1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Chassis LCD/LED driver for HP-PARISC workstations
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>
11 * - speed-up calculations with inlined assembler
12 * - interface to write to second row of LCD from /proc (if technically possible)
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
19 * David Pye <dmp@davidmpye.dyndns.org>
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>
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>
43 #include <asm/processor.h>
44 #include <asm/hardware.h>
45 #include <asm/param.h> /* HZ */
48 #include <linux/uaccess.h>
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) */
56 static int led_type __read_mostly = -1;
57 static unsigned char lastleds; /* LED state from most recent update */
58 static unsigned int led_heartbeat __read_mostly = 1;
59 static unsigned int led_diskio __read_mostly = 1;
60 static unsigned int led_lanrxtx __read_mostly = 1;
61 static char lcd_text[32] __read_mostly;
62 static char lcd_text_default[32] __read_mostly;
63 static int lcd_no_led_support __read_mostly = 0; /* KittyHawk doesn't support LED on its LCD */
66 static struct workqueue_struct *led_wq;
67 static void led_work_func(struct work_struct *);
68 static DECLARE_DELAYED_WORK(led_task, led_work_func);
71 #define DPRINTK(x) printk x
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 */
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 */
85 struct 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;
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)
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. */
108 static struct pdc_chassis_lcd_info_ret_block
109 lcd_info __attribute__((aligned(8))) __read_mostly =
111 .model = DISPLAY_MODEL_LCD,
113 .lcd_cmd_reg_addr = KITTYHAWK_LCD_CMD,
114 .lcd_data_reg_addr = KITTYHAWK_LCD_DATA,
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 */
129 /* The workqueue must be created at init-time */
130 static int start_task(void)
132 /* Display the default text now */
133 if (led_type == LED_HASLCD) lcd_print( lcd_text_default );
135 /* KittyHawk has no LED support on its LCD */
136 if (lcd_no_led_support) return 0;
138 /* Create the work queue and queue the LED task */
139 led_wq = create_singlethread_workqueue("led_wq");
143 queue_delayed_work(led_wq, &led_task, 0);
148 device_initcall(start_task);
150 /* ptr to LCD/LED-specific function */
151 static void (*led_func_ptr) (unsigned char) __read_mostly;
153 #ifdef CONFIG_PROC_FS
154 static int led_proc_show(struct seq_file *m, void *v)
156 switch ((long)m->private)
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);
164 seq_printf(m, "%s\n", lcd_text);
172 static int led_proc_open(struct inode *inode, struct file *file)
174 return single_open(file, led_proc_show, PDE_DATA(inode));
178 static ssize_t led_proc_write(struct file *file, const char __user *buf,
179 size_t count, loff_t *pos)
181 void *data = PDE_DATA(file_inode(file));
185 if (!capable(CAP_SYS_ADMIN))
188 if (count >= sizeof(lbuf))
189 count = sizeof(lbuf)-1;
191 if (copy_from_user(lbuf, buf, count))
201 if (d != 0 && d != 1) goto parse_error;
204 if (*cur++ != ' ') goto parse_error;
207 if (d != 0 && d != 1) goto parse_error;
210 if (*cur++ != ' ') goto parse_error;
213 if (d != 0 && d != 1) goto parse_error;
218 if (*cur && cur[strlen(cur)-1] == '\n')
219 cur[strlen(cur)-1] = 0;
221 cur = lcd_text_default;
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");
236 static const struct file_operations led_proc_fops = {
237 .owner = THIS_MODULE,
238 .open = led_proc_open,
241 .release = single_release,
242 .write = led_proc_write,
245 static int __init led_create_procfs(void)
247 struct proc_dir_entry *proc_pdc_root = NULL;
248 struct proc_dir_entry *ent;
250 if (led_type == -1) return -1;
252 proc_pdc_root = proc_mkdir("pdc", NULL);
253 if (!proc_pdc_root) return -1;
255 if (!lcd_no_led_support)
257 ent = proc_create_data("led", S_IRUGO|S_IWUSR, proc_pdc_root,
258 &led_proc_fops, (void *)LED_NOLCD); /* LED */
262 if (led_type == LED_HASLCD)
264 ent = proc_create_data("lcd", S_IRUGO|S_IWUSR, proc_pdc_root,
265 &led_proc_fops, (void *)LED_HASLCD); /* LCD */
278 #define LED_DATA 0x01 /* data to shift (0:on 1:off) */
279 #define LED_STROBE 0x02 /* strobe to clock data */
280 static void led_ASP_driver(unsigned char leds)
285 for (i = 0; i < 8; i++) {
287 value = (leds & 0x80) >> 7;
288 gsc_writeb( value, LED_DATA_REG );
289 gsc_writeb( value | LED_STROBE, LED_DATA_REG );
300 static void led_LASI_driver(unsigned char leds)
303 gsc_writeb( leds, LED_DATA_REG );
312 static void led_LCD_driver(unsigned char leds)
315 static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
316 LED_LAN_RCV, LED_LAN_TX };
318 static struct lcd_block * blockp[4] = {
325 /* Convert min_cmd_delay to milliseconds */
326 unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000);
330 if ((leds & mask[i]) != (lastleds & mask[i]))
332 gsc_writeb( blockp[i]->command, LCD_CMD_REG );
333 msleep(msec_cmd_delay);
335 gsc_writeb( leds & mask[i] ? blockp[i]->on :
336 blockp[i]->off, LCD_DATA_REG );
337 msleep(msec_cmd_delay);
345 ** led_get_net_activity()
347 ** calculate if there was TX- or RX-throughput on the network interfaces
348 ** (analog to dev_get_info() from net/core/dev.c)
351 static __inline__ int led_get_net_activity(void)
356 static u64 rx_total_last, tx_total_last;
357 u64 rx_total, tx_total;
358 struct net_device *dev;
361 rx_total = tx_total = 0;
363 /* we are running as a workqueue task, so we can use an RCU lookup */
365 for_each_netdev_rcu(&init_net, dev) {
366 const struct rtnl_link_stats64 *stats;
367 struct rtnl_link_stats64 temp;
368 struct in_device *in_dev = __in_dev_get_rcu(dev);
369 if (!in_dev || !in_dev->ifa_list)
371 if (ipv4_is_loopback(in_dev->ifa_list->ifa_local))
373 stats = dev_get_stats(dev, &temp);
374 rx_total += stats->rx_packets;
375 tx_total += stats->tx_packets;
381 if (rx_total != rx_total_last) {
382 rx_total_last = rx_total;
383 retval |= LED_LAN_RCV;
386 if (tx_total != tx_total_last) {
387 tx_total_last = tx_total;
388 retval |= LED_LAN_TX;
398 ** led_get_diskio_activity()
400 ** calculate if there was disk-io in the system
403 static __inline__ int led_get_diskio_activity(void)
405 static unsigned long last_pgpgin, last_pgpgout;
406 unsigned long events[NR_VM_EVENT_ITEMS];
409 all_vm_events(events);
411 /* Just use a very simple calculation here. Do not care about overflow,
412 since we only want to know if there was activity or not. */
413 changed = (events[PGPGIN] != last_pgpgin) ||
414 (events[PGPGOUT] != last_pgpgout);
415 last_pgpgin = events[PGPGIN];
416 last_pgpgout = events[PGPGOUT];
418 return (changed ? LED_DISK_IO : 0);
426 ** manages when and which chassis LCD/LED gets updated
429 - display load average (older machines like 715/64 have 4 "free" LED's for that)
433 #define HEARTBEAT_LEN (HZ*10/100)
434 #define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
435 #define HEARTBEAT_2ND_RANGE_END (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
437 #define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
439 static void led_work_func (struct work_struct *unused)
441 static unsigned long last_jiffies;
442 static unsigned long count_HZ; /* counter in range 0..HZ */
443 unsigned char currentleds = 0; /* stores current value of the LEDs */
445 /* exit if not initialized */
449 /* increment the heartbeat timekeeper */
450 count_HZ += jiffies - last_jiffies;
451 last_jiffies = jiffies;
455 if (likely(led_heartbeat))
457 /* flash heartbeat-LED like a real heart
458 * (2 x short then a long delay)
460 if (count_HZ < HEARTBEAT_LEN ||
461 (count_HZ >= HEARTBEAT_2ND_RANGE_START &&
462 count_HZ < HEARTBEAT_2ND_RANGE_END))
463 currentleds |= LED_HEARTBEAT;
466 if (likely(led_lanrxtx)) currentleds |= led_get_net_activity();
467 if (likely(led_diskio)) currentleds |= led_get_diskio_activity();
469 /* blink LEDs if we got an Oops (HPMC) */
470 if (unlikely(oops_in_progress)) {
471 if (boot_cpu_data.cpu_type >= pcxl2) {
472 /* newer machines don't have loadavg. LEDs, so we
473 * let all LEDs blink twice per second instead */
474 currentleds = (count_HZ <= (HZ/2)) ? 0 : 0xff;
476 /* old machines: blink loadavg. LEDs twice per second */
477 if (count_HZ <= (HZ/2))
478 currentleds &= ~(LED4|LED5|LED6|LED7);
480 currentleds |= (LED4|LED5|LED6|LED7);
484 if (currentleds != lastleds)
486 led_func_ptr(currentleds); /* Update the LCD/LEDs */
487 lastleds = currentleds;
490 queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
496 ** called by the reboot notifier chain at shutdown and stops all
497 ** LED/LCD activities.
501 static int led_halt(struct notifier_block *, unsigned long, void *);
503 static struct notifier_block led_notifier = {
504 .notifier_call = led_halt,
506 static int notifier_disabled = 0;
508 static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
512 if (notifier_disabled)
515 notifier_disabled = 1;
517 case SYS_RESTART: txt = "SYSTEM RESTART";
519 case SYS_HALT: txt = "SYSTEM HALT";
521 case SYS_POWER_OFF: txt = "SYSTEM POWER OFF";
523 default: return NOTIFY_DONE;
526 /* Cancel the work item and delete the queue */
528 cancel_delayed_work_sync(&led_task);
529 destroy_workqueue(led_wq);
533 if (lcd_info.model == DISPLAY_MODEL_LCD)
537 led_func_ptr(0xff); /* turn all LEDs ON */
543 ** register_led_driver()
545 ** registers an external LED or LCD for usage by this driver.
546 ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
550 int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
552 static int initialized;
554 if (initialized || !data_reg)
557 lcd_info.model = model; /* store the values */
558 LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
560 switch (lcd_info.model) {
561 case DISPLAY_MODEL_LCD:
562 LCD_DATA_REG = data_reg;
563 printk(KERN_INFO "LCD display at %lx,%lx registered\n",
564 LCD_CMD_REG , LCD_DATA_REG);
565 led_func_ptr = led_LCD_driver;
566 led_type = LED_HASLCD;
569 case DISPLAY_MODEL_LASI:
570 /* Skip to register LED in QEMU */
573 LED_DATA_REG = data_reg;
574 led_func_ptr = led_LASI_driver;
575 printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
576 led_type = LED_NOLCD;
579 case DISPLAY_MODEL_OLD_ASP:
580 LED_DATA_REG = data_reg;
581 led_func_ptr = led_ASP_driver;
582 printk(KERN_INFO "LED (ASP-style) display at %lx registered\n",
584 led_type = LED_NOLCD;
588 printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
589 __func__, lcd_info.model);
593 /* mark the LCD/LED driver now as initialized and
594 * register to the reboot notifier chain */
596 register_reboot_notifier(&led_notifier);
598 /* Ensure the work is queued */
600 queue_delayed_work(led_wq, &led_task, 0);
607 ** register_led_regions()
609 ** register_led_regions() registers the LCD/LED regions for /procfs.
610 ** At bootup - where the initialisation of the LCD/LED normally happens -
611 ** not all internal structures of request_region() are properly set up,
612 ** so that we delay the led-registration until after busdevices_init()
613 ** has been executed.
617 void __init register_led_regions(void)
619 switch (lcd_info.model) {
620 case DISPLAY_MODEL_LCD:
621 request_mem_region((unsigned long)LCD_CMD_REG, 1, "lcd_cmd");
622 request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
624 case DISPLAY_MODEL_LASI:
625 case DISPLAY_MODEL_OLD_ASP:
626 request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
636 ** Displays the given string on the LCD-Display of newer machines.
637 ** lcd_print() disables/enables the timer-based led work queue to
638 ** avoid a race condition while writing the CMD/DATA register pair.
641 int lcd_print( const char *str )
645 if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
648 /* temporarily disable the led work task */
650 cancel_delayed_work_sync(&led_task);
652 /* copy display string to buffer for procfs */
653 strlcpy(lcd_text, str, sizeof(lcd_text));
655 /* Set LCD Cursor to 1st character */
656 gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
657 udelay(lcd_info.min_cmd_delay);
659 /* Print the string */
660 for (i=0; i < lcd_info.lcd_width; i++) {
662 gsc_writeb(*str++, LCD_DATA_REG);
664 gsc_writeb(' ', LCD_DATA_REG);
665 udelay(lcd_info.min_cmd_delay);
668 /* re-queue the work */
670 queue_delayed_work(led_wq, &led_task, 0);
673 return lcd_info.lcd_width;
679 ** led_init() is called very early in the bootup-process from setup.c
680 ** and asks the PDC for an usable chassis LCD or LED.
681 ** If the PDC doesn't return any info, then the LED
682 ** is detected by lasi.c or asp.c and registered with the
683 ** above functions lasi_led_init() or asp_led_init().
684 ** KittyHawk machines have often a buggy PDC, so that
685 ** we explicitly check for those machines here.
688 int __init led_init(void)
690 struct pdc_chassis_info chassis_info;
693 snprintf(lcd_text_default, sizeof(lcd_text_default),
694 "Linux %s", init_utsname()->release);
696 /* Work around the buggy PDC of KittyHawk-machines */
697 switch (CPU_HVERSION) {
698 case 0x580: /* KittyHawk DC2-100 (K100) */
699 case 0x581: /* KittyHawk DC3-120 (K210) */
700 case 0x582: /* KittyHawk DC3 100 (K400) */
701 case 0x583: /* KittyHawk DC3 120 (K410) */
702 case 0x58B: /* KittyHawk DC2 100 (K200) */
703 printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
704 "LED detection skipped.\n", __FILE__, CPU_HVERSION);
705 lcd_no_led_support = 1;
706 goto found; /* use the preinitialized values of lcd_info */
709 /* initialize the struct, so that we can check for valid return values */
710 lcd_info.model = DISPLAY_MODEL_NONE;
711 chassis_info.actcnt = chassis_info.maxcnt = 0;
713 ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
715 DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
716 "lcd_width=%d, cmd_delay=%u,\n"
717 "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
718 __FILE__, lcd_info.model,
719 (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
720 (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
721 lcd_info.lcd_width, lcd_info.min_cmd_delay,
722 __FILE__, sizeof(lcd_info),
723 chassis_info.actcnt, chassis_info.maxcnt));
724 DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
725 __FILE__, lcd_info.lcd_cmd_reg_addr,
726 lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
727 lcd_info.reset_cmd2, lcd_info.act_enable ));
729 /* check the results. Some machines have a buggy PDC */
730 if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
733 switch (lcd_info.model) {
734 case DISPLAY_MODEL_LCD: /* LCD display */
735 if (chassis_info.actcnt <
736 offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
738 if (!lcd_info.act_enable) {
739 DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
744 case DISPLAY_MODEL_NONE: /* no LED or LCD available */
745 printk(KERN_INFO "PDC reported no LCD or LED.\n");
748 case DISPLAY_MODEL_LASI: /* Lasi style 8 bit LED display */
749 if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
754 printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
760 /* register the LCD/LED driver */
761 register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
765 DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
769 lcd_info.model = DISPLAY_MODEL_NONE;
773 static void __exit led_exit(void)
775 unregister_reboot_notifier(&led_notifier);
779 #ifdef CONFIG_PROC_FS
780 module_init(led_create_procfs)