xref: /openbmc/linux/drivers/parisc/led.c (revision 87c2ce3b)
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 2001-2004 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/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 = -1;
60 static unsigned char lastleds;	/* LED state from most recent update */
61 static unsigned int led_heartbeat = 1;
62 static unsigned int led_diskio = 1;
63 static unsigned int led_lanrxtx = 1;
64 static char lcd_text[32];
65 static char lcd_text_default[32];
66 
67 
68 static struct workqueue_struct *led_wq;
69 static void led_work_func(void *);
70 static DECLARE_WORK(led_task, led_work_func, NULL);
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))) =
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_work(led_wq, &led_task);
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);
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->nlink = 1;
256 	ent->data = (void *)LED_NOLCD; /* LED */
257 	ent->read_proc = led_proc_read;
258 	ent->write_proc = led_proc_write;
259 	ent->owner = THIS_MODULE;
260 
261 	if (led_type == LED_HASLCD)
262 	{
263 		ent = create_proc_entry("lcd", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
264 		if (!ent) return -1;
265 		ent->nlink = 1;
266 		ent->data = (void *)LED_HASLCD; /* LCD */
267 		ent->read_proc = led_proc_read;
268 		ent->write_proc = led_proc_write;
269 		ent->owner = THIS_MODULE;
270 	}
271 
272 	return 0;
273 }
274 #endif
275 
276 /*
277    **
278    ** led_ASP_driver()
279    **
280  */
281 #define	LED_DATA	0x01	/* data to shift (0:on 1:off) */
282 #define	LED_STROBE	0x02	/* strobe to clock data */
283 static void led_ASP_driver(unsigned char leds)
284 {
285 	int i;
286 
287 	leds = ~leds;
288 	for (i = 0; i < 8; i++) {
289 		unsigned char value;
290 		value = (leds & 0x80) >> 7;
291 		gsc_writeb( value,		 LED_DATA_REG );
292 		gsc_writeb( value | LED_STROBE,	 LED_DATA_REG );
293 		leds <<= 1;
294 	}
295 }
296 
297 
298 /*
299    **
300    ** led_LASI_driver()
301    **
302  */
303 static void led_LASI_driver(unsigned char leds)
304 {
305 	leds = ~leds;
306 	gsc_writeb( leds, LED_DATA_REG );
307 }
308 
309 
310 /*
311    **
312    ** led_LCD_driver()
313    **
314  */
315 static void led_LCD_driver(unsigned char leds)
316 {
317 	static int i;
318 	static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
319 		LED_LAN_RCV, LED_LAN_TX };
320 
321 	static struct lcd_block * blockp[4] = {
322 		&lcd_info.heartbeat,
323 		&lcd_info.disk_io,
324 		&lcd_info.lan_rcv,
325 		&lcd_info.lan_tx
326 	};
327 
328 	/* Convert min_cmd_delay to milliseconds */
329 	unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000);
330 
331 	for (i=0; i<4; ++i)
332 	{
333 		if ((leds & mask[i]) != (lastleds & mask[i]))
334 		{
335 			gsc_writeb( blockp[i]->command, LCD_CMD_REG );
336 			msleep(msec_cmd_delay);
337 
338 			gsc_writeb( leds & mask[i] ? blockp[i]->on :
339 					blockp[i]->off, LCD_DATA_REG );
340 			msleep(msec_cmd_delay);
341 		}
342 	}
343 }
344 
345 
346 /*
347    **
348    ** led_get_net_activity()
349    **
350    ** calculate if there was TX- or RX-throughput on the network interfaces
351    ** (analog to dev_get_info() from net/core/dev.c)
352    **
353  */
354 static __inline__ int led_get_net_activity(void)
355 {
356 #ifndef CONFIG_NET
357 	return 0;
358 #else
359 	static unsigned long rx_total_last, tx_total_last;
360 	unsigned long rx_total, tx_total;
361 	struct net_device *dev;
362 	int retval;
363 
364 	rx_total = tx_total = 0;
365 
366 	/* we are running as a workqueue task, so locking dev_base
367 	 * for reading should be OK */
368 	read_lock(&dev_base_lock);
369 	rcu_read_lock();
370 	for (dev = dev_base; dev; dev = dev->next) {
371 	    struct net_device_stats *stats;
372 	    struct in_device *in_dev = __in_dev_get_rcu(dev);
373 	    if (!in_dev || !in_dev->ifa_list)
374 		continue;
375 	    if (LOOPBACK(in_dev->ifa_list->ifa_local))
376 		continue;
377 	    if (!dev->get_stats)
378 		continue;
379 	    stats = dev->get_stats(dev);
380 	    rx_total += stats->rx_packets;
381 	    tx_total += stats->tx_packets;
382 	}
383 	rcu_read_unlock();
384 	read_unlock(&dev_base_lock);
385 
386 	retval = 0;
387 
388 	if (rx_total != rx_total_last) {
389 		rx_total_last = rx_total;
390 		retval |= LED_LAN_RCV;
391 	}
392 
393 	if (tx_total != tx_total_last) {
394 		tx_total_last = tx_total;
395 		retval |= LED_LAN_TX;
396 	}
397 
398 	return retval;
399 #endif
400 }
401 
402 
403 /*
404    **
405    ** led_get_diskio_activity()
406    **
407    ** calculate if there was disk-io in the system
408    **
409  */
410 static __inline__ int led_get_diskio_activity(void)
411 {
412 	static unsigned long last_pgpgin, last_pgpgout;
413 	struct page_state pgstat;
414 	int changed;
415 
416 	get_full_page_state(&pgstat); /* get no of sectors in & out */
417 
418 	/* Just use a very simple calculation here. Do not care about overflow,
419 	   since we only want to know if there was activity or not. */
420 	changed = (pgstat.pgpgin != last_pgpgin) || (pgstat.pgpgout != last_pgpgout);
421 	last_pgpgin  = pgstat.pgpgin;
422 	last_pgpgout = pgstat.pgpgout;
423 
424 	return (changed ? LED_DISK_IO : 0);
425 }
426 
427 
428 
429 /*
430    ** led_work_func()
431    **
432    ** manages when and which chassis LCD/LED gets updated
433 
434     TODO:
435     - display load average (older machines like 715/64 have 4 "free" LED's for that)
436     - optimizations
437  */
438 
439 #define HEARTBEAT_LEN (HZ*10/100)
440 #define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
441 #define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
442 
443 #define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
444 
445 static void led_work_func (void *unused)
446 {
447 	static unsigned long last_jiffies;
448 	static unsigned long count_HZ; /* counter in range 0..HZ */
449 	unsigned char currentleds = 0; /* stores current value of the LEDs */
450 
451 	/* exit if not initialized */
452 	if (!led_func_ptr)
453 	    return;
454 
455 	/* increment the heartbeat timekeeper */
456 	count_HZ += jiffies - last_jiffies;
457 	last_jiffies = jiffies;
458 	if (count_HZ >= HZ)
459 	    count_HZ = 0;
460 
461 	if (likely(led_heartbeat))
462 	{
463 		/* flash heartbeat-LED like a real heart
464 		 * (2 x short then a long delay)
465 		 */
466 		if (count_HZ < HEARTBEAT_LEN ||
467 				(count_HZ >= HEARTBEAT_2ND_RANGE_START &&
468 				count_HZ < HEARTBEAT_2ND_RANGE_END))
469 			currentleds |= LED_HEARTBEAT;
470 	}
471 
472 	if (likely(led_lanrxtx))  currentleds |= led_get_net_activity();
473 	if (likely(led_diskio))   currentleds |= led_get_diskio_activity();
474 
475 	/* blink all LEDs twice a second if we got an Oops (HPMC) */
476 	if (unlikely(oops_in_progress))
477 		currentleds = (count_HZ<=(HZ/2)) ? 0 : 0xff;
478 
479 	if (currentleds != lastleds)
480 	{
481 		led_func_ptr(currentleds);	/* Update the LCD/LEDs */
482 		lastleds = currentleds;
483 	}
484 
485 	queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
486 }
487 
488 /*
489    ** led_halt()
490    **
491    ** called by the reboot notifier chain at shutdown and stops all
492    ** LED/LCD activities.
493    **
494  */
495 
496 static int led_halt(struct notifier_block *, unsigned long, void *);
497 
498 static struct notifier_block led_notifier = {
499 	.notifier_call = led_halt,
500 };
501 
502 static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
503 {
504 	char *txt;
505 
506 	switch (event) {
507 	case SYS_RESTART:	txt = "SYSTEM RESTART";
508 				break;
509 	case SYS_HALT:		txt = "SYSTEM HALT";
510 				break;
511 	case SYS_POWER_OFF:	txt = "SYSTEM POWER OFF";
512 				break;
513 	default:		return NOTIFY_DONE;
514 	}
515 
516 	/* Cancel the work item and delete the queue */
517 	if (led_wq) {
518 		cancel_rearming_delayed_workqueue(led_wq, &led_task);
519 		destroy_workqueue(led_wq);
520 		led_wq = NULL;
521 	}
522 
523 	if (lcd_info.model == DISPLAY_MODEL_LCD)
524 		lcd_print(txt);
525 	else
526 		if (led_func_ptr)
527 			led_func_ptr(0xff); /* turn all LEDs ON */
528 
529 	unregister_reboot_notifier(&led_notifier);
530 	return NOTIFY_OK;
531 }
532 
533 /*
534    ** register_led_driver()
535    **
536    ** registers an external LED or LCD for usage by this driver.
537    ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
538    **
539  */
540 
541 int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
542 {
543 	static int initialized;
544 
545 	if (initialized || !data_reg)
546 		return 1;
547 
548 	lcd_info.model = model;		/* store the values */
549 	LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
550 
551 	switch (lcd_info.model) {
552 	case DISPLAY_MODEL_LCD:
553 		LCD_DATA_REG = data_reg;
554 		printk(KERN_INFO "LCD display at %lx,%lx registered\n",
555 			LCD_CMD_REG , LCD_DATA_REG);
556 		led_func_ptr = led_LCD_driver;
557 		led_type = LED_HASLCD;
558 		break;
559 
560 	case DISPLAY_MODEL_LASI:
561 		LED_DATA_REG = data_reg;
562 		led_func_ptr = led_LASI_driver;
563 		printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
564 		led_type = LED_NOLCD;
565 		break;
566 
567 	case DISPLAY_MODEL_OLD_ASP:
568 		LED_DATA_REG = data_reg;
569 		led_func_ptr = led_ASP_driver;
570 		printk(KERN_INFO "LED (ASP-style) display at %lx registered\n",
571 		    LED_DATA_REG);
572 		led_type = LED_NOLCD;
573 		break;
574 
575 	default:
576 		printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
577 		       __FUNCTION__, lcd_info.model);
578 		return 1;
579 	}
580 
581 	/* mark the LCD/LED driver now as initialized and
582 	 * register to the reboot notifier chain */
583 	initialized++;
584 	register_reboot_notifier(&led_notifier);
585 
586 	/* Ensure the work is queued */
587 	if (led_wq) {
588 		queue_work(led_wq, &led_task);
589 	}
590 
591 	return 0;
592 }
593 
594 /*
595    ** register_led_regions()
596    **
597    ** register_led_regions() registers the LCD/LED regions for /procfs.
598    ** At bootup - where the initialisation of the LCD/LED normally happens -
599    ** not all internal structures of request_region() are properly set up,
600    ** so that we delay the led-registration until after busdevices_init()
601    ** has been executed.
602    **
603  */
604 
605 void __init register_led_regions(void)
606 {
607 	switch (lcd_info.model) {
608 	case DISPLAY_MODEL_LCD:
609 		request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
610 		request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
611 		break;
612 	case DISPLAY_MODEL_LASI:
613 	case DISPLAY_MODEL_OLD_ASP:
614 		request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
615 		break;
616 	}
617 }
618 
619 
620 /*
621    **
622    ** lcd_print()
623    **
624    ** Displays the given string on the LCD-Display of newer machines.
625    ** lcd_print() disables/enables the timer-based led work queue to
626    ** avoid a race condition while writing the CMD/DATA register pair.
627    **
628  */
629 int lcd_print( char *str )
630 {
631 	int i;
632 
633 	if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
634 	    return 0;
635 
636 	/* temporarily disable the led work task */
637 	if (led_wq)
638 		cancel_rearming_delayed_workqueue(led_wq, &led_task);
639 
640 	/* copy display string to buffer for procfs */
641 	strlcpy(lcd_text, str, sizeof(lcd_text));
642 
643 	/* Set LCD Cursor to 1st character */
644 	gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
645 	udelay(lcd_info.min_cmd_delay);
646 
647 	/* Print the string */
648 	for (i=0; i < lcd_info.lcd_width; i++) {
649 	    if (str && *str)
650 		gsc_writeb(*str++, LCD_DATA_REG);
651 	    else
652 		gsc_writeb(' ', LCD_DATA_REG);
653 	    udelay(lcd_info.min_cmd_delay);
654 	}
655 
656 	/* re-queue the work */
657 	if (led_wq) {
658 		queue_work(led_wq, &led_task);
659 	}
660 
661 	return lcd_info.lcd_width;
662 }
663 
664 /*
665    ** led_init()
666    **
667    ** led_init() is called very early in the bootup-process from setup.c
668    ** and asks the PDC for an usable chassis LCD or LED.
669    ** If the PDC doesn't return any info, then the LED
670    ** is detected by lasi.c or asp.c and registered with the
671    ** above functions lasi_led_init() or asp_led_init().
672    ** KittyHawk machines have often a buggy PDC, so that
673    ** we explicitly check for those machines here.
674  */
675 
676 int __init led_init(void)
677 {
678 	struct pdc_chassis_info chassis_info;
679 	int ret;
680 
681 	snprintf(lcd_text_default, sizeof(lcd_text_default),
682 		"Linux %s", system_utsname.release);
683 
684 	/* Work around the buggy PDC of KittyHawk-machines */
685 	switch (CPU_HVERSION) {
686 	case 0x580:		/* KittyHawk DC2-100 (K100) */
687 	case 0x581:		/* KittyHawk DC3-120 (K210) */
688 	case 0x582:		/* KittyHawk DC3 100 (K400) */
689 	case 0x583:		/* KittyHawk DC3 120 (K410) */
690 	case 0x58B:		/* KittyHawk DC2 100 (K200) */
691 		printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
692 				"LED detection skipped.\n", __FILE__, CPU_HVERSION);
693 		goto found;	/* use the preinitialized values of lcd_info */
694 	}
695 
696 	/* initialize the struct, so that we can check for valid return values */
697 	lcd_info.model = DISPLAY_MODEL_NONE;
698 	chassis_info.actcnt = chassis_info.maxcnt = 0;
699 
700 	ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
701 	if (ret == PDC_OK) {
702 		DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
703 			 "lcd_width=%d, cmd_delay=%u,\n"
704 			 "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
705 		         __FILE__, lcd_info.model,
706 			 (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
707 			  (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
708 			 lcd_info.lcd_width, lcd_info.min_cmd_delay,
709 			 __FILE__, sizeof(lcd_info),
710 			 chassis_info.actcnt, chassis_info.maxcnt));
711 		DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
712 			__FILE__, lcd_info.lcd_cmd_reg_addr,
713 			lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
714 			lcd_info.reset_cmd2, lcd_info.act_enable ));
715 
716 		/* check the results. Some machines have a buggy PDC */
717 		if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
718 			goto not_found;
719 
720 		switch (lcd_info.model) {
721 		case DISPLAY_MODEL_LCD:		/* LCD display */
722 			if (chassis_info.actcnt <
723 				offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
724 				goto not_found;
725 			if (!lcd_info.act_enable) {
726 				DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
727 				goto not_found;
728 			}
729 			break;
730 
731 		case DISPLAY_MODEL_NONE:	/* no LED or LCD available */
732 			printk(KERN_INFO "PDC reported no LCD or LED.\n");
733 			goto not_found;
734 
735 		case DISPLAY_MODEL_LASI:	/* Lasi style 8 bit LED display */
736 			if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
737 				goto not_found;
738 			break;
739 
740 		default:
741 			printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
742 			       lcd_info.model);
743 			goto not_found;
744 		} /* switch() */
745 
746 found:
747 		/* register the LCD/LED driver */
748 		register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
749 		return 0;
750 
751 	} else { /* if() */
752 		DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
753 	}
754 
755 not_found:
756 	lcd_info.model = DISPLAY_MODEL_NONE;
757 	return 1;
758 }
759 
760 #ifdef CONFIG_PROC_FS
761 module_init(led_create_procfs)
762 #endif
763