xref: /linux/drivers/parisc/led.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 
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(struct work_struct *);
71 static DECLARE_DELAYED_WORK(led_task, led_work_func);
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_delayed_work(led_wq, &led_task, 0);
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_show(struct seq_file *m, void *v)
152 {
153 	switch ((long)m->private)
154 	{
155 	case LED_NOLCD:
156 		seq_printf(m, "Heartbeat: %d\n", led_heartbeat);
157 		seq_printf(m, "Disk IO: %d\n", led_diskio);
158 		seq_printf(m, "LAN Rx/Tx: %d\n", led_lanrxtx);
159 		break;
160 	case LED_HASLCD:
161 		seq_printf(m, "%s\n", lcd_text);
162 		break;
163 	default:
164 		return 0;
165 	}
166 	return 0;
167 }
168 
169 static int led_proc_open(struct inode *inode, struct file *file)
170 {
171 	return single_open(file, led_proc_show, PDE(inode)->data);
172 }
173 
174 
175 static ssize_t led_proc_write(struct file *file, const char *buf,
176 	size_t count, loff_t *pos)
177 {
178 	void *data = PDE(file->f_path.dentry->d_inode)->data;
179 	char *cur, lbuf[32];
180 	int d;
181 
182 	if (!capable(CAP_SYS_ADMIN))
183 		return -EACCES;
184 
185 	if (count >= sizeof(lbuf))
186 		count = sizeof(lbuf)-1;
187 
188 	if (copy_from_user(lbuf, buf, count))
189 		return -EFAULT;
190 	lbuf[count] = 0;
191 
192 	cur = lbuf;
193 
194 	switch ((long)data)
195 	{
196 	case LED_NOLCD:
197 		d = *cur++ - '0';
198 		if (d != 0 && d != 1) goto parse_error;
199 		led_heartbeat = d;
200 
201 		if (*cur++ != ' ') goto parse_error;
202 
203 		d = *cur++ - '0';
204 		if (d != 0 && d != 1) goto parse_error;
205 		led_diskio = d;
206 
207 		if (*cur++ != ' ') goto parse_error;
208 
209 		d = *cur++ - '0';
210 		if (d != 0 && d != 1) goto parse_error;
211 		led_lanrxtx = d;
212 
213 		break;
214 	case LED_HASLCD:
215 		if (*cur && cur[strlen(cur)-1] == '\n')
216 			cur[strlen(cur)-1] = 0;
217 		if (*cur == 0)
218 			cur = lcd_text_default;
219 		lcd_print(cur);
220 		break;
221 	default:
222 		return 0;
223 	}
224 
225 	return count;
226 
227 parse_error:
228 	if ((long)data == LED_NOLCD)
229 		printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n");
230 	return -EINVAL;
231 }
232 
233 static const struct file_operations led_proc_fops = {
234 	.owner		= THIS_MODULE,
235 	.open		= led_proc_open,
236 	.read		= seq_read,
237 	.llseek		= seq_lseek,
238 	.release	= single_release,
239 	.write		= led_proc_write,
240 };
241 
242 static int __init led_create_procfs(void)
243 {
244 	struct proc_dir_entry *proc_pdc_root = NULL;
245 	struct proc_dir_entry *ent;
246 
247 	if (led_type == -1) return -1;
248 
249 	proc_pdc_root = proc_mkdir("pdc", 0);
250 	if (!proc_pdc_root) return -1;
251 	ent = proc_create_data("led", S_IRUGO|S_IWUSR, proc_pdc_root,
252 				&led_proc_fops, (void *)LED_NOLCD); /* LED */
253 	if (!ent) return -1;
254 
255 	if (led_type == LED_HASLCD)
256 	{
257 		ent = proc_create_data("lcd", S_IRUGO|S_IWUSR, proc_pdc_root,
258 					&led_proc_fops, (void *)LED_HASLCD); /* LCD */
259 		if (!ent) return -1;
260 	}
261 
262 	return 0;
263 }
264 #endif
265 
266 /*
267    **
268    ** led_ASP_driver()
269    **
270  */
271 #define	LED_DATA	0x01	/* data to shift (0:on 1:off) */
272 #define	LED_STROBE	0x02	/* strobe to clock data */
273 static void led_ASP_driver(unsigned char leds)
274 {
275 	int i;
276 
277 	leds = ~leds;
278 	for (i = 0; i < 8; i++) {
279 		unsigned char value;
280 		value = (leds & 0x80) >> 7;
281 		gsc_writeb( value,		 LED_DATA_REG );
282 		gsc_writeb( value | LED_STROBE,	 LED_DATA_REG );
283 		leds <<= 1;
284 	}
285 }
286 
287 
288 /*
289    **
290    ** led_LASI_driver()
291    **
292  */
293 static void led_LASI_driver(unsigned char leds)
294 {
295 	leds = ~leds;
296 	gsc_writeb( leds, LED_DATA_REG );
297 }
298 
299 
300 /*
301    **
302    ** led_LCD_driver()
303    **
304  */
305 static void led_LCD_driver(unsigned char leds)
306 {
307 	static int i;
308 	static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
309 		LED_LAN_RCV, LED_LAN_TX };
310 
311 	static struct lcd_block * blockp[4] = {
312 		&lcd_info.heartbeat,
313 		&lcd_info.disk_io,
314 		&lcd_info.lan_rcv,
315 		&lcd_info.lan_tx
316 	};
317 
318 	/* Convert min_cmd_delay to milliseconds */
319 	unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000);
320 
321 	for (i=0; i<4; ++i)
322 	{
323 		if ((leds & mask[i]) != (lastleds & mask[i]))
324 		{
325 			gsc_writeb( blockp[i]->command, LCD_CMD_REG );
326 			msleep(msec_cmd_delay);
327 
328 			gsc_writeb( leds & mask[i] ? blockp[i]->on :
329 					blockp[i]->off, LCD_DATA_REG );
330 			msleep(msec_cmd_delay);
331 		}
332 	}
333 }
334 
335 
336 /*
337    **
338    ** led_get_net_activity()
339    **
340    ** calculate if there was TX- or RX-throughput on the network interfaces
341    ** (analog to dev_get_info() from net/core/dev.c)
342    **
343  */
344 static __inline__ int led_get_net_activity(void)
345 {
346 #ifndef CONFIG_NET
347 	return 0;
348 #else
349 	static unsigned long rx_total_last, tx_total_last;
350 	unsigned long rx_total, tx_total;
351 	struct net_device *dev;
352 	int retval;
353 
354 	rx_total = tx_total = 0;
355 
356 	/* we are running as a workqueue task, so we can use an RCU lookup */
357 	rcu_read_lock();
358 	for_each_netdev_rcu(&init_net, dev) {
359 	    const struct net_device_stats *stats;
360 	    struct rtnl_link_stats64 temp;
361 	    struct in_device *in_dev = __in_dev_get_rcu(dev);
362 	    if (!in_dev || !in_dev->ifa_list)
363 		continue;
364 	    if (ipv4_is_loopback(in_dev->ifa_list->ifa_local))
365 		continue;
366 	    stats = dev_get_stats(dev, &temp);
367 	    rx_total += stats->rx_packets;
368 	    tx_total += stats->tx_packets;
369 	}
370 	rcu_read_unlock();
371 
372 	retval = 0;
373 
374 	if (rx_total != rx_total_last) {
375 		rx_total_last = rx_total;
376 		retval |= LED_LAN_RCV;
377 	}
378 
379 	if (tx_total != tx_total_last) {
380 		tx_total_last = tx_total;
381 		retval |= LED_LAN_TX;
382 	}
383 
384 	return retval;
385 #endif
386 }
387 
388 
389 /*
390    **
391    ** led_get_diskio_activity()
392    **
393    ** calculate if there was disk-io in the system
394    **
395  */
396 static __inline__ int led_get_diskio_activity(void)
397 {
398 	static unsigned long last_pgpgin, last_pgpgout;
399 	unsigned long events[NR_VM_EVENT_ITEMS];
400 	int changed;
401 
402 	all_vm_events(events);
403 
404 	/* Just use a very simple calculation here. Do not care about overflow,
405 	   since we only want to know if there was activity or not. */
406 	changed = (events[PGPGIN] != last_pgpgin) ||
407 		  (events[PGPGOUT] != last_pgpgout);
408 	last_pgpgin  = events[PGPGIN];
409 	last_pgpgout = events[PGPGOUT];
410 
411 	return (changed ? LED_DISK_IO : 0);
412 }
413 
414 
415 
416 /*
417    ** led_work_func()
418    **
419    ** manages when and which chassis LCD/LED gets updated
420 
421     TODO:
422     - display load average (older machines like 715/64 have 4 "free" LED's for that)
423     - optimizations
424  */
425 
426 #define HEARTBEAT_LEN (HZ*10/100)
427 #define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
428 #define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
429 
430 #define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
431 
432 static void led_work_func (struct work_struct *unused)
433 {
434 	static unsigned long last_jiffies;
435 	static unsigned long count_HZ; /* counter in range 0..HZ */
436 	unsigned char currentleds = 0; /* stores current value of the LEDs */
437 
438 	/* exit if not initialized */
439 	if (!led_func_ptr)
440 	    return;
441 
442 	/* increment the heartbeat timekeeper */
443 	count_HZ += jiffies - last_jiffies;
444 	last_jiffies = jiffies;
445 	if (count_HZ >= HZ)
446 	    count_HZ = 0;
447 
448 	if (likely(led_heartbeat))
449 	{
450 		/* flash heartbeat-LED like a real heart
451 		 * (2 x short then a long delay)
452 		 */
453 		if (count_HZ < HEARTBEAT_LEN ||
454 				(count_HZ >= HEARTBEAT_2ND_RANGE_START &&
455 				count_HZ < HEARTBEAT_2ND_RANGE_END))
456 			currentleds |= LED_HEARTBEAT;
457 	}
458 
459 	if (likely(led_lanrxtx))  currentleds |= led_get_net_activity();
460 	if (likely(led_diskio))   currentleds |= led_get_diskio_activity();
461 
462 	/* blink LEDs if we got an Oops (HPMC) */
463 	if (unlikely(oops_in_progress)) {
464 		if (boot_cpu_data.cpu_type >= pcxl2) {
465 			/* newer machines don't have loadavg. LEDs, so we
466 			 * let all LEDs blink twice per second instead */
467 			currentleds = (count_HZ <= (HZ/2)) ? 0 : 0xff;
468 		} else {
469 			/* old machines: blink loadavg. LEDs twice per second */
470 			if (count_HZ <= (HZ/2))
471 				currentleds &= ~(LED4|LED5|LED6|LED7);
472 			else
473 				currentleds |= (LED4|LED5|LED6|LED7);
474 		}
475 	}
476 
477 	if (currentleds != lastleds)
478 	{
479 		led_func_ptr(currentleds);	/* Update the LCD/LEDs */
480 		lastleds = currentleds;
481 	}
482 
483 	queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
484 }
485 
486 /*
487    ** led_halt()
488    **
489    ** called by the reboot notifier chain at shutdown and stops all
490    ** LED/LCD activities.
491    **
492  */
493 
494 static int led_halt(struct notifier_block *, unsigned long, void *);
495 
496 static struct notifier_block led_notifier = {
497 	.notifier_call = led_halt,
498 };
499 static int notifier_disabled = 0;
500 
501 static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
502 {
503 	char *txt;
504 
505 	if (notifier_disabled)
506 		return NOTIFY_OK;
507 
508 	notifier_disabled = 1;
509 	switch (event) {
510 	case SYS_RESTART:	txt = "SYSTEM RESTART";
511 				break;
512 	case SYS_HALT:		txt = "SYSTEM HALT";
513 				break;
514 	case SYS_POWER_OFF:	txt = "SYSTEM POWER OFF";
515 				break;
516 	default:		return NOTIFY_DONE;
517 	}
518 
519 	/* Cancel the work item and delete the queue */
520 	if (led_wq) {
521 		cancel_delayed_work_sync(&led_task);
522 		destroy_workqueue(led_wq);
523 		led_wq = NULL;
524 	}
525 
526 	if (lcd_info.model == DISPLAY_MODEL_LCD)
527 		lcd_print(txt);
528 	else
529 		if (led_func_ptr)
530 			led_func_ptr(0xff); /* turn all LEDs ON */
531 
532 	return NOTIFY_OK;
533 }
534 
535 /*
536    ** register_led_driver()
537    **
538    ** registers an external LED or LCD for usage by this driver.
539    ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
540    **
541  */
542 
543 int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
544 {
545 	static int initialized;
546 
547 	if (initialized || !data_reg)
548 		return 1;
549 
550 	lcd_info.model = model;		/* store the values */
551 	LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
552 
553 	switch (lcd_info.model) {
554 	case DISPLAY_MODEL_LCD:
555 		LCD_DATA_REG = data_reg;
556 		printk(KERN_INFO "LCD display at %lx,%lx registered\n",
557 			LCD_CMD_REG , LCD_DATA_REG);
558 		led_func_ptr = led_LCD_driver;
559 		led_type = LED_HASLCD;
560 		break;
561 
562 	case DISPLAY_MODEL_LASI:
563 		LED_DATA_REG = data_reg;
564 		led_func_ptr = led_LASI_driver;
565 		printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
566 		led_type = LED_NOLCD;
567 		break;
568 
569 	case DISPLAY_MODEL_OLD_ASP:
570 		LED_DATA_REG = data_reg;
571 		led_func_ptr = led_ASP_driver;
572 		printk(KERN_INFO "LED (ASP-style) display at %lx registered\n",
573 		    LED_DATA_REG);
574 		led_type = LED_NOLCD;
575 		break;
576 
577 	default:
578 		printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
579 		       __func__, lcd_info.model);
580 		return 1;
581 	}
582 
583 	/* mark the LCD/LED driver now as initialized and
584 	 * register to the reboot notifier chain */
585 	initialized++;
586 	register_reboot_notifier(&led_notifier);
587 
588 	/* Ensure the work is queued */
589 	if (led_wq) {
590 		queue_delayed_work(led_wq, &led_task, 0);
591 	}
592 
593 	return 0;
594 }
595 
596 /*
597    ** register_led_regions()
598    **
599    ** register_led_regions() registers the LCD/LED regions for /procfs.
600    ** At bootup - where the initialisation of the LCD/LED normally happens -
601    ** not all internal structures of request_region() are properly set up,
602    ** so that we delay the led-registration until after busdevices_init()
603    ** has been executed.
604    **
605  */
606 
607 void __init register_led_regions(void)
608 {
609 	switch (lcd_info.model) {
610 	case DISPLAY_MODEL_LCD:
611 		request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
612 		request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
613 		break;
614 	case DISPLAY_MODEL_LASI:
615 	case DISPLAY_MODEL_OLD_ASP:
616 		request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
617 		break;
618 	}
619 }
620 
621 
622 /*
623    **
624    ** lcd_print()
625    **
626    ** Displays the given string on the LCD-Display of newer machines.
627    ** lcd_print() disables/enables the timer-based led work queue to
628    ** avoid a race condition while writing the CMD/DATA register pair.
629    **
630  */
631 int lcd_print( const char *str )
632 {
633 	int i;
634 
635 	if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
636 	    return 0;
637 
638 	/* temporarily disable the led work task */
639 	if (led_wq)
640 		cancel_delayed_work_sync(&led_task);
641 
642 	/* copy display string to buffer for procfs */
643 	strlcpy(lcd_text, str, sizeof(lcd_text));
644 
645 	/* Set LCD Cursor to 1st character */
646 	gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
647 	udelay(lcd_info.min_cmd_delay);
648 
649 	/* Print the string */
650 	for (i=0; i < lcd_info.lcd_width; i++) {
651 	    if (str && *str)
652 		gsc_writeb(*str++, LCD_DATA_REG);
653 	    else
654 		gsc_writeb(' ', LCD_DATA_REG);
655 	    udelay(lcd_info.min_cmd_delay);
656 	}
657 
658 	/* re-queue the work */
659 	if (led_wq) {
660 		queue_delayed_work(led_wq, &led_task, 0);
661 	}
662 
663 	return lcd_info.lcd_width;
664 }
665 
666 /*
667    ** led_init()
668    **
669    ** led_init() is called very early in the bootup-process from setup.c
670    ** and asks the PDC for an usable chassis LCD or LED.
671    ** If the PDC doesn't return any info, then the LED
672    ** is detected by lasi.c or asp.c and registered with the
673    ** above functions lasi_led_init() or asp_led_init().
674    ** KittyHawk machines have often a buggy PDC, so that
675    ** we explicitly check for those machines here.
676  */
677 
678 int __init led_init(void)
679 {
680 	struct pdc_chassis_info chassis_info;
681 	int ret;
682 
683 	snprintf(lcd_text_default, sizeof(lcd_text_default),
684 		"Linux %s", init_utsname()->release);
685 
686 	/* Work around the buggy PDC of KittyHawk-machines */
687 	switch (CPU_HVERSION) {
688 	case 0x580:		/* KittyHawk DC2-100 (K100) */
689 	case 0x581:		/* KittyHawk DC3-120 (K210) */
690 	case 0x582:		/* KittyHawk DC3 100 (K400) */
691 	case 0x583:		/* KittyHawk DC3 120 (K410) */
692 	case 0x58B:		/* KittyHawk DC2 100 (K200) */
693 		printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
694 				"LED detection skipped.\n", __FILE__, CPU_HVERSION);
695 		goto found;	/* use the preinitialized values of lcd_info */
696 	}
697 
698 	/* initialize the struct, so that we can check for valid return values */
699 	lcd_info.model = DISPLAY_MODEL_NONE;
700 	chassis_info.actcnt = chassis_info.maxcnt = 0;
701 
702 	ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
703 	if (ret == PDC_OK) {
704 		DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
705 			 "lcd_width=%d, cmd_delay=%u,\n"
706 			 "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
707 		         __FILE__, lcd_info.model,
708 			 (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
709 			  (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
710 			 lcd_info.lcd_width, lcd_info.min_cmd_delay,
711 			 __FILE__, sizeof(lcd_info),
712 			 chassis_info.actcnt, chassis_info.maxcnt));
713 		DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
714 			__FILE__, lcd_info.lcd_cmd_reg_addr,
715 			lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
716 			lcd_info.reset_cmd2, lcd_info.act_enable ));
717 
718 		/* check the results. Some machines have a buggy PDC */
719 		if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
720 			goto not_found;
721 
722 		switch (lcd_info.model) {
723 		case DISPLAY_MODEL_LCD:		/* LCD display */
724 			if (chassis_info.actcnt <
725 				offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
726 				goto not_found;
727 			if (!lcd_info.act_enable) {
728 				DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
729 				goto not_found;
730 			}
731 			break;
732 
733 		case DISPLAY_MODEL_NONE:	/* no LED or LCD available */
734 			printk(KERN_INFO "PDC reported no LCD or LED.\n");
735 			goto not_found;
736 
737 		case DISPLAY_MODEL_LASI:	/* Lasi style 8 bit LED display */
738 			if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
739 				goto not_found;
740 			break;
741 
742 		default:
743 			printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
744 			       lcd_info.model);
745 			goto not_found;
746 		} /* switch() */
747 
748 found:
749 		/* register the LCD/LED driver */
750 		register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
751 		return 0;
752 
753 	} else { /* if() */
754 		DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
755 	}
756 
757 not_found:
758 	lcd_info.model = DISPLAY_MODEL_NONE;
759 	return 1;
760 }
761 
762 static void __exit led_exit(void)
763 {
764 	unregister_reboot_notifier(&led_notifier);
765 	return;
766 }
767 
768 #ifdef CONFIG_PROC_FS
769 module_init(led_create_procfs)
770 #endif
771