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linux/drivers/parisc/led.c

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/*
* Chassis LCD/LED driver for HP-PARISC workstations
*
* (c) Copyright 2000 Red Hat Software
* (c) Copyright 2000 Helge Deller <hdeller@redhat.com>
* (c) Copyright 2001-2005 Helge Deller <deller@gmx.de>
* (c) Copyright 2001 Randolph Chung <tausq@debian.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* TODO:
* - speed-up calculations with inlined assembler
* - interface to write to second row of LCD from /proc (if technically possible)
*
* 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>
*/
#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/ctype.h>
#include <linux/blkdev.h>
#include <linux/workqueue.h>
#include <linux/rcupdate.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 <asm/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 = 1;
static unsigned int led_lanrxtx __read_mostly = 1;
static char lcd_text[32] __read_mostly;
static char lcd_text_default[32] __read_mostly;
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
struct lcd_block {
unsigned char command; /* stores the command byte */
unsigned char on; /* value for turning LED on */
unsigned char off; /* value for turning LED off */
};
/* Structure returned by PDC_RETURN_CHASSIS_INFO */
/* 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 */
unsigned long lcd_width:16; /* width of the LCD in chars (DISPLAY_MODEL_LCD only) */
unsigned long lcd_cmd_reg_addr; /* ptr to LCD cmd-register & data ptr for LED */
unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */
unsigned int min_cmd_delay; /* delay in uS after cmd-write (LCD only) */
unsigned char reset_cmd1; /* command #1 for writing LCD string (LCD only) */
unsigned char reset_cmd2; /* command #2 for writing LCD string (LCD only) */
unsigned char act_enable; /* 0 = no activity (LCD only) */
struct lcd_block heartbeat;
struct lcd_block disk_io;
struct lcd_block lan_rcv;
struct lcd_block lan_tx;
char _pad;
};
/* 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)
/* 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 =
{
.model = DISPLAY_MODEL_LCD,
.lcd_width = 16,
.lcd_cmd_reg_addr = KITTYHAWK_LCD_CMD,
.lcd_data_reg_addr = KITTYHAWK_LCD_DATA,
.min_cmd_delay = 40,
.reset_cmd1 = 0x80,
.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 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 );
/* Create the work queue and queue the LED task */
led_wq = create_singlethread_workqueue("led_wq");
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_read(char *page, char **start, off_t off, int count,
int *eof, void *data)
{
char *out = page;
int len;
switch ((long)data)
{
case LED_NOLCD:
out += sprintf(out, "Heartbeat: %d\n", led_heartbeat);
out += sprintf(out, "Disk IO: %d\n", led_diskio);
out += sprintf(out, "LAN Rx/Tx: %d\n", led_lanrxtx);
break;
case LED_HASLCD:
out += sprintf(out, "%s\n", lcd_text);
break;
default:
*eof = 1;
return 0;
}
len = out - page - off;
if (len < count) {
*eof = 1;
if (len <= 0) return 0;
} else {
len = count;
}
*start = page + off;
return len;
}
static int led_proc_write(struct file *file, const char *buf,
unsigned long count, void *data)
{
char *cur, lbuf[count + 1];
int d;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
memset(lbuf, 0, count + 1);
if (copy_from_user(lbuf, buf, count))
return -EFAULT;
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;
d = *cur++ - '0';
if (d != 0 && d != 1) goto parse_error;
led_diskio = d;
if (*cur++ != ' ') goto parse_error;
d = *cur++ - '0';
if (d != 0 && d != 1) goto parse_error;
led_lanrxtx = d;
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;
}
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 int __init led_create_procfs(void)
{
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", 0);
if (!proc_pdc_root) return -1;
proc_pdc_root->owner = THIS_MODULE;
ent = create_proc_entry("led", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
if (!ent) return -1;
ent->data = (void *)LED_NOLCD; /* LED */
ent->read_proc = led_proc_read;
ent->write_proc = led_proc_write;
ent->owner = THIS_MODULE;
if (led_type == LED_HASLCD)
{
ent = create_proc_entry("lcd", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
if (!ent) return -1;
ent->data = (void *)LED_HASLCD; /* LCD */
ent->read_proc = led_proc_read;
ent->write_proc = led_proc_write;
ent->owner = THIS_MODULE;
}
return 0;
}
#endif
/*
**
** led_ASP_driver()
**
*/
#define LED_DATA 0x01 /* data to shift (0:on 1:off) */
#define LED_STROBE 0x02 /* strobe to clock data */
static void led_ASP_driver(unsigned char leds)
{
int i;
leds = ~leds;
for (i = 0; i < 8; i++) {
unsigned char value;
value = (leds & 0x80) >> 7;
gsc_writeb( value, LED_DATA_REG );
gsc_writeb( value | LED_STROBE, LED_DATA_REG );
leds <<= 1;
}
}
/*
**
** led_LASI_driver()
**
*/
static void led_LASI_driver(unsigned char leds)
{
leds = ~leds;
gsc_writeb( leds, LED_DATA_REG );
}
/*
**
** led_LCD_driver()
**
*/
static void led_LCD_driver(unsigned char leds)
{
static int i;
static unsigned char mask[4] = { LED_HEARTBEAT, LED_DISK_IO,
LED_LAN_RCV, LED_LAN_TX };
static struct lcd_block * blockp[4] = {
&lcd_info.heartbeat,
&lcd_info.disk_io,
&lcd_info.lan_rcv,
&lcd_info.lan_tx
};
/* 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);
}
}
}
/*
**
** 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)
**
*/
static __inline__ int led_get_net_activity(void)
{
#ifndef CONFIG_NET
return 0;
#else
static unsigned long rx_total_last, tx_total_last;
unsigned long rx_total, tx_total;
struct net_device *dev;
int retval;
rx_total = tx_total = 0;
/* we are running as a workqueue task, so locking dev_base
* for reading should be OK */
read_lock(&dev_base_lock);
rcu_read_lock();
for_each_netdev(&init_net, dev) {
const struct net_device_stats *stats;
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);
rx_total += stats->rx_packets;
tx_total += stats->tx_packets;
}
rcu_read_unlock();
read_unlock(&dev_base_lock);
retval = 0;
if (rx_total != rx_total_last) {
rx_total_last = rx_total;
retval |= LED_LAN_RCV;
}
if (tx_total != tx_total_last) {
tx_total_last = tx_total;
retval |= LED_LAN_TX;
}
return retval;
#endif
}
/*
**
** 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);
}
/*
** led_work_func()
**
** manages when and which chassis LCD/LED gets updated
TODO:
- display load average (older machines like 715/64 have 4 "free" LED's for that)
- optimizations
*/
#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)
#define LED_UPDATE_INTERVAL (1 + (HZ*19/1000))
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 */
/* 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;
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;
}
if (likely(led_lanrxtx)) currentleds |= led_get_net_activity();
if (likely(led_diskio)) currentleds |= led_get_diskio_activity();
/* blink all LEDs twice a second if we got an Oops (HPMC) */
if (unlikely(oops_in_progress))
currentleds = (count_HZ<=(HZ/2)) ? 0 : 0xff;
if (currentleds != lastleds)
{
led_func_ptr(currentleds); /* Update the LCD/LEDs */
lastleds = currentleds;
}
queue_delayed_work(led_wq, &led_task, LED_UPDATE_INTERVAL);
}
/*
** led_halt()
**
** called by the reboot notifier chain at shutdown and stops all
** LED/LCD activities.
**
*/
static int led_halt(struct notifier_block *, unsigned long, void *);
static struct notifier_block led_notifier = {
.notifier_call = led_halt,
};
static int notifier_disabled = 0;
static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
{
char *txt;
if (notifier_disabled)
return NOTIFY_OK;
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_rearming_delayed_workqueue(led_wq, &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;
}
/*
** 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.
**
*/
int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
{
static int initialized;
if (initialized || !data_reg)
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",
LCD_CMD_REG , LCD_DATA_REG);
led_func_ptr = led_LCD_driver;
led_type = LED_HASLCD;
break;
case DISPLAY_MODEL_LASI:
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;
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",
LED_DATA_REG);
led_type = LED_NOLCD;
break;
default:
printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
__func__, 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;
}
/*
** 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.
**
*/
void __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;
}
}
/*
**
** 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_rearming_delayed_workqueue(led_wq, &led_task);
/* copy display string to buffer for procfs */
strlcpy(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;
}
/*
** 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.
*/
int __init led_init(void)
{
struct pdc_chassis_info chassis_info;
int ret;
snprintf(lcd_text_default, sizeof(lcd_text_default),
"Linux %s", init_utsname()->release);
/* Work around the buggy PDC of KittyHawk-machines */
switch (CPU_HVERSION) {
case 0x580: /* KittyHawk DC2-100 (K100) */
case 0x581: /* KittyHawk DC3-120 (K210) */
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);
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;
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");
goto not_found;
case DISPLAY_MODEL_LASI: /* Lasi style 8 bit LED display */
if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
goto not_found;
break;
default:
printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
lcd_info.model);
goto not_found;
} /* switch() */
found:
/* register the LCD/LED driver */
register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
return 0;
} else { /* if() */
DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
}
not_found:
lcd_info.model = DISPLAY_MODEL_NONE;
return 1;
}
static void __exit led_exit(void)
{
unregister_reboot_notifier(&led_notifier);
return;
}
#ifdef CONFIG_PROC_FS
module_init(led_create_procfs)
#endif
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