linux/drivers/watchdog/omap_wdt.c

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/*
* omap_wdt.c
*
* Watchdog driver for the TI OMAP 16xx & 24xx/34xx 32KHz (non-secure) watchdog
*
* Author: MontaVista Software, Inc.
* <gdavis@mvista.com> or <source@mvista.com>
*
* 2003 (c) MontaVista Software, Inc. This file is licensed under the
* terms of the GNU General Public License version 2. This program is
* licensed "as is" without any warranty of any kind, whether express
* or implied.
*
* History:
*
* 20030527: George G. Davis <gdavis@mvista.com>
* Initially based on linux-2.4.19-rmk7-pxa1/drivers/char/sa1100_wdt.c
* (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
* Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* Copyright (c) 2004 Texas Instruments.
* 1. Modified to support OMAP1610 32-KHz watchdog timer
* 2. Ported to 2.6 kernel
*
* Copyright (c) 2005 David Brownell
* Use the driver model and standard identifiers; handle bigger timeouts.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/watchdog.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/moduleparam.h>
#include <linux/io.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 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/pm_runtime.h>
watchdog: OMAP: use standard GETBOOTSTATUS interface; use platform_data fn ptr Previously the OMAP watchdog driver used a non-standard way to report the chip reset source via the GETBOOTSTATUS ioctl. This patch converts the driver to use the standard WDIOF_* flags for this purpose. This patch may break existing userspace code that uses the existing non-standard data format returned by the OMAP watchdog driver's GETBOOTSTATUS ioctl. To fetch detailed reset source information, userspace code will need to retrieve it directly from the CGRM or PRM drivers when those are completed. Previously, to fetch the reset source, the driver either read a register outside the watchdog IP block (OMAP1), or called a function exported directly from arch/arm/mach-omap2. Both approaches are broken. This patch also converts the driver to use a platform_data function pointer. This approach is temporary, and is due to the lack of drivers for the OMAP16xx+ Clock Generation and Reset Management IP block and the OMAP2+ Power and Reset Management IP block. Once drivers are available for those IP blocks, the watchdog driver can be converted to call exported functions from those drivers directly. At that point, the platform_data function pointer can be removed. In the short term, this patch is needed to allow the PRM code to be removed from arch/arm/mach-omap2 (it is being moved to a driver). This version integrates a fix from Jon Hunter <jon-hunter@ti.com> that avoids a NULL pointer dereference in a DT-only boot, and integrates a patch commit message fix from Felipe Balbi <balbi@ti.com>. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Wim Van Sebroeck <wim@iguana.be> Acked-by: Wim Van Sebroeck <wim@iguana.be> [paul@pwsan.com: integrated pdata fix from Jon Hunter] Cc: Jon Hunter <jon-hunter@ti.com> [paul@pwsan.com: integrated changelog fix from Felipe Balbi] Cc: Felipe Balbi <balbi@ti.com>
2012-10-30 02:49:44 +00:00
#include <linux/platform_data/omap-wd-timer.h>
#include "omap_wdt.h"
static unsigned timer_margin;
module_param(timer_margin, uint, 0);
MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
struct omap_wdt_dev {
void __iomem *base; /* physical */
struct device *dev;
bool omap_wdt_users;
struct resource *mem;
int wdt_trgr_pattern;
struct mutex lock; /* to avoid races with PM */
};
static void omap_wdt_reload(struct omap_wdt_dev *wdev)
{
void __iomem *base = wdev->base;
/* wait for posted write to complete */
while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
cpu_relax();
wdev->wdt_trgr_pattern = ~wdev->wdt_trgr_pattern;
__raw_writel(wdev->wdt_trgr_pattern, (base + OMAP_WATCHDOG_TGR));
/* wait for posted write to complete */
while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
cpu_relax();
/* reloaded WCRR from WLDR */
}
static void omap_wdt_enable(struct omap_wdt_dev *wdev)
{
void __iomem *base = wdev->base;
/* Sequence to enable the watchdog */
__raw_writel(0xBBBB, base + OMAP_WATCHDOG_SPR);
while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x10)
cpu_relax();
__raw_writel(0x4444, base + OMAP_WATCHDOG_SPR);
while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x10)
cpu_relax();
}
static void omap_wdt_disable(struct omap_wdt_dev *wdev)
{
void __iomem *base = wdev->base;
/* sequence required to disable watchdog */
__raw_writel(0xAAAA, base + OMAP_WATCHDOG_SPR); /* TIMER_MODE */
while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x10)
cpu_relax();
__raw_writel(0x5555, base + OMAP_WATCHDOG_SPR); /* TIMER_MODE */
while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x10)
cpu_relax();
}
static void omap_wdt_set_timer(struct omap_wdt_dev *wdev,
unsigned int timeout)
{
u32 pre_margin = GET_WLDR_VAL(timeout);
void __iomem *base = wdev->base;
/* just count up at 32 KHz */
while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
cpu_relax();
__raw_writel(pre_margin, base + OMAP_WATCHDOG_LDR);
while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
cpu_relax();
}
static int omap_wdt_start(struct watchdog_device *wdog)
{
struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
void __iomem *base = wdev->base;
mutex_lock(&wdev->lock);
wdev->omap_wdt_users = true;
pm_runtime_get_sync(wdev->dev);
/* initialize prescaler */
while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
cpu_relax();
__raw_writel((1 << 5) | (PTV << 2), base + OMAP_WATCHDOG_CNTRL);
while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
cpu_relax();
omap_wdt_set_timer(wdev, wdog->timeout);
omap_wdt_reload(wdev); /* trigger loading of new timeout value */
omap_wdt_enable(wdev);
mutex_unlock(&wdev->lock);
return 0;
}
static int omap_wdt_stop(struct watchdog_device *wdog)
{
struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
mutex_lock(&wdev->lock);
omap_wdt_disable(wdev);
pm_runtime_put_sync(wdev->dev);
wdev->omap_wdt_users = false;
mutex_unlock(&wdev->lock);
return 0;
}
static int omap_wdt_ping(struct watchdog_device *wdog)
{
struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
mutex_lock(&wdev->lock);
omap_wdt_reload(wdev);
mutex_unlock(&wdev->lock);
return 0;
}
static int omap_wdt_set_timeout(struct watchdog_device *wdog,
unsigned int timeout)
{
struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
mutex_lock(&wdev->lock);
omap_wdt_disable(wdev);
omap_wdt_set_timer(wdev, timeout);
omap_wdt_enable(wdev);
omap_wdt_reload(wdev);
wdog->timeout = timeout;
mutex_unlock(&wdev->lock);
return 0;
}
static const struct watchdog_info omap_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "OMAP Watchdog",
};
static const struct watchdog_ops omap_wdt_ops = {
.owner = THIS_MODULE,
.start = omap_wdt_start,
.stop = omap_wdt_stop,
.ping = omap_wdt_ping,
.set_timeout = omap_wdt_set_timeout,
};
static int omap_wdt_probe(struct platform_device *pdev)
{
struct omap_wd_timer_platform_data *pdata = pdev->dev.platform_data;
bool nowayout = WATCHDOG_NOWAYOUT;
struct watchdog_device *omap_wdt;
struct resource *res, *mem;
struct omap_wdt_dev *wdev;
u32 rs;
int ret;
omap_wdt = devm_kzalloc(&pdev->dev, sizeof(*omap_wdt), GFP_KERNEL);
if (!omap_wdt)
return -ENOMEM;
/* reserve static register mappings */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENOENT;
mem = devm_request_mem_region(&pdev->dev, res->start,
resource_size(res), pdev->name);
if (!mem)
return -EBUSY;
wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
if (!wdev)
return -ENOMEM;
wdev->omap_wdt_users = false;
wdev->mem = mem;
wdev->dev = &pdev->dev;
wdev->wdt_trgr_pattern = 0x1234;
mutex_init(&wdev->lock);
wdev->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (!wdev->base)
return -ENOMEM;
omap_wdt->info = &omap_wdt_info;
omap_wdt->ops = &omap_wdt_ops;
omap_wdt->min_timeout = TIMER_MARGIN_MIN;
omap_wdt->max_timeout = TIMER_MARGIN_MAX;
if (timer_margin >= TIMER_MARGIN_MIN &&
timer_margin <= TIMER_MARGIN_MAX)
omap_wdt->timeout = timer_margin;
else
omap_wdt->timeout = TIMER_MARGIN_DEFAULT;
watchdog_set_drvdata(omap_wdt, wdev);
watchdog_set_nowayout(omap_wdt, nowayout);
platform_set_drvdata(pdev, omap_wdt);
pm_runtime_enable(wdev->dev);
pm_runtime_get_sync(wdev->dev);
if (pdata && pdata->read_reset_sources)
rs = pdata->read_reset_sources();
else
rs = 0;
omap_wdt->bootstatus = (rs & (1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT)) ?
WDIOF_CARDRESET : 0;
omap_wdt_disable(wdev);
ret = watchdog_register_device(omap_wdt);
if (ret) {
pm_runtime_disable(wdev->dev);
return ret;
}
pr_info("OMAP Watchdog Timer Rev 0x%02x: initial timeout %d sec\n",
__raw_readl(wdev->base + OMAP_WATCHDOG_REV) & 0xFF,
omap_wdt->timeout);
pm_runtime_put_sync(wdev->dev);
return 0;
}
static void omap_wdt_shutdown(struct platform_device *pdev)
{
struct watchdog_device *wdog = platform_get_drvdata(pdev);
struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
mutex_lock(&wdev->lock);
if (wdev->omap_wdt_users) {
omap_wdt_disable(wdev);
pm_runtime_put_sync(wdev->dev);
}
mutex_unlock(&wdev->lock);
}
static int omap_wdt_remove(struct platform_device *pdev)
{
struct watchdog_device *wdog = platform_get_drvdata(pdev);
struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
pm_runtime_disable(wdev->dev);
watchdog_unregister_device(wdog);
return 0;
}
#ifdef CONFIG_PM
/* REVISIT ... not clear this is the best way to handle system suspend; and
* it's very inappropriate for selective device suspend (e.g. suspending this
* through sysfs rather than by stopping the watchdog daemon). Also, this
* may not play well enough with NOWAYOUT...
*/
static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state)
{
struct watchdog_device *wdog = platform_get_drvdata(pdev);
struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
mutex_lock(&wdev->lock);
if (wdev->omap_wdt_users) {
omap_wdt_disable(wdev);
pm_runtime_put_sync(wdev->dev);
}
mutex_unlock(&wdev->lock);
return 0;
}
static int omap_wdt_resume(struct platform_device *pdev)
{
struct watchdog_device *wdog = platform_get_drvdata(pdev);
struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
mutex_lock(&wdev->lock);
if (wdev->omap_wdt_users) {
pm_runtime_get_sync(wdev->dev);
omap_wdt_enable(wdev);
omap_wdt_reload(wdev);
}
mutex_unlock(&wdev->lock);
return 0;
}
#else
#define omap_wdt_suspend NULL
#define omap_wdt_resume NULL
#endif
static const struct of_device_id omap_wdt_of_match[] = {
{ .compatible = "ti,omap3-wdt", },
{},
};
MODULE_DEVICE_TABLE(of, omap_wdt_of_match);
static struct platform_driver omap_wdt_driver = {
.probe = omap_wdt_probe,
.remove = omap_wdt_remove,
.shutdown = omap_wdt_shutdown,
.suspend = omap_wdt_suspend,
.resume = omap_wdt_resume,
.driver = {
.owner = THIS_MODULE,
.name = "omap_wdt",
.of_match_table = omap_wdt_of_match,
},
};
module_platform_driver(omap_wdt_driver);
MODULE_AUTHOR("George G. Davis");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:omap_wdt");