linux/drivers/parisc/led.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

779 lines
20 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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>
*
* 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/seq_file.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 <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 = 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 int lcd_no_led_support __read_mostly = 0; /* KittyHawk doesn't support LED on its LCD */
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 = 80,
.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 );
/* 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");
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 ssize_t led_proc_write(struct file *file, const char __user *buf,
size_t count, loff_t *pos)
{
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;
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 const struct file_operations led_proc_fops = {
.owner = THIS_MODULE,
.open = led_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.write = led_proc_write,
};
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", NULL);
if (!proc_pdc_root) return -1;
if (!lcd_no_led_support)
{
ent = proc_create_data("led", S_IRUGO|S_IWUSR, proc_pdc_root,
&led_proc_fops, (void *)LED_NOLCD); /* LED */
if (!ent) return -1;
}
if (led_type == LED_HASLCD)
{
ent = proc_create_data("lcd", S_IRUGO|S_IWUSR, proc_pdc_root,
&led_proc_fops, (void *)LED_HASLCD); /* LCD */
if (!ent) return -1;
}
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 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;
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 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);
}
}
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_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;
}
/*
** 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:
/* 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;
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_delayed_work_sync(&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);
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;
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