linux/drivers/watchdog/nuc900_wdt.c

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/*
* Copyright (c) 2009 Nuvoton technology corporation.
*
* Wan ZongShun <mcuos.com@gmail.com>
*
* 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;version 2 of the License.
*
*/
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
#define REG_WTCR 0x1c
#define WTCLK (0x01 << 10)
#define WTE (0x01 << 7) /*wdt enable*/
#define WTIS (0x03 << 4)
#define WTIF (0x01 << 3)
#define WTRF (0x01 << 2)
#define WTRE (0x01 << 1)
#define WTR (0x01 << 0)
/*
* The watchdog time interval can be calculated via following formula:
* WTIS real time interval (formula)
* 0x00 ((2^ 14 ) * ((external crystal freq) / 256))seconds
* 0x01 ((2^ 16 ) * ((external crystal freq) / 256))seconds
* 0x02 ((2^ 18 ) * ((external crystal freq) / 256))seconds
* 0x03 ((2^ 20 ) * ((external crystal freq) / 256))seconds
*
* The external crystal freq is 15Mhz in the nuc900 evaluation board.
* So 0x00 = +-0.28 seconds, 0x01 = +-1.12 seconds, 0x02 = +-4.48 seconds,
* 0x03 = +- 16.92 seconds..
*/
#define WDT_HW_TIMEOUT 0x02
#define WDT_TIMEOUT (HZ/2)
#define WDT_HEARTBEAT 15
static int heartbeat = WDT_HEARTBEAT;
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. "
"(default = " __MODULE_STRING(WDT_HEARTBEAT) ")");
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) ")");
struct nuc900_wdt {
struct resource *res;
struct clk *wdt_clock;
struct platform_device *pdev;
void __iomem *wdt_base;
char expect_close;
struct timer_list timer;
spinlock_t wdt_lock;
unsigned long next_heartbeat;
};
static unsigned long nuc900wdt_busy;
static struct nuc900_wdt *nuc900_wdt;
static inline void nuc900_wdt_keepalive(void)
{
unsigned int val;
spin_lock(&nuc900_wdt->wdt_lock);
val = __raw_readl(nuc900_wdt->wdt_base + REG_WTCR);
val |= (WTR | WTIF);
__raw_writel(val, nuc900_wdt->wdt_base + REG_WTCR);
spin_unlock(&nuc900_wdt->wdt_lock);
}
static inline void nuc900_wdt_start(void)
{
unsigned int val;
spin_lock(&nuc900_wdt->wdt_lock);
val = __raw_readl(nuc900_wdt->wdt_base + REG_WTCR);
val |= (WTRE | WTE | WTR | WTCLK | WTIF);
val &= ~WTIS;
val |= (WDT_HW_TIMEOUT << 0x04);
__raw_writel(val, nuc900_wdt->wdt_base + REG_WTCR);
spin_unlock(&nuc900_wdt->wdt_lock);
nuc900_wdt->next_heartbeat = jiffies + heartbeat * HZ;
mod_timer(&nuc900_wdt->timer, jiffies + WDT_TIMEOUT);
}
static inline void nuc900_wdt_stop(void)
{
unsigned int val;
del_timer(&nuc900_wdt->timer);
spin_lock(&nuc900_wdt->wdt_lock);
val = __raw_readl(nuc900_wdt->wdt_base + REG_WTCR);
val &= ~WTE;
__raw_writel(val, nuc900_wdt->wdt_base + REG_WTCR);
spin_unlock(&nuc900_wdt->wdt_lock);
}
static inline void nuc900_wdt_ping(void)
{
nuc900_wdt->next_heartbeat = jiffies + heartbeat * HZ;
}
static int nuc900_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &nuc900wdt_busy))
return -EBUSY;
nuc900_wdt_start();
return nonseekable_open(inode, file);
}
static int nuc900_wdt_close(struct inode *inode, struct file *file)
{
if (nuc900_wdt->expect_close == 42)
nuc900_wdt_stop();
else {
dev_crit(&nuc900_wdt->pdev->dev,
"Unexpected close, not stopping watchdog!\n");
nuc900_wdt_ping();
}
nuc900_wdt->expect_close = 0;
clear_bit(0, &nuc900wdt_busy);
return 0;
}
static const struct watchdog_info nuc900_wdt_info = {
.identity = "nuc900 watchdog",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
static long nuc900_wdt_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_value;
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &nuc900_wdt_info,
sizeof(nuc900_wdt_info)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
nuc900_wdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_value, p))
return -EFAULT;
heartbeat = new_value;
nuc900_wdt_ping();
return put_user(new_value, p);
case WDIOC_GETTIMEOUT:
return put_user(heartbeat, p);
default:
return -ENOTTY;
}
}
static ssize_t nuc900_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
if (!len)
return 0;
/* Scan for magic character */
if (!nowayout) {
size_t i;
nuc900_wdt->expect_close = 0;
for (i = 0; i < len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V') {
nuc900_wdt->expect_close = 42;
break;
}
}
}
nuc900_wdt_ping();
return len;
}
static void nuc900_wdt_timer_ping(unsigned long data)
{
if (time_before(jiffies, nuc900_wdt->next_heartbeat)) {
nuc900_wdt_keepalive();
mod_timer(&nuc900_wdt->timer, jiffies + WDT_TIMEOUT);
} else
dev_warn(&nuc900_wdt->pdev->dev, "Will reset the machine !\n");
}
static const struct file_operations nuc900wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.unlocked_ioctl = nuc900_wdt_ioctl,
.open = nuc900_wdt_open,
.release = nuc900_wdt_close,
.write = nuc900_wdt_write,
};
static struct miscdevice nuc900wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &nuc900wdt_fops,
};
static int nuc900wdt_probe(struct platform_device *pdev)
{
int ret = 0;
nuc900_wdt = kzalloc(sizeof(struct nuc900_wdt), GFP_KERNEL);
if (!nuc900_wdt)
return -ENOMEM;
nuc900_wdt->pdev = pdev;
spin_lock_init(&nuc900_wdt->wdt_lock);
nuc900_wdt->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (nuc900_wdt->res == NULL) {
dev_err(&pdev->dev, "no memory resource specified\n");
ret = -ENOENT;
goto err_get;
}
if (!request_mem_region(nuc900_wdt->res->start,
resource_size(nuc900_wdt->res), pdev->name)) {
dev_err(&pdev->dev, "failed to get memory region\n");
ret = -ENOENT;
goto err_get;
}
nuc900_wdt->wdt_base = ioremap(nuc900_wdt->res->start,
resource_size(nuc900_wdt->res));
if (nuc900_wdt->wdt_base == NULL) {
dev_err(&pdev->dev, "failed to ioremap() region\n");
ret = -EINVAL;
goto err_req;
}
nuc900_wdt->wdt_clock = clk_get(&pdev->dev, NULL);
if (IS_ERR(nuc900_wdt->wdt_clock)) {
dev_err(&pdev->dev, "failed to find watchdog clock source\n");
ret = PTR_ERR(nuc900_wdt->wdt_clock);
goto err_map;
}
clk_enable(nuc900_wdt->wdt_clock);
setup_timer(&nuc900_wdt->timer, nuc900_wdt_timer_ping, 0);
ret = misc_register(&nuc900wdt_miscdev);
if (ret) {
dev_err(&pdev->dev, "err register miscdev on minor=%d (%d)\n",
WATCHDOG_MINOR, ret);
goto err_clk;
}
return 0;
err_clk:
clk_disable(nuc900_wdt->wdt_clock);
clk_put(nuc900_wdt->wdt_clock);
err_map:
iounmap(nuc900_wdt->wdt_base);
err_req:
release_mem_region(nuc900_wdt->res->start,
resource_size(nuc900_wdt->res));
err_get:
kfree(nuc900_wdt);
return ret;
}
static int nuc900wdt_remove(struct platform_device *pdev)
{
misc_deregister(&nuc900wdt_miscdev);
clk_disable(nuc900_wdt->wdt_clock);
clk_put(nuc900_wdt->wdt_clock);
iounmap(nuc900_wdt->wdt_base);
release_mem_region(nuc900_wdt->res->start,
resource_size(nuc900_wdt->res));
kfree(nuc900_wdt);
return 0;
}
static struct platform_driver nuc900wdt_driver = {
.probe = nuc900wdt_probe,
.remove = nuc900wdt_remove,
.driver = {
.name = "nuc900-wdt",
.owner = THIS_MODULE,
},
};
module_platform_driver(nuc900wdt_driver);
MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
MODULE_DESCRIPTION("Watchdog driver for NUC900");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("platform:nuc900-wdt");