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  • only in /netgear-R7000-V1.0.7.12_1.2.5/components/opensource/linux/linux-2.6.36/drivers/parisc/
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;
67
68
69static struct workqueue_struct *led_wq;
70static void led_work_func(struct work_struct *);
71static DECLARE_DELAYED_WORK(led_task, led_work_func);
72
73#define DPRINTK(x)
74
75struct lcd_block {
76	unsigned char command;	/* stores the command byte      */
77	unsigned char on;	/* value for turning LED on     */
78	unsigned char off;	/* value for turning LED off    */
79};
80
81/* Structure returned by PDC_RETURN_CHASSIS_INFO */
82/* NOTE: we use unsigned long:16 two times, since the following member
83   lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */
84struct pdc_chassis_lcd_info_ret_block {
85	unsigned long model:16;		/* DISPLAY_MODEL_XXXX */
86	unsigned long lcd_width:16;	/* width of the LCD in chars (DISPLAY_MODEL_LCD only) */
87	unsigned long lcd_cmd_reg_addr;	/* ptr to LCD cmd-register & data ptr for LED */
88	unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */
89	unsigned int min_cmd_delay;	/* delay in uS after cmd-write (LCD only) */
90	unsigned char reset_cmd1;	/* command #1 for writing LCD string (LCD only) */
91	unsigned char reset_cmd2;	/* command #2 for writing LCD string (LCD only) */
92	unsigned char act_enable;	/* 0 = no activity (LCD only) */
93	struct lcd_block heartbeat;
94	struct lcd_block disk_io;
95	struct lcd_block lan_rcv;
96	struct lcd_block lan_tx;
97	char _pad;
98};
99
100
101/* LCD_CMD and LCD_DATA for KittyHawk machines */
102#define KITTYHAWK_LCD_CMD  F_EXTEND(0xf0190000UL) /* 64bit-ready */
103#define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1)
104
105/* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's
106 * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
107static struct pdc_chassis_lcd_info_ret_block
108lcd_info __attribute__((aligned(8))) __read_mostly =
109{
110	.model =		DISPLAY_MODEL_LCD,
111	.lcd_width =		16,
112	.lcd_cmd_reg_addr =	KITTYHAWK_LCD_CMD,
113	.lcd_data_reg_addr =	KITTYHAWK_LCD_DATA,
114	.min_cmd_delay =	40,
115	.reset_cmd1 =		0x80,
116	.reset_cmd2 =		0xc0,
117};
118
119
120/* direct access to some of the lcd_info variables */
121#define LCD_CMD_REG	lcd_info.lcd_cmd_reg_addr
122#define LCD_DATA_REG	lcd_info.lcd_data_reg_addr
123#define LED_DATA_REG	lcd_info.lcd_cmd_reg_addr	/* LASI & ASP only */
124
125#define LED_HASLCD 1
126#define LED_NOLCD  0
127
128/* The workqueue must be created at init-time */
129static int start_task(void)
130{
131	/* Display the default text now */
132	if (led_type == LED_HASLCD) lcd_print( lcd_text_default );
133
134	/* Create the work queue and queue the LED task */
135	led_wq = create_singlethread_workqueue("led_wq");
136	queue_delayed_work(led_wq, &led_task, 0);
137
138	return 0;
139}
140
141device_initcall(start_task);
142
143/* ptr to LCD/LED-specific function */
144static void (*led_func_ptr) (unsigned char) __read_mostly;
145
146#ifdef CONFIG_PROC_FS
147static int led_proc_show(struct seq_file *m, void *v)
148{
149	switch ((long)m->private)
150	{
151	case LED_NOLCD:
152		seq_printf(m, "Heartbeat: %d\n", led_heartbeat);
153		seq_printf(m, "Disk IO: %d\n", led_diskio);
154		seq_printf(m, "LAN Rx/Tx: %d\n", led_lanrxtx);
155		break;
156	case LED_HASLCD:
157		seq_printf(m, "%s\n", lcd_text);
158		break;
159	default:
160		return 0;
161	}
162	return 0;
163}
164
165static int led_proc_open(struct inode *inode, struct file *file)
166{
167	return single_open(file, led_proc_show, PDE(inode)->data);
168}
169
170
171static ssize_t led_proc_write(struct file *file, const char *buf,
172	size_t count, loff_t *pos)
173{
174	void *data = PDE(file->f_path.dentry->d_inode)->data;
175	char *cur, lbuf[32];
176	int d;
177
178	if (!capable(CAP_SYS_ADMIN))
179		return -EACCES;
180
181	if (count >= sizeof(lbuf))
182		count = sizeof(lbuf)-1;
183
184	if (copy_from_user(lbuf, buf, count))
185		return -EFAULT;
186	lbuf[count] = 0;
187
188	cur = lbuf;
189
190	switch ((long)data)
191	{
192	case LED_NOLCD:
193		d = *cur++ - '0';
194		if (d != 0 && d != 1) goto parse_error;
195		led_heartbeat = d;
196
197		if (*cur++ != ' ') goto parse_error;
198
199		d = *cur++ - '0';
200		if (d != 0 && d != 1) goto parse_error;
201		led_diskio = d;
202
203		if (*cur++ != ' ') goto parse_error;
204
205		d = *cur++ - '0';
206		if (d != 0 && d != 1) goto parse_error;
207		led_lanrxtx = d;
208
209		break;
210	case LED_HASLCD:
211		if (*cur && cur[strlen(cur)-1] == '\n')
212			cur[strlen(cur)-1] = 0;
213		if (*cur == 0)
214			cur = lcd_text_default;
215		lcd_print(cur);
216		break;
217	default:
218		return 0;
219	}
220
221	return count;
222
223parse_error:
224	if ((long)data == LED_NOLCD)
225		printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n");
226	return -EINVAL;
227}
228
229static const struct file_operations led_proc_fops = {
230	.owner		= THIS_MODULE,
231	.open		= led_proc_open,
232	.read		= seq_read,
233	.llseek		= seq_lseek,
234	.release	= single_release,
235	.write		= led_proc_write,
236};
237
238static int __init led_create_procfs(void)
239{
240	struct proc_dir_entry *proc_pdc_root = NULL;
241	struct proc_dir_entry *ent;
242
243	if (led_type == -1) return -1;
244
245	proc_pdc_root = proc_mkdir("pdc", 0);
246	if (!proc_pdc_root) return -1;
247	ent = proc_create_data("led", S_IRUGO|S_IWUSR, proc_pdc_root,
248				&led_proc_fops, (void *)LED_NOLCD); /* LED */
249	if (!ent) return -1;
250
251	if (led_type == LED_HASLCD)
252	{
253		ent = proc_create_data("lcd", S_IRUGO|S_IWUSR, proc_pdc_root,
254					&led_proc_fops, (void *)LED_HASLCD); /* LCD */
255		if (!ent) return -1;
256	}
257
258	return 0;
259}
260#endif
261
262/*
263   **
264   ** led_ASP_driver()
265   **
266 */
267#define	LED_DATA	0x01	/* data to shift (0:on 1:off) */
268#define	LED_STROBE	0x02	/* strobe to clock data */
269static void led_ASP_driver(unsigned char leds)
270{
271	int i;
272
273	leds = ~leds;
274	for (i = 0; i < 8; i++) {
275		unsigned char value;
276		value = (leds & 0x80) >> 7;
277		gsc_writeb( value,		 LED_DATA_REG );
278		gsc_writeb( value | LED_STROBE,	 LED_DATA_REG );
279		leds <<= 1;
280	}
281}
282
283
284/*
285   **
286   ** led_LASI_driver()
287   **
288 */
289static void led_LASI_driver(unsigned char leds)
290{
291	leds = ~leds;
292	gsc_writeb( leds, LED_DATA_REG );
293}
294
295
296/*
297   **
298   ** led_LCD_driver()
299   **
300 */
301static void led_LCD_driver(unsigned char leds)
302{
303	static int i;
304	static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
305		LED_LAN_RCV, LED_LAN_TX };
306
307	static struct lcd_block * blockp[4] = {
308		&lcd_info.heartbeat,
309		&lcd_info.disk_io,
310		&lcd_info.lan_rcv,
311		&lcd_info.lan_tx
312	};
313
314	/* Convert min_cmd_delay to milliseconds */
315	unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000);
316
317	for (i=0; i<4; ++i)
318	{
319		if ((leds & mask[i]) != (lastleds & mask[i]))
320		{
321			gsc_writeb( blockp[i]->command, LCD_CMD_REG );
322			msleep(msec_cmd_delay);
323
324			gsc_writeb( leds & mask[i] ? blockp[i]->on :
325					blockp[i]->off, LCD_DATA_REG );
326			msleep(msec_cmd_delay);
327		}
328	}
329}
330
331
332/*
333   **
334   ** led_get_net_activity()
335   **
336   ** calculate if there was TX- or RX-throughput on the network interfaces
337   ** (analog to dev_get_info() from net/core/dev.c)
338   **
339 */
340static __inline__ int led_get_net_activity(void)
341{
342#ifndef CONFIG_NET
343	return 0;
344#else
345	static unsigned long rx_total_last, tx_total_last;
346	unsigned long rx_total, tx_total;
347	struct net_device *dev;
348	int retval;
349
350	rx_total = tx_total = 0;
351
352	/* we are running as a workqueue task, so we can use an RCU lookup */
353	rcu_read_lock();
354	for_each_netdev_rcu(&init_net, dev) {
355	    const struct net_device_stats *stats;
356	    struct rtnl_link_stats64 temp;
357	    struct in_device *in_dev = __in_dev_get_rcu(dev);
358	    if (!in_dev || !in_dev->ifa_list)
359		continue;
360	    if (ipv4_is_loopback(in_dev->ifa_list->ifa_local))
361		continue;
362	    stats = dev_get_stats(dev, &temp);
363	    rx_total += stats->rx_packets;
364	    tx_total += stats->tx_packets;
365	}
366	rcu_read_unlock();
367
368	retval = 0;
369
370	if (rx_total != rx_total_last) {
371		rx_total_last = rx_total;
372		retval |= LED_LAN_RCV;
373	}
374
375	if (tx_total != tx_total_last) {
376		tx_total_last = tx_total;
377		retval |= LED_LAN_TX;
378	}
379
380	return retval;
381#endif
382}
383
384
385/*
386   **
387   ** led_get_diskio_activity()
388   **
389   ** calculate if there was disk-io in the system
390   **
391 */
392static __inline__ int led_get_diskio_activity(void)
393{
394	static unsigned long last_pgpgin, last_pgpgout;
395	unsigned long events[NR_VM_EVENT_ITEMS];
396	int changed;
397
398	all_vm_events(events);
399
400	/* Just use a very simple calculation here. Do not care about overflow,
401	   since we only want to know if there was activity or not. */
402	changed = (events[PGPGIN] != last_pgpgin) ||
403		  (events[PGPGOUT] != last_pgpgout);
404	last_pgpgin  = events[PGPGIN];
405	last_pgpgout = events[PGPGOUT];
406
407	return (changed ? LED_DISK_IO : 0);
408}
409
410
411
412/*
413   ** led_work_func()
414   **
415   ** manages when and which chassis LCD/LED gets updated
416
417    TODO:
418    - display load average (older machines like 715/64 have 4 "free" LED's for that)
419    - optimizations
420 */
421
422#define HEARTBEAT_LEN (HZ*10/100)
423#define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
424#define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
425
426#define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
427
428static void led_work_func (struct work_struct *unused)
429{
430	static unsigned long last_jiffies;
431	static unsigned long count_HZ; /* counter in range 0..HZ */
432	unsigned char currentleds = 0; /* stores current value of the LEDs */
433
434	/* exit if not initialized */
435	if (!led_func_ptr)
436	    return;
437
438	/* increment the heartbeat timekeeper */
439	count_HZ += jiffies - last_jiffies;
440	last_jiffies = jiffies;
441	if (count_HZ >= HZ)
442	    count_HZ = 0;
443
444	if (likely(led_heartbeat))
445	{
446		/* flash heartbeat-LED like a real heart
447		 * (2 x short then a long delay)
448		 */
449		if (count_HZ < HEARTBEAT_LEN ||
450				(count_HZ >= HEARTBEAT_2ND_RANGE_START &&
451				count_HZ < HEARTBEAT_2ND_RANGE_END))
452			currentleds |= LED_HEARTBEAT;
453	}
454
455	if (likely(led_lanrxtx))  currentleds |= led_get_net_activity();
456	if (likely(led_diskio))   currentleds |= led_get_diskio_activity();
457
458	/* blink LEDs if we got an Oops (HPMC) */
459	if (unlikely(oops_in_progress)) {
460		if (boot_cpu_data.cpu_type >= pcxl2) {
461			/* newer machines don't have loadavg. LEDs, so we
462			 * let all LEDs blink twice per second instead */
463			currentleds = (count_HZ <= (HZ/2)) ? 0 : 0xff;
464		} else {
465			/* old machines: blink loadavg. LEDs twice per second */
466			if (count_HZ <= (HZ/2))
467				currentleds &= ~(LED4|LED5|LED6|LED7);
468			else
469				currentleds |= (LED4|LED5|LED6|LED7);
470		}
471	}
472
473	if (currentleds != lastleds)
474	{
475		led_func_ptr(currentleds);	/* Update the LCD/LEDs */
476		lastleds = currentleds;
477	}
478
479	queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
480}
481
482/*
483   ** led_halt()
484   **
485   ** called by the reboot notifier chain at shutdown and stops all
486   ** LED/LCD activities.
487   **
488 */
489
490static int led_halt(struct notifier_block *, unsigned long, void *);
491
492static struct notifier_block led_notifier = {
493	.notifier_call = led_halt,
494};
495static int notifier_disabled = 0;
496
497static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
498{
499	char *txt;
500
501	if (notifier_disabled)
502		return NOTIFY_OK;
503
504	notifier_disabled = 1;
505	switch (event) {
506	case SYS_RESTART:	txt = "SYSTEM RESTART";
507				break;
508	case SYS_HALT:		txt = "SYSTEM HALT";
509				break;
510	case SYS_POWER_OFF:	txt = "SYSTEM POWER OFF";
511				break;
512	default:		return NOTIFY_DONE;
513	}
514
515	/* Cancel the work item and delete the queue */
516	if (led_wq) {
517		cancel_delayed_work_sync(&led_task);
518		destroy_workqueue(led_wq);
519		led_wq = NULL;
520	}
521
522	if (lcd_info.model == DISPLAY_MODEL_LCD)
523		lcd_print(txt);
524	else
525		if (led_func_ptr)
526			led_func_ptr(0xff); /* turn all LEDs ON */
527
528	return NOTIFY_OK;
529}
530
531/*
532   ** register_led_driver()
533   **
534   ** registers an external LED or LCD for usage by this driver.
535   ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
536   **
537 */
538
539int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
540{
541	static int initialized;
542
543	if (initialized || !data_reg)
544		return 1;
545
546	lcd_info.model = model;		/* store the values */
547	LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
548
549	switch (lcd_info.model) {
550	case DISPLAY_MODEL_LCD:
551		LCD_DATA_REG = data_reg;
552		printk(KERN_INFO "LCD display at %lx,%lx registered\n",
553			LCD_CMD_REG , LCD_DATA_REG);
554		led_func_ptr = led_LCD_driver;
555		led_type = LED_HASLCD;
556		break;
557
558	case DISPLAY_MODEL_LASI:
559		LED_DATA_REG = data_reg;
560		led_func_ptr = led_LASI_driver;
561		printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
562		led_type = LED_NOLCD;
563		break;
564
565	case DISPLAY_MODEL_OLD_ASP:
566		LED_DATA_REG = data_reg;
567		led_func_ptr = led_ASP_driver;
568		printk(KERN_INFO "LED (ASP-style) display at %lx registered\n",
569		    LED_DATA_REG);
570		led_type = LED_NOLCD;
571		break;
572
573	default:
574		printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
575		       __func__, lcd_info.model);
576		return 1;
577	}
578
579	/* mark the LCD/LED driver now as initialized and
580	 * register to the reboot notifier chain */
581	initialized++;
582	register_reboot_notifier(&led_notifier);
583
584	/* Ensure the work is queued */
585	if (led_wq) {
586		queue_delayed_work(led_wq, &led_task, 0);
587	}
588
589	return 0;
590}
591
592/*
593   ** register_led_regions()
594   **
595   ** register_led_regions() registers the LCD/LED regions for /procfs.
596   ** At bootup - where the initialisation of the LCD/LED normally happens -
597   ** not all internal structures of request_region() are properly set up,
598   ** so that we delay the led-registration until after busdevices_init()
599   ** has been executed.
600   **
601 */
602
603void __init register_led_regions(void)
604{
605	switch (lcd_info.model) {
606	case DISPLAY_MODEL_LCD:
607		request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
608		request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
609		break;
610	case DISPLAY_MODEL_LASI:
611	case DISPLAY_MODEL_OLD_ASP:
612		request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
613		break;
614	}
615}
616
617
618/*
619   **
620   ** lcd_print()
621   **
622   ** Displays the given string on the LCD-Display of newer machines.
623   ** lcd_print() disables/enables the timer-based led work queue to
624   ** avoid a race condition while writing the CMD/DATA register pair.
625   **
626 */
627int lcd_print( const char *str )
628{
629	int i;
630
631	if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
632	    return 0;
633
634	/* temporarily disable the led work task */
635	if (led_wq)
636		cancel_delayed_work_sync(&led_task);
637
638	/* copy display string to buffer for procfs */
639	strlcpy(lcd_text, str, sizeof(lcd_text));
640
641	/* Set LCD Cursor to 1st character */
642	gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
643	udelay(lcd_info.min_cmd_delay);
644
645	/* Print the string */
646	for (i=0; i < lcd_info.lcd_width; i++) {
647	    if (str && *str)
648		gsc_writeb(*str++, LCD_DATA_REG);
649	    else
650		gsc_writeb(' ', LCD_DATA_REG);
651	    udelay(lcd_info.min_cmd_delay);
652	}
653
654	/* re-queue the work */
655	if (led_wq) {
656		queue_delayed_work(led_wq, &led_task, 0);
657	}
658
659	return lcd_info.lcd_width;
660}
661
662/*
663   ** led_init()
664   **
665   ** led_init() is called very early in the bootup-process from setup.c
666   ** and asks the PDC for an usable chassis LCD or LED.
667   ** If the PDC doesn't return any info, then the LED
668   ** is detected by lasi.c or asp.c and registered with the
669   ** above functions lasi_led_init() or asp_led_init().
670   ** KittyHawk machines have often a buggy PDC, so that
671   ** we explicitly check for those machines here.
672 */
673
674int __init led_init(void)
675{
676	struct pdc_chassis_info chassis_info;
677	int ret;
678
679	snprintf(lcd_text_default, sizeof(lcd_text_default),
680		"Linux %s", init_utsname()->release);
681
682	switch (CPU_HVERSION) {
683	case 0x580:		/* KittyHawk DC2-100 (K100) */
684	case 0x581:		/* KittyHawk DC3-120 (K210) */
685	case 0x582:		/* KittyHawk DC3 100 (K400) */
686	case 0x583:		/* KittyHawk DC3 120 (K410) */
687	case 0x58B:		/* KittyHawk DC2 100 (K200) */
688		printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
689				"LED detection skipped.\n", __FILE__, CPU_HVERSION);
690		goto found;	/* use the preinitialized values of lcd_info */
691	}
692
693	/* initialize the struct, so that we can check for valid return values */
694	lcd_info.model = DISPLAY_MODEL_NONE;
695	chassis_info.actcnt = chassis_info.maxcnt = 0;
696
697	ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
698	if (ret == PDC_OK) {
699		DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
700			 "lcd_width=%d, cmd_delay=%u,\n"
701			 "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
702		         __FILE__, lcd_info.model,
703			 (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
704			  (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
705			 lcd_info.lcd_width, lcd_info.min_cmd_delay,
706			 __FILE__, sizeof(lcd_info),
707			 chassis_info.actcnt, chassis_info.maxcnt));
708		DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
709			__FILE__, lcd_info.lcd_cmd_reg_addr,
710			lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
711			lcd_info.reset_cmd2, lcd_info.act_enable ));
712
713		/* check the results. Some machines have a buggy PDC */
714		if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
715			goto not_found;
716
717		switch (lcd_info.model) {
718		case DISPLAY_MODEL_LCD:		/* LCD display */
719			if (chassis_info.actcnt <
720				offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
721				goto not_found;
722			if (!lcd_info.act_enable) {
723				DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
724				goto not_found;
725			}
726			break;
727
728		case DISPLAY_MODEL_NONE:	/* no LED or LCD available */
729			printk(KERN_INFO "PDC reported no LCD or LED.\n");
730			goto not_found;
731
732		case DISPLAY_MODEL_LASI:	/* Lasi style 8 bit LED display */
733			if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
734				goto not_found;
735			break;
736
737		default:
738			printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
739			       lcd_info.model);
740			goto not_found;
741		} /* switch() */
742
743found:
744		/* register the LCD/LED driver */
745		register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
746		return 0;
747
748	} else { /* if() */
749		DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
750	}
751
752not_found:
753	lcd_info.model = DISPLAY_MODEL_NONE;
754	return 1;
755}
756
757static void __exit led_exit(void)
758{
759	unregister_reboot_notifier(&led_notifier);
760	return;
761}
762
763#ifdef CONFIG_PROC_FS
764module_init(led_create_procfs)
765#endif
766