[PATCH RESEND V6 1/3] watchdog: imx_sc: Add i.MX system controller watchdog support

[PATCH RESEND V6 1/3] watchdog: imx_sc: Add i.MX system controller watchdog support

[Anson Huang]

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 V5:
	- move the watchdog platform device register to SCU driver probe, be child device of
	  SCU device.
---
 drivers/watchdog/Kconfig      |  14 ++++
 drivers/watchdog/Makefile     |   1 +
 drivers/watchdog/imx_sc_wdt.c | 185 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 200 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..2645203
--- /dev/null
+++ b/drivers/watchdog/imx_sc_wdt.c
@@ -0,0 +1,185 @@
+// 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,
+	},
+};
+
+static int __init imx_sc_wdt_init(void)
+{
+	return platform_driver_register(&imx_sc_wdt_driver);
+}
+module_init(imx_sc_wdt_init);
+
+static void __exit imx_sc_wdt_exit(void)
+{
+	platform_driver_unregister(&imx_sc_wdt_driver);
+}
+module_exit(imx_sc_wdt_exit);
+
+MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>");
+MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

[PATCH RESEND V6 2/3] arm64: defconfig: add support for i.MX system controller watchdog

[Anson Huang]

Enable CONFIG_IMX_SC_WDT as module to support i.MX system
controller watchdog.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
No changes.
---
 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 2d9c390..690f4ba 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -427,6 +427,7 @@ CONFIG_WATCHDOG=y
 CONFIG_ARM_SP805_WATCHDOG=y
 CONFIG_S3C2410_WATCHDOG=y
 CONFIG_IMX2_WDT=y
+CONFIG_IMX_SC_WDT=m
 CONFIG_MESON_GXBB_WATCHDOG=m
 CONFIG_MESON_WATCHDOG=m
 CONFIG_RENESAS_WDT=y
-- 
2.7.4

[PATCH RESEND V6 3/3] firmware: imx: imx-scu: register build-in child devices

[Anson Huang]

For some devices which are controlled by system controller,
they are NOT present in device tree since no hardware info
needed, just register these devices as children of SCU device.
This patch registers i.MX system controller watchdog platform
device as child device of SCU.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
New added patch, it is to register SCU build-in child devices what are NOT in device tree.
---
 drivers/firmware/imx/imx-scu.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/firmware/imx/imx-scu.c b/drivers/firmware/imx/imx-scu.c
index 2bb1a19..df75ead 100644
--- a/drivers/firmware/imx/imx-scu.c
+++ b/drivers/firmware/imx/imx-scu.c
@@ -196,6 +196,7 @@ EXPORT_SYMBOL(imx_scu_call_rpc);
 
 static int imx_scu_probe(struct platform_device *pdev)
 {
+	struct platform_device *child_pdev;
 	struct device *dev = &pdev->dev;
 	struct imx_sc_ipc *sc_ipc;
 	struct imx_sc_chan *sc_chan;
@@ -248,6 +249,13 @@ static int imx_scu_probe(struct platform_device *pdev)
 
 	dev_info(dev, "NXP i.MX SCU Initialized\n");
 
+	/* register SCU child devices which are NOT in device tree */
+	child_pdev = platform_device_register_data(dev, "imx-sc-wdt",
+				PLATFORM_DEVID_NONE, NULL, 0);
+	if (IS_ERR(child_pdev))
+		dev_warn(dev, "failed to register scu watchdog device %ld!\n",
+			 PTR_ERR(child_pdev));
+
 	return devm_of_platform_populate(dev);
 }
 
-- 
2.7.4

Re: [PATCH RESEND V6 1/3] watchdog: imx_sc: Add i.MX system controller watchdog support

[Guenter Roeck]

On 3/4/19 7:37 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>
> ---
> Changes since V5:
> 	- move the watchdog platform device register to SCU driver probe, be child device of
> 	  SCU device.
> ---
>   drivers/watchdog/Kconfig      |  14 ++++
>   drivers/watchdog/Makefile     |   1 +
>   drivers/watchdog/imx_sc_wdt.c | 185 ++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 200 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..2645203
> --- /dev/null
> +++ b/drivers/watchdog/imx_sc_wdt.c
> @@ -0,0 +1,185 @@
> +// 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,
> +	},
> +};
> +
> +static int __init imx_sc_wdt_init(void)
> +{
> +	return platform_driver_register(&imx_sc_wdt_driver);
> +}
> +module_init(imx_sc_wdt_init);
> +
> +static void __exit imx_sc_wdt_exit(void)
> +{
> +	platform_driver_unregister(&imx_sc_wdt_driver);
> +}
> +module_exit(imx_sc_wdt_exit);
> +

module_platform_driver ?

Guenter

> +MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>");
> +MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver");
> +MODULE_LICENSE("GPL v2");
> 

RE: [PATCH RESEND V6 1/3] watchdog: imx_sc: Add i.MX system controller watchdog support

[Anson Huang]

Hi, Guenter

Best Regards!
Anson Huang

> -----Original Message-----
> From: Guenter Roeck [mailto:groeck7@gmail.com] On Behalf Of Guenter
> Roeck
> Sent: 2019年3月5日 22:07
> 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;
> Andy Gross <andy.gross@linaro.org>; heiko@sntech.de; arnd@arndb.de;
> horms+renesas@verge.net.au; bjorn.andersson@linaro.org;
> jagan@amarulasolutions.com; enric.balletbo@collabora.com;
> marc.w.gonzalez@free.fr; olof@lixom.net; Aisheng Dong
> <aisheng.dong@nxp.com>; 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 RESEND V6 1/3] watchdog: imx_sc: Add i.MX system
> controller watchdog support
> 
> On 3/4/19 7:37 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>
> > ---
> > Changes since V5:
> > 	- move the watchdog platform device register to SCU driver probe, be
> child device of
> > 	  SCU device.
> > ---
> >   drivers/watchdog/Kconfig      |  14 ++++
> >   drivers/watchdog/Makefile     |   1 +
> >   drivers/watchdog/imx_sc_wdt.c | 185
> ++++++++++++++++++++++++++++++++++++++++++
> >   3 files changed, 200 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..2645203
> > --- /dev/null
> > +++ b/drivers/watchdog/imx_sc_wdt.c
> > @@ -0,0 +1,185 @@
> > +// 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,
> > +	},
> > +};
> > +
> > +static int __init imx_sc_wdt_init(void) {
> > +	return platform_driver_register(&imx_sc_wdt_driver);
> > +}
> > +module_init(imx_sc_wdt_init);
> > +
> > +static void __exit imx_sc_wdt_exit(void) {
> > +	platform_driver_unregister(&imx_sc_wdt_driver);
> > +}
> > +module_exit(imx_sc_wdt_exit);
> > +
> 
> module_platform_driver ?

Ah, yes, I forgot it can be as simple as previous patch if we ONLY need
to register platform driver. Thanks for reminder, will fix it in V7.

Anson.

> 
> Guenter
> 
> > +MODULE_AUTHOR("Robin Gong <yibin.gong@nxp.com>");
> > +MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver");
> > +MODULE_LICENSE("GPL v2");
> >