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kernel/drivers/watchdog/sch311x_wdt.c

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/*
* sch311x_wdt.c - Driver for the SCH311x Super-I/O chips
* integrated watchdog.
*
* (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.
*
* 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.
*
* Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
* provide warranty for any of this software. This material is
* provided "AS-IS" and at no charge.
*/
/*
* Includes, defines, variables, module parameters, ...
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
/* Includes */
#include <linux/module.h> /* For module specific items */
#include <linux/moduleparam.h> /* For new moduleparam's */
#include <linux/types.h> /* For standard types (like size_t) */
#include <linux/errno.h> /* For the -ENODEV/... values */
#include <linux/kernel.h> /* For printk/... */
#include <linux/miscdevice.h> /* For struct miscdevice */
#include <linux/watchdog.h> /* For the watchdog specific items */
#include <linux/init.h> /* For __init/__exit/... */
#include <linux/fs.h> /* For file operations */
#include <linux/platform_device.h> /* For platform_driver framework */
#include <linux/ioport.h> /* For io-port access */
#include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
#include <linux/io.h> /* For inb/outb/... */
/* Module and version information */
#define DRV_NAME "sch311x_wdt"
/* Runtime registers */
#define GP60 0x47
#define WDT_TIME_OUT 0x65
#define WDT_VAL 0x66
#define WDT_CFG 0x67
#define WDT_CTRL 0x68
/* internal variables */
static unsigned long sch311x_wdt_is_open;
static char sch311x_wdt_expect_close;
static struct platform_device *sch311x_wdt_pdev;
static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 };
static struct { /* The devices private data */
/* the Runtime Register base address */
unsigned short runtime_reg;
/* The card's boot status */
int boot_status;
/* the lock for io operations */
spinlock_t io_lock;
} sch311x_wdt_data;
/* Module load parameters */
static unsigned short force_id;
module_param(force_id, ushort, 0);
MODULE_PARM_DESC(force_id, "Override the detected device ID");
#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. 1<= timeout <=15300, default="
__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
/*
* Super-IO functions
*/
static inline void sch311x_sio_enter(int sio_config_port)
{
outb(0x55, sio_config_port);
}
static inline void sch311x_sio_exit(int sio_config_port)
{
outb(0xaa, sio_config_port);
}
static inline int sch311x_sio_inb(int sio_config_port, int reg)
{
outb(reg, sio_config_port);
return inb(sio_config_port + 1);
}
static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
{
outb(reg, sio_config_port);
outb(val, sio_config_port + 1);
}
/*
* Watchdog Operations
*/
static void sch311x_wdt_set_timeout(int t)
{
unsigned char timeout_unit = 0x80;
/* When new timeout is bigger then 255 seconds, we will use minutes */
if (t > 255) {
timeout_unit = 0;
t /= 60;
}
/* -- Watchdog Timeout --
* Bit 0-6 (Reserved)
* Bit 7 WDT Time-out Value Units Select
* (0 = Minutes, 1 = Seconds)
*/
outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT);
/* -- Watchdog Timer Time-out Value --
* Bit 0-7 Binary coded units (0=Disabled, 1..255)
*/
outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL);
}
static void sch311x_wdt_start(void)
{
unsigned char t;
spin_lock(&sch311x_wdt_data.io_lock);
/* set watchdog's timeout */
sch311x_wdt_set_timeout(timeout);
/* enable the watchdog */
/* -- General Purpose I/O Bit 6.0 --
* Bit 0, In/Out: 0 = Output, 1 = Input
* Bit 1, Polarity: 0 = No Invert, 1 = Invert
* Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT,
* 10 = Either Edge Triggered Intr.4
* Bit 4-6 (Reserved)
* Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
*/
t = inb(sch311x_wdt_data.runtime_reg + GP60);
outb((t & ~0x0d) | 0x0c, sch311x_wdt_data.runtime_reg + GP60);
spin_unlock(&sch311x_wdt_data.io_lock);
}
static void sch311x_wdt_stop(void)
{
unsigned char t;
spin_lock(&sch311x_wdt_data.io_lock);
/* stop the watchdog */
t = inb(sch311x_wdt_data.runtime_reg + GP60);
outb((t & ~0x0d) | 0x01, sch311x_wdt_data.runtime_reg + GP60);
/* disable timeout by setting it to 0 */
sch311x_wdt_set_timeout(0);
spin_unlock(&sch311x_wdt_data.io_lock);
}
static void sch311x_wdt_keepalive(void)
{
spin_lock(&sch311x_wdt_data.io_lock);
sch311x_wdt_set_timeout(timeout);
spin_unlock(&sch311x_wdt_data.io_lock);
}
static int sch311x_wdt_set_heartbeat(int t)
{
if (t < 1 || t > (255*60))
return -EINVAL;
/* When new timeout is bigger then 255 seconds,
* we will round up to minutes (with a max of 255) */
if (t > 255)
t = (((t - 1) / 60) + 1) * 60;
timeout = t;
return 0;
}
static void sch311x_wdt_get_status(int *status)
{
unsigned char new_status;
*status = 0;
spin_lock(&sch311x_wdt_data.io_lock);
/* -- Watchdog timer control --
* Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred
* Bit 1 Reserved
* Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)
* Bit 3 P20 Force Timeout enabled:
* 0 = P20 activity does not generate the WD timeout event
* 1 = P20 Allows rising edge of P20, from the keyboard
* controller, to force the WD timeout event.
* Bit 4-7 Reserved
*/
new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);
if (new_status & 0x01)
*status |= WDIOF_CARDRESET;
spin_unlock(&sch311x_wdt_data.io_lock);
}
/*
* /dev/watchdog handling
*/
static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (count) {
if (!nowayout) {
size_t i;
sch311x_wdt_expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
sch311x_wdt_expect_close = 42;
}
}
sch311x_wdt_keepalive();
}
return count;
}
static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int status;
int new_timeout;
void __user *argp = (void __user *)arg;
int __user *p = argp;
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING |
WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = DRV_NAME,
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
break;
case WDIOC_GETSTATUS:
{
sch311x_wdt_get_status(&status);
return put_user(status, p);
}
case WDIOC_GETBOOTSTATUS:
return put_user(sch311x_wdt_data.boot_status, p);
case WDIOC_SETOPTIONS:
{
int options, retval = -EINVAL;
if (get_user(options, p))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
sch311x_wdt_stop();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
sch311x_wdt_start();
retval = 0;
}
return retval;
}
case WDIOC_KEEPALIVE:
sch311x_wdt_keepalive();
break;
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, p))
return -EFAULT;
if (sch311x_wdt_set_heartbeat(new_timeout))
return -EINVAL;
sch311x_wdt_keepalive();
/* Fall through */
case WDIOC_GETTIMEOUT:
return put_user(timeout, p);
default:
return -ENOTTY;
}
return 0;
}
static int sch311x_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &sch311x_wdt_is_open))
return -EBUSY;
/*
* Activate
*/
sch311x_wdt_start();
return nonseekable_open(inode, file);
}
static int sch311x_wdt_close(struct inode *inode, struct file *file)
{
if (sch311x_wdt_expect_close == 42) {
sch311x_wdt_stop();
} else {
pr_crit("Unexpected close, not stopping watchdog!\n");
sch311x_wdt_keepalive();
}
clear_bit(0, &sch311x_wdt_is_open);
sch311x_wdt_expect_close = 0;
return 0;
}
/*
* Kernel Interfaces
*/
static const struct file_operations sch311x_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = sch311x_wdt_write,
.unlocked_ioctl = sch311x_wdt_ioctl,
.open = sch311x_wdt_open,
.release = sch311x_wdt_close,
};
static struct miscdevice sch311x_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &sch311x_wdt_fops,
};
/*
* Init & exit routines
*/
static int sch311x_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
int err;
spin_lock_init(&sch311x_wdt_data.io_lock);
if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {
dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
sch311x_wdt_data.runtime_reg + GP60,
sch311x_wdt_data.runtime_reg + GP60);
err = -EBUSY;
goto exit;
}
if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,
DRV_NAME)) {
dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,
sch311x_wdt_data.runtime_reg + WDT_CTRL);
err = -EBUSY;
goto exit_release_region;
}
/* Make sure that the watchdog is not running */
sch311x_wdt_stop();
/* Disable keyboard and mouse interaction and interrupt */
/* -- Watchdog timer configuration --
* Bit 0 Reserved
* Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
* Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
* Bit 3 Reserved
* Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
* 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
*/
outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);
/* Check that the heartbeat value is within it's range ;
* if not reset to the default */
if (sch311x_wdt_set_heartbeat(timeout)) {
sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);
dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",
timeout);
}
/* Get status at boot */
sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);
sch311x_wdt_miscdev.parent = dev;
err = misc_register(&sch311x_wdt_miscdev);
if (err != 0) {
dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, err);
goto exit_release_region2;
}
dev_info(dev,
"SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",
timeout, nowayout);
return 0;
exit_release_region2:
release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
exit_release_region:
release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
sch311x_wdt_data.runtime_reg = 0;
exit:
return err;
}
static int sch311x_wdt_remove(struct platform_device *pdev)
{
/* Stop the timer before we leave */
if (!nowayout)
sch311x_wdt_stop();
/* Deregister */
misc_deregister(&sch311x_wdt_miscdev);
release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
sch311x_wdt_data.runtime_reg = 0;
return 0;
}
static void sch311x_wdt_shutdown(struct platform_device *dev)
{
/* Turn the WDT off if we have a soft shutdown */
sch311x_wdt_stop();
}
static struct platform_driver sch311x_wdt_driver = {
.probe = sch311x_wdt_probe,
.remove = sch311x_wdt_remove,
.shutdown = sch311x_wdt_shutdown,
.driver = {
.name = DRV_NAME,
},
};
static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
{
int err = 0, reg;
unsigned short base_addr;
unsigned char dev_id;
sch311x_sio_enter(sio_config_port);
/* Check device ID. We currently know about:
* SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */
reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);
if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
err = -ENODEV;
goto exit;
}
dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
/* Select logical device A (runtime registers) */
sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
/* Check if Logical Device Register is currently active */
if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
pr_info("Seems that LDN 0x0a is not active...\n");
/* Get the base address of the runtime registers */
base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
sch311x_sio_inb(sio_config_port, 0x61);
if (!base_addr) {
pr_err("Base address not set\n");
err = -ENODEV;
goto exit;
}
*addr = base_addr;
pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
exit:
sch311x_sio_exit(sio_config_port);
return err;
}
static int __init sch311x_wdt_init(void)
{
int err, i, found = 0;
unsigned short addr = 0;
for (i = 0; !found && sch311x_ioports[i]; i++)
if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
found++;
if (!found)
return -ENODEV;
sch311x_wdt_data.runtime_reg = addr;
err = platform_driver_register(&sch311x_wdt_driver);
if (err)
return err;
sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,
NULL, 0);
if (IS_ERR(sch311x_wdt_pdev)) {
err = PTR_ERR(sch311x_wdt_pdev);
goto unreg_platform_driver;
}
return 0;
unreg_platform_driver:
platform_driver_unregister(&sch311x_wdt_driver);
return err;
}
static void __exit sch311x_wdt_exit(void)
{
platform_device_unregister(sch311x_wdt_pdev);
platform_driver_unregister(&sch311x_wdt_driver);
}
module_init(sch311x_wdt_init);
module_exit(sch311x_wdt_exit);
MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
MODULE_LICENSE("GPL");
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