linux/drivers/watchdog/s3c2410_wdt.c

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/* linux/drivers/char/watchdog/s3c2410_wdt.c
*
* Copyright (c) 2004 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2410 Watchdog Timer Support
*
* Based on, softdog.c by Alan Cox,
* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* 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.
*
* 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
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/miscdevice.h> /* for MODULE_ALIAS_MISCDEV */
#include <linux/watchdog.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/cpufreq.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/err.h>
#include <linux/of.h>
#define S3C2410_WTCON 0x00
#define S3C2410_WTDAT 0x04
#define S3C2410_WTCNT 0x08
#define S3C2410_WTCON_RSTEN (1 << 0)
#define S3C2410_WTCON_INTEN (1 << 2)
#define S3C2410_WTCON_ENABLE (1 << 5)
#define S3C2410_WTCON_DIV16 (0 << 3)
#define S3C2410_WTCON_DIV32 (1 << 3)
#define S3C2410_WTCON_DIV64 (2 << 3)
#define S3C2410_WTCON_DIV128 (3 << 3)
#define S3C2410_WTCON_PRESCALE(x) ((x) << 8)
#define S3C2410_WTCON_PRESCALE_MASK (0xff << 8)
#define CONFIG_S3C2410_WATCHDOG_ATBOOT (0)
#define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME (15)
static bool nowayout = WATCHDOG_NOWAYOUT;
static int tmr_margin;
static int tmr_atboot = CONFIG_S3C2410_WATCHDOG_ATBOOT;
static int soft_noboot;
static int debug;
module_param(tmr_margin, int, 0);
module_param(tmr_atboot, int, 0);
module_param(nowayout, bool, 0);
module_param(soft_noboot, int, 0);
module_param(debug, int, 0);
MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default="
__MODULE_STRING(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME) ")");
MODULE_PARM_DESC(tmr_atboot,
"Watchdog is started at boot time if set to 1, default="
__MODULE_STRING(CONFIG_S3C2410_WATCHDOG_ATBOOT));
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
"0 to reboot (default 0)");
MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
struct s3c2410_wdt {
struct device *dev;
struct clk *clock;
void __iomem *reg_base;
unsigned int count;
spinlock_t lock;
unsigned long wtcon_save;
unsigned long wtdat_save;
struct watchdog_device wdt_device;
struct notifier_block freq_transition;
};
/* watchdog control routines */
#define DBG(fmt, ...) \
do { \
if (debug) \
pr_info(fmt, ##__VA_ARGS__); \
} while (0)
/* functions */
static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
{
return container_of(nb, struct s3c2410_wdt, freq_transition);
}
static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
{
struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
spin_lock(&wdt->lock);
writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
spin_unlock(&wdt->lock);
return 0;
}
static void __s3c2410wdt_stop(struct s3c2410_wdt *wdt)
{
unsigned long wtcon;
wtcon = readl(wdt->reg_base + S3C2410_WTCON);
wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN);
writel(wtcon, wdt->reg_base + S3C2410_WTCON);
}
static int s3c2410wdt_stop(struct watchdog_device *wdd)
{
struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
spin_lock(&wdt->lock);
__s3c2410wdt_stop(wdt);
spin_unlock(&wdt->lock);
return 0;
}
static int s3c2410wdt_start(struct watchdog_device *wdd)
{
unsigned long wtcon;
struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
spin_lock(&wdt->lock);
__s3c2410wdt_stop(wdt);
wtcon = readl(wdt->reg_base + S3C2410_WTCON);
wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128;
if (soft_noboot) {
wtcon |= S3C2410_WTCON_INTEN;
wtcon &= ~S3C2410_WTCON_RSTEN;
} else {
wtcon &= ~S3C2410_WTCON_INTEN;
wtcon |= S3C2410_WTCON_RSTEN;
}
DBG("%s: count=0x%08x, wtcon=%08lx\n",
__func__, wdt->count, wtcon);
writel(wdt->count, wdt->reg_base + S3C2410_WTDAT);
writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
writel(wtcon, wdt->reg_base + S3C2410_WTCON);
spin_unlock(&wdt->lock);
return 0;
}
static inline int s3c2410wdt_is_running(struct s3c2410_wdt *wdt)
{
return readl(wdt->reg_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE;
}
static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd, unsigned timeout)
{
struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
unsigned long freq = clk_get_rate(wdt->clock);
unsigned int count;
unsigned int divisor = 1;
unsigned long wtcon;
if (timeout < 1)
return -EINVAL;
freq /= 128;
count = timeout * freq;
DBG("%s: count=%d, timeout=%d, freq=%lu\n",
__func__, count, timeout, freq);
/* if the count is bigger than the watchdog register,
then work out what we need to do (and if) we can
actually make this value
*/
if (count >= 0x10000) {
for (divisor = 1; divisor <= 0x100; divisor++) {
if ((count / divisor) < 0x10000)
break;
}
if ((count / divisor) >= 0x10000) {
dev_err(wdt->dev, "timeout %d too big\n", timeout);
return -EINVAL;
}
}
DBG("%s: timeout=%d, divisor=%d, count=%d (%08x)\n",
__func__, timeout, divisor, count, count/divisor);
count /= divisor;
wdt->count = count;
/* update the pre-scaler */
wtcon = readl(wdt->reg_base + S3C2410_WTCON);
wtcon &= ~S3C2410_WTCON_PRESCALE_MASK;
wtcon |= S3C2410_WTCON_PRESCALE(divisor-1);
writel(count, wdt->reg_base + S3C2410_WTDAT);
writel(wtcon, wdt->reg_base + S3C2410_WTCON);
wdd->timeout = (count * divisor) / freq;
return 0;
}
#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
static const struct watchdog_info s3c2410_wdt_ident = {
.options = OPTIONS,
.firmware_version = 0,
.identity = "S3C2410 Watchdog",
};
static struct watchdog_ops s3c2410wdt_ops = {
.owner = THIS_MODULE,
.start = s3c2410wdt_start,
.stop = s3c2410wdt_stop,
.ping = s3c2410wdt_keepalive,
.set_timeout = s3c2410wdt_set_heartbeat,
};
static struct watchdog_device s3c2410_wdd = {
.info = &s3c2410_wdt_ident,
.ops = &s3c2410wdt_ops,
.timeout = CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME,
};
/* interrupt handler code */
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 21:55:46 +08:00
static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
{
struct s3c2410_wdt *wdt = platform_get_drvdata(param);
dev_info(wdt->dev, "watchdog timer expired (irq)\n");
s3c2410wdt_keepalive(&wdt->wdt_device);
return IRQ_HANDLED;
}
#ifdef CONFIG_CPU_FREQ
static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
unsigned long val, void *data)
{
int ret;
struct s3c2410_wdt *wdt = freq_to_wdt(nb);
if (!s3c2410wdt_is_running(wdt))
goto done;
if (val == CPUFREQ_PRECHANGE) {
/* To ensure that over the change we don't cause the
* watchdog to trigger, we perform an keep-alive if
* the watchdog is running.
*/
s3c2410wdt_keepalive(&wdt->wdt_device);
} else if (val == CPUFREQ_POSTCHANGE) {
s3c2410wdt_stop(&wdt->wdt_device);
ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
wdt->wdt_device.timeout);
if (ret >= 0)
s3c2410wdt_start(&wdt->wdt_device);
else
goto err;
}
done:
return 0;
err:
dev_err(wdt->dev, "cannot set new value for timeout %d\n",
wdt->wdt_device.timeout);
return ret;
}
static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
{
wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
return cpufreq_register_notifier(&wdt->freq_transition,
CPUFREQ_TRANSITION_NOTIFIER);
}
static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
{
wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
cpufreq_unregister_notifier(&wdt->freq_transition,
CPUFREQ_TRANSITION_NOTIFIER);
}
#else
static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
{
return 0;
}
static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
{
}
#endif
static int s3c2410wdt_probe(struct platform_device *pdev)
{
struct device *dev;
struct s3c2410_wdt *wdt;
struct resource *wdt_mem;
struct resource *wdt_irq;
unsigned int wtcon;
int started = 0;
int ret;
DBG("%s: probe=%p\n", __func__, pdev);
dev = &pdev->dev;
wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdt->dev = &pdev->dev;
spin_lock_init(&wdt->lock);
wdt->wdt_device = s3c2410_wdd;
wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (wdt_irq == NULL) {
dev_err(dev, "no irq resource specified\n");
ret = -ENOENT;
goto err;
}
/* get the memory region for the watchdog timer */
wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
wdt->reg_base = devm_ioremap_resource(dev, wdt_mem);
if (IS_ERR(wdt->reg_base)) {
ret = PTR_ERR(wdt->reg_base);
goto err;
}
DBG("probe: mapped reg_base=%p\n", wdt->reg_base);
wdt->clock = devm_clk_get(dev, "watchdog");
if (IS_ERR(wdt->clock)) {
dev_err(dev, "failed to find watchdog clock source\n");
ret = PTR_ERR(wdt->clock);
goto err;
}
clk_prepare_enable(wdt->clock);
ret = s3c2410wdt_cpufreq_register(wdt);
if (ret < 0) {
dev_err(dev, "failed to register cpufreq\n");
goto err_clk;
}
watchdog_set_drvdata(&wdt->wdt_device, wdt);
/* see if we can actually set the requested timer margin, and if
* not, try the default value */
watchdog_init_timeout(&wdt->wdt_device, tmr_margin, &pdev->dev);
ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
wdt->wdt_device.timeout);
if (ret) {
started = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
if (started == 0)
dev_info(dev,
"tmr_margin value out of range, default %d used\n",
CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
else
dev_info(dev, "default timer value is out of range, "
"cannot start\n");
}
ret = devm_request_irq(dev, wdt_irq->start, s3c2410wdt_irq, 0,
pdev->name, pdev);
if (ret != 0) {
dev_err(dev, "failed to install irq (%d)\n", ret);
goto err_cpufreq;
}
watchdog_set_nowayout(&wdt->wdt_device, nowayout);
ret = watchdog_register_device(&wdt->wdt_device);
if (ret) {
dev_err(dev, "cannot register watchdog (%d)\n", ret);
goto err_cpufreq;
}
if (tmr_atboot && started == 0) {
dev_info(dev, "starting watchdog timer\n");
s3c2410wdt_start(&wdt->wdt_device);
} else if (!tmr_atboot) {
/* if we're not enabling the watchdog, then ensure it is
* disabled if it has been left running from the bootloader
* or other source */
s3c2410wdt_stop(&wdt->wdt_device);
}
platform_set_drvdata(pdev, wdt);
/* print out a statement of readiness */
wtcon = readl(wdt->reg_base + S3C2410_WTCON);
dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n",
(wtcon & S3C2410_WTCON_ENABLE) ? "" : "in",
(wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
(wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
return 0;
err_cpufreq:
s3c2410wdt_cpufreq_deregister(wdt);
err_clk:
clk_disable_unprepare(wdt->clock);
wdt->clock = NULL;
err:
return ret;
}
static int s3c2410wdt_remove(struct platform_device *dev)
{
struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
watchdog_unregister_device(&wdt->wdt_device);
s3c2410wdt_cpufreq_deregister(wdt);
clk_disable_unprepare(wdt->clock);
wdt->clock = NULL;
return 0;
}
static void s3c2410wdt_shutdown(struct platform_device *dev)
{
struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
s3c2410wdt_stop(&wdt->wdt_device);
}
#ifdef CONFIG_PM_SLEEP
static int s3c2410wdt_suspend(struct device *dev)
{
struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
/* Save watchdog state, and turn it off. */
wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
/* Note that WTCNT doesn't need to be saved. */
s3c2410wdt_stop(&wdt->wdt_device);
return 0;
}
static int s3c2410wdt_resume(struct device *dev)
{
struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
/* Restore watchdog state. */
writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTDAT);
writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
dev_info(dev, "watchdog %sabled\n",
(wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend,
s3c2410wdt_resume);
#ifdef CONFIG_OF
static const struct of_device_id s3c2410_wdt_match[] = {
{ .compatible = "samsung,s3c2410-wdt" },
{},
};
MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
#endif
static struct platform_driver s3c2410wdt_driver = {
.probe = s3c2410wdt_probe,
.remove = s3c2410wdt_remove,
.shutdown = s3c2410wdt_shutdown,
.driver = {
.owner = THIS_MODULE,
.name = "s3c2410-wdt",
.pm = &s3c2410wdt_pm_ops,
.of_match_table = of_match_ptr(s3c2410_wdt_match),
},
};
module_platform_driver(s3c2410wdt_driver);
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, "
"Dimitry Andric <dimitry.andric@tomtom.com>");
MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("platform:s3c2410-wdt");