot notifier chain at shutdown and stops all
489    ** LED/LCD activities.
490    **
491  */
492 
493 static int led_halt(struct notifier_block *, unsigned long, void *);
494 
495 static struct notifier_block led_notifier = {
496 	.notifier_call = led_halt,
497 };
498 static int notifier_disabled = 0;
499 
500 static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
501 {
502 	char *txt;
503 
504 	if (notifier_disabled)
505 		return NOTIFY_OK;
506 
507 	notifier_disabled = 1;
508 	switch (event) {
509 	case SYS_RESTART:	txt = "SYSTEM RESTART";
510 				break;
511 	case SYS_HALT:		txt = "SYSTEM HALT";
512 				break;
513 	case SYS_POWER_OFF:	txt = "SYSTEM POWER OFF";
514 				break;
515 	default:		return NOTIFY_DONE;
516 	}
517 
518 	/* Cancel the work item and delete the queue */
519 	if (led_wq) {
520 		cancel_rearming_delayed_workqueue(led_wq, &led_task);
521 		destroy_workqueue(led_wq);
522 		led_wq = NULL;
523 	}
524 
525 	if (lcd_info.model == DISPLAY_MODEL_LCD)
526 		lcd_print(txt);
527 	else
528 		if (led_func_ptr)
529 			led_func_ptr(0xff); /* turn all LEDs ON */
530 
531 	return NOTIFY_OK;
532 }
533 
534 /*
535    ** register_led_driver()
536    **
537    ** registers an external LED or LCD for usage by this driver.
538    ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
539    **
540  */
541 
542 int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
543 {
544 	static int initialized;
545 
546 	if (initialized || !data_reg)
547 		return 1;
548 
549 	lcd_info.model = model;		/* store the values */
550 	LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
551 
552 	switch (lcd_info.model) {
553 	case DISPLAY_MODEL_LCD:
554 		LCD_DATA_REG = data_reg;
555 		printk(KERN_INFO "LCD display at %lx,%lx registered\n",
556 			LCD_CMD_REG , LCD_DATA_REG);
557 		led_func_ptr = led_LCD_driver;
558 		led_type = LED_HASLCD;
559 		break;
560 
561 	case DISPLAY_MODEL_LASI:
562 		LED_DATA_REG = data_reg;
563 		led_func_ptr = led_LASI_driver;
564 		printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
565 		led_type = LED_NOLCD;
566 		break;
567 
568 	case DISPLAY_MODEL_OLD_ASP:
569 		LED_DATA_REG = data_reg;
570 		led_func_ptr = led_ASP_driver;
571 		printk(KERN_INFO "LED (ASP-style) display at %lx registered\n",
572 		    LED_DATA_REG);
573 		led_type = LED_NOLCD;
574 		break;
575 
576 	default:
577 		printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
578 		       __FUNCTION__, lcd_info.model);
579 		return 1;
580 	}
581 
582 	/* mark the LCD/LED driver now as initialized and
583 	 * register to the reboot notifier chain */
584 	initialized++;
585 	register_reboot_notifier(&led_notifier);
586 
587 	/* Ensure the work is queued */
588 	if (led_wq) {
589 		queue_delayed_work(led_wq, &led_task, 0);
590 	}
591 
592 	return 0;
593 }
594 
595 /*
596    ** register_led_regions()
597    **
598    ** register_led_regions() registers the LCD/LED regions for /procfs.
599    ** At bootup - where the initialisation of the LCD/LED normally happens -
600    ** not all internal structures of request_region() are properly set up,
601    ** so that we delay the led-registration until after busdevices_init()
602    ** has been executed.
603    **
604  */
605 
606 void __init register_led_regions(void)
607 {
608 	switch (lcd_info.model) {
609 	case DISPLAY_MODEL_LCD:
610 		request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
611 		request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
612 		break;
613 	case DISPLAY_MODEL_LASI:
614 	case DISPLAY_MODEL_OLD_ASP:
615 		request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
616 		break;
617 	}
618 }
619 
620 
621 /*
622    **
623    ** lcd_print()
624    **
625    ** Displays the given string on the LCD-Display of newer machines.
626    ** lcd_print() disables/enables the timer-based led work queue to
627    ** avoid a race condition while writing the CMD/DATA register pair.
628    **
629  */
630 int lcd_print( const char *str )
631 {
632 	int i;
633 
634 	if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
635 	    return 0;
636 
637 	/* temporarily disable the led work task */
638 	if (led_wq)
639 		cancel_rearming_delayed_workqueue(led_wq, &led_task);
640 
641 	/* copy display string to buffer for procfs */
642 	strlcpy(lcd_text, str, sizeof(lcd_text));
643 
644 	/* Set LCD Cursor to 1st character */
645 	gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
646 	udelay(lcd_info.min_cmd_delay);
647 
648 	/* Print the string */
649 	for (i=0; i < lcd_info.lcd_width; i++) {
650 	    if (str && *str)
651 		gsc_writeb(*str++, LCD_DATA_REG);
652 	    else
653 		gsc_writeb(' ', LCD_DATA_REG);
654 	    udelay(lcd_info.min_cmd_delay);
655 	}
656 
657 	/* re-queue the work */
658 	if (led_wq) {
659 		queue_delayed_work(led_wq, &led_task, 0);
660 	}
661 
662 	return lcd_info.lcd_width;
663 }
664 
665 /*
666    ** led_init()
667    **
668    ** led_init() is called very early in the bootup-process from setup.c
669    ** and asks the PDC for an usable chassis LCD or LED.
670    ** If the PDC doesn't return any info, then the LED
671    ** is detected by lasi.c or asp.c and registered with the
672    ** above functions lasi_led_init() or asp_led_init().
673    ** KittyHawk machines have often a buggy PDC, so that
674    ** we explicitly check for those machines here.
675  */
676 
677 int __init led_init(void)
678 {
679 	struct pdc_chassis_info chassis_info;
680 	int ret;
681 
682 	snprintf(lcd_text_default, sizeof(lcd_text_default),
683 		"Linux %s", init_utsname()->release);
684 
685 	/* Work around the buggy PDC of KittyHawk-machines */
686 	switch (CPU_HVERSION) {
687 	case 0x580:		/* KittyHawk DC2-100 (K100) */
688 	case 0x581:		/* KittyHawk DC3-120 (K210) */
689 	case 0x582:		/* KittyHawk DC3 100 (K400) */
690 	case 0x583:		/* KittyHawk DC3 120 (K410) */
691 	case 0x58B:		/* KittyHawk DC2 100 (K200) */
692 		printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
693 				"LED detection skipped.\n", __FILE__, CPU_HVERSION);
694 		goto found;	/* use the preinitialized values of lcd_info */
695 	}
696 
697 	/* initialize the struct, so that we can check for valid return values */
698 	lcd_info.model = DISPLAY_MODEL_NONE;
699 	chassis_info.actcnt = chassis_info.maxcnt = 0;
700 
701 	ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
702 	if (ret == PDC_OK) {
703 		DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
704 			 "lcd_width=%d, cmd_delay=%u,\n"
705 			 "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
706 		         __FILE__, lcd_info.model,
707 			 (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
708 			  (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
709 			 lcd_info.lcd_width, lcd_info.min_cmd_delay,
710 			 __FILE__, sizeof(lcd_info),
711 			 chassis_info.actcnt, chassis_info.maxcnt));
712 		DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
713 			__FILE__, lcd_info.lcd_cmd_reg_addr,
714 			lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
715 			lcd_info.reset_cmd2, lcd_info.act_enable ));
716 
717 		/* check the results. Some machines have a buggy PDC */
718 		if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
719 			goto not_found;
720 
721 		switch (lcd_info.model) {
722 		case DISPLAY_MODEL_LCD:		/* LCD display */
723 			if (chassis_info.actcnt <
724 				offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
725 				goto not_found;
726 			if (!lcd_info.act_enable) {
727 				DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
728 				goto not_found;
729 			}
730 			break;
731 
732 		case DISPLAY_MODEL_NONE:	/* no LED or LCD available */
733 			printk(KERN_INFO "PDC reported no LCD or LED.\n");
734 			goto not_found;
735 
736 		case DISPLAY_MODEL_LASI:	/* Lasi style 8 bit LED display */
737 			if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
738 				goto not_found;
739 			break;
740 
741 		default:
742 			printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
743 			       lcd_info.model);
744 			goto not_found;
745 		} /* switch() */
746 
747 found:
748 		/* register the LCD/LED driver */
749 		register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
750 		return 0;
751 
752 	} else { /* if() */
753 		DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
754 	}
755 
756 not_found:
757 	lcd_info.model = DISPLAY_MODEL_NONE;
758 	return 1;
759 }
760 
761 static void __exit led_exit(void)
762 {
763 	unregister_reboot_notifier(&led_notifier);
764 	return;
765 }
766 
767 #ifdef CONFIG_PROC_FS
768 module_init(led_create_procfs)
769 #endif
770