[PATCH V9 0/4] Add i.MX8QXP system controller watchdog

[PATCH V9 0/4] Add i.MX8QXP system controller watchdog

[Anson Huang]

i.MX8QXP is an ARMv8 Cortex-A35 SoC with a Cortex-M4 system controller
inside, the system controller manages overall power, clock, secure RTC
and watchdog etc., so Linux kernel running on A35 needs to communicate
with system controller for watchdog operation, this system controller
watchdog will call SMC to trap to EL3 secure world ARM-Trusted-Firmware
and then it will request system controller to do the watchdog operation
via IPC.

Changes since V8:
	- change the timeout value to be from DT instead of from module parameter,
	  and also update the binding doc and dts to add timeout property.

Anson Huang (4):
  dt-bindings: watchdog: add i.MX system controller watchdog
  watchdog: imx_sc: Add i.MX system controller watchdog support
  arm64: defconfig: add support for i.MX system controller watchdog
  arm64: dts: imx8qxp: add system controller watchdog support

 .../bindings/watchdog/fsl-imx-sc-wdt.txt           |  24 +++
 arch/arm64/boot/dts/freescale/imx8qxp.dtsi         |   5 +
 arch/arm64/configs/defconfig                       |   1 +
 drivers/watchdog/Kconfig                           |  16 ++
 drivers/watchdog/Makefile                          |   1 +
 drivers/watchdog/imx_sc_wdt.c                      | 177 +++++++++++++++++++++
 6 files changed, 224 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/fsl-imx-sc-wdt.txt
 create mode 100644 drivers/watchdog/imx_sc_wdt.c

-- 
2.7.4

[PATCH V9 1/4] dt-bindings: watchdog: add i.MX system controller watchdog

[Anson Huang]

Add i.MX system controller watchdog binding doc.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
Changes since V8:
	- add optional property "timeout-sec" according to driver change.
---
 .../bindings/watchdog/fsl-imx-sc-wdt.txt           | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/fsl-imx-sc-wdt.txt

diff --git a/Documentation/devicetree/bindings/watchdog/fsl-imx-sc-wdt.txt b/Documentation/devicetree/bindings/watchdog/fsl-imx-sc-wdt.txt
new file mode 100644
index 0000000..02b87e9
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/fsl-imx-sc-wdt.txt
@@ -0,0 +1,24 @@
+* Freescale i.MX System Controller Watchdog
+
+i.MX system controller watchdog is for i.MX SoCs with system controller inside,
+the watchdog is managed by system controller, users can ONLY communicate with
+system controller from secure mode for watchdog operations, so Linux i.MX system
+controller watchdog driver will call ARM SMC API and trap into ARM-Trusted-Firmware
+for watchdog operations, ARM-Trusted-Firmware is running at secure EL3 mode and
+it will request system controller to execute the watchdog operation passed from
+Linux kernel.
+
+Required properties:
+- compatible:	Should be :
+		"fsl,imx8qxp-sc-wdt"
+		followed by "fsl,imx-sc-wdt";
+
+Optional properties:
+- timeout-sec : Contains the watchdog timeout in seconds.
+
+Examples:
+
+watchdog {
+	compatible = "fsl,imx8qxp-sc-wdt", "fsl,imx-sc-wdt";
+	timeout-sec = <60>;
+};
-- 
2.7.4

[PATCH V9 2/4] 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>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
---
Changes since V8:
	- change timeout value to be from DT instead of from module parameter.
---
 drivers/watchdog/Kconfig      |  16 ++++
 drivers/watchdog/Makefile     |   1 +
 drivers/watchdog/imx_sc_wdt.c | 177 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 194 insertions(+)
 create mode 100644 drivers/watchdog/imx_sc_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 242eea8..44a3158 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -641,6 +641,22 @@ 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 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, the
+	  watchdog driver will call ARM SMC API and trap into
+	  ARM-Trusted-Firmware for operations, ARM-Trusted-Firmware
+	  will request system controller to execute the operations.
+	  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..86c2722
--- /dev/null
+++ b/drivers/watchdog/imx_sc_wdt.c
@@ -0,0 +1,177 @@
+// 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/of.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 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, 0, &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 const struct of_device_id imx_sc_wdt_dt_ids[] = {
+	{ .compatible = "fsl,imx-sc-wdt", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx_sc_wdt_dt_ids);
+
+static struct platform_driver imx_sc_wdt_driver = {
+	.probe		= imx_sc_wdt_probe,
+	.driver		= {
+		.name	= "imx-sc-wdt",
+		.of_match_table = imx_sc_wdt_dt_ids,
+		.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

[PATCH V9 3/4] 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 f575401..b4000aa 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -429,6 +429,7 @@ 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 V9 4/4] arm64: dts: imx8qxp: add system controller watchdog support

[Anson Huang]

Add i.MX8QXP system controller watchdog support.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
Changes since V8:
	- add timeout property.
---
 arch/arm64/boot/dts/freescale/imx8qxp.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8qxp.dtsi b/arch/arm64/boot/dts/freescale/imx8qxp.dtsi
index 019abce..ca4541e 100644
--- a/arch/arm64/boot/dts/freescale/imx8qxp.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8qxp.dtsi
@@ -473,4 +473,9 @@
 			power-domains = <&pd IMX_SC_R_GPIO_7>;
 		};
 	};
+
+	watchdog {
+		compatible = "fsl,imx8qxp-sc-wdt", "fsl,imx-sc-wdt";
+		timeout-sec = <60>;
+	};
 };
-- 
2.7.4

Re: [PATCH V9 1/4] dt-bindings: watchdog: add i.MX system controller watchdog

[Rob Herring]

On Thu, Mar 21, 2019 at 02:26:38AM +0000, Anson Huang wrote:
> Add i.MX system controller watchdog binding doc.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---
> Changes since V8:
> 	- add optional property "timeout-sec" according to driver change.
> ---
>  .../bindings/watchdog/fsl-imx-sc-wdt.txt           | 24 ++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/watchdog/fsl-imx-sc-wdt.txt

I still think what's in ATF should be discoverable, but:

Acked-by: Rob Herring <robh@kernel.org>

RE: [PATCH V9 1/4] dt-bindings: watchdog: add i.MX system controller watchdog

[Anson Huang]

Hi, Guenter/Shawn
	Since DT has been acked, would you pick up this patch series if no additional comments?

Best Regards!
Anson Huang

> -----Original Message-----
> From: Rob Herring [mailto:robh@kernel.org]
> Sent: 2019年3月26日 4:37
> To: Anson Huang <anson.huang@nxp.com>
> Cc: wim@linux-watchdog.org; linux@roeck-us.net; mark.rutland@arm.com;
> shawnguo@kernel.org; s.hauer@pengutronix.de; kernel@pengutronix.de;
> festevam@gmail.com; catalin.marinas@arm.com; will.deacon@arm.com;
> Aisheng Dong <aisheng.dong@nxp.com>; Daniel Baluta
> <daniel.baluta@nxp.com>; horms+renesas@verge.net.au; heiko@sntech.de;
> maxime.ripard@bootlin.com; Andy Gross <andy.gross@linaro.org>;
> jagan@amarulasolutions.com; bjorn.andersson@linaro.org;
> enric.balletbo@collabora.com; ezequiel@collabora.com;
> stefan.wahren@i2se.com; marc.w.gonzalez@free.fr; olof@lixom.net; linux-
> watchdog@vger.kernel.org; devicetree@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; linux-kernel@vger.kernel.org; dl-linux-imx
> <linux-imx@nxp.com>
> Subject: Re: [PATCH V9 1/4] dt-bindings: watchdog: add i.MX system
> controller watchdog
> 
> On Thu, Mar 21, 2019 at 02:26:38AM +0000, Anson Huang wrote:
> > Add i.MX system controller watchdog binding doc.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > ---
> > Changes since V8:
> > 	- add optional property "timeout-sec" according to driver change.
> > ---
> >  .../bindings/watchdog/fsl-imx-sc-wdt.txt           | 24
> ++++++++++++++++++++++
> >  1 file changed, 24 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/watchdog/fsl-
> imx-sc-wdt.txt
> 
> I still think what's in ATF should be discoverable, but:
> 
> Acked-by: Rob Herring <robh@kernel.org>

Re: [PATCH V9 1/4] dt-bindings: watchdog: add i.MX system controller watchdog

[Guenter Roeck]

On Fri, Mar 29, 2019 at 07:44:21AM +0000, Anson Huang wrote:
> Hi, Guenter/Shawn
> 	Since DT has been acked, would you pick up this patch series if no additional comments?
> 

I added patch 1 and 2 of the series to my watchdog-next tree.
Wim usually picks it up from there.

Guenter

> Best Regards!
> Anson Huang
> 
> > -----Original Message-----
> > From: Rob Herring [mailto:robh@kernel.org]
> > Sent: 2019年3月26日 4:37
> > To: Anson Huang <anson.huang@nxp.com>
> > Cc: wim@linux-watchdog.org; linux@roeck-us.net; mark.rutland@arm.com;
> > shawnguo@kernel.org; s.hauer@pengutronix.de; kernel@pengutronix.de;
> > festevam@gmail.com; catalin.marinas@arm.com; will.deacon@arm.com;
> > Aisheng Dong <aisheng.dong@nxp.com>; Daniel Baluta
> > <daniel.baluta@nxp.com>; horms+renesas@verge.net.au; heiko@sntech.de;
> > maxime.ripard@bootlin.com; Andy Gross <andy.gross@linaro.org>;
> > jagan@amarulasolutions.com; bjorn.andersson@linaro.org;
> > enric.balletbo@collabora.com; ezequiel@collabora.com;
> > stefan.wahren@i2se.com; marc.w.gonzalez@free.fr; olof@lixom.net; linux-
> > watchdog@vger.kernel.org; devicetree@vger.kernel.org; linux-arm-
> > kernel@lists.infradead.org; linux-kernel@vger.kernel.org; dl-linux-imx
> > <linux-imx@nxp.com>
> > Subject: Re: [PATCH V9 1/4] dt-bindings: watchdog: add i.MX system
> > controller watchdog
> > 
> > On Thu, Mar 21, 2019 at 02:26:38AM +0000, Anson Huang wrote:
> > > Add i.MX system controller watchdog binding doc.
> > >
> > > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > > ---
> > > Changes since V8:
> > > 	- add optional property "timeout-sec" according to driver change.
> > > ---
> > >  .../bindings/watchdog/fsl-imx-sc-wdt.txt           | 24
> > ++++++++++++++++++++++
> > >  1 file changed, 24 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/watchdog/fsl-
> > imx-sc-wdt.txt
> > 
> > I still think what's in ATF should be discoverable, but:
> > 
> > Acked-by: Rob Herring <robh@kernel.org>

Re: [PATCH V9 1/4] dt-bindings: watchdog: add i.MX system controller watchdog

[Shawn Guo]

On Fri, Mar 29, 2019 at 07:44:21AM +0000, Anson Huang wrote:
> Hi, Guenter/Shawn
> 	Since DT has been acked, would you pick up this patch series if no additional comments?
> 

Applied patch #3 and #4, thanks.