xref: /kernel/linux/linux-5.10/drivers/parisc/led.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *    Chassis LCD/LED driver for HP-PARISC workstations
4 *
5 *      (c) Copyright 2000 Red Hat Software
6 *      (c) Copyright 2000 Helge Deller <hdeller@redhat.com>
7 *      (c) Copyright 2001-2009 Helge Deller <deller@gmx.de>
8 *      (c) Copyright 2001 Randolph Chung <tausq@debian.org>
9 *
10 * TODO:
11 *	- speed-up calculations with inlined assembler
12 *	- interface to write to second row of LCD from /proc (if technically possible)
13 *
14 * Changes:
15 *      - Audit copy_from_user in led_proc_write.
16 *                                Daniele Bellucci <bellucda@tiscali.it>
17 *	- Switch from using a tasklet to a work queue, so the led_LCD_driver
18 *	  	can sleep.
19 *	  			  David Pye <dmp@davidmpye.dyndns.org>
20 */
21
22#include <linux/module.h>
23#include <linux/stddef.h>	/* for offsetof() */
24#include <linux/init.h>
25#include <linux/types.h>
26#include <linux/ioport.h>
27#include <linux/utsname.h>
28#include <linux/capability.h>
29#include <linux/delay.h>
30#include <linux/netdevice.h>
31#include <linux/inetdevice.h>
32#include <linux/in.h>
33#include <linux/interrupt.h>
34#include <linux/kernel_stat.h>
35#include <linux/reboot.h>
36#include <linux/proc_fs.h>
37#include <linux/seq_file.h>
38#include <linux/ctype.h>
39#include <linux/blkdev.h>
40#include <linux/workqueue.h>
41#include <linux/rcupdate.h>
42#include <asm/io.h>
43#include <asm/processor.h>
44#include <asm/hardware.h>
45#include <asm/param.h>		/* HZ */
46#include <asm/led.h>
47#include <asm/pdc.h>
48#include <linux/uaccess.h>
49
50/* The control of the LEDs and LCDs on PARISC-machines have to be done
51   completely in software. The necessary calculations are done in a work queue
52   task which is scheduled regularly, and since the calculations may consume a
53   relatively large amount of CPU time, some of the calculations can be
54   turned off with the following variables (controlled via procfs) */
55
56static int led_type __read_mostly = -1;
57static unsigned char lastleds;	/* LED state from most recent update */
58static unsigned int led_heartbeat __read_mostly = 1;
59static unsigned int led_diskio    __read_mostly;
60static unsigned int led_lanrxtx   __read_mostly;
61static char lcd_text[32]          __read_mostly;
62static char lcd_text_default[32]  __read_mostly;
63static int  lcd_no_led_support    __read_mostly = 0; /* KittyHawk doesn't support LED on its LCD */
64
65
66static struct workqueue_struct *led_wq;
67static void led_work_func(struct work_struct *);
68static DECLARE_DELAYED_WORK(led_task, led_work_func);
69
70#if 0
71#define DPRINTK(x)	printk x
72#else
73#define DPRINTK(x)
74#endif
75
76struct lcd_block {
77	unsigned char command;	/* stores the command byte      */
78	unsigned char on;	/* value for turning LED on     */
79	unsigned char off;	/* value for turning LED off    */
80};
81
82/* Structure returned by PDC_RETURN_CHASSIS_INFO */
83/* NOTE: we use unsigned long:16 two times, since the following member
84   lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */
85struct pdc_chassis_lcd_info_ret_block {
86	unsigned long model:16;		/* DISPLAY_MODEL_XXXX */
87	unsigned long lcd_width:16;	/* width of the LCD in chars (DISPLAY_MODEL_LCD only) */
88	unsigned long lcd_cmd_reg_addr;	/* ptr to LCD cmd-register & data ptr for LED */
89	unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */
90	unsigned int min_cmd_delay;	/* delay in uS after cmd-write (LCD only) */
91	unsigned char reset_cmd1;	/* command #1 for writing LCD string (LCD only) */
92	unsigned char reset_cmd2;	/* command #2 for writing LCD string (LCD only) */
93	unsigned char act_enable;	/* 0 = no activity (LCD only) */
94	struct lcd_block heartbeat;
95	struct lcd_block disk_io;
96	struct lcd_block lan_rcv;
97	struct lcd_block lan_tx;
98	char _pad;
99};
100
101
102/* LCD_CMD and LCD_DATA for KittyHawk machines */
103#define KITTYHAWK_LCD_CMD  F_EXTEND(0xf0190000UL) /* 64bit-ready */
104#define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1)
105
106/* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's
107 * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
108static struct pdc_chassis_lcd_info_ret_block
109lcd_info __attribute__((aligned(8))) __read_mostly =
110{
111	.model =		DISPLAY_MODEL_LCD,
112	.lcd_width =		16,
113	.lcd_cmd_reg_addr =	KITTYHAWK_LCD_CMD,
114	.lcd_data_reg_addr =	KITTYHAWK_LCD_DATA,
115	.min_cmd_delay =	80,
116	.reset_cmd1 =		0x80,
117	.reset_cmd2 =		0xc0,
118};
119
120
121/* direct access to some of the lcd_info variables */
122#define LCD_CMD_REG	lcd_info.lcd_cmd_reg_addr
123#define LCD_DATA_REG	lcd_info.lcd_data_reg_addr
124#define LED_DATA_REG	lcd_info.lcd_cmd_reg_addr	/* LASI & ASP only */
125
126#define LED_HASLCD 1
127#define LED_NOLCD  0
128
129/* The workqueue must be created at init-time */
130static int start_task(void)
131{
132	/* Display the default text now */
133	if (led_type == LED_HASLCD) lcd_print( lcd_text_default );
134
135	/* KittyHawk has no LED support on its LCD */
136	if (lcd_no_led_support) return 0;
137
138	/* Create the work queue and queue the LED task */
139	led_wq = create_singlethread_workqueue("led_wq");
140	if (!led_wq)
141		return -ENOMEM;
142
143	queue_delayed_work(led_wq, &led_task, 0);
144
145	return 0;
146}
147
148device_initcall(start_task);
149
150/* ptr to LCD/LED-specific function */
151static void (*led_func_ptr) (unsigned char) __read_mostly;
152
153#ifdef CONFIG_PROC_FS
154static int led_proc_show(struct seq_file *m, void *v)
155{
156	switch ((long)m->private)
157	{
158	case LED_NOLCD:
159		seq_printf(m, "Heartbeat: %d\n", led_heartbeat);
160		seq_printf(m, "Disk IO: %d\n", led_diskio);
161		seq_printf(m, "LAN Rx/Tx: %d\n", led_lanrxtx);
162		break;
163	case LED_HASLCD:
164		seq_printf(m, "%s\n", lcd_text);
165		break;
166	default:
167		return 0;
168	}
169	return 0;
170}
171
172static int led_proc_open(struct inode *inode, struct file *file)
173{
174	return single_open(file, led_proc_show, PDE_DATA(inode));
175}
176
177
178static ssize_t led_proc_write(struct file *file, const char __user *buf,
179	size_t count, loff_t *pos)
180{
181	void *data = PDE_DATA(file_inode(file));
182	char *cur, lbuf[32];
183	int d;
184
185	if (!capable(CAP_SYS_ADMIN))
186		return -EACCES;
187
188	if (count >= sizeof(lbuf))
189		count = sizeof(lbuf)-1;
190
191	if (copy_from_user(lbuf, buf, count))
192		return -EFAULT;
193	lbuf[count] = 0;
194
195	cur = lbuf;
196
197	switch ((long)data)
198	{
199	case LED_NOLCD:
200		d = *cur++ - '0';
201		if (d != 0 && d != 1) goto parse_error;
202		led_heartbeat = d;
203
204		if (*cur++ != ' ') goto parse_error;
205
206		d = *cur++ - '0';
207		if (d != 0 && d != 1) goto parse_error;
208		led_diskio = d;
209
210		if (*cur++ != ' ') goto parse_error;
211
212		d = *cur++ - '0';
213		if (d != 0 && d != 1) goto parse_error;
214		led_lanrxtx = d;
215
216		break;
217	case LED_HASLCD:
218		if (*cur && cur[strlen(cur)-1] == '\n')
219			cur[strlen(cur)-1] = 0;
220		if (*cur == 0)
221			cur = lcd_text_default;
222		lcd_print(cur);
223		break;
224	default:
225		return 0;
226	}
227
228	return count;
229
230parse_error:
231	if ((long)data == LED_NOLCD)
232		printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n");
233	return -EINVAL;
234}
235
236static const struct proc_ops led_proc_ops = {
237	.proc_open	= led_proc_open,
238	.proc_read	= seq_read,
239	.proc_lseek	= seq_lseek,
240	.proc_release	= single_release,
241	.proc_write	= led_proc_write,
242};
243
244static 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", NULL);
252	if (!proc_pdc_root) return -1;
253
254	if (!lcd_no_led_support)
255	{
256		ent = proc_create_data("led", S_IRUGO|S_IWUSR, proc_pdc_root,
257					&led_proc_ops, (void *)LED_NOLCD); /* LED */
258		if (!ent) return -1;
259	}
260
261	if (led_type == LED_HASLCD)
262	{
263		ent = proc_create_data("lcd", S_IRUGO|S_IWUSR, proc_pdc_root,
264					&led_proc_ops, (void *)LED_HASLCD); /* LCD */
265		if (!ent) return -1;
266	}
267
268	return 0;
269}
270#endif
271
272/*
273   **
274   ** led_ASP_driver()
275   **
276 */
277#define	LED_DATA	0x01	/* data to shift (0:on 1:off) */
278#define	LED_STROBE	0x02	/* strobe to clock data */
279static void led_ASP_driver(unsigned char leds)
280{
281	int i;
282
283	leds = ~leds;
284	for (i = 0; i < 8; i++) {
285		unsigned char value;
286		value = (leds & 0x80) >> 7;
287		gsc_writeb( value,		 LED_DATA_REG );
288		gsc_writeb( value | LED_STROBE,	 LED_DATA_REG );
289		leds <<= 1;
290	}
291}
292
293
294/*
295   **
296   ** led_LASI_driver()
297   **
298 */
299static void led_LASI_driver(unsigned char leds)
300{
301	leds = ~leds;
302	gsc_writeb( leds, LED_DATA_REG );
303}
304
305
306/*
307   **
308   ** led_LCD_driver()
309   **
310 */
311static void led_LCD_driver(unsigned char leds)
312{
313	static int i;
314	static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
315		LED_LAN_RCV, LED_LAN_TX };
316
317	static struct lcd_block * blockp[4] = {
318		&lcd_info.heartbeat,
319		&lcd_info.disk_io,
320		&lcd_info.lan_rcv,
321		&lcd_info.lan_tx
322	};
323
324	/* Convert min_cmd_delay to milliseconds */
325	unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000);
326
327	for (i=0; i<4; ++i)
328	{
329		if ((leds & mask[i]) != (lastleds & mask[i]))
330		{
331			gsc_writeb( blockp[i]->command, LCD_CMD_REG );
332			msleep(msec_cmd_delay);
333
334			gsc_writeb( leds & mask[i] ? blockp[i]->on :
335					blockp[i]->off, LCD_DATA_REG );
336			msleep(msec_cmd_delay);
337		}
338	}
339}
340
341
342/*
343   **
344   ** led_get_net_activity()
345   **
346   ** calculate if there was TX- or RX-throughput on the network interfaces
347   ** (analog to dev_get_info() from net/core/dev.c)
348   **
349 */
350static __inline__ int led_get_net_activity(void)
351{
352#ifndef CONFIG_NET
353	return 0;
354#else
355	static u64 rx_total_last, tx_total_last;
356	u64 rx_total, tx_total;
357	struct net_device *dev;
358	int retval;
359
360	rx_total = tx_total = 0;
361
362	/* we are running as a workqueue task, so we can use an RCU lookup */
363	rcu_read_lock();
364	for_each_netdev_rcu(&init_net, dev) {
365	    const struct rtnl_link_stats64 *stats;
366	    struct rtnl_link_stats64 temp;
367	    struct in_device *in_dev = __in_dev_get_rcu(dev);
368	    if (!in_dev || !in_dev->ifa_list)
369		continue;
370	    if (ipv4_is_loopback(in_dev->ifa_list->ifa_local))
371		continue;
372	    stats = dev_get_stats(dev, &temp);
373	    rx_total += stats->rx_packets;
374	    tx_total += stats->tx_packets;
375	}
376	rcu_read_unlock();
377
378	retval = 0;
379
380	if (rx_total != rx_total_last) {
381		rx_total_last = rx_total;
382		retval |= LED_LAN_RCV;
383	}
384
385	if (tx_total != tx_total_last) {
386		tx_total_last = tx_total;
387		retval |= LED_LAN_TX;
388	}
389
390	return retval;
391#endif
392}
393
394
395/*
396   **
397   ** led_get_diskio_activity()
398   **
399   ** calculate if there was disk-io in the system
400   **
401 */
402static __inline__ int led_get_diskio_activity(void)
403{
404	static unsigned long last_pgpgin, last_pgpgout;
405	unsigned long events[NR_VM_EVENT_ITEMS];
406	int changed;
407
408	all_vm_events(events);
409
410	/* Just use a very simple calculation here. Do not care about overflow,
411	   since we only want to know if there was activity or not. */
412	changed = (events[PGPGIN] != last_pgpgin) ||
413		  (events[PGPGOUT] != last_pgpgout);
414	last_pgpgin  = events[PGPGIN];
415	last_pgpgout = events[PGPGOUT];
416
417	return (changed ? LED_DISK_IO : 0);
418}
419
420
421
422/*
423   ** led_work_func()
424   **
425   ** manages when and which chassis LCD/LED gets updated
426
427    TODO:
428    - display load average (older machines like 715/64 have 4 "free" LED's for that)
429    - optimizations
430 */
431
432#define HEARTBEAT_LEN (HZ*10/100)
433#define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
434#define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
435
436#define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
437
438static void led_work_func (struct work_struct *unused)
439{
440	static unsigned long last_jiffies;
441	static unsigned long count_HZ; /* counter in range 0..HZ */
442	unsigned char currentleds = 0; /* stores current value of the LEDs */
443
444	/* exit if not initialized */
445	if (!led_func_ptr)
446	    return;
447
448	/* increment the heartbeat timekeeper */
449	count_HZ += jiffies - last_jiffies;
450	last_jiffies = jiffies;
451	if (count_HZ >= HZ)
452	    count_HZ = 0;
453
454	if (likely(led_heartbeat))
455	{
456		/* flash heartbeat-LED like a real heart
457		 * (2 x short then a long delay)
458		 */
459		if (count_HZ < HEARTBEAT_LEN ||
460				(count_HZ >= HEARTBEAT_2ND_RANGE_START &&
461				count_HZ < HEARTBEAT_2ND_RANGE_END))
462			currentleds |= LED_HEARTBEAT;
463	}
464
465	if (likely(led_lanrxtx))  currentleds |= led_get_net_activity();
466	if (likely(led_diskio))   currentleds |= led_get_diskio_activity();
467
468	/* blink LEDs if we got an Oops (HPMC) */
469	if (unlikely(oops_in_progress)) {
470		if (boot_cpu_data.cpu_type >= pcxl2) {
471			/* newer machines don't have loadavg. LEDs, so we
472			 * let all LEDs blink twice per second instead */
473			currentleds = (count_HZ <= (HZ/2)) ? 0 : 0xff;
474		} else {
475			/* old machines: blink loadavg. LEDs twice per second */
476			if (count_HZ <= (HZ/2))
477				currentleds &= ~(LED4|LED5|LED6|LED7);
478			else
479				currentleds |= (LED4|LED5|LED6|LED7);
480		}
481	}
482
483	if (currentleds != lastleds)
484	{
485		led_func_ptr(currentleds);	/* Update the LCD/LEDs */
486		lastleds = currentleds;
487	}
488
489	queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
490}
491
492/*
493   ** led_halt()
494   **
495   ** called by the reboot notifier chain at shutdown and stops all
496   ** LED/LCD activities.
497   **
498 */
499
500static int led_halt(struct notifier_block *, unsigned long, void *);
501
502static struct notifier_block led_notifier = {
503	.notifier_call = led_halt,
504};
505static int notifier_disabled = 0;
506
507static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
508{
509	char *txt;
510
511	if (notifier_disabled)
512		return NOTIFY_OK;
513
514	notifier_disabled = 1;
515	switch (event) {
516	case SYS_RESTART:	txt = "SYSTEM RESTART";
517				break;
518	case SYS_HALT:		txt = "SYSTEM HALT";
519				break;
520	case SYS_POWER_OFF:	txt = "SYSTEM POWER OFF";
521				break;
522	default:		return NOTIFY_DONE;
523	}
524
525	/* Cancel the work item and delete the queue */
526	if (led_wq) {
527		cancel_delayed_work_sync(&led_task);
528		destroy_workqueue(led_wq);
529		led_wq = NULL;
530	}
531
532	if (lcd_info.model == DISPLAY_MODEL_LCD)
533		lcd_print(txt);
534	else
535		if (led_func_ptr)
536			led_func_ptr(0xff); /* turn all LEDs ON */
537
538	return NOTIFY_OK;
539}
540
541/*
542   ** register_led_driver()
543   **
544   ** registers an external LED or LCD for usage by this driver.
545   ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
546   **
547 */
548
549int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
550{
551	static int initialized;
552
553	if (initialized || !data_reg)
554		return 1;
555
556	lcd_info.model = model;		/* store the values */
557	LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
558
559	switch (lcd_info.model) {
560	case DISPLAY_MODEL_LCD:
561		LCD_DATA_REG = data_reg;
562		printk(KERN_INFO "LCD display at %lx,%lx registered\n",
563			LCD_CMD_REG , LCD_DATA_REG);
564		led_func_ptr = led_LCD_driver;
565		led_type = LED_HASLCD;
566		break;
567
568	case DISPLAY_MODEL_LASI:
569		/* Skip to register LED in QEMU */
570		if (running_on_qemu)
571			return 1;
572		LED_DATA_REG = data_reg;
573		led_func_ptr = led_LASI_driver;
574		printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
575		led_type = LED_NOLCD;
576		break;
577
578	case DISPLAY_MODEL_OLD_ASP:
579		LED_DATA_REG = data_reg;
580		led_func_ptr = led_ASP_driver;
581		printk(KERN_INFO "LED (ASP-style) display at %lx registered\n",
582		    LED_DATA_REG);
583		led_type = LED_NOLCD;
584		break;
585
586	default:
587		printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
588		       __func__, lcd_info.model);
589		return 1;
590	}
591
592	/* mark the LCD/LED driver now as initialized and
593	 * register to the reboot notifier chain */
594	initialized++;
595	register_reboot_notifier(&led_notifier);
596
597	/* Ensure the work is queued */
598	if (led_wq) {
599		queue_delayed_work(led_wq, &led_task, 0);
600	}
601
602	return 0;
603}
604
605/*
606   ** register_led_regions()
607   **
608   ** register_led_regions() registers the LCD/LED regions for /procfs.
609   ** At bootup - where the initialisation of the LCD/LED normally happens -
610   ** not all internal structures of request_region() are properly set up,
611   ** so that we delay the led-registration until after busdevices_init()
612   ** has been executed.
613   **
614 */
615
616void __init register_led_regions(void)
617{
618	switch (lcd_info.model) {
619	case DISPLAY_MODEL_LCD:
620		request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
621		request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
622		break;
623	case DISPLAY_MODEL_LASI:
624	case DISPLAY_MODEL_OLD_ASP:
625		request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
626		break;
627	}
628}
629
630
631/*
632   **
633   ** lcd_print()
634   **
635   ** Displays the given string on the LCD-Display of newer machines.
636   ** lcd_print() disables/enables the timer-based led work queue to
637   ** avoid a race condition while writing the CMD/DATA register pair.
638   **
639 */
640int lcd_print( const char *str )
641{
642	int i;
643
644	if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
645	    return 0;
646
647	/* temporarily disable the led work task */
648	if (led_wq)
649		cancel_delayed_work_sync(&led_task);
650
651	/* copy display string to buffer for procfs */
652	strlcpy(lcd_text, str, sizeof(lcd_text));
653
654	/* Set LCD Cursor to 1st character */
655	gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
656	udelay(lcd_info.min_cmd_delay);
657
658	/* Print the string */
659	for (i=0; i < lcd_info.lcd_width; i++) {
660	    if (str && *str)
661		gsc_writeb(*str++, LCD_DATA_REG);
662	    else
663		gsc_writeb(' ', LCD_DATA_REG);
664	    udelay(lcd_info.min_cmd_delay);
665	}
666
667	/* re-queue the work */
668	if (led_wq) {
669		queue_delayed_work(led_wq, &led_task, 0);
670	}
671
672	return lcd_info.lcd_width;
673}
674
675/*
676   ** led_init()
677   **
678   ** led_init() is called very early in the bootup-process from setup.c
679   ** and asks the PDC for an usable chassis LCD or LED.
680   ** If the PDC doesn't return any info, then the LED
681   ** is detected by lasi.c or asp.c and registered with the
682   ** above functions lasi_led_init() or asp_led_init().
683   ** KittyHawk machines have often a buggy PDC, so that
684   ** we explicitly check for those machines here.
685 */
686
687int __init led_init(void)
688{
689	struct pdc_chassis_info chassis_info;
690	int ret;
691
692	snprintf(lcd_text_default, sizeof(lcd_text_default),
693		"Linux %s", init_utsname()->release);
694
695	/* Work around the buggy PDC of KittyHawk-machines */
696	switch (CPU_HVERSION) {
697	case 0x580:		/* KittyHawk DC2-100 (K100) */
698	case 0x581:		/* KittyHawk DC3-120 (K210) */
699	case 0x582:		/* KittyHawk DC3 100 (K400) */
700	case 0x583:		/* KittyHawk DC3 120 (K410) */
701	case 0x58B:		/* KittyHawk DC2 100 (K200) */
702		printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
703				"LED detection skipped.\n", __FILE__, CPU_HVERSION);
704		lcd_no_led_support = 1;
705		goto found;	/* use the preinitialized values of lcd_info */
706	}
707
708	/* initialize the struct, so that we can check for valid return values */
709	lcd_info.model = DISPLAY_MODEL_NONE;
710	chassis_info.actcnt = chassis_info.maxcnt = 0;
711
712	ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
713	if (ret == PDC_OK) {
714		DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
715			 "lcd_width=%d, cmd_delay=%u,\n"
716			 "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
717		         __FILE__, lcd_info.model,
718			 (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
719			  (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
720			 lcd_info.lcd_width, lcd_info.min_cmd_delay,
721			 __FILE__, sizeof(lcd_info),
722			 chassis_info.actcnt, chassis_info.maxcnt));
723		DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
724			__FILE__, lcd_info.lcd_cmd_reg_addr,
725			lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
726			lcd_info.reset_cmd2, lcd_info.act_enable ));
727
728		/* check the results. Some machines have a buggy PDC */
729		if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
730			goto not_found;
731
732		switch (lcd_info.model) {
733		case DISPLAY_MODEL_LCD:		/* LCD display */
734			if (chassis_info.actcnt <
735				offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
736				goto not_found;
737			if (!lcd_info.act_enable) {
738				DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
739				goto not_found;
740			}
741			break;
742
743		case DISPLAY_MODEL_NONE:	/* no LED or LCD available */
744			printk(KERN_INFO "PDC reported no LCD or LED.\n");
745			goto not_found;
746
747		case DISPLAY_MODEL_LASI:	/* Lasi style 8 bit LED display */
748			if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
749				goto not_found;
750			break;
751
752		default:
753			printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
754			       lcd_info.model);
755			goto not_found;
756		} /* switch() */
757
758found:
759		/* register the LCD/LED driver */
760		register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
761		return 0;
762
763	} else { /* if() */
764		DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
765	}
766
767not_found:
768	lcd_info.model = DISPLAY_MODEL_NONE;
769	return 1;
770}
771
772static void __exit led_exit(void)
773{
774	unregister_reboot_notifier(&led_notifier);
775	return;
776}
777
778#ifdef CONFIG_PROC_FS
779module_init(led_create_procfs)
780#endif
781