xref: /linux/drivers/parisc/led.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/config.h>
27 #include <linux/module.h>
28 #include <linux/stddef.h>	/* for offsetof() */
29 #include <linux/init.h>
30 #include <linux/types.h>
31 #include <linux/ioport.h>
32 #include <linux/utsname.h>
33 #include <linux/capability.h>
34 #include <linux/delay.h>
35 #include <linux/netdevice.h>
36 #include <linux/inetdevice.h>
37 #include <linux/in.h>
38 #include <linux/interrupt.h>
39 #include <linux/kernel_stat.h>
40 #include <linux/reboot.h>
41 #include <linux/proc_fs.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 
60 static int led_type __read_mostly = -1;
61 static unsigned char lastleds;	/* LED state from most recent update */
62 static unsigned int led_heartbeat __read_mostly = 1;
63 static unsigned int led_diskio    __read_mostly = 1;
64 static unsigned int led_lanrxtx   __read_mostly = 1;
65 static char lcd_text[32]          __read_mostly;
66 static char lcd_text_default[32]  __read_mostly;
67 
68 
69 static struct workqueue_struct *led_wq;
70 static void led_work_func(void *);
71 static DECLARE_WORK(led_task, led_work_func, NULL);
72 
73 #if 0
74 #define DPRINTK(x)	printk x
75 #else
76 #define DPRINTK(x)
77 #endif
78 
79 struct lcd_block {
80 	unsigned char command;	/* stores the command byte      */
81 	unsigned char on;	/* value for turning LED on     */
82 	unsigned char off;	/* value for turning LED off    */
83 };
84 
85 /* Structure returned by PDC_RETURN_CHASSIS_INFO */
86 /* NOTE: we use unsigned long:16 two times, since the following member
87    lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */
88 struct pdc_chassis_lcd_info_ret_block {
89 	unsigned long model:16;		/* DISPLAY_MODEL_XXXX */
90 	unsigned long lcd_width:16;	/* width of the LCD in chars (DISPLAY_MODEL_LCD only) */
91 	unsigned long lcd_cmd_reg_addr;	/* ptr to LCD cmd-register & data ptr for LED */
92 	unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */
93 	unsigned int min_cmd_delay;	/* delay in uS after cmd-write (LCD only) */
94 	unsigned char reset_cmd1;	/* command #1 for writing LCD string (LCD only) */
95 	unsigned char reset_cmd2;	/* command #2 for writing LCD string (LCD only) */
96 	unsigned char act_enable;	/* 0 = no activity (LCD only) */
97 	struct lcd_block heartbeat;
98 	struct lcd_block disk_io;
99 	struct lcd_block lan_rcv;
100 	struct lcd_block lan_tx;
101 	char _pad;
102 };
103 
104 
105 /* LCD_CMD and LCD_DATA for KittyHawk machines */
106 #define KITTYHAWK_LCD_CMD  F_EXTEND(0xf0190000UL) /* 64bit-ready */
107 #define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1)
108 
109 /* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's
110  * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
111 static struct pdc_chassis_lcd_info_ret_block
112 lcd_info __attribute__((aligned(8))) __read_mostly =
113 {
114 	.model =		DISPLAY_MODEL_LCD,
115 	.lcd_width =		16,
116 	.lcd_cmd_reg_addr =	KITTYHAWK_LCD_CMD,
117 	.lcd_data_reg_addr =	KITTYHAWK_LCD_DATA,
118 	.min_cmd_delay =	40,
119 	.reset_cmd1 =		0x80,
120 	.reset_cmd2 =		0xc0,
121 };
122 
123 
124 /* direct access to some of the lcd_info variables */
125 #define LCD_CMD_REG	lcd_info.lcd_cmd_reg_addr
126 #define LCD_DATA_REG	lcd_info.lcd_data_reg_addr
127 #define LED_DATA_REG	lcd_info.lcd_cmd_reg_addr	/* LASI & ASP only */
128 
129 #define LED_HASLCD 1
130 #define LED_NOLCD  0
131 
132 /* The workqueue must be created at init-time */
133 static int start_task(void)
134 {
135 	/* Display the default text now */
136 	if (led_type == LED_HASLCD) lcd_print( lcd_text_default );
137 
138 	/* Create the work queue and queue the LED task */
139 	led_wq = create_singlethread_workqueue("led_wq");
140 	queue_work(led_wq, &led_task);
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_read(char *page, char **start, off_t off, int count,
152 	int *eof, void *data)
153 {
154 	char *out = page;
155 	int len;
156 
157 	switch ((long)data)
158 	{
159 	case LED_NOLCD:
160 		out += sprintf(out, "Heartbeat: %d\n", led_heartbeat);
161 		out += sprintf(out, "Disk IO: %d\n", led_diskio);
162 		out += sprintf(out, "LAN Rx/Tx: %d\n", led_lanrxtx);
163 		break;
164 	case LED_HASLCD:
165 		out += sprintf(out, "%s\n", lcd_text);
166 		break;
167 	default:
168 		*eof = 1;
169 		return 0;
170 	}
171 
172 	len = out - page - off;
173 	if (len < count) {
174 		*eof = 1;
175 		if (len <= 0) return 0;
176 	} else {
177 		len = count;
178 	}
179 	*start = page + off;
180 	return len;
181 }
182 
183 static int led_proc_write(struct file *file, const char *buf,
184 	unsigned long count, void *data)
185 {
186 	char *cur, lbuf[count + 1];
187 	int d;
188 
189 	if (!capable(CAP_SYS_ADMIN))
190 		return -EACCES;
191 
192 	memset(lbuf, 0, count + 1);
193 
194 	if (copy_from_user(lbuf, buf, count))
195 		return -EFAULT;
196 
197 	cur = lbuf;
198 
199 	/* skip initial spaces */
200 	while (*cur && isspace(*cur))
201 	{
202 		cur++;
203 	}
204 
205 	switch ((long)data)
206 	{
207 	case LED_NOLCD:
208 		d = *cur++ - '0';
209 		if (d != 0 && d != 1) goto parse_error;
210 		led_heartbeat = d;
211 
212 		if (*cur++ != ' ') goto parse_error;
213 
214 		d = *cur++ - '0';
215 		if (d != 0 && d != 1) goto parse_error;
216 		led_diskio = d;
217 
218 		if (*cur++ != ' ') goto parse_error;
219 
220 		d = *cur++ - '0';
221 		if (d != 0 && d != 1) goto parse_error;
222 		led_lanrxtx = d;
223 
224 		break;
225 	case LED_HASLCD:
226 		if (*cur && cur[strlen(cur)-1] == '\n')
227 			cur[strlen(cur)-1] = 0;
228 		if (*cur == 0)
229 			cur = lcd_text_default;
230 		lcd_print(cur);
231 		break;
232 	default:
233 		return 0;
234 	}
235 
236 	return count;
237 
238 parse_error:
239 	if ((long)data == LED_NOLCD)
240 		printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n");
241 	return -EINVAL;
242 }
243 
244 static int __init led_create_procfs(void)
245 {
246 	struct proc_dir_entry *proc_pdc_root = NULL;
247 	struct proc_dir_entry *ent;
248 
249 	if (led_type == -1) return -1;
250 
251 	proc_pdc_root = proc_mkdir("pdc", 0);
252 	if (!proc_pdc_root) return -1;
253 	proc_pdc_root->owner = THIS_MODULE;
254 	ent = create_proc_entry("led", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
255 	if (!ent) return -1;
256 	ent->nlink = 1;
257 	ent->data = (void *)LED_NOLCD; /* LED */
258 	ent->read_proc = led_proc_read;
259 	ent->write_proc = led_proc_write;
260 	ent->owner = THIS_MODULE;
261 
262 	if (led_type == LED_HASLCD)
263 	{
264 		ent = create_proc_entry("lcd", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
265 		if (!ent) return -1;
266 		ent->nlink = 1;
267 		ent->data = (void *)LED_HASLCD; /* LCD */
268 		ent->read_proc = led_proc_read;
269 		ent->write_proc = led_proc_write;
270 		ent->owner = THIS_MODULE;
271 	}
272 
273 	return 0;
274 }
275 #endif
276 
277 /*
278    **
279    ** led_ASP_driver()
280    **
281  */
282 #define	LED_DATA	0x01	/* data to shift (0:on 1:off) */
283 #define	LED_STROBE	0x02	/* strobe to clock data */
284 static void led_ASP_driver(unsigned char leds)
285 {
286 	int i;
287 
288 	leds = ~leds;
289 	for (i = 0; i < 8; i++) {
290 		unsigned char value;
291 		value = (leds & 0x80) >> 7;
292 		gsc_writeb( value,		 LED_DATA_REG );
293 		gsc_writeb( value | LED_STROBE,	 LED_DATA_REG );
294 		leds <<= 1;
295 	}
296 }
297 
298 
299 /*
300    **
301    ** led_LASI_driver()
302    **
303  */
304 static void led_LASI_driver(unsigned char leds)
305 {
306 	leds = ~leds;
307 	gsc_writeb( leds, LED_DATA_REG );
308 }
309 
310 
311 /*
312    **
313    ** led_LCD_driver()
314    **
315  */
316 static void led_LCD_driver(unsigned char leds)
317 {
318 	static int i;
319 	static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
320 		LED_LAN_RCV, LED_LAN_TX };
321 
322 	static struct lcd_block * blockp[4] = {
323 		&lcd_info.heartbeat,
324 		&lcd_info.disk_io,
325 		&lcd_info.lan_rcv,
326 		&lcd_info.lan_tx
327 	};
328 
329 	/* Convert min_cmd_delay to milliseconds */
330 	unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000);
331 
332 	for (i=0; i<4; ++i)
333 	{
334 		if ((leds & mask[i]) != (lastleds & mask[i]))
335 		{
336 			gsc_writeb( blockp[i]->command, LCD_CMD_REG );
337 			msleep(msec_cmd_delay);
338 
339 			gsc_writeb( leds & mask[i] ? blockp[i]->on :
340 					blockp[i]->off, LCD_DATA_REG );
341 			msleep(msec_cmd_delay);
342 		}
343 	}
344 }
345 
346 
347 /*
348    **
349    ** led_get_net_activity()
350    **
351    ** calculate if there was TX- or RX-throughput on the network interfaces
352    ** (analog to dev_get_info() from net/core/dev.c)
353    **
354  */
355 static __inline__ int led_get_net_activity(void)
356 {
357 #ifndef CONFIG_NET
358 	return 0;
359 #else
360 	static unsigned long rx_total_last, tx_total_last;
361 	unsigned long rx_total, tx_total;
362 	struct net_device *dev;
363 	int retval;
364 
365 	rx_total = tx_total = 0;
366 
367 	/* we are running as a workqueue task, so locking dev_base
368 	 * for reading should be OK */
369 	read_lock(&dev_base_lock);
370 	rcu_read_lock();
371 	for (dev = dev_base; dev; dev = dev->next) {
372 	    struct net_device_stats *stats;
373 	    struct in_device *in_dev = __in_dev_get_rcu(dev);
374 	    if (!in_dev || !in_dev->ifa_list)
375 		continue;
376 	    if (LOOPBACK(in_dev->ifa_list->ifa_local))
377 		continue;
378 	    if (!dev->get_stats)
379 		continue;
380 	    stats = dev->get_stats(dev);
381 	    rx_total += stats->rx_packets;
382 	    tx_total += stats->tx_packets;
383 	}
384 	rcu_read_unlock();
385 	read_unlock(&dev_base_lock);
386 
387 	retval = 0;
388 
389 	if (rx_total != rx_total_last) {
390 		rx_total_last = rx_total;
391 		retval |= LED_LAN_RCV;
392 	}
393 
394 	if (tx_total != tx_total_last) {
395 		tx_total_last = tx_total;
396 		retval |= LED_LAN_TX;
397 	}
398 
399 	return retval;
400 #endif
401 }
402 
403 
404 /*
405    **
406    ** led_get_diskio_activity()
407    **
408    ** calculate if there was disk-io in the system
409    **
410  */
411 static __inline__ int led_get_diskio_activity(void)
412 {
413 	static unsigned long last_pgpgin, last_pgpgout;
414 	struct page_state pgstat;
415 	int changed;
416 
417 	get_full_page_state(&pgstat); /* get no of sectors in & out */
418 
419 	/* Just use a very simple calculation here. Do not care about overflow,
420 	   since we only want to know if there was activity or not. */
421 	changed = (pgstat.pgpgin != last_pgpgin) || (pgstat.pgpgout != last_pgpgout);
422 	last_pgpgin  = pgstat.pgpgin;
423 	last_pgpgout = pgstat.pgpgout;
424 
425 	return (changed ? LED_DISK_IO : 0);
426 }
427 
428 
429 
430 /*
431    ** led_work_func()
432    **
433    ** manages when and which chassis LCD/LED gets updated
434 
435     TODO:
436     - display load average (older machines like 715/64 have 4 "free" LED's for that)
437     - optimizations
438  */
439 
440 #define HEARTBEAT_LEN (HZ*10/100)
441 #define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
442 #define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
443 
444 #define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
445 
446 static void led_work_func (void *unused)
447 {
448 	static unsigned long last_jiffies;
449 	static unsigned long count_HZ; /* counter in range 0..HZ */
450 	unsigned char currentleds = 0; /* stores current value of the LEDs */
451 
452 	/* exit if not initialized */
453 	if (!led_func_ptr)
454 	    return;
455 
456 	/* increment the heartbeat timekeeper */
457 	count_HZ += jiffies - last_jiffies;
458 	last_jiffies = jiffies;
459 	if (count_HZ >= HZ)
460 	    count_HZ = 0;
461 
462 	if (likely(led_heartbeat))
463 	{
464 		/* flash heartbeat-LED like a real heart
465 		 * (2 x short then a long delay)
466 		 */
467 		if (count_HZ < HEARTBEAT_LEN ||
468 				(count_HZ >= HEARTBEAT_2ND_RANGE_START &&
469 				count_HZ < HEARTBEAT_2ND_RANGE_END))
470 			currentleds |= LED_HEARTBEAT;
471 	}
472 
473 	if (likely(led_lanrxtx))  currentleds |= led_get_net_activity();
474 	if (likely(led_diskio))   currentleds |= led_get_diskio_activity();
475 
476 	/* blink all LEDs twice a second if we got an Oops (HPMC) */
477 	if (unlikely(oops_in_progress))
478 		currentleds = (count_HZ<=(HZ/2)) ? 0 : 0xff;
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_rearming_delayed_workqueue(led_wq, &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 		LED_DATA_REG = data_reg;
567 		led_func_ptr = led_LASI_driver;
568 		printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
569 		led_type = LED_NOLCD;
570 		break;
571 
572 	case DISPLAY_MODEL_OLD_ASP:
573 		LED_DATA_REG = data_reg;
574 		led_func_ptr = led_ASP_driver;
575 		printk(KERN_INFO "LED (ASP-style) display at %lx registered\n",
576 		    LED_DATA_REG);
577 		led_type = LED_NOLCD;
578 		break;
579 
580 	default:
581 		printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
582 		       __FUNCTION__, lcd_info.model);
583 		return 1;
584 	}
585 
586 	/* mark the LCD/LED driver now as initialized and
587 	 * register to the reboot notifier chain */
588 	initialized++;
589 	register_reboot_notifier(&led_notifier);
590 
591 	/* Ensure the work is queued */
592 	if (led_wq) {
593 		queue_work(led_wq, &led_task);
594 	}
595 
596 	return 0;
597 }
598 
599 /*
600    ** register_led_regions()
601    **
602    ** register_led_regions() registers the LCD/LED regions for /procfs.
603    ** At bootup - where the initialisation of the LCD/LED normally happens -
604    ** not all internal structures of request_region() are properly set up,
605    ** so that we delay the led-registration until after busdevices_init()
606    ** has been executed.
607    **
608  */
609 
610 void __init register_led_regions(void)
611 {
612 	switch (lcd_info.model) {
613 	case DISPLAY_MODEL_LCD:
614 		request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
615 		request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
616 		break;
617 	case DISPLAY_MODEL_LASI:
618 	case DISPLAY_MODEL_OLD_ASP:
619 		request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
620 		break;
621 	}
622 }
623 
624 
625 /*
626    **
627    ** lcd_print()
628    **
629    ** Displays the given string on the LCD-Display of newer machines.
630    ** lcd_print() disables/enables the timer-based led work queue to
631    ** avoid a race condition while writing the CMD/DATA register pair.
632    **
633  */
634 int lcd_print( char *str )
635 {
636 	int i;
637 
638 	if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
639 	    return 0;
640 
641 	/* temporarily disable the led work task */
642 	if (led_wq)
643 		cancel_rearming_delayed_workqueue(led_wq, &led_task);
644 
645 	/* copy display string to buffer for procfs */
646 	strlcpy(lcd_text, str, sizeof(lcd_text));
647 
648 	/* Set LCD Cursor to 1st character */
649 	gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
650 	udelay(lcd_info.min_cmd_delay);
651 
652 	/* Print the string */
653 	for (i=0; i < lcd_info.lcd_width; i++) {
654 	    if (str && *str)
655 		gsc_writeb(*str++, LCD_DATA_REG);
656 	    else
657 		gsc_writeb(' ', LCD_DATA_REG);
658 	    udelay(lcd_info.min_cmd_delay);
659 	}
660 
661 	/* re-queue the work */
662 	if (led_wq) {
663 		queue_work(led_wq, &led_task);
664 	}
665 
666 	return lcd_info.lcd_width;
667 }
668 
669 /*
670    ** led_init()
671    **
672    ** led_init() is called very early in the bootup-process from setup.c
673    ** and asks the PDC for an usable chassis LCD or LED.
674    ** If the PDC doesn't return any info, then the LED
675    ** is detected by lasi.c or asp.c and registered with the
676    ** above functions lasi_led_init() or asp_led_init().
677    ** KittyHawk machines have often a buggy PDC, so that
678    ** we explicitly check for those machines here.
679  */
680 
681 int __init led_init(void)
682 {
683 	struct pdc_chassis_info chassis_info;
684 	int ret;
685 
686 	snprintf(lcd_text_default, sizeof(lcd_text_default),
687 		"Linux %s", system_utsname.release);
688 
689 	/* Work around the buggy PDC of KittyHawk-machines */
690 	switch (CPU_HVERSION) {
691 	case 0x580:		/* KittyHawk DC2-100 (K100) */
692 	case 0x581:		/* KittyHawk DC3-120 (K210) */
693 	case 0x582:		/* KittyHawk DC3 100 (K400) */
694 	case 0x583:		/* KittyHawk DC3 120 (K410) */
695 	case 0x58B:		/* KittyHawk DC2 100 (K200) */
696 		printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
697 				"LED detection skipped.\n", __FILE__, CPU_HVERSION);
698 		goto found;	/* use the preinitialized values of lcd_info */
699 	}
700 
701 	/* initialize the struct, so that we can check for valid return values */
702 	lcd_info.model = DISPLAY_MODEL_NONE;
703 	chassis_info.actcnt = chassis_info.maxcnt = 0;
704 
705 	ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
706 	if (ret == PDC_OK) {
707 		DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
708 			 "lcd_width=%d, cmd_delay=%u,\n"
709 			 "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
710 		         __FILE__, lcd_info.model,
711 			 (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
712 			  (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
713 			 lcd_info.lcd_width, lcd_info.min_cmd_delay,
714 			 __FILE__, sizeof(lcd_info),
715 			 chassis_info.actcnt, chassis_info.maxcnt));
716 		DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
717 			__FILE__, lcd_info.lcd_cmd_reg_addr,
718 			lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
719 			lcd_info.reset_cmd2, lcd_info.act_enable ));
720 
721 		/* check the results. Some machines have a buggy PDC */
722 		if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
723 			goto not_found;
724 
725 		switch (lcd_info.model) {
726 		case DISPLAY_MODEL_LCD:		/* LCD display */
727 			if (chassis_info.actcnt <
728 				offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
729 				goto not_found;
730 			if (!lcd_info.act_enable) {
731 				DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
732 				goto not_found;
733 			}
734 			break;
735 
736 		case DISPLAY_MODEL_NONE:	/* no LED or LCD available */
737 			printk(KERN_INFO "PDC reported no LCD or LED.\n");
738 			goto not_found;
739 
740 		case DISPLAY_MODEL_LASI:	/* Lasi style 8 bit LED display */
741 			if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
742 				goto not_found;
743 			break;
744 
745 		default:
746 			printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
747 			       lcd_info.model);
748 			goto not_found;
749 		} /* switch() */
750 
751 found:
752 		/* register the LCD/LED driver */
753 		register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
754 		return 0;
755 
756 	} else { /* if() */
757 		DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
758 	}
759 
760 not_found:
761 	lcd_info.model = DISPLAY_MODEL_NONE;
762 	return 1;
763 }
764 
765 static void __exit led_exit(void)
766 {
767 	unregister_reboot_notifier(&led_notifier);
768 	return;
769 }
770 
771 #ifdef CONFIG_PROC_FS
772 module_init(led_create_procfs)
773 #endif
774