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* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-watchdog: (25 commits)
  watchdog: WatchDog Timer Driver Core - Add minimum and max timeout
  watchdog: WatchDog Timer Driver Core - Add ioctl call
  watchdog: WatchDog Timer Driver Core - Add nowayout feature
  watchdog: WatchDog Timer Driver Core - Add Magic Close feature
  watchdog: WatchDog Timer Driver Core - Add WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT ioctl
  watchdog: WatchDog Timer Driver Core - Add WDIOC_SETOPTIONS ioctl
  watchdog: WatchDog Timer Driver Core - Add WDIOC_KEEPALIVE ioctl
  watchdog: WatchDog Timer Driver Core - Add basic ioctl functionality
  watchdog: WatchDog Timer Driver Core - Add basic framework
  watchdog: hpwdt: add next gen HP servers
  watchdog: it8712f_wdt.c: improve includes
  watchdog: at91sam9/wdt: move register header to drivers
  watchdog: Add Xilinx watchdog timer driver
  watchdog: remove empty pm-functions
  watchdog: sp805: Flush posted writes in enable/disable.
  watchdog: sp805: Don't write 0 to the load value register.
  watchdog: imx2_wdt: add device tree probe support
  watchdog: s3c2410: Add support for device tree based probe
  watchdog: mpcore_wdt: Add suspend/resume support.
  watchdog: mtx1-wdt: use dev_{err,info} instead of printk()
  ...
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Linus Torvalds committed Jul 30, 2011
2 parents 59ed2bb + 3f43f68 commit 2313bcd
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14 changes: 14 additions & 0 deletions Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt
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* Freescale i.MX Watchdog Timer (WDT) Controller

Required properties:
- compatible : Should be "fsl,<soc>-wdt"
- reg : Should contain WDT registers location and length
- interrupts : Should contain WDT interrupt

Examples:

wdt@73f98000 {
compatible = "fsl,imx51-wdt", "fsl,imx21-wdt";
reg = <0x73f98000 0x4000>;
interrupts = <58>;
};
11 changes: 11 additions & 0 deletions Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
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* Samsung's Watchdog Timer Controller

The Samsung's Watchdog controller is used for resuming system operation
after a preset amount of time during which the WDT reset event has not
occured.

Required properties:
- compatible : should be "samsung,s3c2410-wdt"
- reg : base physical address of the controller and length of memory mapped
region.
- interrupts : interrupt number to the cpu.
2 changes: 2 additions & 0 deletions Documentation/watchdog/00-INDEX
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,8 @@ src/
- directory holding watchdog related example programs.
watchdog-api.txt
- description of the Linux Watchdog driver API.
watchdog-kernel-api.txt
- description of the Linux WatchDog Timer Driver Core kernel API.
watchdog-parameters.txt
- information on driver parameters (for drivers other than
the ones that have driver-specific files here)
Expand Down
162 changes: 162 additions & 0 deletions Documentation/watchdog/watchdog-kernel-api.txt
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@@ -0,0 +1,162 @@
The Linux WatchDog Timer Driver Core kernel API.
===============================================
Last reviewed: 22-Jul-2011

Wim Van Sebroeck <wim@iguana.be>

Introduction
------------
This document does not describe what a WatchDog Timer (WDT) Driver or Device is.
It also does not describe the API which can be used by user space to communicate
with a WatchDog Timer. If you want to know this then please read the following
file: Documentation/watchdog/watchdog-api.txt .

So what does this document describe? It describes the API that can be used by
WatchDog Timer Drivers that want to use the WatchDog Timer Driver Core
Framework. This framework provides all interfacing towards user space so that
the same code does not have to be reproduced each time. This also means that
a watchdog timer driver then only needs to provide the different routines
(operations) that control the watchdog timer (WDT).

The API
-------
Each watchdog timer driver that wants to use the WatchDog Timer Driver Core
must #include <linux/watchdog.h> (you would have to do this anyway when
writing a watchdog device driver). This include file contains following
register/unregister routines:

extern int watchdog_register_device(struct watchdog_device *);
extern void watchdog_unregister_device(struct watchdog_device *);

The watchdog_register_device routine registers a watchdog timer device.
The parameter of this routine is a pointer to a watchdog_device structure.
This routine returns zero on success and a negative errno code for failure.

The watchdog_unregister_device routine deregisters a registered watchdog timer
device. The parameter of this routine is the pointer to the registered
watchdog_device structure.

The watchdog device structure looks like this:

struct watchdog_device {
const struct watchdog_info *info;
const struct watchdog_ops *ops;
unsigned int bootstatus;
unsigned int timeout;
unsigned int min_timeout;
unsigned int max_timeout;
void *driver_data;
unsigned long status;
};

It contains following fields:
* info: a pointer to a watchdog_info structure. This structure gives some
additional information about the watchdog timer itself. (Like it's unique name)
* ops: a pointer to the list of watchdog operations that the watchdog supports.
* timeout: the watchdog timer's timeout value (in seconds).
* min_timeout: the watchdog timer's minimum timeout value (in seconds).
* max_timeout: the watchdog timer's maximum timeout value (in seconds).
* bootstatus: status of the device after booting (reported with watchdog
WDIOF_* status bits).
* driver_data: a pointer to the drivers private data of a watchdog device.
This data should only be accessed via the watchdog_set_drvadata and
watchdog_get_drvdata routines.
* status: this field contains a number of status bits that give extra
information about the status of the device (Like: is the watchdog timer
running/active, is the nowayout bit set, is the device opened via
the /dev/watchdog interface or not, ...).

The list of watchdog operations is defined as:

struct watchdog_ops {
struct module *owner;
/* mandatory operations */
int (*start)(struct watchdog_device *);
int (*stop)(struct watchdog_device *);
/* optional operations */
int (*ping)(struct watchdog_device *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
};

It is important that you first define the module owner of the watchdog timer
driver's operations. This module owner will be used to lock the module when
the watchdog is active. (This to avoid a system crash when you unload the
module and /dev/watchdog is still open).
Some operations are mandatory and some are optional. The mandatory operations
are:
* start: this is a pointer to the routine that starts the watchdog timer
device.
The routine needs a pointer to the watchdog timer device structure as a
parameter. It returns zero on success or a negative errno code for failure.
* stop: with this routine the watchdog timer device is being stopped.
The routine needs a pointer to the watchdog timer device structure as a
parameter. It returns zero on success or a negative errno code for failure.
Some watchdog timer hardware can only be started and not be stopped. The
driver supporting this hardware needs to make sure that a start and stop
routine is being provided. This can be done by using a timer in the driver
that regularly sends a keepalive ping to the watchdog timer hardware.

Not all watchdog timer hardware supports the same functionality. That's why
all other routines/operations are optional. They only need to be provided if
they are supported. These optional routines/operations are:
* ping: this is the routine that sends a keepalive ping to the watchdog timer
hardware.
The routine needs a pointer to the watchdog timer device structure as a
parameter. It returns zero on success or a negative errno code for failure.
Most hardware that does not support this as a separate function uses the
start function to restart the watchdog timer hardware. And that's also what
the watchdog timer driver core does: to send a keepalive ping to the watchdog
timer hardware it will either use the ping operation (when available) or the
start operation (when the ping operation is not available).
(Note: the WDIOC_KEEPALIVE ioctl call will only be active when the
WDIOF_KEEPALIVEPING bit has been set in the option field on the watchdog's
info structure).
* status: this routine checks the status of the watchdog timer device. The
status of the device is reported with watchdog WDIOF_* status flags/bits.
* set_timeout: this routine checks and changes the timeout of the watchdog
timer device. It returns 0 on success, -EINVAL for "parameter out of range"
and -EIO for "could not write value to the watchdog". On success the timeout
value of the watchdog_device will be changed to the value that was just used
to re-program the watchdog timer device.
(Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the
watchdog's info structure).
* ioctl: if this routine is present then it will be called first before we do
our own internal ioctl call handling. This routine should return -ENOIOCTLCMD
if a command is not supported. The parameters that are passed to the ioctl
call are: watchdog_device, cmd and arg.

The status bits should (preferably) be set with the set_bit and clear_bit alike
bit-operations. The status bits that are defined are:
* WDOG_ACTIVE: this status bit indicates whether or not a watchdog timer device
is active or not. When the watchdog is active after booting, then you should
set this status bit (Note: when you register the watchdog timer device with
this bit set, then opening /dev/watchdog will skip the start operation)
* WDOG_DEV_OPEN: this status bit shows whether or not the watchdog device
was opened via /dev/watchdog.
(This bit should only be used by the WatchDog Timer Driver Core).
* WDOG_ALLOW_RELEASE: this bit stores whether or not the magic close character
has been sent (so that we can support the magic close feature).
(This bit should only be used by the WatchDog Timer Driver Core).
* WDOG_NO_WAY_OUT: this bit stores the nowayout setting for the watchdog.
If this bit is set then the watchdog timer will not be able to stop.

Note: The WatchDog Timer Driver Core supports the magic close feature and
the nowayout feature. To use the magic close feature you must set the
WDIOF_MAGICCLOSE bit in the options field of the watchdog's info structure.
The nowayout feature will overrule the magic close feature.

To get or set driver specific data the following two helper functions should be
used:

static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data)
static inline void *watchdog_get_drvdata(struct watchdog_device *wdd)

The watchdog_set_drvdata function allows you to add driver specific data. The
arguments of this function are the watchdog device where you want to add the
driver specific data to and a pointer to the data itself.

The watchdog_get_drvdata function allows you to retrieve driver specific data.
The argument of this function is the watchdog device where you want to retrieve
data from. The function retruns the pointer to the driver specific data.
36 changes: 35 additions & 1 deletion drivers/watchdog/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,17 @@ menuconfig WATCHDOG

if WATCHDOG

config WATCHDOG_CORE
bool "WatchDog Timer Driver Core"
---help---
Say Y here if you want to use the new watchdog timer driver core.
This driver provides a framework for all watchdog timer drivers
and gives them the /dev/watchdog interface (and later also the
sysfs interface).

To compile this driver as a module, choose M here: the module will
be called watchdog.

config WATCHDOG_NOWAYOUT
bool "Disable watchdog shutdown on close"
help
Expand Down Expand Up @@ -186,6 +197,15 @@ config SA1100_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called sa1100_wdt.

config DW_WATCHDOG
tristate "Synopsys DesignWare watchdog"
depends on ARM && HAVE_CLK
help
Say Y here if to include support for the Synopsys DesignWare
watchdog timer found in many ARM chips.
To compile this driver as a module, choose M here: the
module will be called dw_wdt.

config MPCORE_WATCHDOG
tristate "MPcore watchdog"
depends on HAVE_ARM_TWD
Expand Down Expand Up @@ -321,7 +341,7 @@ config MAX63XX_WATCHDOG

config IMX2_WDT
tristate "IMX2+ Watchdog"
depends on ARCH_MX2 || ARCH_MX25 || ARCH_MX3 || ARCH_MX5
depends on IMX_HAVE_PLATFORM_IMX2_WDT
help
This is the driver for the hardware watchdog
on the Freescale IMX2 and later processors.
Expand Down Expand Up @@ -879,6 +899,20 @@ config M54xx_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called m54xx_wdt.

# MicroBlaze Architecture

config XILINX_WATCHDOG
tristate "Xilinx Watchdog timer"
depends on MICROBLAZE
---help---
Watchdog driver for the xps_timebase_wdt ip core.

IMPORTANT: The xps_timebase_wdt parent must have the property
"clock-frequency" at device tree.

To compile this driver as a module, choose M here: the
module will be called of_xilinx_wdt.

# MIPS Architecture

config ATH79_WDT
Expand Down
8 changes: 8 additions & 0 deletions drivers/watchdog/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,10 @@
# Makefile for the WatchDog device drivers.
#

# The WatchDog Timer Driver Core.
watchdog-objs += watchdog_core.o watchdog_dev.o
obj-$(CONFIG_WATCHDOG_CORE) += watchdog.o

# Only one watchdog can succeed. We probe the ISA/PCI/USB based
# watchdog-cards first, then the architecture specific watchdog
# drivers and then the architecture independent "softdog" driver.
Expand Down Expand Up @@ -37,6 +41,7 @@ obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o
obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o
obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o
obj-$(CONFIG_DW_WATCHDOG) += dw_wdt.o
obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o
obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o
obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
Expand Down Expand Up @@ -109,6 +114,9 @@ obj-$(CONFIG_INTEL_SCU_WATCHDOG) += intel_scu_watchdog.o
# M68K Architecture
obj-$(CONFIG_M54xx_WATCHDOG) += m54xx_wdt.o

# MicroBlaze Architecture
obj-$(CONFIG_XILINX_WATCHDOG) += of_xilinx_wdt.o

# MIPS Architecture
obj-$(CONFIG_ATH79_WDT) += ath79_wdt.o
obj-$(CONFIG_BCM47XX_WDT) += bcm47xx_wdt.o
Expand Down
21 changes: 1 addition & 20 deletions drivers/watchdog/at91sam9_wdt.c
Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,7 @@
#include <linux/bitops.h>
#include <linux/uaccess.h>

#include <mach/at91_wdt.h>
#include "at91sam9_wdt.h"

#define DRV_NAME "AT91SAM9 Watchdog"

Expand Down Expand Up @@ -284,27 +284,8 @@ static int __exit at91wdt_remove(struct platform_device *pdev)
return res;
}

#ifdef CONFIG_PM

static int at91wdt_suspend(struct platform_device *pdev, pm_message_t message)
{
return 0;
}

static int at91wdt_resume(struct platform_device *pdev)
{
return 0;
}

#else
#define at91wdt_suspend NULL
#define at91wdt_resume NULL
#endif

static struct platform_driver at91wdt_driver = {
.remove = __exit_p(at91wdt_remove),
.suspend = at91wdt_suspend,
.resume = at91wdt_resume,
.driver = {
.name = "at91_wdt",
.owner = THIS_MODULE,
Expand Down
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* arch/arm/mach-at91/include/mach/at91_wdt.h
* drivers/watchdog/at91sam9_wdt.h
*
* Copyright (C) 2007 Andrew Victor
* Copyright (C) 2007 Atmel Corporation.
Expand Down
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