[V7,1/3] watchdog: imx_sc: Add i.MX system controller watchdog support
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Message ID 1551834095-19950-1-git-send-email-Anson.Huang@nxp.com
State Superseded
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Series
  • [V7,1/3] watchdog: imx_sc: Add i.MX system controller watchdog support
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Commit Message

Anson Huang March 6, 2019, 1:06 a.m. UTC
i.MX8QXP is an ARMv8 SoC which has a Cortex-M4 system controller
inside, the system controller is in charge of controlling power,
clock and watchdog etc..

This patch adds i.MX system controller watchdog driver support,
watchdog operation needs to be done in secure EL3 mode via
ARM-Trusted-Firmware, using SMC call, CPU will trap into
ARM-Trusted-Firmware and then it will request system controller
to do watchdog operation via IPC.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
Changes since V6:
	- use module_platform_driver() instead of module_init/exit to make code simple.
---
 drivers/watchdog/Kconfig      |  14 ++++
 drivers/watchdog/Makefile     |   1 +
 drivers/watchdog/imx_sc_wdt.c | 174 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 189 insertions(+)
 create mode 100644 drivers/watchdog/imx_sc_wdt.c

Comments

Guenter Roeck March 6, 2019, 4:06 p.m. UTC | #1
On 3/5/19 5:06 PM, Anson Huang wrote:
> i.MX8QXP is an ARMv8 SoC which has a Cortex-M4 system controller
> inside, the system controller is in charge of controlling power,
> clock and watchdog etc..
> 
> This patch adds i.MX system controller watchdog driver support,
> watchdog operation needs to be done in secure EL3 mode via
> ARM-Trusted-Firmware, using SMC call, CPU will trap into
> ARM-Trusted-Firmware and then it will request system controller
> to do watchdog operation via IPC.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>

Reviewed-by: Guenter Roeck <linux@roekc-us.net>

> ---
> Changes since V6:
> 	- use module_platform_driver() instead of module_init/exit to make code simple.
> ---
>   drivers/watchdog/Kconfig      |  14 ++++
>   drivers/watchdog/Makefile     |   1 +
>   drivers/watchdog/imx_sc_wdt.c | 174 ++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 189 insertions(+)
>   create mode 100644 drivers/watchdog/imx_sc_wdt.c
> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 242eea8..33a6523 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -641,6 +641,20 @@ config IMX2_WDT
>   	  To compile this driver as a module, choose M here: the
>   	  module will be called imx2_wdt.
>   
> +config IMX_SC_WDT
> +	tristate "IMX SC Watchdog"
> +	depends on IMX_SCU
> +	depends on HAVE_ARM_SMCCC
> +	select WATCHDOG_CORE
> +	help
> +	  This is the driver for the system controller watchdog
> +	  on the NXP i.MX SoCs with system controller inside.
> +	  If you have one of these processors and wish to have
> +	  watchdog support enabled, say Y, otherwise say N.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called imx_sc_wdt.
> +
>   config UX500_WATCHDOG
>   	tristate "ST-Ericsson Ux500 watchdog"
>   	depends on MFD_DB8500_PRCMU
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index ba930e4..136d9f0 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -68,6 +68,7 @@ obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
>   obj-$(CONFIG_TS4800_WATCHDOG) += ts4800_wdt.o
>   obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
>   obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
> +obj-$(CONFIG_IMX_SC_WDT) += imx_sc_wdt.o
>   obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
>   obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
>   obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
> diff --git a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c
> new file mode 100644
> index 0000000..ee48709
> --- /dev/null
> +++ b/drivers/watchdog/imx_sc_wdt.c
> @@ -0,0 +1,174 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2018-2019 NXP.
> + */
> +
> +#include <linux/arm-smccc.h>
> +#include <linux/io.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/platform_device.h>
> +#include <linux/reboot.h>
> +#include <linux/watchdog.h>
> +
> +#define DEFAULT_TIMEOUT 60
> +/*
> + * Software timer tick implemented in scfw side, support 10ms to 0xffffffff ms
> + * in theory, but for normal case, 1s~128s is enough, you can change this max
> + * value in case it's not enough.
> + */
> +#define MAX_TIMEOUT 128
> +
> +#define IMX_SIP_TIMER			0xC2000002
> +#define IMX_SIP_TIMER_START_WDOG		0x01
> +#define IMX_SIP_TIMER_STOP_WDOG		0x02
> +#define IMX_SIP_TIMER_SET_WDOG_ACT	0x03
> +#define IMX_SIP_TIMER_PING_WDOG		0x04
> +#define IMX_SIP_TIMER_SET_TIMEOUT_WDOG	0x05
> +#define IMX_SIP_TIMER_GET_WDOG_STAT	0x06
> +#define IMX_SIP_TIMER_SET_PRETIME_WDOG	0x07
> +
> +#define SC_TIMER_WDOG_ACTION_PARTITION	0
> +
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +module_param(nowayout, bool, 0000);
> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> +		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +static unsigned int timeout = DEFAULT_TIMEOUT;
> +module_param(timeout, uint, 0000);
> +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
> +		 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
> +
> +static int imx_sc_wdt_ping(struct watchdog_device *wdog)
> +{
> +	struct arm_smccc_res res;
> +
> +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG,
> +		      0, 0, 0, 0, 0, 0, &res);
> +
> +	return 0;
> +}
> +
> +static int imx_sc_wdt_start(struct watchdog_device *wdog)
> +{
> +	struct arm_smccc_res res;
> +
> +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG,
> +		      0, 0, 0, 0, 0, 0, &res);
> +	if (res.a0)
> +		return -EACCES;
> +
> +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT,
> +		      SC_TIMER_WDOG_ACTION_PARTITION,
> +		      0, 0, 0, 0, 0, &res);
> +	return res.a0 ? -EACCES : 0;
> +}
> +
> +static int imx_sc_wdt_stop(struct watchdog_device *wdog)
> +{
> +	struct arm_smccc_res res;
> +
> +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG,
> +		      0, 0, 0, 0, 0, 0, &res);
> +
> +	return res.a0 ? -EACCES : 0;
> +}
> +
> +static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog,
> +				unsigned int timeout)
> +{
> +	struct arm_smccc_res res;
> +
> +	wdog->timeout = timeout;
> +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG,
> +		      timeout * 1000, 0, 0, 0, 0, 0, &res);
> +
> +	return res.a0 ? -EACCES : 0;
> +}
> +
> +static const struct watchdog_ops imx_sc_wdt_ops = {
> +	.owner = THIS_MODULE,
> +	.start = imx_sc_wdt_start,
> +	.stop  = imx_sc_wdt_stop,
> +	.ping  = imx_sc_wdt_ping,
> +	.set_timeout = imx_sc_wdt_set_timeout,
> +};
> +
> +static const struct watchdog_info imx_sc_wdt_info = {
> +	.identity	= "i.MX SC watchdog timer",
> +	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
> +			  WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT,
> +};
> +
> +static int imx_sc_wdt_probe(struct platform_device *pdev)
> +{
> +	struct watchdog_device *imx_sc_wdd;
> +	int ret;
> +
> +	imx_sc_wdd = devm_kzalloc(&pdev->dev, sizeof(*imx_sc_wdd), GFP_KERNEL);
> +	if (!imx_sc_wdd)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, imx_sc_wdd);
> +
> +	imx_sc_wdd->info = &imx_sc_wdt_info;
> +	imx_sc_wdd->ops = &imx_sc_wdt_ops;
> +	imx_sc_wdd->min_timeout = 1;
> +	imx_sc_wdd->max_timeout = MAX_TIMEOUT;
> +	imx_sc_wdd->parent = &pdev->dev;
> +	imx_sc_wdd->timeout = DEFAULT_TIMEOUT;
> +
> +	ret = watchdog_init_timeout(imx_sc_wdd, timeout, &pdev->dev);
> +	if (ret)
> +		dev_warn(&pdev->dev, "Failed to set timeout value, using default\n");
> +
> +	watchdog_stop_on_reboot(imx_sc_wdd);
> +	watchdog_stop_on_unregister(imx_sc_wdd);
> +
> +	ret = devm_watchdog_register_device(&pdev->dev, imx_sc_wdd);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to register watchdog device\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused imx_sc_wdt_suspend(struct device *dev)
> +{
> +	struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
> +
> +	if (watchdog_active(imx_sc_wdd))
> +		imx_sc_wdt_stop(imx_sc_wdd);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused imx_sc_wdt_resume(struct device *dev)
> +{
> +	struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
> +
> +	if (watchdog_active(imx_sc_wdd))
> +		imx_sc_wdt_start(imx_sc_wdd);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops,
> +			 imx_sc_wdt_suspend, imx_sc_wdt_resume);
> +
> +static struct platform_driver imx_sc_wdt_driver = {
> +	.probe		= imx_sc_wdt_probe,
> +	.driver		= {
> +		.name	= "imx-sc-wdt",
> +		.pm	= &imx_sc_wdt_pm_ops,
> +	},
> +};
> +module_platform_driver(imx_sc_wdt_driver);
> +
> +MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>");
> +MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver");
> +MODULE_LICENSE("GPL v2");
>
Dong Aisheng March 7, 2019, 1:33 p.m. UTC | #2
> From: Anson Huang
> Sent: Wednesday, March 6, 2019 9:06 AM
> 
> i.MX8QXP is an ARMv8 SoC which has a Cortex-M4 system controller inside,
> the system controller is in charge of controlling power, clock and watchdog
> etc..
> 
> This patch adds i.MX system controller watchdog driver support, watchdog
> operation needs to be done in secure EL3 mode via ARM-Trusted-Firmware,
> using SMC call, CPU will trap into ARM-Trusted-Firmware and then it will
> request system controller to do watchdog operation via IPC.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---
> Changes since V6:
> 	- use module_platform_driver() instead of module_init/exit to make code
> simple.
> ---
>  drivers/watchdog/Kconfig      |  14 ++++
>  drivers/watchdog/Makefile     |   1 +
>  drivers/watchdog/imx_sc_wdt.c | 174
> ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 189 insertions(+)
>  create mode 100644 drivers/watchdog/imx_sc_wdt.c
> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index
> 242eea8..33a6523 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -641,6 +641,20 @@ config IMX2_WDT
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called imx2_wdt.
> 
> +config IMX_SC_WDT
> +	tristate "IMX SC Watchdog"
> +	depends on IMX_SCU

As I replied in another mail, it actually does not depend on SCU.
Let's wait for Rob's comment on whether we could move watchdog
Out of SCU node.

> +	depends on HAVE_ARM_SMCCC
> +	select WATCHDOG_CORE
> +	help
> +	  This is the driver for the system controller watchdog
> +	  on the NXP i.MX SoCs with system controller inside.
> +	  If you have one of these processors and wish to have
> +	  watchdog support enabled, say Y, otherwise say N.
> +

Nitpick:
If resend, please also add description here that we need to use
ARM SMC call as your commit message.

Regards
Dong Aisheng

> +	  To compile this driver as a module, choose M here: the
> +	  module will be called imx_sc_wdt.
> +
>  config UX500_WATCHDOG
>  	tristate "ST-Ericsson Ux500 watchdog"
>  	depends on MFD_DB8500_PRCMU
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index
> ba930e4..136d9f0 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -68,6 +68,7 @@ obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
>  obj-$(CONFIG_TS4800_WATCHDOG) += ts4800_wdt.o
>  obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
>  obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
> +obj-$(CONFIG_IMX_SC_WDT) += imx_sc_wdt.o
>  obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
>  obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
>  obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o diff --git
> a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c new file
> mode 100644 index 0000000..ee48709
> --- /dev/null
> +++ b/drivers/watchdog/imx_sc_wdt.c
> @@ -0,0 +1,174 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2018-2019 NXP.
> + */
> +
> +#include <linux/arm-smccc.h>
> +#include <linux/io.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/platform_device.h>
> +#include <linux/reboot.h>
> +#include <linux/watchdog.h>
> +
> +#define DEFAULT_TIMEOUT 60
> +/*
> + * Software timer tick implemented in scfw side, support 10ms to
> +0xffffffff ms
> + * in theory, but for normal case, 1s~128s is enough, you can change
> +this max
> + * value in case it's not enough.
> + */
> +#define MAX_TIMEOUT 128
> +
> +#define IMX_SIP_TIMER			0xC2000002
> +#define IMX_SIP_TIMER_START_WDOG		0x01
> +#define IMX_SIP_TIMER_STOP_WDOG		0x02
> +#define IMX_SIP_TIMER_SET_WDOG_ACT	0x03
> +#define IMX_SIP_TIMER_PING_WDOG		0x04
> +#define IMX_SIP_TIMER_SET_TIMEOUT_WDOG	0x05
> +#define IMX_SIP_TIMER_GET_WDOG_STAT	0x06
> +#define IMX_SIP_TIMER_SET_PRETIME_WDOG	0x07
> +
> +#define SC_TIMER_WDOG_ACTION_PARTITION	0
> +
> +static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout,
> bool,
> +0000); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once
> +started (default="
> +		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +static unsigned int timeout = DEFAULT_TIMEOUT; 
> module_param(timeout,
> +uint, 0000); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds
> +(default="
> +		 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
> +
> +static int imx_sc_wdt_ping(struct watchdog_device *wdog) {
> +	struct arm_smccc_res res;
> +
> +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG,
> +		      0, 0, 0, 0, 0, 0, &res);
> +
> +	return 0;
> +}
> +
> +static int imx_sc_wdt_start(struct watchdog_device *wdog) {
> +	struct arm_smccc_res res;
> +
> +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG,
> +		      0, 0, 0, 0, 0, 0, &res);
> +	if (res.a0)
> +		return -EACCES;
> +
> +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT,
> +		      SC_TIMER_WDOG_ACTION_PARTITION,
> +		      0, 0, 0, 0, 0, &res);
> +	return res.a0 ? -EACCES : 0;
> +}
> +
> +static int imx_sc_wdt_stop(struct watchdog_device *wdog) {
> +	struct arm_smccc_res res;
> +
> +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG,
> +		      0, 0, 0, 0, 0, 0, &res);
> +
> +	return res.a0 ? -EACCES : 0;
> +}
> +
> +static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog,
> +				unsigned int timeout)
> +{
> +	struct arm_smccc_res res;
> +
> +	wdog->timeout = timeout;
> +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG,
> +		      timeout * 1000, 0, 0, 0, 0, 0, &res);
> +
> +	return res.a0 ? -EACCES : 0;
> +}
> +
> +static const struct watchdog_ops imx_sc_wdt_ops = {
> +	.owner = THIS_MODULE,
> +	.start = imx_sc_wdt_start,
> +	.stop  = imx_sc_wdt_stop,
> +	.ping  = imx_sc_wdt_ping,
> +	.set_timeout = imx_sc_wdt_set_timeout, };
> +
> +static const struct watchdog_info imx_sc_wdt_info = {
> +	.identity	= "i.MX SC watchdog timer",
> +	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
> +			  WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT, };
> +
> +static int imx_sc_wdt_probe(struct platform_device *pdev) {
> +	struct watchdog_device *imx_sc_wdd;
> +	int ret;
> +
> +	imx_sc_wdd = devm_kzalloc(&pdev->dev, sizeof(*imx_sc_wdd),
> GFP_KERNEL);
> +	if (!imx_sc_wdd)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, imx_sc_wdd);
> +
> +	imx_sc_wdd->info = &imx_sc_wdt_info;
> +	imx_sc_wdd->ops = &imx_sc_wdt_ops;
> +	imx_sc_wdd->min_timeout = 1;
> +	imx_sc_wdd->max_timeout = MAX_TIMEOUT;
> +	imx_sc_wdd->parent = &pdev->dev;
> +	imx_sc_wdd->timeout = DEFAULT_TIMEOUT;
> +
> +	ret = watchdog_init_timeout(imx_sc_wdd, timeout, &pdev->dev);
> +	if (ret)
> +		dev_warn(&pdev->dev, "Failed to set timeout value, using
> default\n");
> +
> +	watchdog_stop_on_reboot(imx_sc_wdd);
> +	watchdog_stop_on_unregister(imx_sc_wdd);
> +
> +	ret = devm_watchdog_register_device(&pdev->dev, imx_sc_wdd);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to register watchdog device\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused imx_sc_wdt_suspend(struct device *dev) {
> +	struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
> +
> +	if (watchdog_active(imx_sc_wdd))
> +		imx_sc_wdt_stop(imx_sc_wdd);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused imx_sc_wdt_resume(struct device *dev) {
> +	struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
> +
> +	if (watchdog_active(imx_sc_wdd))
> +		imx_sc_wdt_start(imx_sc_wdd);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops,
> +			 imx_sc_wdt_suspend, imx_sc_wdt_resume);
> +
> +static struct platform_driver imx_sc_wdt_driver = {
> +	.probe		= imx_sc_wdt_probe,
> +	.driver		= {
> +		.name	= "imx-sc-wdt",
> +		.pm	= &imx_sc_wdt_pm_ops,
> +	},
> +};
> +module_platform_driver(imx_sc_wdt_driver);
> +
> +MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>");
> +MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.7.4
Anson Huang March 7, 2019, 1:56 p.m. UTC | #3
Best Regards!
Anson Huang

> -----Original Message-----
> From: Aisheng Dong
> Sent: 2019年3月7日 21:33
> To: Anson Huang <anson.huang@nxp.com>; catalin.marinas@arm.com;
> will.deacon@arm.com; shawnguo@kernel.org; s.hauer@pengutronix.de;
> kernel@pengutronix.de; festevam@gmail.com; wim@linux-watchdog.org;
> linux@roeck-us.net; Andy Gross <andy.gross@linaro.org>; heiko@sntech.de;
> horms+renesas@verge.net.au; arnd@arndb.de;
> maxime.ripard@bootlin.com; jagan@amarulasolutions.com;
> bjorn.andersson@linaro.org; enric.balletbo@collabora.com;
> marc.w.gonzalez@free.fr; olof@lixom.net; linux-arm-
> kernel@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
> watchdog@vger.kernel.org
> Cc: dl-linux-imx <linux-imx@nxp.com>
> Subject: RE: [PATCH V7 1/3] watchdog: imx_sc: Add i.MX system controller
> watchdog support
> 
> > From: Anson Huang
> > Sent: Wednesday, March 6, 2019 9:06 AM
> >
> > i.MX8QXP is an ARMv8 SoC which has a Cortex-M4 system controller
> > inside, the system controller is in charge of controlling power, clock
> > and watchdog etc..
> >
> > This patch adds i.MX system controller watchdog driver support,
> > watchdog operation needs to be done in secure EL3 mode via
> > ARM-Trusted-Firmware, using SMC call, CPU will trap into
> > ARM-Trusted-Firmware and then it will request system controller to do
> watchdog operation via IPC.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > ---
> > Changes since V6:
> > 	- use module_platform_driver() instead of module_init/exit to make
> > code simple.
> > ---
> >  drivers/watchdog/Kconfig      |  14 ++++
> >  drivers/watchdog/Makefile     |   1 +
> >  drivers/watchdog/imx_sc_wdt.c | 174
> > ++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 189 insertions(+)
> >  create mode 100644 drivers/watchdog/imx_sc_wdt.c
> >
> > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index
> > 242eea8..33a6523 100644
> > --- a/drivers/watchdog/Kconfig
> > +++ b/drivers/watchdog/Kconfig
> > @@ -641,6 +641,20 @@ config IMX2_WDT
> >  	  To compile this driver as a module, choose M here: the
> >  	  module will be called imx2_wdt.
> >
> > +config IMX_SC_WDT
> > +	tristate "IMX SC Watchdog"
> > +	depends on IMX_SCU
> 
> As I replied in another mail, it actually does not depend on SCU.
> Let's wait for Rob's comment on whether we could move watchdog Out of
> SCU node.

Per previous discussion, the dependency here is to prevent enabling this module
for platform without IMX SCU, although it does NOT use SCU IPC call, but the SMC
call trap into ARM-Trusted-Firmware will eventually call SCU API, so it still depends
on IMX SCU hardware, I am NOT very sure if it is correct to remove it here.

> 
> > +	depends on HAVE_ARM_SMCCC
> > +	select WATCHDOG_CORE
> > +	help
> > +	  This is the driver for the system controller watchdog
> > +	  on the NXP i.MX SoCs with system controller inside.
> > +	  If you have one of these processors and wish to have
> > +	  watchdog support enabled, say Y, otherwise say N.
> > +
> 
> Nitpick:
> If resend, please also add description here that we need to use ARM SMC call
> as your commit message.

Sure, will add it if need resend.

Anson.

> 
> Regards
> Dong Aisheng
> 
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called imx_sc_wdt.
> > +
> >  config UX500_WATCHDOG
> >  	tristate "ST-Ericsson Ux500 watchdog"
> >  	depends on MFD_DB8500_PRCMU
> > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> > index
> > ba930e4..136d9f0 100644
> > --- a/drivers/watchdog/Makefile
> > +++ b/drivers/watchdog/Makefile
> > @@ -68,6 +68,7 @@ obj-$(CONFIG_NUC900_WATCHDOG) +=
> nuc900_wdt.o
> >  obj-$(CONFIG_TS4800_WATCHDOG) += ts4800_wdt.o
> >  obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
> >  obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
> > +obj-$(CONFIG_IMX_SC_WDT) += imx_sc_wdt.o
> >  obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
> >  obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
> >  obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o diff --git
> > a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c new
> > file mode 100644 index 0000000..ee48709
> > --- /dev/null
> > +++ b/drivers/watchdog/imx_sc_wdt.c
> > @@ -0,0 +1,174 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright 2018-2019 NXP.
> > + */
> > +
> > +#include <linux/arm-smccc.h>
> > +#include <linux/io.h>
> > +#include <linux/init.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/moduleparam.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/reboot.h>
> > +#include <linux/watchdog.h>
> > +
> > +#define DEFAULT_TIMEOUT 60
> > +/*
> > + * Software timer tick implemented in scfw side, support 10ms to
> > +0xffffffff ms
> > + * in theory, but for normal case, 1s~128s is enough, you can change
> > +this max
> > + * value in case it's not enough.
> > + */
> > +#define MAX_TIMEOUT 128
> > +
> > +#define IMX_SIP_TIMER			0xC2000002
> > +#define IMX_SIP_TIMER_START_WDOG		0x01
> > +#define IMX_SIP_TIMER_STOP_WDOG		0x02
> > +#define IMX_SIP_TIMER_SET_WDOG_ACT	0x03
> > +#define IMX_SIP_TIMER_PING_WDOG		0x04
> > +#define IMX_SIP_TIMER_SET_TIMEOUT_WDOG	0x05
> > +#define IMX_SIP_TIMER_GET_WDOG_STAT	0x06
> > +#define IMX_SIP_TIMER_SET_PRETIME_WDOG	0x07
> > +
> > +#define SC_TIMER_WDOG_ACTION_PARTITION	0
> > +
> > +static bool nowayout = WATCHDOG_NOWAYOUT;
> module_param(nowayout,
> > bool,
> > +0000); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped
> once
> > +started (default="
> > +		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> > +
> > +static unsigned int timeout = DEFAULT_TIMEOUT;
> > module_param(timeout,
> > +uint, 0000); MODULE_PARM_DESC(timeout, "Watchdog timeout in
> seconds
> > +(default="
> > +		 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
> > +
> > +static int imx_sc_wdt_ping(struct watchdog_device *wdog) {
> > +	struct arm_smccc_res res;
> > +
> > +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG,
> > +		      0, 0, 0, 0, 0, 0, &res);
> > +
> > +	return 0;
> > +}
> > +
> > +static int imx_sc_wdt_start(struct watchdog_device *wdog) {
> > +	struct arm_smccc_res res;
> > +
> > +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG,
> > +		      0, 0, 0, 0, 0, 0, &res);
> > +	if (res.a0)
> > +		return -EACCES;
> > +
> > +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT,
> > +		      SC_TIMER_WDOG_ACTION_PARTITION,
> > +		      0, 0, 0, 0, 0, &res);
> > +	return res.a0 ? -EACCES : 0;
> > +}
> > +
> > +static int imx_sc_wdt_stop(struct watchdog_device *wdog) {
> > +	struct arm_smccc_res res;
> > +
> > +	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG,
> > +		      0, 0, 0, 0, 0, 0, &res);
> > +
> > +	return res.a0 ? -EACCES : 0;
> > +}
> > +
> > +static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog,
> > +				unsigned int timeout)
> > +{
> > +	struct arm_smccc_res res;
> > +
> > +	wdog->timeout = timeout;
> > +	arm_smccc_smc(IMX_SIP_TIMER,
> IMX_SIP_TIMER_SET_TIMEOUT_WDOG,
> > +		      timeout * 1000, 0, 0, 0, 0, 0, &res);
> > +
> > +	return res.a0 ? -EACCES : 0;
> > +}
> > +
> > +static const struct watchdog_ops imx_sc_wdt_ops = {
> > +	.owner = THIS_MODULE,
> > +	.start = imx_sc_wdt_start,
> > +	.stop  = imx_sc_wdt_stop,
> > +	.ping  = imx_sc_wdt_ping,
> > +	.set_timeout = imx_sc_wdt_set_timeout, };
> > +
> > +static const struct watchdog_info imx_sc_wdt_info = {
> > +	.identity	= "i.MX SC watchdog timer",
> > +	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
> > +			  WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT, };
> > +
> > +static int imx_sc_wdt_probe(struct platform_device *pdev) {
> > +	struct watchdog_device *imx_sc_wdd;
> > +	int ret;
> > +
> > +	imx_sc_wdd = devm_kzalloc(&pdev->dev, sizeof(*imx_sc_wdd),
> > GFP_KERNEL);
> > +	if (!imx_sc_wdd)
> > +		return -ENOMEM;
> > +
> > +	platform_set_drvdata(pdev, imx_sc_wdd);
> > +
> > +	imx_sc_wdd->info = &imx_sc_wdt_info;
> > +	imx_sc_wdd->ops = &imx_sc_wdt_ops;
> > +	imx_sc_wdd->min_timeout = 1;
> > +	imx_sc_wdd->max_timeout = MAX_TIMEOUT;
> > +	imx_sc_wdd->parent = &pdev->dev;
> > +	imx_sc_wdd->timeout = DEFAULT_TIMEOUT;
> > +
> > +	ret = watchdog_init_timeout(imx_sc_wdd, timeout, &pdev->dev);
> > +	if (ret)
> > +		dev_warn(&pdev->dev, "Failed to set timeout value, using
> > default\n");
> > +
> > +	watchdog_stop_on_reboot(imx_sc_wdd);
> > +	watchdog_stop_on_unregister(imx_sc_wdd);
> > +
> > +	ret = devm_watchdog_register_device(&pdev->dev, imx_sc_wdd);
> > +	if (ret) {
> > +		dev_err(&pdev->dev, "Failed to register watchdog device\n");
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused imx_sc_wdt_suspend(struct device *dev) {
> > +	struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
> > +
> > +	if (watchdog_active(imx_sc_wdd))
> > +		imx_sc_wdt_stop(imx_sc_wdd);
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused imx_sc_wdt_resume(struct device *dev) {
> > +	struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
> > +
> > +	if (watchdog_active(imx_sc_wdd))
> > +		imx_sc_wdt_start(imx_sc_wdd);
> > +
> > +	return 0;
> > +}
> > +
> > +static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops,
> > +			 imx_sc_wdt_suspend, imx_sc_wdt_resume);
> > +
> > +static struct platform_driver imx_sc_wdt_driver = {
> > +	.probe		= imx_sc_wdt_probe,
> > +	.driver		= {
> > +		.name	= "imx-sc-wdt",
> > +		.pm	= &imx_sc_wdt_pm_ops,
> > +	},
> > +};
> > +module_platform_driver(imx_sc_wdt_driver);
> > +
> > +MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>");
> > +MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.7.4
Dong Aisheng March 7, 2019, 1:59 p.m. UTC | #4
[...]

> > As I replied in another mail, it actually does not depend on SCU.
> > Let's wait for Rob's comment on whether we could move watchdog Out of
> > SCU node.
> 
> Per previous discussion, the dependency here is to prevent enabling this
> module for platform without IMX SCU, although it does NOT use SCU IPC call,
> but the SMC call trap into ARM-Trusted-Firmware will eventually call SCU API,
> so it still depends on IMX SCU hardware, I am NOT very sure if it is correct to
> remove it here.
> 

Then it's ATF depends on SCU, not this virtual watchdog based on ARM SIP, right?

Regards
Dong Aisheng

> >
> > > +	depends on HAVE_ARM_SMCCC
> > > +	select WATCHDOG_CORE
> > > +	help
> > > +	  This is the driver for the system controller watchdog
> > > +	  on the NXP i.MX SoCs with system controller inside.
> > > +	  If you have one of these processors and wish to have
> > > +	  watchdog support enabled, say Y, otherwise say N.
> > > +
Anson Huang March 7, 2019, 2:13 p.m. UTC | #5
Best Regards!
Anson Huang

> -----Original Message-----
> From: Aisheng Dong
> Sent: 2019年3月7日 22:00
> To: Anson Huang <anson.huang@nxp.com>; catalin.marinas@arm.com;
> will.deacon@arm.com; shawnguo@kernel.org; s.hauer@pengutronix.de;
> kernel@pengutronix.de; festevam@gmail.com; wim@linux-watchdog.org;
> linux@roeck-us.net; Andy Gross <andy.gross@linaro.org>; heiko@sntech.de;
> horms+renesas@verge.net.au; arnd@arndb.de;
> maxime.ripard@bootlin.com; jagan@amarulasolutions.com;
> bjorn.andersson@linaro.org; enric.balletbo@collabora.com;
> marc.w.gonzalez@free.fr; olof@lixom.net; linux-arm-
> kernel@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
> watchdog@vger.kernel.org
> Cc: dl-linux-imx <linux-imx@nxp.com>
> Subject: RE: [PATCH V7 1/3] watchdog: imx_sc: Add i.MX system controller
> watchdog support
> 
> [...]
> 
> > > As I replied in another mail, it actually does not depend on SCU.
> > > Let's wait for Rob's comment on whether we could move watchdog Out
> > > of SCU node.
> >
> > Per previous discussion, the dependency here is to prevent enabling
> > this module for platform without IMX SCU, although it does NOT use SCU
> > IPC call, but the SMC call trap into ARM-Trusted-Firmware will
> > eventually call SCU API, so it still depends on IMX SCU hardware, I am
> > NOT very sure if it is correct to remove it here.
> >
> 
> Then it's ATF depends on SCU, not this virtual watchdog based on ARM SIP,
> right?

But we don't have ATF driver in Linux kernel..., I am confused, anyway, if Guenter
agrees, I can remove this dependency here.

Anson.

> 
> Regards
> Dong Aisheng
> 
> > >
> > > > +	depends on HAVE_ARM_SMCCC
> > > > +	select WATCHDOG_CORE
> > > > +	help
> > > > +	  This is the driver for the system controller watchdog
> > > > +	  on the NXP i.MX SoCs with system controller inside.
> > > > +	  If you have one of these processors and wish to have
> > > > +	  watchdog support enabled, say Y, otherwise say N.
> > > > +
Dong Aisheng March 8, 2019, 2:25 a.m. UTC | #6
[...]

> >
> > > > As I replied in another mail, it actually does not depend on SCU.
> > > > Let's wait for Rob's comment on whether we could move watchdog Out
> > > > of SCU node.
> > >
> > > Per previous discussion, the dependency here is to prevent enabling
> > > this module for platform without IMX SCU, although it does NOT use
> > > SCU IPC call, but the SMC call trap into ARM-Trusted-Firmware will
> > > eventually call SCU API, so it still depends on IMX SCU hardware, I
> > > am NOT very sure if it is correct to remove it here.
> > >
> >
> > Then it's ATF depends on SCU, not this virtual watchdog based on ARM
> > SIP, right?
> 
> But we don't have ATF driver in Linux kernel..., I am confused, anyway, if
> Guenter agrees, I can remove this dependency here.
> 

So far the only thing that watchdog depends on SCU driver is that it needs
SCU driver to create a platform devices for it.
We need wait Rob's feedback, if he agree moved the watchdog node
Out of SCU, we can remove this dependency.

Regards
Dong Aisheng

> Anson.
> 
> >
> > Regards
> > Dong Aisheng
> >
> > > >
> > > > > +	depends on HAVE_ARM_SMCCC
> > > > > +	select WATCHDOG_CORE
> > > > > +	help
> > > > > +	  This is the driver for the system controller watchdog
> > > > > +	  on the NXP i.MX SoCs with system controller inside.
> > > > > +	  If you have one of these processors and wish to have
> > > > > +	  watchdog support enabled, say Y, otherwise say N.
> > > > > +

Patch
diff mbox series

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 242eea8..33a6523 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -641,6 +641,20 @@  config IMX2_WDT
 	  To compile this driver as a module, choose M here: the
 	  module will be called imx2_wdt.
 
+config IMX_SC_WDT
+	tristate "IMX SC Watchdog"
+	depends on IMX_SCU
+	depends on HAVE_ARM_SMCCC
+	select WATCHDOG_CORE
+	help
+	  This is the driver for the system controller watchdog
+	  on the NXP i.MX SoCs with system controller inside.
+	  If you have one of these processors and wish to have
+	  watchdog support enabled, say Y, otherwise say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called imx_sc_wdt.
+
 config UX500_WATCHDOG
 	tristate "ST-Ericsson Ux500 watchdog"
 	depends on MFD_DB8500_PRCMU
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index ba930e4..136d9f0 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -68,6 +68,7 @@  obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
 obj-$(CONFIG_TS4800_WATCHDOG) += ts4800_wdt.o
 obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
 obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
+obj-$(CONFIG_IMX_SC_WDT) += imx_sc_wdt.o
 obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
 obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
 obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
diff --git a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c
new file mode 100644
index 0000000..ee48709
--- /dev/null
+++ b/drivers/watchdog/imx_sc_wdt.c
@@ -0,0 +1,174 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2018-2019 NXP.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/watchdog.h>
+
+#define DEFAULT_TIMEOUT 60
+/*
+ * Software timer tick implemented in scfw side, support 10ms to 0xffffffff ms
+ * in theory, but for normal case, 1s~128s is enough, you can change this max
+ * value in case it's not enough.
+ */
+#define MAX_TIMEOUT 128
+
+#define IMX_SIP_TIMER			0xC2000002
+#define IMX_SIP_TIMER_START_WDOG		0x01
+#define IMX_SIP_TIMER_STOP_WDOG		0x02
+#define IMX_SIP_TIMER_SET_WDOG_ACT	0x03
+#define IMX_SIP_TIMER_PING_WDOG		0x04
+#define IMX_SIP_TIMER_SET_TIMEOUT_WDOG	0x05
+#define IMX_SIP_TIMER_GET_WDOG_STAT	0x06
+#define IMX_SIP_TIMER_SET_PRETIME_WDOG	0x07
+
+#define SC_TIMER_WDOG_ACTION_PARTITION	0
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0000);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static unsigned int timeout = DEFAULT_TIMEOUT;
+module_param(timeout, uint, 0000);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
+		 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
+
+static int imx_sc_wdt_ping(struct watchdog_device *wdog)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG,
+		      0, 0, 0, 0, 0, 0, &res);
+
+	return 0;
+}
+
+static int imx_sc_wdt_start(struct watchdog_device *wdog)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG,
+		      0, 0, 0, 0, 0, 0, &res);
+	if (res.a0)
+		return -EACCES;
+
+	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT,
+		      SC_TIMER_WDOG_ACTION_PARTITION,
+		      0, 0, 0, 0, 0, &res);
+	return res.a0 ? -EACCES : 0;
+}
+
+static int imx_sc_wdt_stop(struct watchdog_device *wdog)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG,
+		      0, 0, 0, 0, 0, 0, &res);
+
+	return res.a0 ? -EACCES : 0;
+}
+
+static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog,
+				unsigned int timeout)
+{
+	struct arm_smccc_res res;
+
+	wdog->timeout = timeout;
+	arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG,
+		      timeout * 1000, 0, 0, 0, 0, 0, &res);
+
+	return res.a0 ? -EACCES : 0;
+}
+
+static const struct watchdog_ops imx_sc_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = imx_sc_wdt_start,
+	.stop  = imx_sc_wdt_stop,
+	.ping  = imx_sc_wdt_ping,
+	.set_timeout = imx_sc_wdt_set_timeout,
+};
+
+static const struct watchdog_info imx_sc_wdt_info = {
+	.identity	= "i.MX SC watchdog timer",
+	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
+			  WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT,
+};
+
+static int imx_sc_wdt_probe(struct platform_device *pdev)
+{
+	struct watchdog_device *imx_sc_wdd;
+	int ret;
+
+	imx_sc_wdd = devm_kzalloc(&pdev->dev, sizeof(*imx_sc_wdd), GFP_KERNEL);
+	if (!imx_sc_wdd)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, imx_sc_wdd);
+
+	imx_sc_wdd->info = &imx_sc_wdt_info;
+	imx_sc_wdd->ops = &imx_sc_wdt_ops;
+	imx_sc_wdd->min_timeout = 1;
+	imx_sc_wdd->max_timeout = MAX_TIMEOUT;
+	imx_sc_wdd->parent = &pdev->dev;
+	imx_sc_wdd->timeout = DEFAULT_TIMEOUT;
+
+	ret = watchdog_init_timeout(imx_sc_wdd, timeout, &pdev->dev);
+	if (ret)
+		dev_warn(&pdev->dev, "Failed to set timeout value, using default\n");
+
+	watchdog_stop_on_reboot(imx_sc_wdd);
+	watchdog_stop_on_unregister(imx_sc_wdd);
+
+	ret = devm_watchdog_register_device(&pdev->dev, imx_sc_wdd);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register watchdog device\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused imx_sc_wdt_suspend(struct device *dev)
+{
+	struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
+
+	if (watchdog_active(imx_sc_wdd))
+		imx_sc_wdt_stop(imx_sc_wdd);
+
+	return 0;
+}
+
+static int __maybe_unused imx_sc_wdt_resume(struct device *dev)
+{
+	struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev);
+
+	if (watchdog_active(imx_sc_wdd))
+		imx_sc_wdt_start(imx_sc_wdd);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops,
+			 imx_sc_wdt_suspend, imx_sc_wdt_resume);
+
+static struct platform_driver imx_sc_wdt_driver = {
+	.probe		= imx_sc_wdt_probe,
+	.driver		= {
+		.name	= "imx-sc-wdt",
+		.pm	= &imx_sc_wdt_pm_ops,
+	},
+};
+module_platform_driver(imx_sc_wdt_driver);
+
+MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>");
+MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver");
+MODULE_LICENSE("GPL v2");