parisc: led: Rewrite LED/LCD driver to utilizize Linux LED subsystem

Rewrite the whole driver and drop the own code to calculate load
average, disk and LAN load. Switch instead to use the in-kernel LED
subsystem, which gives us quite some advantages, e.g.
- existing triggers for heartbeat and disk/lan activity can be used
- users can configre the LEDs at will to any existing trigger via
  /sys/class/leds
- less overhead since we don't need to run own timers
- fully integrated in Linux and as such cleaner code.

Note that the driver now depends on CONFIG_LEDS_CLASS which has to
be built-in and not as module.

Signed-off-by: Helge Deller <deller@gmx.de>

2 files changed, 340 insertions, 566 deletions

diff --git a/drivers/parisc/Kconfig b/drivers/parisc/Kconfig
index 2fc3222d26346..9cbcf15527b6b 100644
--- a/drivers/parisc/Kconfig
+++ b/drivers/parisc/Kconfig
@@ -100,8 +100,9 @@ config SUPERIO
 
 config CHASSIS_LCD_LED
 	bool "Chassis LCD and LED support"
+	depends on LEDS_CLASS=y
 	default y
-	select VM_EVENT_COUNTERS
+	select LEDS_TRIGGERS
 	help
 	  Say Y here if you want to enable support for the Heartbeat,
 	  Disk/Network activities LEDs on some PA-RISC machines,
diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c
index 38cd14530ff26..1f75d2416001e 100644
--- a/drivers/parisc/led.c
+++ b/drivers/parisc/led.c
@@ -1,77 +1,46 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
- *    Chassis LCD/LED driver for HP-PARISC workstations
+ *	Chassis LCD/LED driver for HP-PARISC workstations
  *
- *      (c) Copyright 2000 Red Hat Software
- *      (c) Copyright 2000 Helge Deller <hdeller@redhat.com>
- *      (c) Copyright 2001-2009 Helge Deller <deller@gmx.de>
- *      (c) Copyright 2001 Randolph Chung <tausq@debian.org>
+ *	(c) Copyright 2000 Red Hat Software
+ *	(c) Copyright 2000 Helge Deller <hdeller@redhat.com>
+ *	(c) Copyright 2001 Randolph Chung <tausq@debian.org>
+ *	(c) Copyright 2000-2023 Helge Deller <deller@gmx.de>
  *
- * TODO:
- *	- speed-up calculations with inlined assembler
- *	- interface to write to second row of LCD from /proc (if technically possible)
+ *	The control of the LEDs and LCDs on PARISC machines has to be done
+ *	completely in software.
  *
- * Changes:
- *      - Audit copy_from_user in led_proc_write.
- *                                Daniele Bellucci <bellucda@tiscali.it>
- *	- Switch from using a tasklet to a work queue, so the led_LCD_driver
- *	  	can sleep.
- *	  			  David Pye <dmp@davidmpye.dyndns.org>
+ *	The LEDs can be configured at runtime in /sys/class/leds/
  */
 
 #include <linux/module.h>
-#include <linux/stddef.h>	/* for offsetof() */
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/ioport.h>
 #include <linux/utsname.h>
 #include <linux/capability.h>
 #include <linux/delay.h>
-#include <linux/netdevice.h>
-#include <linux/inetdevice.h>
-#include <linux/in.h>
-#include <linux/interrupt.h>
-#include <linux/kernel_stat.h>
 #include <linux/reboot.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <linux/ctype.h>
-#include <linux/blkdev.h>
-#include <linux/workqueue.h>
-#include <linux/rcupdate.h>
+#include <linux/uaccess.h>
+#include <linux/leds.h>
+#include <linux/platform_device.h>
+
 #include <asm/io.h>
 #include <asm/processor.h>
 #include <asm/hardware.h>
 #include <asm/param.h>		/* HZ */
 #include <asm/led.h>
 #include <asm/pdc.h>
-#include <linux/uaccess.h>
-
-/* The control of the LEDs and LCDs on PARISC-machines have to be done 
-   completely in software. The necessary calculations are done in a work queue
-   task which is scheduled regularly, and since the calculations may consume a 
-   relatively large amount of CPU time, some of the calculations can be 
-   turned off with the following variables (controlled via procfs) */
 
-static int led_type __read_mostly = -1;
-static unsigned char lastleds;	/* LED state from most recent update */
-static unsigned int led_heartbeat __read_mostly = 1;
-static unsigned int led_diskio    __read_mostly;
-static unsigned int led_lanrxtx   __read_mostly;
-static char lcd_text[32]          __read_mostly;
-static char lcd_text_default[32]  __read_mostly;
-static int  lcd_no_led_support    __read_mostly = 0; /* KittyHawk doesn't support LED on its LCD */
+#define LED_HAS_LCD 1
+#define LED_HAS_LED 2
 
-
-static struct workqueue_struct *led_wq;
-static void led_work_func(struct work_struct *);
-static DECLARE_DELAYED_WORK(led_task, led_work_func);
-
-#if 0
-#define DPRINTK(x)	printk x
-#else
-#define DPRINTK(x)
-#endif
+static unsigned char led_type;		/* bitmask of LED_HAS_XXX */
+static unsigned char lastleds;		/* LED state from most recent update */
+static unsigned char lcd_new_text;
+static unsigned char lcd_text[20];
+static unsigned char lcd_text_default[20];
+static unsigned char lcd_no_led_support; /* KittyHawk doesn't support LED on its LCD */
 
 struct lcd_block {
 	unsigned char command;	/* stores the command byte      */
@@ -80,7 +49,7 @@ struct lcd_block {
 };
 
 /* Structure returned by PDC_RETURN_CHASSIS_INFO */
-/* NOTE: we use unsigned long:16 two times, since the following member 
+/* NOTE: we use unsigned long:16 two times, since the following member
    lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */
 struct pdc_chassis_lcd_info_ret_block {
 	unsigned long model:16;		/* DISPLAY_MODEL_XXXX */
@@ -100,15 +69,15 @@ struct pdc_chassis_lcd_info_ret_block {
 
 
 /* LCD_CMD and LCD_DATA for KittyHawk machines */
-#define KITTYHAWK_LCD_CMD  F_EXTEND(0xf0190000UL) /* 64bit-ready */
-#define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1)
+#define KITTYHAWK_LCD_CMD  F_EXTEND(0xf0190000UL)
+#define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD + 1)
 
-/* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's 
+/* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's
  * HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
 static struct pdc_chassis_lcd_info_ret_block
-lcd_info __attribute__((aligned(8))) __read_mostly =
+lcd_info __attribute__((aligned(8)))  =
 {
-	.model =		DISPLAY_MODEL_LCD,
+	.model =		DISPLAY_MODEL_NONE,
 	.lcd_width =		16,
 	.lcd_cmd_reg_addr =	KITTYHAWK_LCD_CMD,
 	.lcd_data_reg_addr =	KITTYHAWK_LCD_DATA,
@@ -117,165 +86,65 @@ lcd_info __attribute__((aligned(8))) __read_mostly =
 	.reset_cmd2 =		0xc0,
 };
 
-
 /* direct access to some of the lcd_info variables */
-#define LCD_CMD_REG	lcd_info.lcd_cmd_reg_addr	 
-#define LCD_DATA_REG	lcd_info.lcd_data_reg_addr	 
+#define LCD_CMD_REG	lcd_info.lcd_cmd_reg_addr
+#define LCD_DATA_REG	lcd_info.lcd_data_reg_addr
 #define LED_DATA_REG	lcd_info.lcd_cmd_reg_addr	/* LASI & ASP only */
 
-#define LED_HASLCD 1
-#define LED_NOLCD  0
-
-/* The workqueue must be created at init-time */
-static int start_task(void) 
-{	
-	/* Display the default text now */
-	if (led_type == LED_HASLCD) lcd_print( lcd_text_default );
-
-	/* KittyHawk has no LED support on its LCD */
-	if (lcd_no_led_support) return 0;
-
-	/* Create the work queue and queue the LED task */
-	led_wq = create_singlethread_workqueue("led_wq");	
-	if (!led_wq)
-		return -ENOMEM;
-
-	queue_delayed_work(led_wq, &led_task, 0);
-
-	return 0;
-}
-
-device_initcall(start_task);
-
 /* ptr to LCD/LED-specific function */
-static void (*led_func_ptr) (unsigned char) __read_mostly;
-
-#ifdef CONFIG_PROC_FS
-static int led_proc_show(struct seq_file *m, void *v)
-{
-	switch ((long)m->private)
-	{
-	case LED_NOLCD:
-		seq_printf(m, "Heartbeat: %d\n", led_heartbeat);
-		seq_printf(m, "Disk IO: %d\n", led_diskio);
-		seq_printf(m, "LAN Rx/Tx: %d\n", led_lanrxtx);
-		break;
-	case LED_HASLCD:
-		seq_printf(m, "%s\n", lcd_text);
-		break;
-	default:
-		return 0;
-	}
-	return 0;
-}
-
-static int led_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, led_proc_show, pde_data(inode));
-}
+static void (*led_func_ptr) (unsigned char);
 
 
-static ssize_t led_proc_write(struct file *file, const char __user *buf,
-	size_t count, loff_t *pos)
+static void lcd_print_now(void)
 {
-	void *data = pde_data(file_inode(file));
-	char *cur, lbuf[32];
-	int d;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EACCES;
-
-	if (count >= sizeof(lbuf))
-		count = sizeof(lbuf)-1;
-
-	if (copy_from_user(lbuf, buf, count))
-		return -EFAULT;
-	lbuf[count] = 0;
-
-	cur = lbuf;
-
-	switch ((long)data)
-	{
-	case LED_NOLCD:
-		d = *cur++ - '0';
-		if (d != 0 && d != 1) goto parse_error;
-		led_heartbeat = d;
-
-		if (*cur++ != ' ') goto parse_error;
+	int i;
+	char *str = lcd_text;
 
-		d = *cur++ - '0';
-		if (d != 0 && d != 1) goto parse_error;
-		led_diskio = d;
+	if (lcd_info.model != DISPLAY_MODEL_LCD)
+		return;
 
-		if (*cur++ != ' ') goto parse_error;
+	if (!lcd_new_text)
+		return;
+	lcd_new_text = 0;
 
-		d = *cur++ - '0';
-		if (d != 0 && d != 1) goto parse_error;
-		led_lanrxtx = d;
+	/* Set LCD Cursor to 1st character */
+	gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
+	udelay(lcd_info.min_cmd_delay);
 
-		break;
-	case LED_HASLCD:
-		if (*cur && cur[strlen(cur)-1] == '\n')
-			cur[strlen(cur)-1] = 0;
-		if (*cur == 0) 
-			cur = lcd_text_default;
-		lcd_print(cur);
-		break;
-	default:
-		return 0;
+	/* Print the string */
+	for (i = 0; i < lcd_info.lcd_width; i++) {
+		gsc_writeb(*str ? *str++ : ' ', LCD_DATA_REG);
+		udelay(lcd_info.min_cmd_delay);
 	}
-	
-	return count;
-
-parse_error:
-	if ((long)data == LED_NOLCD)
-		printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n");
-	return -EINVAL;
 }
 
-static const struct proc_ops led_proc_ops = {
-	.proc_open	= led_proc_open,
-	.proc_read	= seq_read,
-	.proc_lseek	= seq_lseek,
-	.proc_release	= single_release,
-	.proc_write	= led_proc_write,
-};
-
-static int __init led_create_procfs(void)
+/**
+ *	lcd_print()
+ *
+ *	@str: string to show on the LCD. If NULL, print current string again.
+ *
+ *	Displays the given string on the LCD-Display of newer machines.
+ */
+void lcd_print(const char *str)
 {
-	struct proc_dir_entry *proc_pdc_root = NULL;
-	struct proc_dir_entry *ent;
-
-	if (led_type == -1) return -1;
-
-	proc_pdc_root = proc_mkdir("pdc", NULL);
-	if (!proc_pdc_root) return -1;
-
-	if (!lcd_no_led_support)
-	{
-		ent = proc_create_data("led", 0644, proc_pdc_root,
-					&led_proc_ops, (void *)LED_NOLCD); /* LED */
-		if (!ent) return -1;
-	}
-
-	if (led_type == LED_HASLCD)
-	{
-		ent = proc_create_data("lcd", 0644, proc_pdc_root,
-					&led_proc_ops, (void *)LED_HASLCD); /* LCD */
-		if (!ent) return -1;
-	}
+	/* copy display string to buffer for procfs */
+	if (str)
+		strscpy(lcd_text, str, sizeof(lcd_text));
+	lcd_new_text = 1;
 
-	return 0;
+	/* print now if LCD without any LEDs */
+	if (led_type == LED_HAS_LCD)
+		lcd_print_now();
 }
-#endif
 
-/*
-   ** 
-   ** led_ASP_driver()
-   ** 
- */
 #define	LED_DATA	0x01	/* data to shift (0:on 1:off) */
 #define	LED_STROBE	0x02	/* strobe to clock data */
+
+/**
+ *	led_ASP_driver() - LED driver for the ASP controller chip
+ *
+ *	@leds: bitmap representing the LED status
+ */
 static void led_ASP_driver(unsigned char leds)
 {
 	int i;
@@ -290,11 +159,10 @@ static void led_ASP_driver(unsigned char leds)
 	}
 }
 
-
-/*
-   ** 
-   ** led_LASI_driver()
-   ** 
+/**
+ *	led_LASI_driver() - LED driver for the LASI controller chip
+ *
+ *	@leds: bitmap representing the LED status
  */
 static void led_LASI_driver(unsigned char leds)
 {
@@ -302,397 +170,298 @@ static void led_LASI_driver(unsigned char leds)
 	gsc_writeb( leds, LED_DATA_REG );
 }
 
-
-/*
-   ** 
-   ** led_LCD_driver()
-   **   
+/**
+ *	led_LCD_driver() - LED & LCD driver for LCD chips
+ *
+ *	@leds: bitmap representing the LED status
  */
 static void led_LCD_driver(unsigned char leds)
 {
-	static int i;
-	static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
+	static const unsigned char mask[4] = {
+		LED_HEARTBEAT, LED_DISK_IO,
 		LED_LAN_RCV, LED_LAN_TX };
-	
-	static struct lcd_block * blockp[4] = {
+
+	static struct lcd_block * const blockp[4] = {
 		&lcd_info.heartbeat,
 		&lcd_info.disk_io,
 		&lcd_info.lan_rcv,
 		&lcd_info.lan_tx
 	};
+	static unsigned char latest_leds;
+	int i;
 
-	/* Convert min_cmd_delay to milliseconds */
-	unsigned int msec_cmd_delay = 1 + (lcd_info.min_cmd_delay / 1000);
-	
-	for (i=0; i<4; ++i) 
-	{
-		if ((leds & mask[i]) != (lastleds & mask[i])) 
-		{
-			gsc_writeb( blockp[i]->command, LCD_CMD_REG );
-			msleep(msec_cmd_delay);
-			
-			gsc_writeb( leds & mask[i] ? blockp[i]->on : 
-					blockp[i]->off, LCD_DATA_REG );
-			msleep(msec_cmd_delay);
-		}
+	for (i = 0; i < 4; ++i) {
+		if ((leds & mask[i]) == (latest_leds & mask[i]))
+			continue;
+
+		gsc_writeb( blockp[i]->command, LCD_CMD_REG );
+		udelay(lcd_info.min_cmd_delay);
+
+		gsc_writeb( leds & mask[i] ? blockp[i]->on :
+				blockp[i]->off, LCD_DATA_REG );
+		udelay(lcd_info.min_cmd_delay);
 	}
+	latest_leds = leds;
+
+	lcd_print_now();
 }
 
 
-/*
-   ** 
-   ** led_get_net_activity()
-   ** 
-   ** calculate if there was TX- or RX-throughput on the network interfaces
-   ** (analog to dev_get_info() from net/core/dev.c)
-   **   
+/**
+ *	lcd_system_halt()
+ *
+ *	@nb: pointer to the notifier_block structure
+ *	@event: the event (SYS_RESTART, SYS_HALT or SYS_POWER_OFF)
+ *	@buf: pointer to a buffer (not used)
+ *
+ *	Called by the reboot notifier chain at shutdown. Stops all
+ *	LED/LCD activities.
  */
-static __inline__ int led_get_net_activity(void)
-{ 
-#ifndef CONFIG_NET
-	return 0;
-#else
-	static u64 rx_total_last, tx_total_last;
-	u64 rx_total, tx_total;
-	struct net_device *dev;
-	int retval;
-
-	rx_total = tx_total = 0;
-	
-	/* we are running as a workqueue task, so we can use an RCU lookup */
-	rcu_read_lock();
-	for_each_netdev_rcu(&init_net, dev) {
-	    const struct rtnl_link_stats64 *stats;
-	    struct rtnl_link_stats64 temp;
-	    struct in_device *in_dev = __in_dev_get_rcu(dev);
-	    if (!in_dev || !in_dev->ifa_list)
-		continue;
-	    if (ipv4_is_loopback(in_dev->ifa_list->ifa_local))
-		continue;
-	    stats = dev_get_stats(dev, &temp);
-	    rx_total += stats->rx_packets;
-	    tx_total += stats->tx_packets;
-	}
-	rcu_read_unlock();
-
-	retval = 0;
+static int lcd_system_halt(struct notifier_block *nb, unsigned long event, void *buf)
+{
+	const char *txt;
 
-	if (rx_total != rx_total_last) {
-		rx_total_last = rx_total;
-		retval |= LED_LAN_RCV;
+	switch (event) {
+	case SYS_RESTART:	txt = "SYSTEM RESTART";
+				break;
+	case SYS_HALT:		txt = "SYSTEM HALT";
+				break;
+	case SYS_POWER_OFF:	txt = "SYSTEM POWER OFF";
+				break;
+	default:		return NOTIFY_DONE;
 	}
 
-	if (tx_total != tx_total_last) {
-		tx_total_last = tx_total;
-		retval |= LED_LAN_TX;
-	}
+	lcd_print(txt);
 
-	return retval;
-#endif
+	return NOTIFY_OK;
 }
 
+static struct notifier_block lcd_system_halt_notifier = {
+	.notifier_call = lcd_system_halt,
+};
 
-/*
-   ** 
-   ** led_get_diskio_activity()
-   ** 
-   ** calculate if there was disk-io in the system
-   **   
- */
-static __inline__ int led_get_diskio_activity(void)
-{	
-	static unsigned long last_pgpgin, last_pgpgout;
-	unsigned long events[NR_VM_EVENT_ITEMS];
-	int changed;
-
-	all_vm_events(events);
-
-	/* Just use a very simple calculation here. Do not care about overflow,
-	   since we only want to know if there was activity or not. */
-	changed = (events[PGPGIN] != last_pgpgin) ||
-		  (events[PGPGOUT] != last_pgpgout);
-	last_pgpgin  = events[PGPGIN];
-	last_pgpgout = events[PGPGOUT];
-
-	return (changed ? LED_DISK_IO : 0);
-}
-
+static void set_led(struct led_classdev *led_cdev, enum led_brightness brightness);
 
+struct hppa_led {
+	struct led_classdev	led_cdev;
+	unsigned char		led_bit;
+};
+#define to_hppa_led(d) container_of(d, struct hppa_led, led_cdev)
 
-/*
-   ** led_work_func()
-   ** 
-   ** manages when and which chassis LCD/LED gets updated
+typedef void (*set_handler)(struct led_classdev *, enum led_brightness);
+struct led_type {
+	const char	*name;
+	set_handler	handler;
+	const char	*default_trigger;
+};
 
-    TODO:
-    - display load average (older machines like 715/64 have 4 "free" LED's for that)
-    - optimizations
- */
+#define NUM_LEDS_PER_BOARD	8
+struct hppa_drvdata {
+	struct hppa_led	leds[NUM_LEDS_PER_BOARD];
+};
 
-#define HEARTBEAT_LEN (HZ*10/100)
-#define HEARTBEAT_2ND_RANGE_START (HZ*28/100)
-#define HEARTBEAT_2ND_RANGE_END   (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
+static void set_led(struct led_classdev *led_cdev, enum led_brightness brightness)
+{
+	struct hppa_led *p = to_hppa_led(led_cdev);
+	unsigned char led_bit = p->led_bit;
 
-#define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
+	if (brightness == LED_OFF)
+		lastleds &= ~led_bit;
+	else
+		lastleds |= led_bit;
 
-static void led_work_func (struct work_struct *unused)
-{
-	static unsigned long last_jiffies;
-	static unsigned long count_HZ; /* counter in range 0..HZ */
-	unsigned char currentleds = 0; /* stores current value of the LEDs */
+	if (led_func_ptr)
+		led_func_ptr(lastleds);
+}
 
-	/* exit if not initialized */
-	if (!led_func_ptr)
-	    return;
 
-	/* increment the heartbeat timekeeper */
-	count_HZ += jiffies - last_jiffies;
-	last_jiffies = jiffies;
-	if (count_HZ >= HZ)
-	    count_HZ = 0;
+static int hppa_led_generic_probe(struct platform_device *pdev,
+				  struct led_type *types)
+{
+	struct hppa_drvdata *p;
+	int i, err;
 
-	if (likely(led_heartbeat))
-	{
-		/* flash heartbeat-LED like a real heart
-		 * (2 x short then a long delay)
-		 */
-		if (count_HZ < HEARTBEAT_LEN || 
-				(count_HZ >= HEARTBEAT_2ND_RANGE_START &&
-				count_HZ < HEARTBEAT_2ND_RANGE_END)) 
-			currentleds |= LED_HEARTBEAT;
-	}
+	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
 
-	if (likely(led_lanrxtx))  currentleds |= led_get_net_activity();
-	if (likely(led_diskio))   currentleds |= led_get_diskio_activity();
-
-	/* blink LEDs if we got an Oops (HPMC) */
-	if (unlikely(oops_in_progress)) {
-		if (boot_cpu_data.cpu_type >= pcxl2) {
-			/* newer machines don't have loadavg. LEDs, so we
-			 * let all LEDs blink twice per second instead */
-			currentleds = (count_HZ <= (HZ/2)) ? 0 : 0xff;
-		} else {
-			/* old machines: blink loadavg. LEDs twice per second */
-			if (count_HZ <= (HZ/2))
-				currentleds &= ~(LED4|LED5|LED6|LED7);
-			else
-				currentleds |= (LED4|LED5|LED6|LED7);
+	for (i = 0; i < NUM_LEDS_PER_BOARD; i++) {
+		struct led_classdev *lp = &p->leds[i].led_cdev;
+
+		p->leds[i].led_bit = BIT(i);
+		lp->name = types[i].name;
+		lp->brightness = LED_FULL;
+		lp->brightness_set = types[i].handler;
+		lp->default_trigger = types[i].default_trigger;
+		err = led_classdev_register(&pdev->dev, lp);
+		if (err) {
+			dev_err(&pdev->dev, "Could not register %s LED\n",
+			       lp->name);
+			for (i--; i >= 0; i--)
+				led_classdev_unregister(&p->leds[i].led_cdev);
+			return err;
 		}
 	}
 
-	if (currentleds != lastleds)
-	{
-		led_func_ptr(currentleds);	/* Update the LCD/LEDs */
-		lastleds = currentleds;
-	}
+	platform_set_drvdata(pdev, p);
 
-	queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
+	return 0;
 }
 
-/*
-   ** led_halt()
-   ** 
-   ** called by the reboot notifier chain at shutdown and stops all
-   ** LED/LCD activities.
-   ** 
- */
+static int platform_led_remove(struct platform_device *pdev)
+{
+	struct hppa_drvdata *p = platform_get_drvdata(pdev);
+	int i;
 
-static int led_halt(struct notifier_block *, unsigned long, void *);
+	for (i = 0; i < NUM_LEDS_PER_BOARD; i++)
+		led_classdev_unregister(&p->leds[i].led_cdev);
 
-static struct notifier_block led_notifier = {
-	.notifier_call = led_halt,
+	return 0;
+}
+
+static struct led_type mainboard_led_types[NUM_LEDS_PER_BOARD] = {
+	{
+		.name		= "platform-lan-tx",
+		.handler	= set_led,
+		.default_trigger = "tx",
+	},
+	{
+		.name		= "platform-lan-rx",
+		.handler	= set_led,
+		.default_trigger = "rx",
+	},
+	{
+		.name		= "platform-disk",
+		.handler	= set_led,
+		.default_trigger = "disk-activity",
+	},
+	{
+		.name		= "platform-heartbeat",
+		.handler	= set_led,
+		.default_trigger = "heartbeat",
+	},
+	{
+		.name		= "platform-LED4",
+		.handler	= set_led,
+		.default_trigger = "panic",
+	},
+	{
+		.name		= "platform-LED5",
+		.handler	= set_led,
+		.default_trigger = "panic",
+	},
+	{
+		.name		= "platform-LED6",
+		.handler	= set_led,
+		.default_trigger = "panic",
+	},
+	{
+		.name		= "platform-LED7",
+		.handler	= set_led,
+		.default_trigger = "panic",
+	},
 };
-static int notifier_disabled = 0;
 
-static int led_halt(struct notifier_block *nb, unsigned long event, void *buf) 
+static int platform_led_probe(struct platform_device *pdev)
 {
-	char *txt;
+	return hppa_led_generic_probe(pdev, mainboard_led_types);
+}
 
-	if (notifier_disabled)
-		return NOTIFY_OK;
+MODULE_ALIAS("platform:platform-leds");
 
-	notifier_disabled = 1;
-	switch (event) {
-	case SYS_RESTART:	txt = "SYSTEM RESTART";
-				break;
-	case SYS_HALT:		txt = "SYSTEM HALT";
-				break;
-	case SYS_POWER_OFF:	txt = "SYSTEM POWER OFF";
-				break;
-	default:		return NOTIFY_DONE;
-	}
-	
-	/* Cancel the work item and delete the queue */
-	if (led_wq) {
-		cancel_delayed_work_sync(&led_task);
-		destroy_workqueue(led_wq);
-		led_wq = NULL;
-	}
- 
-	if (lcd_info.model == DISPLAY_MODEL_LCD)
-		lcd_print(txt);
-	else
-		if (led_func_ptr)
-			led_func_ptr(0xff); /* turn all LEDs ON */
-	
-	return NOTIFY_OK;
-}
+static struct platform_driver hppa_mainboard_led_driver = {
+	.probe		= platform_led_probe,
+	.remove		= platform_led_remove,
+	.driver		= {
+		.name	= "platform-leds",
+	},
+};
 
-/*
-   ** register_led_driver()
-   ** 
-   ** registers an external LED or LCD for usage by this driver.
-   ** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
-   ** 
- */
+static struct platform_driver * const drivers[] = {
+	&hppa_mainboard_led_driver,
+};
+
+static struct platform_device platform_leds = {
+	.name = "platform-leds",
+};
 
+/**
+ *	register_led_driver()
+ *
+ *	@model: model type, one of the DISPLAY_MODEL_XXXX values
+ *	@cmd_reg: physical address of cmd register for the LED/LCD
+ *	@data_reg: physical address of data register for the LED/LCD
+ *
+ *	Registers a chassis LED or LCD which should be driven by this driver.
+ *	Only PDC-based, LASI- or ASP-style LEDs and LCDs are supported.
+ */
 int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
 {
-	static int initialized;
-	
-	if (initialized || !data_reg)
+	if (led_func_ptr || !data_reg)
 		return 1;
-	
+
+	/* No LEDs when running in QEMU */
+	if (running_on_qemu)
+		return 1;
+
 	lcd_info.model = model;		/* store the values */
 	LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
 
 	switch (lcd_info.model) {
 	case DISPLAY_MODEL_LCD:
 		LCD_DATA_REG = data_reg;
-		printk(KERN_INFO "LCD display at %lx,%lx registered\n", 
+		pr_info("led: LCD display at %#lx and %#lx\n",
 			LCD_CMD_REG , LCD_DATA_REG);
 		led_func_ptr = led_LCD_driver;
-		led_type = LED_HASLCD;
+		if (lcd_no_led_support)
+			led_type = LED_HAS_LCD;
+		else
+			led_type = LED_HAS_LCD | LED_HAS_LED;
 		break;
 
 	case DISPLAY_MODEL_LASI:
-		/* Skip to register LED in QEMU */
-		if (running_on_qemu)
-			return 1;
 		LED_DATA_REG = data_reg;
 		led_func_ptr = led_LASI_driver;
-		printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
-		led_type = LED_NOLCD;
+		pr_info("led: LED display at %#lx\n", LED_DATA_REG);
+		led_type = LED_HAS_LED;
 		break;
 
 	case DISPLAY_MODEL_OLD_ASP:
 		LED_DATA_REG = data_reg;
 		led_func_ptr = led_ASP_driver;
-		printk(KERN_INFO "LED (ASP-style) display at %lx registered\n", 
+		pr_info("led: LED (ASP-style) display at %#lx\n",
 		    LED_DATA_REG);
-		led_type = LED_NOLCD;
+		led_type = LED_HAS_LED;
 		break;
 
 	default:
-		printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
-		       __func__, lcd_info.model);
+		pr_err("led: Unknown LCD/LED model type %d\n", lcd_info.model);
 		return 1;
 	}
-	
-	/* mark the LCD/LED driver now as initialized and 
-	 * register to the reboot notifier chain */
-	initialized++;
-	register_reboot_notifier(&led_notifier);
-
-	/* Ensure the work is queued */
-	if (led_wq) {
-		queue_delayed_work(led_wq, &led_task, 0);
-	}
 
-	return 0;
-}
+	platform_register_drivers(drivers, ARRAY_SIZE(drivers));
 
-/*
-   ** register_led_regions()
-   ** 
-   ** register_led_regions() registers the LCD/LED regions for /procfs.
-   ** At bootup - where the initialisation of the LCD/LED normally happens - 
-   ** not all internal structures of request_region() are properly set up,
-   ** so that we delay the led-registration until after busdevices_init() 
-   ** has been executed.
-   **
- */
-
-static int __init register_led_regions(void)
-{
-	switch (lcd_info.model) {
-	case DISPLAY_MODEL_LCD:
-		request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
-		request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
-		break;
-	case DISPLAY_MODEL_LASI:
-	case DISPLAY_MODEL_OLD_ASP:
-		request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
-		break;
-	}
-	return 0;
-}
-late_initcall(register_led_regions);
-
-
-/*
-   ** 
-   ** lcd_print()
-   ** 
-   ** Displays the given string on the LCD-Display of newer machines.
-   ** lcd_print() disables/enables the timer-based led work queue to
-   ** avoid a race condition while writing the CMD/DATA register pair.
-   **
- */
-int lcd_print( const char *str )
-{
-	int i;
-
-	if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
-	    return 0;
-	
-	/* temporarily disable the led work task */
-	if (led_wq)
-		cancel_delayed_work_sync(&led_task);
-
-	/* copy display string to buffer for procfs */
-	strscpy(lcd_text, str, sizeof(lcd_text));
-
-	/* Set LCD Cursor to 1st character */
-	gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
-	udelay(lcd_info.min_cmd_delay);
-
-	/* Print the string */
-	for (i=0; i < lcd_info.lcd_width; i++) {
-	    if (str && *str)
-		gsc_writeb(*str++, LCD_DATA_REG);
-	    else
-		gsc_writeb(' ', LCD_DATA_REG);
-	    udelay(lcd_info.min_cmd_delay);
-	}
-	
-	/* re-queue the work */
-	if (led_wq) {
-		queue_delayed_work(led_wq, &led_task, 0);
-	}
-
-	return lcd_info.lcd_width;
+	return register_reboot_notifier(&lcd_system_halt_notifier);
 }
 
-/*
-   ** led_init()
-   ** 
-   ** led_init() is called very early in the bootup-process from setup.c 
-   ** and asks the PDC for an usable chassis LCD or LED.
-   ** If the PDC doesn't return any info, then the LED
-   ** is detected by lasi.c or asp.c and registered with the
-   ** above functions lasi_led_init() or asp_led_init().
-   ** KittyHawk machines have often a buggy PDC, so that
-   ** we explicitly check for those machines here.
+/**
+ *	early_led_init()
+ *
+ *	early_led_init() is called early in the bootup-process and asks the
+ *	PDC for an usable chassis LCD or LED. If the PDC doesn't return any
+ *	info, then a LED might be detected by the LASI or ASP drivers later.
+ *	KittyHawk machines have often a buggy PDC, so that we explicitly check
+ *	for those machines here.
  */
-
-int __init led_init(void)
+static int __init early_led_init(void)
 {
 	struct pdc_chassis_info chassis_info;
 	int ret;
 
 	snprintf(lcd_text_default, sizeof(lcd_text_default),
 		"Linux %s", init_utsname()->release);
+	strcpy(lcd_text, lcd_text_default);
+	lcd_new_text = 1;
 
 	/* Work around the buggy PDC of KittyHawk-machines */
 	switch (CPU_HVERSION) {
@@ -701,82 +470,86 @@ int __init led_init(void)
 	case 0x582:		/* KittyHawk DC3 100 (K400) */
 	case 0x583:		/* KittyHawk DC3 120 (K410) */
 	case 0x58B:		/* KittyHawk DC2 100 (K200) */
-		printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
-				"LED detection skipped.\n", __FILE__, CPU_HVERSION);
+		pr_info("LCD on KittyHawk-Machine found.\n");
+		lcd_info.model = DISPLAY_MODEL_LCD;
+		/* KittyHawk has no LED support on its LCD, so skip LED detection */
 		lcd_no_led_support = 1;
 		goto found;	/* use the preinitialized values of lcd_info */
 	}
 
 	/* initialize the struct, so that we can check for valid return values */
-	lcd_info.model = DISPLAY_MODEL_NONE;
 	chassis_info.actcnt = chassis_info.maxcnt = 0;
 
 	ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
-	if (ret == PDC_OK) {
-		DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
-			 "lcd_width=%d, cmd_delay=%u,\n"
-			 "%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
-		         __FILE__, lcd_info.model,
-			 (lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
-			  (lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
-			 lcd_info.lcd_width, lcd_info.min_cmd_delay,
-			 __FILE__, sizeof(lcd_info), 
-			 chassis_info.actcnt, chassis_info.maxcnt));
-		DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
-			__FILE__, lcd_info.lcd_cmd_reg_addr, 
-			lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,  
-			lcd_info.reset_cmd2, lcd_info.act_enable ));
-	
-		/* check the results. Some machines have a buggy PDC */
-		if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
-			goto not_found;
+	if (ret != PDC_OK) {
+not_found:
+		lcd_info.model = DISPLAY_MODEL_NONE;
+		return 1;
+	}
 
-		switch (lcd_info.model) {
-		case DISPLAY_MODEL_LCD:		/* LCD display */
-			if (chassis_info.actcnt < 
-				offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
-				goto not_found;
-			if (!lcd_info.act_enable) {
-				DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
-				goto not_found;
-			}
-			break;
-
-		case DISPLAY_MODEL_NONE:	/* no LED or LCD available */
-			printk(KERN_INFO "PDC reported no LCD or LED.\n");
+	/* check the results. Some machines have a buggy PDC */
+	if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
+		goto not_found;
+
+	switch (lcd_info.model) {
+	case DISPLAY_MODEL_LCD:		/* LCD display */
+		if (chassis_info.actcnt <
+			offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
 			goto not_found;
+		if (!lcd_info.act_enable) {
+			/* PDC tells LCD should not be used. */
+			goto not_found;
+		}
+		break;
 
-		case DISPLAY_MODEL_LASI:	/* Lasi style 8 bit LED display */
-			if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
-				goto not_found;
-			break;
+	case DISPLAY_MODEL_NONE:	/* no LED or LCD available */
+		goto not_found;
 
-		default:
-			printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
-			       lcd_info.model);
+	case DISPLAY_MODEL_LASI:	/* Lasi style 8 bit LED display */
+		if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
 			goto not_found;
-		} /* switch() */
-
-found:
-		/* register the LCD/LED driver */
-		register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
-		return 0;
+		break;
 
-	} else { /* if() */
-		DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
+	default:
+		pr_warn("PDC reported unknown LCD/LED model %d\n",
+		       lcd_info.model);
+		goto not_found;
 	}
 
-not_found:
-	lcd_info.model = DISPLAY_MODEL_NONE;
-	return 1;
+found:
+	/* register the LCD/LED driver */
+	return register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
 }
+arch_initcall(early_led_init);
 
-static void __exit led_exit(void)
+/**
+ *	register_led_regions()
+ *
+ *	Register_led_regions() registers the LCD/LED regions for /procfs.
+ *	At bootup - where the initialisation of the LCD/LED often happens
+ *	not all internal structures of request_region() are properly set up,
+ *	so that we delay the led-registration until after busdevices_init()
+ *	has been executed.
+ */
+static void __init register_led_regions(void)
 {
-	unregister_reboot_notifier(&led_notifier);
-	return;
+	switch (lcd_info.model) {
+	case DISPLAY_MODEL_LCD:
+		request_mem_region((unsigned long)LCD_CMD_REG,  1, "lcd_cmd");
+		request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
+		break;
+	case DISPLAY_MODEL_LASI:
+	case DISPLAY_MODEL_OLD_ASP:
+		request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
+		break;
+	}
 }
 
-#ifdef CONFIG_PROC_FS
-module_init(led_create_procfs)
-#endif
+static int __init startup_leds(void)
+{
+	if (platform_device_register(&platform_leds))
+                printk(KERN_INFO "LED: failed to register LEDs\n");
+	register_led_regions();
+	return 0;
+}
+device_initcall(startup_leds);