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* [PATCH V2 1/4] dt-bindings: watchdog: Add i.MX7ULP bindings
@ 2019-08-12  8:53 Anson.Huang
  2019-08-12  8:53 ` [PATCH V2 2/4] watchdog: Add i.MX7ULP watchdog support Anson.Huang
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Anson.Huang @ 2019-08-12  8:53 UTC (permalink / raw)
  To: wim, linux, robh+dt, mark.rutland, shawnguo, s.hauer, kernel,
	festevam, linux, otavio, leonard.crestez, u.kleine-koenig,
	schnitzeltony, jan.tuerk, linux-watchdog, devicetree,
	linux-arm-kernel, linux-kernel
  Cc: Linux-imx

From: Anson Huang <Anson.Huang@nxp.com>

Add the watchdog bindings for Freescale i.MX7ULP.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
No changes.
---
 .../bindings/watchdog/fsl-imx7ulp-wdt.txt          | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/fsl-imx7ulp-wdt.txt

diff --git a/Documentation/devicetree/bindings/watchdog/fsl-imx7ulp-wdt.txt b/Documentation/devicetree/bindings/watchdog/fsl-imx7ulp-wdt.txt
new file mode 100644
index 0000000..d83fc5c
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/fsl-imx7ulp-wdt.txt
@@ -0,0 +1,22 @@
+* Freescale i.MX7ULP Watchdog Timer (WDT) Controller
+
+Required properties:
+- compatible : Should be "fsl,imx7ulp-wdt"
+- reg : Should contain WDT registers location and length
+- interrupts : Should contain WDT interrupt
+- clocks: Should contain a phandle pointing to the gated peripheral clock.
+
+Optional properties:
+- timeout-sec : Contains the watchdog timeout in seconds
+
+Examples:
+
+wdog1: wdog@403d0000 {
+	compatible = "fsl,imx7ulp-wdt";
+	reg = <0x403d0000 0x10000>;
+	interrupts = <GIC_SPI 55 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&pcc2 IMX7ULP_CLK_WDG1>;
+	assigned-clocks = <&pcc2 IMX7ULP_CLK_WDG1>;
+	assigned-clocks-parents = <&scg1 IMX7ULP_CLK_FIRC_BUS_CLK>;
+	timeout-sec = <40>;
+};
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [PATCH V2 2/4] watchdog: Add i.MX7ULP watchdog support
  2019-08-12  8:53 [PATCH V2 1/4] dt-bindings: watchdog: Add i.MX7ULP bindings Anson.Huang
@ 2019-08-12  8:53 ` Anson.Huang
  2019-08-20 15:31   ` Guenter Roeck
  2019-08-12  8:53 ` [PATCH V2 3/4] ARM: imx_v6_v7_defconfig: Enable CONFIG_IMX7ULP_WDT by default Anson.Huang
  2019-08-12  8:53 ` [PATCH V2 4/4] ARM: dts: imx7ulp: Add wdog1 node Anson.Huang
  2 siblings, 1 reply; 7+ messages in thread
From: Anson.Huang @ 2019-08-12  8:53 UTC (permalink / raw)
  To: wim, linux, robh+dt, mark.rutland, shawnguo, s.hauer, kernel,
	festevam, linux, otavio, leonard.crestez, u.kleine-koenig,
	schnitzeltony, jan.tuerk, linux-watchdog, devicetree,
	linux-arm-kernel, linux-kernel
  Cc: Linux-imx

From: Anson Huang <Anson.Huang@nxp.com>

The i.MX7ULP Watchdog Timer (WDOG) module is an independent timer
that is available for system use.
It provides a safety feature to ensure that software is executing
as planned and that the CPU is not stuck in an infinite loop or
executing unintended code. If the WDOG module is not serviced
(refreshed) within a certain period, it resets the MCU.

Add driver support for i.MX7ULP watchdog.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
Changes since V1:
	- Add clock operation;
	- Remove unneccsary error message when registering watchdog device failed;
	- Use BIT() instead of hard code;
---
 drivers/watchdog/Kconfig       |  13 +++
 drivers/watchdog/Makefile      |   1 +
 drivers/watchdog/imx7ulp_wdt.c | 244 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 258 insertions(+)
 create mode 100644 drivers/watchdog/imx7ulp_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 8188963..0884e53 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -740,6 +740,19 @@ config IMX_SC_WDT
 	  To compile this driver as a module, choose M here: the
 	  module will be called imx_sc_wdt.
 
+config IMX7ULP_WDT
+	tristate "IMX7ULP Watchdog"
+	depends on ARCH_MXC || COMPILE_TEST
+	select WATCHDOG_CORE
+	help
+	  This is the driver for the hardware watchdog on the Freescale
+	  IMX7ULP and later processors. 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 imx7ulp_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 7caa920..7d32537 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -69,6 +69,7 @@ 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-$(CONFIG_IMX7ULP_WDT) += imx7ulp_wdt.o
 obj-$(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/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c
new file mode 100644
index 0000000..c20fba4
--- /dev/null
+++ b/drivers/watchdog/imx7ulp_wdt.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP.
+ */
+
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/watchdog.h>
+
+#define WDOG_CS			0x0
+#define WDOG_CS_CMD32EN		BIT(13)
+#define WDOG_CS_ULK		BIT(11)
+#define WDOG_CS_RCS		BIT(10)
+#define WDOG_CS_EN		BIT(7)
+#define WDOG_CS_UPDATE		BIT(5)
+
+#define WDOG_CNT	0x4
+#define WDOG_TOVAL	0x8
+
+#define REFRESH_SEQ0	0xA602
+#define REFRESH_SEQ1	0xB480
+#define REFRESH		((REFRESH_SEQ1 << 16) | REFRESH_SEQ0)
+
+#define UNLOCK_SEQ0	0xC520
+#define UNLOCK_SEQ1	0xD928
+#define UNLOCK		((UNLOCK_SEQ1 << 16) | UNLOCK_SEQ0)
+
+#define DEFAULT_TIMEOUT	60
+#define MAX_TIMEOUT	128
+
+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) ")");
+
+struct imx7ulp_wdt_device {
+	struct notifier_block restart_handler;
+	struct watchdog_device wdd;
+	void __iomem *base;
+	struct clk *clk;
+	int rate;
+};
+
+static inline void imx7ulp_wdt_enable(void __iomem *base, bool enable)
+{
+	u32 val = readl(base + WDOG_CS);
+
+	writel(UNLOCK, base + WDOG_CNT);
+	if (enable)
+		writel(val | WDOG_CS_EN, base + WDOG_CS);
+	else
+		writel(val & ~WDOG_CS_EN, base + WDOG_CS);
+}
+
+static inline bool imx7ulp_wdt_is_enabled(void __iomem *base)
+{
+	u32 val = readl(base + WDOG_CS);
+
+	return val & WDOG_CS_EN;
+}
+
+static int imx7ulp_wdt_ping(struct watchdog_device *wdog)
+{
+	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
+
+	writel(REFRESH, wdt->base + WDOG_CNT);
+
+	return 0;
+}
+
+static int imx7ulp_wdt_start(struct watchdog_device *wdog)
+{
+	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
+
+	imx7ulp_wdt_enable(wdt->base, true);
+
+	return 0;
+}
+
+static int imx7ulp_wdt_stop(struct watchdog_device *wdog)
+{
+	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
+
+	imx7ulp_wdt_enable(wdt->base, false);
+
+	return 0;
+}
+
+static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog,
+				   unsigned int timeout)
+{
+	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
+	u32 val = wdt->rate * timeout;
+
+	writel(UNLOCK, wdt->base + WDOG_CNT);
+	writel(val, wdt->base + WDOG_TOVAL);
+
+	wdog->timeout = timeout;
+
+	return 0;
+}
+
+static const struct watchdog_ops imx7ulp_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = imx7ulp_wdt_start,
+	.stop  = imx7ulp_wdt_stop,
+	.ping  = imx7ulp_wdt_ping,
+	.set_timeout = imx7ulp_wdt_set_timeout,
+};
+
+static const struct watchdog_info imx7ulp_wdt_info = {
+	.identity = "i.MX7ULP watchdog timer",
+	.options  = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
+		    WDIOF_MAGICCLOSE,
+};
+
+static inline void imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
+{
+	u32 val;
+
+	/* unlock the wdog for reconfiguration */
+	writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
+	writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
+
+	/* set an initial timeout value in TOVAL */
+	writel(timeout, base + WDOG_TOVAL);
+	/* enable 32bit command sequence and reconfigure */
+	val = BIT(13) | BIT(8) | BIT(5);
+	writel(val, base + WDOG_CS);
+}
+
+static int imx7ulp_wdt_probe(struct platform_device *pdev)
+{
+	struct imx7ulp_wdt_device *imx7ulp_wdt;
+	struct device *dev = &pdev->dev;
+	struct watchdog_device *wdog;
+	int ret;
+
+	imx7ulp_wdt = devm_kzalloc(dev, sizeof(*imx7ulp_wdt), GFP_KERNEL);
+	if (!imx7ulp_wdt)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, imx7ulp_wdt);
+
+	imx7ulp_wdt->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(imx7ulp_wdt->base))
+		return PTR_ERR(imx7ulp_wdt->base);
+
+	imx7ulp_wdt->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(imx7ulp_wdt->clk)) {
+		dev_err(dev, "Failed to get watchdog clock\n");
+		return PTR_ERR(imx7ulp_wdt->clk);
+	}
+
+	ret = clk_prepare_enable(imx7ulp_wdt->clk);
+	if (ret)
+		return ret;
+
+	imx7ulp_wdt->rate = 1000;
+	wdog = &imx7ulp_wdt->wdd;
+	wdog->info = &imx7ulp_wdt_info;
+	wdog->ops = &imx7ulp_wdt_ops;
+	wdog->min_timeout = 1;
+	wdog->max_timeout = MAX_TIMEOUT;
+	wdog->parent = dev;
+	wdog->timeout = DEFAULT_TIMEOUT;
+
+	watchdog_init_timeout(wdog, 0, dev);
+	watchdog_stop_on_reboot(wdog);
+	watchdog_stop_on_unregister(wdog);
+	watchdog_set_drvdata(wdog, imx7ulp_wdt);
+	imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * imx7ulp_wdt->rate);
+
+	ret = devm_watchdog_register_device(dev, wdog);
+	if (ret)
+		goto disable_clk;
+
+	return 0;
+
+disable_clk:
+	clk_disable_unprepare(imx7ulp_wdt->clk);
+
+	return ret;
+}
+
+static int __maybe_unused imx7ulp_wdt_suspend(struct device *dev)
+{
+	struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev);
+
+	if (watchdog_active(&imx7ulp_wdt->wdd))
+		imx7ulp_wdt_stop(&imx7ulp_wdt->wdd);
+
+	clk_disable_unprepare(imx7ulp_wdt->clk);
+
+	return 0;
+}
+
+static int __maybe_unused imx7ulp_wdt_resume(struct device *dev)
+{
+	struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev);
+	u32 timeout = imx7ulp_wdt->wdd.timeout * imx7ulp_wdt->rate;
+	int ret;
+
+	ret = clk_prepare_enable(imx7ulp_wdt->clk);
+	if (ret)
+		return ret;
+
+	if (imx7ulp_wdt_is_enabled(imx7ulp_wdt->base))
+		imx7ulp_wdt_init(imx7ulp_wdt->base, timeout);
+
+	if (watchdog_active(&imx7ulp_wdt->wdd))
+		imx7ulp_wdt_start(&imx7ulp_wdt->wdd);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(imx7ulp_wdt_pm_ops, imx7ulp_wdt_suspend,
+			 imx7ulp_wdt_resume);
+
+static const struct of_device_id imx7ulp_wdt_dt_ids[] = {
+	{ .compatible = "fsl,imx7ulp-wdt", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx7ulp_wdt_dt_ids);
+
+static struct platform_driver imx7ulp_wdt_driver = {
+	.probe		= imx7ulp_wdt_probe,
+	.driver		= {
+		.name	= "imx7ulp-wdt",
+		.pm	= &imx7ulp_wdt_pm_ops,
+		.of_match_table = imx7ulp_wdt_dt_ids,
+	},
+};
+module_platform_driver(imx7ulp_wdt_driver);
+
+MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
+MODULE_DESCRIPTION("Freescale i.MX7ULP watchdog driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [PATCH V2 3/4] ARM: imx_v6_v7_defconfig: Enable CONFIG_IMX7ULP_WDT by default
  2019-08-12  8:53 [PATCH V2 1/4] dt-bindings: watchdog: Add i.MX7ULP bindings Anson.Huang
  2019-08-12  8:53 ` [PATCH V2 2/4] watchdog: Add i.MX7ULP watchdog support Anson.Huang
@ 2019-08-12  8:53 ` Anson.Huang
  2019-08-12  8:53 ` [PATCH V2 4/4] ARM: dts: imx7ulp: Add wdog1 node Anson.Huang
  2 siblings, 0 replies; 7+ messages in thread
From: Anson.Huang @ 2019-08-12  8:53 UTC (permalink / raw)
  To: wim, linux, robh+dt, mark.rutland, shawnguo, s.hauer, kernel,
	festevam, linux, otavio, leonard.crestez, u.kleine-koenig,
	schnitzeltony, jan.tuerk, linux-watchdog, devicetree,
	linux-arm-kernel, linux-kernel
  Cc: Linux-imx

From: Anson Huang <Anson.Huang@nxp.com>

Select CONFIG_IMX7ULP_WDT by default to support i.MX7ULP watchdog.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
No changes.
---
 arch/arm/configs/imx_v6_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/imx_v6_v7_defconfig b/arch/arm/configs/imx_v6_v7_defconfig
index bd2e2f5..f69075b 100644
--- a/arch/arm/configs/imx_v6_v7_defconfig
+++ b/arch/arm/configs/imx_v6_v7_defconfig
@@ -235,6 +235,7 @@ CONFIG_DA9062_WATCHDOG=y
 CONFIG_DA9063_WATCHDOG=m
 CONFIG_RN5T618_WATCHDOG=y
 CONFIG_IMX2_WDT=y
+CONFIG_IMX7ULP_WDT=y
 CONFIG_MFD_DA9052_I2C=y
 CONFIG_MFD_DA9062=y
 CONFIG_MFD_DA9063=y
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [PATCH V2 4/4] ARM: dts: imx7ulp: Add wdog1 node
  2019-08-12  8:53 [PATCH V2 1/4] dt-bindings: watchdog: Add i.MX7ULP bindings Anson.Huang
  2019-08-12  8:53 ` [PATCH V2 2/4] watchdog: Add i.MX7ULP watchdog support Anson.Huang
  2019-08-12  8:53 ` [PATCH V2 3/4] ARM: imx_v6_v7_defconfig: Enable CONFIG_IMX7ULP_WDT by default Anson.Huang
@ 2019-08-12  8:53 ` Anson.Huang
  2 siblings, 0 replies; 7+ messages in thread
From: Anson.Huang @ 2019-08-12  8:53 UTC (permalink / raw)
  To: wim, linux, robh+dt, mark.rutland, shawnguo, s.hauer, kernel,
	festevam, linux, otavio, leonard.crestez, u.kleine-koenig,
	schnitzeltony, jan.tuerk, linux-watchdog, devicetree,
	linux-arm-kernel, linux-kernel
  Cc: Linux-imx

From: Anson Huang <Anson.Huang@nxp.com>

Add wdog1 node to support watchdog driver.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
No changes.
---
 arch/arm/boot/dts/imx7ulp.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/imx7ulp.dtsi b/arch/arm/boot/dts/imx7ulp.dtsi
index 6859a3a..1fdb5a35 100644
--- a/arch/arm/boot/dts/imx7ulp.dtsi
+++ b/arch/arm/boot/dts/imx7ulp.dtsi
@@ -264,6 +264,16 @@
 			#clock-cells = <1>;
 		};
 
+		wdog1: wdog@403d0000 {
+			compatible = "fsl,imx7ulp-wdt";
+			reg = <0x403d0000 0x10000>;
+			interrupts = <GIC_SPI 55 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&pcc2 IMX7ULP_CLK_WDG1>;
+			assigned-clocks = <&pcc2 IMX7ULP_CLK_WDG1>;
+			assigned-clocks-parents = <&scg1 IMX7ULP_CLK_FIRC_BUS_CLK>;
+			timeout-sec = <40>;
+		};
+
 		pcc2: clock-controller@403f0000 {
 			compatible = "fsl,imx7ulp-pcc2";
 			reg = <0x403f0000 0x10000>;
-- 
2.7.4


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH V2 2/4] watchdog: Add i.MX7ULP watchdog support
  2019-08-12  8:53 ` [PATCH V2 2/4] watchdog: Add i.MX7ULP watchdog support Anson.Huang
@ 2019-08-20 15:31   ` Guenter Roeck
  2019-08-20 15:48     ` Guenter Roeck
  0 siblings, 1 reply; 7+ messages in thread
From: Guenter Roeck @ 2019-08-20 15:31 UTC (permalink / raw)
  To: Anson.Huang
  Cc: wim, robh+dt, mark.rutland, shawnguo, s.hauer, kernel, festevam,
	linux, otavio, leonard.crestez, u.kleine-koenig, schnitzeltony,
	jan.tuerk, linux-watchdog, devicetree, linux-arm-kernel,
	linux-kernel, Linux-imx

On Mon, Aug 12, 2019 at 04:53:19PM +0800, Anson.Huang@nxp.com wrote:
> From: Anson Huang <Anson.Huang@nxp.com>
> 
> The i.MX7ULP Watchdog Timer (WDOG) module is an independent timer
> that is available for system use.
> It provides a safety feature to ensure that software is executing
> as planned and that the CPU is not stuck in an infinite loop or
> executing unintended code. If the WDOG module is not serviced
> (refreshed) within a certain period, it resets the MCU.
> 
> Add driver support for i.MX7ULP watchdog.
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>

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

> ---
> Changes since V1:
> 	- Add clock operation;
> 	- Remove unneccsary error message when registering watchdog device failed;
> 	- Use BIT() instead of hard code;
> ---
>  drivers/watchdog/Kconfig       |  13 +++
>  drivers/watchdog/Makefile      |   1 +
>  drivers/watchdog/imx7ulp_wdt.c | 244 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 258 insertions(+)
>  create mode 100644 drivers/watchdog/imx7ulp_wdt.c
> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 8188963..0884e53 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -740,6 +740,19 @@ config IMX_SC_WDT
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called imx_sc_wdt.
>  
> +config IMX7ULP_WDT
> +	tristate "IMX7ULP Watchdog"
> +	depends on ARCH_MXC || COMPILE_TEST
> +	select WATCHDOG_CORE
> +	help
> +	  This is the driver for the hardware watchdog on the Freescale
> +	  IMX7ULP and later processors. 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 imx7ulp_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 7caa920..7d32537 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -69,6 +69,7 @@ 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-$(CONFIG_IMX7ULP_WDT) += imx7ulp_wdt.o
>  obj-$(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/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c
> new file mode 100644
> index 0000000..c20fba4
> --- /dev/null
> +++ b/drivers/watchdog/imx7ulp_wdt.c
> @@ -0,0 +1,244 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2019 NXP.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/reboot.h>
> +#include <linux/watchdog.h>
> +
> +#define WDOG_CS			0x0
> +#define WDOG_CS_CMD32EN		BIT(13)
> +#define WDOG_CS_ULK		BIT(11)
> +#define WDOG_CS_RCS		BIT(10)
> +#define WDOG_CS_EN		BIT(7)
> +#define WDOG_CS_UPDATE		BIT(5)
> +
> +#define WDOG_CNT	0x4
> +#define WDOG_TOVAL	0x8
> +
> +#define REFRESH_SEQ0	0xA602
> +#define REFRESH_SEQ1	0xB480
> +#define REFRESH		((REFRESH_SEQ1 << 16) | REFRESH_SEQ0)
> +
> +#define UNLOCK_SEQ0	0xC520
> +#define UNLOCK_SEQ1	0xD928
> +#define UNLOCK		((UNLOCK_SEQ1 << 16) | UNLOCK_SEQ0)
> +
> +#define DEFAULT_TIMEOUT	60
> +#define MAX_TIMEOUT	128
> +
> +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) ")");
> +
> +struct imx7ulp_wdt_device {
> +	struct notifier_block restart_handler;
> +	struct watchdog_device wdd;
> +	void __iomem *base;
> +	struct clk *clk;
> +	int rate;
> +};
> +
> +static inline void imx7ulp_wdt_enable(void __iomem *base, bool enable)
> +{
> +	u32 val = readl(base + WDOG_CS);
> +
> +	writel(UNLOCK, base + WDOG_CNT);
> +	if (enable)
> +		writel(val | WDOG_CS_EN, base + WDOG_CS);
> +	else
> +		writel(val & ~WDOG_CS_EN, base + WDOG_CS);
> +}
> +
> +static inline bool imx7ulp_wdt_is_enabled(void __iomem *base)
> +{
> +	u32 val = readl(base + WDOG_CS);
> +
> +	return val & WDOG_CS_EN;
> +}
> +
> +static int imx7ulp_wdt_ping(struct watchdog_device *wdog)
> +{
> +	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
> +
> +	writel(REFRESH, wdt->base + WDOG_CNT);
> +
> +	return 0;
> +}
> +
> +static int imx7ulp_wdt_start(struct watchdog_device *wdog)
> +{
> +	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
> +
> +	imx7ulp_wdt_enable(wdt->base, true);
> +
> +	return 0;
> +}
> +
> +static int imx7ulp_wdt_stop(struct watchdog_device *wdog)
> +{
> +	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
> +
> +	imx7ulp_wdt_enable(wdt->base, false);
> +
> +	return 0;
> +}
> +
> +static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog,
> +				   unsigned int timeout)
> +{
> +	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
> +	u32 val = wdt->rate * timeout;
> +
> +	writel(UNLOCK, wdt->base + WDOG_CNT);
> +	writel(val, wdt->base + WDOG_TOVAL);
> +
> +	wdog->timeout = timeout;
> +
> +	return 0;
> +}
> +
> +static const struct watchdog_ops imx7ulp_wdt_ops = {
> +	.owner = THIS_MODULE,
> +	.start = imx7ulp_wdt_start,
> +	.stop  = imx7ulp_wdt_stop,
> +	.ping  = imx7ulp_wdt_ping,
> +	.set_timeout = imx7ulp_wdt_set_timeout,
> +};
> +
> +static const struct watchdog_info imx7ulp_wdt_info = {
> +	.identity = "i.MX7ULP watchdog timer",
> +	.options  = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
> +		    WDIOF_MAGICCLOSE,
> +};
> +
> +static inline void imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
> +{
> +	u32 val;
> +
> +	/* unlock the wdog for reconfiguration */
> +	writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
> +	writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
> +
> +	/* set an initial timeout value in TOVAL */
> +	writel(timeout, base + WDOG_TOVAL);
> +	/* enable 32bit command sequence and reconfigure */
> +	val = BIT(13) | BIT(8) | BIT(5);
> +	writel(val, base + WDOG_CS);
> +}
> +
> +static int imx7ulp_wdt_probe(struct platform_device *pdev)
> +{
> +	struct imx7ulp_wdt_device *imx7ulp_wdt;
> +	struct device *dev = &pdev->dev;
> +	struct watchdog_device *wdog;
> +	int ret;
> +
> +	imx7ulp_wdt = devm_kzalloc(dev, sizeof(*imx7ulp_wdt), GFP_KERNEL);
> +	if (!imx7ulp_wdt)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, imx7ulp_wdt);
> +
> +	imx7ulp_wdt->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(imx7ulp_wdt->base))
> +		return PTR_ERR(imx7ulp_wdt->base);
> +
> +	imx7ulp_wdt->clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(imx7ulp_wdt->clk)) {
> +		dev_err(dev, "Failed to get watchdog clock\n");
> +		return PTR_ERR(imx7ulp_wdt->clk);
> +	}
> +
> +	ret = clk_prepare_enable(imx7ulp_wdt->clk);
> +	if (ret)
> +		return ret;
> +
> +	imx7ulp_wdt->rate = 1000;
> +	wdog = &imx7ulp_wdt->wdd;
> +	wdog->info = &imx7ulp_wdt_info;
> +	wdog->ops = &imx7ulp_wdt_ops;
> +	wdog->min_timeout = 1;
> +	wdog->max_timeout = MAX_TIMEOUT;
> +	wdog->parent = dev;
> +	wdog->timeout = DEFAULT_TIMEOUT;
> +
> +	watchdog_init_timeout(wdog, 0, dev);
> +	watchdog_stop_on_reboot(wdog);
> +	watchdog_stop_on_unregister(wdog);
> +	watchdog_set_drvdata(wdog, imx7ulp_wdt);
> +	imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * imx7ulp_wdt->rate);
> +
> +	ret = devm_watchdog_register_device(dev, wdog);
> +	if (ret)
> +		goto disable_clk;
> +
> +	return 0;
> +
> +disable_clk:
> +	clk_disable_unprepare(imx7ulp_wdt->clk);
> +
> +	return ret;
> +}
> +
> +static int __maybe_unused imx7ulp_wdt_suspend(struct device *dev)
> +{
> +	struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev);
> +
> +	if (watchdog_active(&imx7ulp_wdt->wdd))
> +		imx7ulp_wdt_stop(&imx7ulp_wdt->wdd);
> +
> +	clk_disable_unprepare(imx7ulp_wdt->clk);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused imx7ulp_wdt_resume(struct device *dev)
> +{
> +	struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev);
> +	u32 timeout = imx7ulp_wdt->wdd.timeout * imx7ulp_wdt->rate;
> +	int ret;
> +
> +	ret = clk_prepare_enable(imx7ulp_wdt->clk);
> +	if (ret)
> +		return ret;
> +
> +	if (imx7ulp_wdt_is_enabled(imx7ulp_wdt->base))
> +		imx7ulp_wdt_init(imx7ulp_wdt->base, timeout);
> +
> +	if (watchdog_active(&imx7ulp_wdt->wdd))
> +		imx7ulp_wdt_start(&imx7ulp_wdt->wdd);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(imx7ulp_wdt_pm_ops, imx7ulp_wdt_suspend,
> +			 imx7ulp_wdt_resume);
> +
> +static const struct of_device_id imx7ulp_wdt_dt_ids[] = {
> +	{ .compatible = "fsl,imx7ulp-wdt", },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, imx7ulp_wdt_dt_ids);
> +
> +static struct platform_driver imx7ulp_wdt_driver = {
> +	.probe		= imx7ulp_wdt_probe,
> +	.driver		= {
> +		.name	= "imx7ulp-wdt",
> +		.pm	= &imx7ulp_wdt_pm_ops,
> +		.of_match_table = imx7ulp_wdt_dt_ids,
> +	},
> +};
> +module_platform_driver(imx7ulp_wdt_driver);
> +
> +MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
> +MODULE_DESCRIPTION("Freescale i.MX7ULP watchdog driver");
> +MODULE_LICENSE("GPL v2");

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH V2 2/4] watchdog: Add i.MX7ULP watchdog support
  2019-08-20 15:31   ` Guenter Roeck
@ 2019-08-20 15:48     ` Guenter Roeck
  2019-08-21  2:27       ` Anson Huang
  0 siblings, 1 reply; 7+ messages in thread
From: Guenter Roeck @ 2019-08-20 15:48 UTC (permalink / raw)
  To: Anson.Huang
  Cc: wim, robh+dt, mark.rutland, shawnguo, s.hauer, kernel, festevam,
	linux, otavio, leonard.crestez, u.kleine-koenig, schnitzeltony,
	jan.tuerk, linux-watchdog, devicetree, linux-arm-kernel,
	linux-kernel, Linux-imx

On Tue, Aug 20, 2019 at 08:31:55AM -0700, Guenter Roeck wrote:
> On Mon, Aug 12, 2019 at 04:53:19PM +0800, Anson.Huang@nxp.com wrote:
> > From: Anson Huang <Anson.Huang@nxp.com>
> > 
> > The i.MX7ULP Watchdog Timer (WDOG) module is an independent timer
> > that is available for system use.
> > It provides a safety feature to ensure that software is executing
> > as planned and that the CPU is not stuck in an infinite loop or
> > executing unintended code. If the WDOG module is not serviced
> > (refreshed) within a certain period, it resets the MCU.
> > 
> > Add driver support for i.MX7ULP watchdog.
> > 
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> 
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> 

Wait, I have to withdraw that.

With clk_prepare_enable(), you'll also need to call clk_disable_unprepare()
on remove. An easy way to do this and keep the code simple would be:

static void imx7ulp_wdt_clk_disable_unprepare(void *data)
{
	clk_disable_unprepare(data);
}

static int imx7ulp_wdt_probe(...)
{
	...
	ret = clk_prepare_enable(imx7ulp_wdt->clk);
	if (ret)
		return ret;
	ret = devm_add_action_or_reset(dev, imx7ulp_wdt_clk_disable_unprepare);
	if (ret)
		return ret;
	...

Thanks,
Guenter

> > ---
> > Changes since V1:
> > 	- Add clock operation;
> > 	- Remove unneccsary error message when registering watchdog device failed;
> > 	- Use BIT() instead of hard code;
> > ---
> >  drivers/watchdog/Kconfig       |  13 +++
> >  drivers/watchdog/Makefile      |   1 +
> >  drivers/watchdog/imx7ulp_wdt.c | 244 +++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 258 insertions(+)
> >  create mode 100644 drivers/watchdog/imx7ulp_wdt.c
> > 
> > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> > index 8188963..0884e53 100644
> > --- a/drivers/watchdog/Kconfig
> > +++ b/drivers/watchdog/Kconfig
> > @@ -740,6 +740,19 @@ config IMX_SC_WDT
> >  	  To compile this driver as a module, choose M here: the
> >  	  module will be called imx_sc_wdt.
> >  
> > +config IMX7ULP_WDT
> > +	tristate "IMX7ULP Watchdog"
> > +	depends on ARCH_MXC || COMPILE_TEST
> > +	select WATCHDOG_CORE
> > +	help
> > +	  This is the driver for the hardware watchdog on the Freescale
> > +	  IMX7ULP and later processors. 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 imx7ulp_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 7caa920..7d32537 100644
> > --- a/drivers/watchdog/Makefile
> > +++ b/drivers/watchdog/Makefile
> > @@ -69,6 +69,7 @@ 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-$(CONFIG_IMX7ULP_WDT) += imx7ulp_wdt.o
> >  obj-$(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/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c
> > new file mode 100644
> > index 0000000..c20fba4
> > --- /dev/null
> > +++ b/drivers/watchdog/imx7ulp_wdt.c
> > @@ -0,0 +1,244 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright 2019 NXP.
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/init.h>
> > +#include <linux/io.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/reboot.h>
> > +#include <linux/watchdog.h>
> > +
> > +#define WDOG_CS			0x0
> > +#define WDOG_CS_CMD32EN		BIT(13)
> > +#define WDOG_CS_ULK		BIT(11)
> > +#define WDOG_CS_RCS		BIT(10)
> > +#define WDOG_CS_EN		BIT(7)
> > +#define WDOG_CS_UPDATE		BIT(5)
> > +
> > +#define WDOG_CNT	0x4
> > +#define WDOG_TOVAL	0x8
> > +
> > +#define REFRESH_SEQ0	0xA602
> > +#define REFRESH_SEQ1	0xB480
> > +#define REFRESH		((REFRESH_SEQ1 << 16) | REFRESH_SEQ0)
> > +
> > +#define UNLOCK_SEQ0	0xC520
> > +#define UNLOCK_SEQ1	0xD928
> > +#define UNLOCK		((UNLOCK_SEQ1 << 16) | UNLOCK_SEQ0)
> > +
> > +#define DEFAULT_TIMEOUT	60
> > +#define MAX_TIMEOUT	128
> > +
> > +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) ")");
> > +
> > +struct imx7ulp_wdt_device {
> > +	struct notifier_block restart_handler;
> > +	struct watchdog_device wdd;
> > +	void __iomem *base;
> > +	struct clk *clk;
> > +	int rate;
> > +};
> > +
> > +static inline void imx7ulp_wdt_enable(void __iomem *base, bool enable)
> > +{
> > +	u32 val = readl(base + WDOG_CS);
> > +
> > +	writel(UNLOCK, base + WDOG_CNT);
> > +	if (enable)
> > +		writel(val | WDOG_CS_EN, base + WDOG_CS);
> > +	else
> > +		writel(val & ~WDOG_CS_EN, base + WDOG_CS);
> > +}
> > +
> > +static inline bool imx7ulp_wdt_is_enabled(void __iomem *base)
> > +{
> > +	u32 val = readl(base + WDOG_CS);
> > +
> > +	return val & WDOG_CS_EN;
> > +}
> > +
> > +static int imx7ulp_wdt_ping(struct watchdog_device *wdog)
> > +{
> > +	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
> > +
> > +	writel(REFRESH, wdt->base + WDOG_CNT);
> > +
> > +	return 0;
> > +}
> > +
> > +static int imx7ulp_wdt_start(struct watchdog_device *wdog)
> > +{
> > +	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
> > +
> > +	imx7ulp_wdt_enable(wdt->base, true);
> > +
> > +	return 0;
> > +}
> > +
> > +static int imx7ulp_wdt_stop(struct watchdog_device *wdog)
> > +{
> > +	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
> > +
> > +	imx7ulp_wdt_enable(wdt->base, false);
> > +
> > +	return 0;
> > +}
> > +
> > +static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog,
> > +				   unsigned int timeout)
> > +{
> > +	struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
> > +	u32 val = wdt->rate * timeout;
> > +
> > +	writel(UNLOCK, wdt->base + WDOG_CNT);
> > +	writel(val, wdt->base + WDOG_TOVAL);
> > +
> > +	wdog->timeout = timeout;
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct watchdog_ops imx7ulp_wdt_ops = {
> > +	.owner = THIS_MODULE,
> > +	.start = imx7ulp_wdt_start,
> > +	.stop  = imx7ulp_wdt_stop,
> > +	.ping  = imx7ulp_wdt_ping,
> > +	.set_timeout = imx7ulp_wdt_set_timeout,
> > +};
> > +
> > +static const struct watchdog_info imx7ulp_wdt_info = {
> > +	.identity = "i.MX7ULP watchdog timer",
> > +	.options  = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
> > +		    WDIOF_MAGICCLOSE,
> > +};
> > +
> > +static inline void imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
> > +{
> > +	u32 val;
> > +
> > +	/* unlock the wdog for reconfiguration */
> > +	writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
> > +	writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
> > +
> > +	/* set an initial timeout value in TOVAL */
> > +	writel(timeout, base + WDOG_TOVAL);
> > +	/* enable 32bit command sequence and reconfigure */
> > +	val = BIT(13) | BIT(8) | BIT(5);
> > +	writel(val, base + WDOG_CS);
> > +}
> > +
> > +static int imx7ulp_wdt_probe(struct platform_device *pdev)
> > +{
> > +	struct imx7ulp_wdt_device *imx7ulp_wdt;
> > +	struct device *dev = &pdev->dev;
> > +	struct watchdog_device *wdog;
> > +	int ret;
> > +
> > +	imx7ulp_wdt = devm_kzalloc(dev, sizeof(*imx7ulp_wdt), GFP_KERNEL);
> > +	if (!imx7ulp_wdt)
> > +		return -ENOMEM;
> > +
> > +	platform_set_drvdata(pdev, imx7ulp_wdt);
> > +
> > +	imx7ulp_wdt->base = devm_platform_ioremap_resource(pdev, 0);
> > +	if (IS_ERR(imx7ulp_wdt->base))
> > +		return PTR_ERR(imx7ulp_wdt->base);
> > +
> > +	imx7ulp_wdt->clk = devm_clk_get(dev, NULL);
> > +	if (IS_ERR(imx7ulp_wdt->clk)) {
> > +		dev_err(dev, "Failed to get watchdog clock\n");
> > +		return PTR_ERR(imx7ulp_wdt->clk);
> > +	}
> > +
> > +	ret = clk_prepare_enable(imx7ulp_wdt->clk);
> > +	if (ret)
> > +		return ret;
> > +
> > +	imx7ulp_wdt->rate = 1000;
> > +	wdog = &imx7ulp_wdt->wdd;
> > +	wdog->info = &imx7ulp_wdt_info;
> > +	wdog->ops = &imx7ulp_wdt_ops;
> > +	wdog->min_timeout = 1;
> > +	wdog->max_timeout = MAX_TIMEOUT;
> > +	wdog->parent = dev;
> > +	wdog->timeout = DEFAULT_TIMEOUT;
> > +
> > +	watchdog_init_timeout(wdog, 0, dev);
> > +	watchdog_stop_on_reboot(wdog);
> > +	watchdog_stop_on_unregister(wdog);
> > +	watchdog_set_drvdata(wdog, imx7ulp_wdt);
> > +	imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * imx7ulp_wdt->rate);
> > +
> > +	ret = devm_watchdog_register_device(dev, wdog);
> > +	if (ret)
> > +		goto disable_clk;
> > +
> > +	return 0;
> > +
> > +disable_clk:
> > +	clk_disable_unprepare(imx7ulp_wdt->clk);
> > +
> > +	return ret;
> > +}
> > +
> > +static int __maybe_unused imx7ulp_wdt_suspend(struct device *dev)
> > +{
> > +	struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev);
> > +
> > +	if (watchdog_active(&imx7ulp_wdt->wdd))
> > +		imx7ulp_wdt_stop(&imx7ulp_wdt->wdd);
> > +
> > +	clk_disable_unprepare(imx7ulp_wdt->clk);
> > +
> > +	return 0;
> > +}
> > +
> > +static int __maybe_unused imx7ulp_wdt_resume(struct device *dev)
> > +{
> > +	struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev);
> > +	u32 timeout = imx7ulp_wdt->wdd.timeout * imx7ulp_wdt->rate;
> > +	int ret;
> > +
> > +	ret = clk_prepare_enable(imx7ulp_wdt->clk);
> > +	if (ret)
> > +		return ret;
> > +
> > +	if (imx7ulp_wdt_is_enabled(imx7ulp_wdt->base))
> > +		imx7ulp_wdt_init(imx7ulp_wdt->base, timeout);
> > +
> > +	if (watchdog_active(&imx7ulp_wdt->wdd))
> > +		imx7ulp_wdt_start(&imx7ulp_wdt->wdd);
> > +
> > +	return 0;
> > +}
> > +
> > +static SIMPLE_DEV_PM_OPS(imx7ulp_wdt_pm_ops, imx7ulp_wdt_suspend,
> > +			 imx7ulp_wdt_resume);
> > +
> > +static const struct of_device_id imx7ulp_wdt_dt_ids[] = {
> > +	{ .compatible = "fsl,imx7ulp-wdt", },
> > +	{ /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, imx7ulp_wdt_dt_ids);
> > +
> > +static struct platform_driver imx7ulp_wdt_driver = {
> > +	.probe		= imx7ulp_wdt_probe,
> > +	.driver		= {
> > +		.name	= "imx7ulp-wdt",
> > +		.pm	= &imx7ulp_wdt_pm_ops,
> > +		.of_match_table = imx7ulp_wdt_dt_ids,
> > +	},
> > +};
> > +module_platform_driver(imx7ulp_wdt_driver);
> > +
> > +MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
> > +MODULE_DESCRIPTION("Freescale i.MX7ULP watchdog driver");
> > +MODULE_LICENSE("GPL v2");

^ permalink raw reply	[flat|nested] 7+ messages in thread

* RE: [PATCH V2 2/4] watchdog: Add i.MX7ULP watchdog support
  2019-08-20 15:48     ` Guenter Roeck
@ 2019-08-21  2:27       ` Anson Huang
  0 siblings, 0 replies; 7+ messages in thread
From: Anson Huang @ 2019-08-21  2:27 UTC (permalink / raw)
  To: Guenter Roeck
  Cc: wim, robh+dt, mark.rutland, shawnguo, s.hauer, kernel, festevam,
	linux, otavio, Leonard Crestez, u.kleine-koenig, schnitzeltony,
	jan.tuerk, linux-watchdog, devicetree, linux-arm-kernel,
	linux-kernel, dl-linux-imx

Hi, Guenter

> On Tue, Aug 20, 2019 at 08:31:55AM -0700, Guenter Roeck wrote:
> > On Mon, Aug 12, 2019 at 04:53:19PM +0800, Anson.Huang@nxp.com
> wrote:
> > > From: Anson Huang <Anson.Huang@nxp.com>
> > >
> > > The i.MX7ULP Watchdog Timer (WDOG) module is an independent timer
> > > that is available for system use.
> > > It provides a safety feature to ensure that software is executing as
> > > planned and that the CPU is not stuck in an infinite loop or
> > > executing unintended code. If the WDOG module is not serviced
> > > (refreshed) within a certain period, it resets the MCU.
> > >
> > > Add driver support for i.MX7ULP watchdog.
> > >
> > > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> >
> > Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> >
> 
> Wait, I have to withdraw that.
> 
> With clk_prepare_enable(), you'll also need to call clk_disable_unprepare()
> on remove. An easy way to do this and keep the code simple would be:
> 
> static void imx7ulp_wdt_clk_disable_unprepare(void *data) {
> 	clk_disable_unprepare(data);
> }
> 
> static int imx7ulp_wdt_probe(...)
> {
> 	...
> 	ret = clk_prepare_enable(imx7ulp_wdt->clk);
> 	if (ret)
> 		return ret;
> 	ret = devm_add_action_or_reset(dev,
> imx7ulp_wdt_clk_disable_unprepare);
> 	if (ret)
> 		return ret;
> 	...
> 

Ah, yes, I added the error handle but missed the remove case, thanks for your kindly
suggestion, please help review V3.

Thanks,
Anson.

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2019-08-21  2:27 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-08-12  8:53 [PATCH V2 1/4] dt-bindings: watchdog: Add i.MX7ULP bindings Anson.Huang
2019-08-12  8:53 ` [PATCH V2 2/4] watchdog: Add i.MX7ULP watchdog support Anson.Huang
2019-08-20 15:31   ` Guenter Roeck
2019-08-20 15:48     ` Guenter Roeck
2019-08-21  2:27       ` Anson Huang
2019-08-12  8:53 ` [PATCH V2 3/4] ARM: imx_v6_v7_defconfig: Enable CONFIG_IMX7ULP_WDT by default Anson.Huang
2019-08-12  8:53 ` [PATCH V2 4/4] ARM: dts: imx7ulp: Add wdog1 node Anson.Huang

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