349 lines
8.7 KiB
C
349 lines
8.7 KiB
C
/*
|
|
* Intel Atom E6xx Watchdog driver
|
|
*
|
|
* Copyright (C) 2011 Alexander Stein
|
|
* <alexander.stein@systec-electronic.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of version 2 of the GNU General
|
|
* Public License as published by the Free Software Foundation.
|
|
*
|
|
* 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.
|
|
* You should have received a copy of the GNU General Public
|
|
* License along with this program; if not, write to the Free
|
|
* Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
* Boston, MA 02111-1307, USA.
|
|
* The full GNU General Public License is included in this
|
|
* distribution in the file called COPYING.
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/types.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/debugfs.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/spinlock.h>
|
|
|
|
#define DRIVER_NAME "ie6xx_wdt"
|
|
|
|
#define PV1 0x00
|
|
#define PV2 0x04
|
|
|
|
#define RR0 0x0c
|
|
#define RR1 0x0d
|
|
#define WDT_RELOAD 0x01
|
|
#define WDT_TOUT 0x02
|
|
|
|
#define WDTCR 0x10
|
|
#define WDT_PRE_SEL 0x04
|
|
#define WDT_RESET_SEL 0x08
|
|
#define WDT_RESET_EN 0x10
|
|
#define WDT_TOUT_EN 0x20
|
|
|
|
#define DCR 0x14
|
|
|
|
#define WDTLR 0x18
|
|
#define WDT_LOCK 0x01
|
|
#define WDT_ENABLE 0x02
|
|
#define WDT_TOUT_CNF 0x03
|
|
|
|
#define MIN_TIME 1
|
|
#define MAX_TIME (10 * 60) /* 10 minutes */
|
|
#define DEFAULT_TIME 60
|
|
|
|
static unsigned int timeout = DEFAULT_TIME;
|
|
module_param(timeout, uint, 0);
|
|
MODULE_PARM_DESC(timeout,
|
|
"Default Watchdog timer setting ("
|
|
__MODULE_STRING(DEFAULT_TIME) "s)."
|
|
"The range is from 1 to 600");
|
|
|
|
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) ")");
|
|
|
|
static u8 resetmode = 0x10;
|
|
module_param(resetmode, byte, 0);
|
|
MODULE_PARM_DESC(resetmode,
|
|
"Resetmode bits: 0x08 warm reset (cold reset otherwise), "
|
|
"0x10 reset enable, 0x20 disable toggle GPIO[4] (default=0x10)");
|
|
|
|
static struct {
|
|
unsigned short sch_wdtba;
|
|
struct spinlock unlock_sequence;
|
|
#ifdef CONFIG_DEBUG_FS
|
|
struct dentry *debugfs;
|
|
#endif
|
|
} ie6xx_wdt_data;
|
|
|
|
/*
|
|
* This is needed to write to preload and reload registers
|
|
* struct ie6xx_wdt_data.unlock_sequence must be used
|
|
* to prevent sequence interrupts
|
|
*/
|
|
static void ie6xx_wdt_unlock_registers(void)
|
|
{
|
|
outb(0x80, ie6xx_wdt_data.sch_wdtba + RR0);
|
|
outb(0x86, ie6xx_wdt_data.sch_wdtba + RR0);
|
|
}
|
|
|
|
static int ie6xx_wdt_ping(struct watchdog_device *wdd)
|
|
{
|
|
spin_lock(&ie6xx_wdt_data.unlock_sequence);
|
|
ie6xx_wdt_unlock_registers();
|
|
outb(WDT_RELOAD, ie6xx_wdt_data.sch_wdtba + RR1);
|
|
spin_unlock(&ie6xx_wdt_data.unlock_sequence);
|
|
return 0;
|
|
}
|
|
|
|
static int ie6xx_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
|
|
{
|
|
u32 preload;
|
|
u64 clock;
|
|
u8 wdtcr;
|
|
|
|
/* Watchdog clock is PCI Clock (33MHz) */
|
|
clock = 33000000;
|
|
/* and the preload value is loaded into [34:15] of the down counter */
|
|
preload = (t * clock) >> 15;
|
|
/*
|
|
* Manual states preload must be one less.
|
|
* Does not wrap as t is at least 1
|
|
*/
|
|
preload -= 1;
|
|
|
|
spin_lock(&ie6xx_wdt_data.unlock_sequence);
|
|
|
|
/* Set ResetMode & Enable prescaler for range 10ms to 10 min */
|
|
wdtcr = resetmode & 0x38;
|
|
outb(wdtcr, ie6xx_wdt_data.sch_wdtba + WDTCR);
|
|
|
|
ie6xx_wdt_unlock_registers();
|
|
outl(0, ie6xx_wdt_data.sch_wdtba + PV1);
|
|
|
|
ie6xx_wdt_unlock_registers();
|
|
outl(preload, ie6xx_wdt_data.sch_wdtba + PV2);
|
|
|
|
ie6xx_wdt_unlock_registers();
|
|
outb(WDT_RELOAD | WDT_TOUT, ie6xx_wdt_data.sch_wdtba + RR1);
|
|
|
|
spin_unlock(&ie6xx_wdt_data.unlock_sequence);
|
|
|
|
wdd->timeout = t;
|
|
return 0;
|
|
}
|
|
|
|
static int ie6xx_wdt_start(struct watchdog_device *wdd)
|
|
{
|
|
ie6xx_wdt_set_timeout(wdd, wdd->timeout);
|
|
|
|
/* Enable the watchdog timer */
|
|
spin_lock(&ie6xx_wdt_data.unlock_sequence);
|
|
outb(WDT_ENABLE, ie6xx_wdt_data.sch_wdtba + WDTLR);
|
|
spin_unlock(&ie6xx_wdt_data.unlock_sequence);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ie6xx_wdt_stop(struct watchdog_device *wdd)
|
|
{
|
|
if (inb(ie6xx_wdt_data.sch_wdtba + WDTLR) & WDT_LOCK)
|
|
return -1;
|
|
|
|
/* Disable the watchdog timer */
|
|
spin_lock(&ie6xx_wdt_data.unlock_sequence);
|
|
outb(0, ie6xx_wdt_data.sch_wdtba + WDTLR);
|
|
spin_unlock(&ie6xx_wdt_data.unlock_sequence);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct watchdog_info ie6xx_wdt_info = {
|
|
.identity = "Intel Atom E6xx Watchdog",
|
|
.options = WDIOF_SETTIMEOUT |
|
|
WDIOF_MAGICCLOSE |
|
|
WDIOF_KEEPALIVEPING,
|
|
};
|
|
|
|
static const struct watchdog_ops ie6xx_wdt_ops = {
|
|
.owner = THIS_MODULE,
|
|
.start = ie6xx_wdt_start,
|
|
.stop = ie6xx_wdt_stop,
|
|
.ping = ie6xx_wdt_ping,
|
|
.set_timeout = ie6xx_wdt_set_timeout,
|
|
};
|
|
|
|
static struct watchdog_device ie6xx_wdt_dev = {
|
|
.info = &ie6xx_wdt_info,
|
|
.ops = &ie6xx_wdt_ops,
|
|
.min_timeout = MIN_TIME,
|
|
.max_timeout = MAX_TIME,
|
|
};
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
|
|
static int ie6xx_wdt_dbg_show(struct seq_file *s, void *unused)
|
|
{
|
|
seq_printf(s, "PV1 = 0x%08x\n",
|
|
inl(ie6xx_wdt_data.sch_wdtba + PV1));
|
|
seq_printf(s, "PV2 = 0x%08x\n",
|
|
inl(ie6xx_wdt_data.sch_wdtba + PV2));
|
|
seq_printf(s, "RR = 0x%08x\n",
|
|
inw(ie6xx_wdt_data.sch_wdtba + RR0));
|
|
seq_printf(s, "WDTCR = 0x%08x\n",
|
|
inw(ie6xx_wdt_data.sch_wdtba + WDTCR));
|
|
seq_printf(s, "DCR = 0x%08x\n",
|
|
inl(ie6xx_wdt_data.sch_wdtba + DCR));
|
|
seq_printf(s, "WDTLR = 0x%08x\n",
|
|
inw(ie6xx_wdt_data.sch_wdtba + WDTLR));
|
|
|
|
seq_printf(s, "\n");
|
|
return 0;
|
|
}
|
|
|
|
static int ie6xx_wdt_dbg_open(struct inode *inode, struct file *file)
|
|
{
|
|
return single_open(file, ie6xx_wdt_dbg_show, NULL);
|
|
}
|
|
|
|
static const struct file_operations ie6xx_wdt_dbg_operations = {
|
|
.open = ie6xx_wdt_dbg_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
};
|
|
|
|
static void __devinit ie6xx_wdt_debugfs_init(void)
|
|
{
|
|
/* /sys/kernel/debug/ie6xx_wdt */
|
|
ie6xx_wdt_data.debugfs = debugfs_create_file("ie6xx_wdt",
|
|
S_IFREG | S_IRUGO, NULL, NULL, &ie6xx_wdt_dbg_operations);
|
|
}
|
|
|
|
static void ie6xx_wdt_debugfs_exit(void)
|
|
{
|
|
debugfs_remove(ie6xx_wdt_data.debugfs);
|
|
}
|
|
|
|
#else
|
|
static void __devinit ie6xx_wdt_debugfs_init(void)
|
|
{
|
|
}
|
|
|
|
static void ie6xx_wdt_debugfs_exit(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static int __devinit ie6xx_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
struct resource *res;
|
|
u8 wdtlr;
|
|
int ret;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
|
|
if (!res)
|
|
return -ENODEV;
|
|
|
|
if (!request_region(res->start, resource_size(res), pdev->name)) {
|
|
dev_err(&pdev->dev, "Watchdog region 0x%llx already in use!\n",
|
|
(u64)res->start);
|
|
return -EBUSY;
|
|
}
|
|
|
|
ie6xx_wdt_data.sch_wdtba = res->start;
|
|
dev_dbg(&pdev->dev, "WDT = 0x%X\n", ie6xx_wdt_data.sch_wdtba);
|
|
|
|
ie6xx_wdt_dev.timeout = timeout;
|
|
watchdog_set_nowayout(&ie6xx_wdt_dev, nowayout);
|
|
|
|
spin_lock_init(&ie6xx_wdt_data.unlock_sequence);
|
|
|
|
wdtlr = inb(ie6xx_wdt_data.sch_wdtba + WDTLR);
|
|
if (wdtlr & WDT_LOCK)
|
|
dev_warn(&pdev->dev,
|
|
"Watchdog Timer is Locked (Reg=0x%x)\n", wdtlr);
|
|
|
|
ie6xx_wdt_debugfs_init();
|
|
|
|
ret = watchdog_register_device(&ie6xx_wdt_dev);
|
|
if (ret) {
|
|
dev_err(&pdev->dev,
|
|
"Watchdog timer: cannot register device (err =%d)\n",
|
|
ret);
|
|
goto misc_register_error;
|
|
}
|
|
|
|
return 0;
|
|
|
|
misc_register_error:
|
|
ie6xx_wdt_debugfs_exit();
|
|
release_region(res->start, resource_size(res));
|
|
ie6xx_wdt_data.sch_wdtba = 0;
|
|
return ret;
|
|
}
|
|
|
|
static int __devexit ie6xx_wdt_remove(struct platform_device *pdev)
|
|
{
|
|
struct resource *res;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
|
|
ie6xx_wdt_stop(NULL);
|
|
watchdog_unregister_device(&ie6xx_wdt_dev);
|
|
ie6xx_wdt_debugfs_exit();
|
|
release_region(res->start, resource_size(res));
|
|
ie6xx_wdt_data.sch_wdtba = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver ie6xx_wdt_driver = {
|
|
.probe = ie6xx_wdt_probe,
|
|
.remove = __devexit_p(ie6xx_wdt_remove),
|
|
.driver = {
|
|
.name = DRIVER_NAME,
|
|
.owner = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static int __init ie6xx_wdt_init(void)
|
|
{
|
|
/* Check boot parameters to verify that their initial values */
|
|
/* are in range. */
|
|
if ((timeout < MIN_TIME) ||
|
|
(timeout > MAX_TIME)) {
|
|
pr_err("Watchdog timer: value of timeout %d (dec) "
|
|
"is out of range from %d to %d (dec)\n",
|
|
timeout, MIN_TIME, MAX_TIME);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return platform_driver_register(&ie6xx_wdt_driver);
|
|
}
|
|
|
|
static void __exit ie6xx_wdt_exit(void)
|
|
{
|
|
platform_driver_unregister(&ie6xx_wdt_driver);
|
|
}
|
|
|
|
late_initcall(ie6xx_wdt_init);
|
|
module_exit(ie6xx_wdt_exit);
|
|
|
|
MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
|
|
MODULE_DESCRIPTION("Intel Atom E6xx Watchdog Device Driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
|
MODULE_ALIAS("platform:" DRIVER_NAME);
|