linux/drivers/watchdog/it87_wdt.c
Thomas Gleixner c942fddf87 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
Based on 3 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 this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  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 [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] this program is distributed in the hope that
  it will be useful but without any warranty without even the implied
  warranty of merchantability or fitness for a particular purpose see
  the gnu general public license for more details

  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 [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] this program is distributed in the hope
  that it will be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:37 -07:00

357 lines
7.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Watchdog Timer Driver
* for ITE IT87xx Environment Control - Low Pin Count Input / Output
*
* (c) Copyright 2007 Oliver Schuster <olivers137@aol.com>
*
* Based on softdog.c by Alan Cox,
* 83977f_wdt.c by Jose Goncalves,
* it87.c by Chris Gauthron, Jean Delvare
*
* Data-sheets: Publicly available at the ITE website
* http://www.ite.com.tw/
*
* Support of the watchdog timers, which are available on
* IT8607, IT8620, IT8622, IT8625, IT8628, IT8655, IT8665, IT8686,
* IT8702, IT8712, IT8716, IT8718, IT8720, IT8721, IT8726, IT8728,
* and IT8783.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#define WATCHDOG_NAME "IT87 WDT"
/* Defaults for Module Parameter */
#define DEFAULT_TIMEOUT 60
#define DEFAULT_TESTMODE 0
#define DEFAULT_NOWAYOUT WATCHDOG_NOWAYOUT
/* IO Ports */
#define REG 0x2e
#define VAL 0x2f
/* Logical device Numbers LDN */
#define GPIO 0x07
/* Configuration Registers and Functions */
#define LDNREG 0x07
#define CHIPID 0x20
#define CHIPREV 0x22
/* Chip Id numbers */
#define NO_DEV_ID 0xffff
#define IT8607_ID 0x8607
#define IT8620_ID 0x8620
#define IT8622_ID 0x8622
#define IT8625_ID 0x8625
#define IT8628_ID 0x8628
#define IT8655_ID 0x8655
#define IT8665_ID 0x8665
#define IT8686_ID 0x8686
#define IT8702_ID 0x8702
#define IT8705_ID 0x8705
#define IT8712_ID 0x8712
#define IT8716_ID 0x8716
#define IT8718_ID 0x8718
#define IT8720_ID 0x8720
#define IT8721_ID 0x8721
#define IT8726_ID 0x8726 /* the data sheet suggest wrongly 0x8716 */
#define IT8728_ID 0x8728
#define IT8783_ID 0x8783
/* GPIO Configuration Registers LDN=0x07 */
#define WDTCTRL 0x71
#define WDTCFG 0x72
#define WDTVALLSB 0x73
#define WDTVALMSB 0x74
/* GPIO Bits WDTCFG */
#define WDT_TOV1 0x80
#define WDT_KRST 0x40
#define WDT_TOVE 0x20
#define WDT_PWROK 0x10 /* not in it8721 */
#define WDT_INT_MASK 0x0f
static unsigned int max_units, chip_type;
static unsigned int timeout = DEFAULT_TIMEOUT;
static int testmode = DEFAULT_TESTMODE;
static bool nowayout = DEFAULT_NOWAYOUT;
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default="
__MODULE_STRING(DEFAULT_TIMEOUT));
module_param(testmode, int, 0);
MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default="
__MODULE_STRING(DEFAULT_TESTMODE));
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default="
__MODULE_STRING(WATCHDOG_NOWAYOUT));
/* Superio Chip */
static inline int superio_enter(void)
{
/*
* Try to reserve REG and REG + 1 for exclusive access.
*/
if (!request_muxed_region(REG, 2, WATCHDOG_NAME))
return -EBUSY;
outb(0x87, REG);
outb(0x01, REG);
outb(0x55, REG);
outb(0x55, REG);
return 0;
}
static inline void superio_exit(void)
{
outb(0x02, REG);
outb(0x02, VAL);
release_region(REG, 2);
}
static inline void superio_select(int ldn)
{
outb(LDNREG, REG);
outb(ldn, VAL);
}
static inline int superio_inb(int reg)
{
outb(reg, REG);
return inb(VAL);
}
static inline void superio_outb(int val, int reg)
{
outb(reg, REG);
outb(val, VAL);
}
static inline int superio_inw(int reg)
{
int val;
outb(reg++, REG);
val = inb(VAL) << 8;
outb(reg, REG);
val |= inb(VAL);
return val;
}
static inline void superio_outw(int val, int reg)
{
outb(reg++, REG);
outb(val >> 8, VAL);
outb(reg, REG);
outb(val, VAL);
}
/* Internal function, should be called after superio_select(GPIO) */
static void _wdt_update_timeout(unsigned int t)
{
unsigned char cfg = WDT_KRST;
if (testmode)
cfg = 0;
if (t <= max_units)
cfg |= WDT_TOV1;
else
t /= 60;
if (chip_type != IT8721_ID)
cfg |= WDT_PWROK;
superio_outb(cfg, WDTCFG);
superio_outb(t, WDTVALLSB);
if (max_units > 255)
superio_outb(t >> 8, WDTVALMSB);
}
static int wdt_update_timeout(unsigned int t)
{
int ret;
ret = superio_enter();
if (ret)
return ret;
superio_select(GPIO);
_wdt_update_timeout(t);
superio_exit();
return 0;
}
static int wdt_round_time(int t)
{
t += 59;
t -= t % 60;
return t;
}
/* watchdog timer handling */
static int wdt_start(struct watchdog_device *wdd)
{
return wdt_update_timeout(wdd->timeout);
}
static int wdt_stop(struct watchdog_device *wdd)
{
return wdt_update_timeout(0);
}
/**
* wdt_set_timeout - set a new timeout value with watchdog ioctl
* @t: timeout value in seconds
*
* The hardware device has a 8 or 16 bit watchdog timer (depends on
* chip version) that can be configured to count seconds or minutes.
*
* Used within WDIOC_SETTIMEOUT watchdog device ioctl.
*/
static int wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
{
int ret = 0;
if (t > max_units)
t = wdt_round_time(t);
wdd->timeout = t;
if (watchdog_hw_running(wdd))
ret = wdt_update_timeout(t);
return ret;
}
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.firmware_version = 1,
.identity = WATCHDOG_NAME,
};
static const struct watchdog_ops wdt_ops = {
.owner = THIS_MODULE,
.start = wdt_start,
.stop = wdt_stop,
.set_timeout = wdt_set_timeout,
};
static struct watchdog_device wdt_dev = {
.info = &ident,
.ops = &wdt_ops,
.min_timeout = 1,
};
static int __init it87_wdt_init(void)
{
u8 chip_rev;
int rc;
rc = superio_enter();
if (rc)
return rc;
chip_type = superio_inw(CHIPID);
chip_rev = superio_inb(CHIPREV) & 0x0f;
superio_exit();
switch (chip_type) {
case IT8702_ID:
max_units = 255;
break;
case IT8712_ID:
max_units = (chip_rev < 8) ? 255 : 65535;
break;
case IT8716_ID:
case IT8726_ID:
max_units = 65535;
break;
case IT8607_ID:
case IT8620_ID:
case IT8622_ID:
case IT8625_ID:
case IT8628_ID:
case IT8655_ID:
case IT8665_ID:
case IT8686_ID:
case IT8718_ID:
case IT8720_ID:
case IT8721_ID:
case IT8728_ID:
case IT8783_ID:
max_units = 65535;
break;
case IT8705_ID:
pr_err("Unsupported Chip found, Chip %04x Revision %02x\n",
chip_type, chip_rev);
return -ENODEV;
case NO_DEV_ID:
pr_err("no device\n");
return -ENODEV;
default:
pr_err("Unknown Chip found, Chip %04x Revision %04x\n",
chip_type, chip_rev);
return -ENODEV;
}
rc = superio_enter();
if (rc)
return rc;
superio_select(GPIO);
superio_outb(WDT_TOV1, WDTCFG);
superio_outb(0x00, WDTCTRL);
superio_exit();
if (timeout < 1 || timeout > max_units * 60) {
timeout = DEFAULT_TIMEOUT;
pr_warn("Timeout value out of range, use default %d sec\n",
DEFAULT_TIMEOUT);
}
if (timeout > max_units)
timeout = wdt_round_time(timeout);
wdt_dev.timeout = timeout;
wdt_dev.max_timeout = max_units * 60;
watchdog_stop_on_reboot(&wdt_dev);
rc = watchdog_register_device(&wdt_dev);
if (rc) {
pr_err("Cannot register watchdog device (err=%d)\n", rc);
return rc;
}
pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
chip_type, chip_rev, timeout, nowayout, testmode);
return 0;
}
static void __exit it87_wdt_exit(void)
{
watchdog_unregister_device(&wdt_dev);
}
module_init(it87_wdt_init);
module_exit(it87_wdt_exit);
MODULE_AUTHOR("Oliver Schuster");
MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O");
MODULE_LICENSE("GPL");