From: Ming Yu <a0282524688@gmail.com>

This driver supports Watchdog timer functionality for NCT6694 MFD
device based on USB interface.

Signed-off-by: Ming Yu <a0282524688@gmail.com>
---
Changes since version 12:
- Implement IDA in MFD driver to handle per-device IDs
- Use same email address in the signaturei

Changes since version 11:
- Use platform_device's id to replace IDA

Changes since version 10:
- Implement IDA to allocate id
- Add module parameters to configure WDT's timeout and pretimeout value

Changes since version 9:

Changes since version 8:
- Modify the signed-off-by with my work address

Changes since version 7:
- Add error handling for devm_mutex_init()

Changes since version 6:
- Fix warning

Changes since version 5:
- Modify the module name and the driver name consistently

Changes since version 4:
- Modify arguments in read/write function to a pointer to cmd_header
- Modify all callers that call the read/write function

Changes since version 3:
- Modify array buffer to structure
- Fix defines and comments
- Modify mutex_init() to devm_mutex_init()
- Drop watchdog_init_timeout()

Changes since version 2:
- Add MODULE_ALIAS()
- Modify the pretimeout validation procedure

Changes since version 1:
- Add each driver's command structure
- Fix platform driver registration
- Fix warnings
- Drop unnecessary logs
- Modify start() function to setup device

 MAINTAINERS                    |   1 +
 drivers/watchdog/Kconfig       |  11 ++
 drivers/watchdog/Makefile      |   1 +
 drivers/watchdog/nct6694_wdt.c | 307 +++++++++++++++++++++++++++++++++
 4 files changed, 320 insertions(+)
 create mode 100644 drivers/watchdog/nct6694_wdt.c

diff --git a/MAINTAINERS b/MAINTAINERS
index ce276999625e..7c3edac315b4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17796,6 +17796,7 @@ F:	drivers/gpio/gpio-nct6694.c
 F:	drivers/i2c/busses/i2c-nct6694.c
 F:	drivers/mfd/nct6694.c
 F:	drivers/net/can/usb/nct6694_canfd.c
+F:	drivers/watchdog/nct6694_wdt.c
 F:	include/linux/mfd/nct6694.h
 
 NUVOTON NCT7201 IIO DRIVER
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 0c25b2ed44eb..05008d937e40 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -760,6 +760,17 @@ config MAX77620_WATCHDOG
 	  MAX77620 chips. To compile this driver as a module,
 	  choose M here: the module will be called max77620_wdt.
 
+config NCT6694_WATCHDOG
+	tristate "Nuvoton NCT6694 watchdog support"
+	depends on MFD_NCT6694
+	select WATCHDOG_CORE
+	help
+	  Say Y here to support Nuvoton NCT6694 watchdog timer
+	  functionality.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called nct6694_wdt.
+
 config IMX2_WDT
 	tristate "IMX2+ Watchdog"
 	depends on ARCH_MXC || ARCH_LAYERSCAPE || COMPILE_TEST
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index bbd4d62d2cc3..b680e4d3c1bc 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -235,6 +235,7 @@ obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
 obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
 obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
 obj-$(CONFIG_MAX77620_WATCHDOG) += max77620_wdt.o
+obj-$(CONFIG_NCT6694_WATCHDOG) += nct6694_wdt.o
 obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o
 obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
 obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o
diff --git a/drivers/watchdog/nct6694_wdt.c b/drivers/watchdog/nct6694_wdt.c
new file mode 100644
index 000000000000..bc3689bd4b6b
--- /dev/null
+++ b/drivers/watchdog/nct6694_wdt.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NCT6694 WDT driver based on USB interface.
+ *
+ * Copyright (C) 2025 Nuvoton Technology Corp.
+ */
+
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/mfd/nct6694.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/watchdog.h>
+
+#define DEVICE_NAME "nct6694-wdt"
+
+#define NCT6694_DEFAULT_TIMEOUT		10
+#define NCT6694_DEFAULT_PRETIMEOUT	0
+
+#define NCT6694_WDT_MAX_DEVS		2
+
+/*
+ * USB command module type for NCT6694 WDT controller.
+ * This defines the module type used for communication with the NCT6694
+ * WDT controller over the USB interface.
+ */
+#define NCT6694_WDT_MOD			0x07
+
+/* Command 00h - WDT Setup */
+#define NCT6694_WDT_SETUP		0x00
+#define NCT6694_WDT_SETUP_SEL(idx)	(idx ? 0x01 : 0x00)
+
+/* Command 01h - WDT Command */
+#define NCT6694_WDT_COMMAND		0x01
+#define NCT6694_WDT_COMMAND_SEL(idx)	(idx ? 0x01 : 0x00)
+
+static unsigned int timeout[NCT6694_WDT_MAX_DEVS] = {
+	[0 ... (NCT6694_WDT_MAX_DEVS - 1)] = NCT6694_DEFAULT_TIMEOUT
+};
+module_param_array(timeout, int, NULL, 0644);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
+
+static unsigned int pretimeout[NCT6694_WDT_MAX_DEVS] = {
+	[0 ... (NCT6694_WDT_MAX_DEVS - 1)] = NCT6694_DEFAULT_PRETIMEOUT
+};
+module_param_array(pretimeout, int, NULL, 0644);
+MODULE_PARM_DESC(pretimeout, "Watchdog pre-timeout in seconds");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+			   __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+enum {
+	NCT6694_ACTION_NONE = 0,
+	NCT6694_ACTION_SIRQ,
+	NCT6694_ACTION_GPO,
+};
+
+struct __packed nct6694_wdt_setup {
+	__le32 pretimeout;
+	__le32 timeout;
+	u8 owner;
+	u8 scratch;
+	u8 control;
+	u8 status;
+	__le32 countdown;
+};
+
+struct __packed nct6694_wdt_cmd {
+	__le32 wdt_cmd;
+	__le32 reserved;
+};
+
+union __packed nct6694_wdt_msg {
+	struct nct6694_wdt_setup setup;
+	struct nct6694_wdt_cmd cmd;
+};
+
+struct nct6694_wdt_data {
+	struct watchdog_device wdev;
+	struct device *dev;
+	struct nct6694 *nct6694;
+	union nct6694_wdt_msg *msg;
+	unsigned char wdev_idx;
+};
+
+static int nct6694_wdt_setting(struct watchdog_device *wdev,
+			       u32 timeout_val, u8 timeout_act,
+			       u32 pretimeout_val, u8 pretimeout_act)
+{
+	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
+	struct nct6694_wdt_setup *setup = &data->msg->setup;
+	const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_WDT_MOD,
+		.cmd = NCT6694_WDT_SETUP,
+		.sel = NCT6694_WDT_SETUP_SEL(data->wdev_idx),
+		.len = cpu_to_le16(sizeof(*setup))
+	};
+	unsigned int timeout_fmt, pretimeout_fmt;
+
+	if (pretimeout_val == 0)
+		pretimeout_act = NCT6694_ACTION_NONE;
+
+	timeout_fmt = (timeout_val * 1000) | (timeout_act << 24);
+	pretimeout_fmt = (pretimeout_val * 1000) | (pretimeout_act << 24);
+
+	memset(setup, 0, sizeof(*setup));
+	setup->timeout = cpu_to_le32(timeout_fmt);
+	setup->pretimeout = cpu_to_le32(pretimeout_fmt);
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, setup);
+}
+
+static int nct6694_wdt_start(struct watchdog_device *wdev)
+{
+	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
+	int ret;
+
+	ret = nct6694_wdt_setting(wdev, wdev->timeout, NCT6694_ACTION_GPO,
+				  wdev->pretimeout, NCT6694_ACTION_GPO);
+	if (ret)
+		return ret;
+
+	dev_dbg(data->dev, "Setting WDT(%d): timeout = %d, pretimeout = %d\n",
+		data->wdev_idx, wdev->timeout, wdev->pretimeout);
+
+	return ret;
+}
+
+static int nct6694_wdt_stop(struct watchdog_device *wdev)
+{
+	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
+	struct nct6694_wdt_cmd *cmd = &data->msg->cmd;
+	const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_WDT_MOD,
+		.cmd = NCT6694_WDT_COMMAND,
+		.sel = NCT6694_WDT_COMMAND_SEL(data->wdev_idx),
+		.len = cpu_to_le16(sizeof(*cmd))
+	};
+
+	memcpy(&cmd->wdt_cmd, "WDTC", 4);
+	cmd->reserved = 0;
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, cmd);
+}
+
+static int nct6694_wdt_ping(struct watchdog_device *wdev)
+{
+	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
+	struct nct6694_wdt_cmd *cmd = &data->msg->cmd;
+	const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_WDT_MOD,
+		.cmd = NCT6694_WDT_COMMAND,
+		.sel = NCT6694_WDT_COMMAND_SEL(data->wdev_idx),
+		.len = cpu_to_le16(sizeof(*cmd))
+	};
+
+	memcpy(&cmd->wdt_cmd, "WDTS", 4);
+	cmd->reserved = 0;
+
+	return nct6694_write_msg(data->nct6694, &cmd_hd, cmd);
+}
+
+static int nct6694_wdt_set_timeout(struct watchdog_device *wdev,
+				   unsigned int new_timeout)
+{
+	int ret;
+
+	ret = nct6694_wdt_setting(wdev, new_timeout, NCT6694_ACTION_GPO,
+				  wdev->pretimeout, NCT6694_ACTION_GPO);
+	if (ret)
+		return ret;
+
+	wdev->timeout = new_timeout;
+
+	return 0;
+}
+
+static int nct6694_wdt_set_pretimeout(struct watchdog_device *wdev,
+				      unsigned int new_pretimeout)
+{
+	int ret;
+
+	ret = nct6694_wdt_setting(wdev, wdev->timeout, NCT6694_ACTION_GPO,
+				  new_pretimeout, NCT6694_ACTION_GPO);
+	if (ret)
+		return ret;
+
+	wdev->pretimeout = new_pretimeout;
+
+	return 0;
+}
+
+static unsigned int nct6694_wdt_get_time(struct watchdog_device *wdev)
+{
+	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
+	struct nct6694_wdt_setup *setup = &data->msg->setup;
+	const struct nct6694_cmd_header cmd_hd = {
+		.mod = NCT6694_WDT_MOD,
+		.cmd = NCT6694_WDT_SETUP,
+		.sel = NCT6694_WDT_SETUP_SEL(data->wdev_idx),
+		.len = cpu_to_le16(sizeof(*setup))
+	};
+	unsigned int timeleft_ms;
+	int ret;
+
+	ret = nct6694_read_msg(data->nct6694, &cmd_hd, setup);
+	if (ret)
+		return 0;
+
+	timeleft_ms = le32_to_cpu(setup->countdown);
+
+	return timeleft_ms / 1000;
+}
+
+static const struct watchdog_info nct6694_wdt_info = {
+	.options = WDIOF_SETTIMEOUT	|
+		   WDIOF_KEEPALIVEPING	|
+		   WDIOF_MAGICCLOSE	|
+		   WDIOF_PRETIMEOUT,
+	.identity = DEVICE_NAME,
+};
+
+static const struct watchdog_ops nct6694_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = nct6694_wdt_start,
+	.stop = nct6694_wdt_stop,
+	.set_timeout = nct6694_wdt_set_timeout,
+	.set_pretimeout = nct6694_wdt_set_pretimeout,
+	.get_timeleft = nct6694_wdt_get_time,
+	.ping = nct6694_wdt_ping,
+};
+
+static void nct6694_wdt_ida_free(void *d)
+{
+	struct nct6694_wdt_data *data = d;
+	struct nct6694 *nct6694 = data->nct6694;
+
+	ida_free(&nct6694->wdt_ida, data->wdev_idx);
+}
+
+static int nct6694_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct nct6694 *nct6694 = dev_get_drvdata(dev->parent);
+	struct nct6694_wdt_data *data;
+	struct watchdog_device *wdev;
+	int ret;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->msg = devm_kzalloc(dev, sizeof(union nct6694_wdt_msg),
+				 GFP_KERNEL);
+	if (!data->msg)
+		return -ENOMEM;
+
+	data->dev = dev;
+	data->nct6694 = nct6694;
+
+	ret = ida_alloc(&nct6694->wdt_ida, GFP_KERNEL);
+	if (ret < 0)
+		return ret;
+	data->wdev_idx = ret;
+
+	ret = devm_add_action_or_reset(dev, nct6694_wdt_ida_free, data);
+	if (ret)
+		return ret;
+
+	wdev = &data->wdev;
+	wdev->info = &nct6694_wdt_info;
+	wdev->ops = &nct6694_wdt_ops;
+	wdev->timeout = timeout[data->wdev_idx];
+	wdev->pretimeout = pretimeout[data->wdev_idx];
+	if (timeout[data->wdev_idx] < pretimeout[data->wdev_idx]) {
+		dev_warn(data->dev, "pretimeout < timeout. Setting to zero\n");
+		wdev->pretimeout = 0;
+	}
+
+	wdev->min_timeout = 1;
+	wdev->max_timeout = 255;
+
+	platform_set_drvdata(pdev, data);
+
+	watchdog_set_drvdata(&data->wdev, data);
+	watchdog_set_nowayout(&data->wdev, nowayout);
+	watchdog_stop_on_reboot(&data->wdev);
+
+	return devm_watchdog_register_device(dev, &data->wdev);
+}
+
+static struct platform_driver nct6694_wdt_driver = {
+	.driver = {
+		.name	= DEVICE_NAME,
+	},
+	.probe		= nct6694_wdt_probe,
+};
+
+module_platform_driver(nct6694_wdt_driver);
+
+MODULE_DESCRIPTION("USB-WDT driver for NCT6694");
+MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nct6694-wdt");
-- 
2.34.1

On Fri, Jun 27, 2025 at 06:27:28PM +0800, a0282524688@gmail.com wrote:
> From: Ming Yu <a0282524688@gmail.com>
> 
> This driver supports Watchdog timer functionality for NCT6694 MFD
> device based on USB interface.
> 
> Signed-off-by: Ming Yu <a0282524688@gmail.com>

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

> ---
> Changes since version 12:
> - Implement IDA in MFD driver to handle per-device IDs
> - Use same email address in the signaturei
> 
> Changes since version 11:
> - Use platform_device's id to replace IDA
> 
> Changes since version 10:
> - Implement IDA to allocate id
> - Add module parameters to configure WDT's timeout and pretimeout value
> 
> Changes since version 9:
> 
> Changes since version 8:
> - Modify the signed-off-by with my work address
> 
> Changes since version 7:
> - Add error handling for devm_mutex_init()
> 
> Changes since version 6:
> - Fix warning
> 
> Changes since version 5:
> - Modify the module name and the driver name consistently
> 
> Changes since version 4:
> - Modify arguments in read/write function to a pointer to cmd_header
> - Modify all callers that call the read/write function
> 
> Changes since version 3:
> - Modify array buffer to structure
> - Fix defines and comments
> - Modify mutex_init() to devm_mutex_init()
> - Drop watchdog_init_timeout()
> 
> Changes since version 2:
> - Add MODULE_ALIAS()
> - Modify the pretimeout validation procedure
> 
> Changes since version 1:
> - Add each driver's command structure
> - Fix platform driver registration
> - Fix warnings
> - Drop unnecessary logs
> - Modify start() function to setup device
> 
>  MAINTAINERS                    |   1 +
>  drivers/watchdog/Kconfig       |  11 ++
>  drivers/watchdog/Makefile      |   1 +
>  drivers/watchdog/nct6694_wdt.c | 307 +++++++++++++++++++++++++++++++++
>  4 files changed, 320 insertions(+)
>  create mode 100644 drivers/watchdog/nct6694_wdt.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index ce276999625e..7c3edac315b4 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -17796,6 +17796,7 @@ F:	drivers/gpio/gpio-nct6694.c
>  F:	drivers/i2c/busses/i2c-nct6694.c
>  F:	drivers/mfd/nct6694.c
>  F:	drivers/net/can/usb/nct6694_canfd.c
> +F:	drivers/watchdog/nct6694_wdt.c
>  F:	include/linux/mfd/nct6694.h
>  
>  NUVOTON NCT7201 IIO DRIVER
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 0c25b2ed44eb..05008d937e40 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -760,6 +760,17 @@ config MAX77620_WATCHDOG
>  	  MAX77620 chips. To compile this driver as a module,
>  	  choose M here: the module will be called max77620_wdt.
>  
> +config NCT6694_WATCHDOG
> +	tristate "Nuvoton NCT6694 watchdog support"
> +	depends on MFD_NCT6694
> +	select WATCHDOG_CORE
> +	help
> +	  Say Y here to support Nuvoton NCT6694 watchdog timer
> +	  functionality.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called nct6694_wdt.
> +
>  config IMX2_WDT
>  	tristate "IMX2+ Watchdog"
>  	depends on ARCH_MXC || ARCH_LAYERSCAPE || COMPILE_TEST
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index bbd4d62d2cc3..b680e4d3c1bc 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -235,6 +235,7 @@ obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
>  obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
>  obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
>  obj-$(CONFIG_MAX77620_WATCHDOG) += max77620_wdt.o
> +obj-$(CONFIG_NCT6694_WATCHDOG) += nct6694_wdt.o
>  obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o
>  obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
>  obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o
> diff --git a/drivers/watchdog/nct6694_wdt.c b/drivers/watchdog/nct6694_wdt.c
> new file mode 100644
> index 000000000000..bc3689bd4b6b
> --- /dev/null
> +++ b/drivers/watchdog/nct6694_wdt.c
> @@ -0,0 +1,307 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Nuvoton NCT6694 WDT driver based on USB interface.
> + *
> + * Copyright (C) 2025 Nuvoton Technology Corp.
> + */
> +
> +#include <linux/idr.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/nct6694.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/watchdog.h>
> +
> +#define DEVICE_NAME "nct6694-wdt"
> +
> +#define NCT6694_DEFAULT_TIMEOUT		10
> +#define NCT6694_DEFAULT_PRETIMEOUT	0
> +
> +#define NCT6694_WDT_MAX_DEVS		2
> +
> +/*
> + * USB command module type for NCT6694 WDT controller.
> + * This defines the module type used for communication with the NCT6694
> + * WDT controller over the USB interface.
> + */
> +#define NCT6694_WDT_MOD			0x07
> +
> +/* Command 00h - WDT Setup */
> +#define NCT6694_WDT_SETUP		0x00
> +#define NCT6694_WDT_SETUP_SEL(idx)	(idx ? 0x01 : 0x00)
> +
> +/* Command 01h - WDT Command */
> +#define NCT6694_WDT_COMMAND		0x01
> +#define NCT6694_WDT_COMMAND_SEL(idx)	(idx ? 0x01 : 0x00)
> +
> +static unsigned int timeout[NCT6694_WDT_MAX_DEVS] = {
> +	[0 ... (NCT6694_WDT_MAX_DEVS - 1)] = NCT6694_DEFAULT_TIMEOUT
> +};
> +module_param_array(timeout, int, NULL, 0644);
> +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
> +
> +static unsigned int pretimeout[NCT6694_WDT_MAX_DEVS] = {
> +	[0 ... (NCT6694_WDT_MAX_DEVS - 1)] = NCT6694_DEFAULT_PRETIMEOUT
> +};
> +module_param_array(pretimeout, int, NULL, 0644);
> +MODULE_PARM_DESC(pretimeout, "Watchdog pre-timeout in seconds");
> +
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +module_param(nowayout, bool, 0);
> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> +			   __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> +enum {
> +	NCT6694_ACTION_NONE = 0,
> +	NCT6694_ACTION_SIRQ,
> +	NCT6694_ACTION_GPO,
> +};
> +
> +struct __packed nct6694_wdt_setup {
> +	__le32 pretimeout;
> +	__le32 timeout;
> +	u8 owner;
> +	u8 scratch;
> +	u8 control;
> +	u8 status;
> +	__le32 countdown;
> +};
> +
> +struct __packed nct6694_wdt_cmd {
> +	__le32 wdt_cmd;
> +	__le32 reserved;
> +};
> +
> +union __packed nct6694_wdt_msg {
> +	struct nct6694_wdt_setup setup;
> +	struct nct6694_wdt_cmd cmd;
> +};
> +
> +struct nct6694_wdt_data {
> +	struct watchdog_device wdev;
> +	struct device *dev;
> +	struct nct6694 *nct6694;
> +	union nct6694_wdt_msg *msg;
> +	unsigned char wdev_idx;
> +};
> +
> +static int nct6694_wdt_setting(struct watchdog_device *wdev,
> +			       u32 timeout_val, u8 timeout_act,
> +			       u32 pretimeout_val, u8 pretimeout_act)
> +{
> +	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
> +	struct nct6694_wdt_setup *setup = &data->msg->setup;
> +	const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_WDT_MOD,
> +		.cmd = NCT6694_WDT_SETUP,
> +		.sel = NCT6694_WDT_SETUP_SEL(data->wdev_idx),
> +		.len = cpu_to_le16(sizeof(*setup))
> +	};
> +	unsigned int timeout_fmt, pretimeout_fmt;
> +
> +	if (pretimeout_val == 0)
> +		pretimeout_act = NCT6694_ACTION_NONE;
> +
> +	timeout_fmt = (timeout_val * 1000) | (timeout_act << 24);
> +	pretimeout_fmt = (pretimeout_val * 1000) | (pretimeout_act << 24);
> +
> +	memset(setup, 0, sizeof(*setup));
> +	setup->timeout = cpu_to_le32(timeout_fmt);
> +	setup->pretimeout = cpu_to_le32(pretimeout_fmt);
> +
> +	return nct6694_write_msg(data->nct6694, &cmd_hd, setup);
> +}
> +
> +static int nct6694_wdt_start(struct watchdog_device *wdev)
> +{
> +	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
> +	int ret;
> +
> +	ret = nct6694_wdt_setting(wdev, wdev->timeout, NCT6694_ACTION_GPO,
> +				  wdev->pretimeout, NCT6694_ACTION_GPO);
> +	if (ret)
> +		return ret;
> +
> +	dev_dbg(data->dev, "Setting WDT(%d): timeout = %d, pretimeout = %d\n",
> +		data->wdev_idx, wdev->timeout, wdev->pretimeout);
> +
> +	return ret;
> +}
> +
> +static int nct6694_wdt_stop(struct watchdog_device *wdev)
> +{
> +	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
> +	struct nct6694_wdt_cmd *cmd = &data->msg->cmd;
> +	const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_WDT_MOD,
> +		.cmd = NCT6694_WDT_COMMAND,
> +		.sel = NCT6694_WDT_COMMAND_SEL(data->wdev_idx),
> +		.len = cpu_to_le16(sizeof(*cmd))
> +	};
> +
> +	memcpy(&cmd->wdt_cmd, "WDTC", 4);
> +	cmd->reserved = 0;
> +
> +	return nct6694_write_msg(data->nct6694, &cmd_hd, cmd);
> +}
> +
> +static int nct6694_wdt_ping(struct watchdog_device *wdev)
> +{
> +	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
> +	struct nct6694_wdt_cmd *cmd = &data->msg->cmd;
> +	const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_WDT_MOD,
> +		.cmd = NCT6694_WDT_COMMAND,
> +		.sel = NCT6694_WDT_COMMAND_SEL(data->wdev_idx),
> +		.len = cpu_to_le16(sizeof(*cmd))
> +	};
> +
> +	memcpy(&cmd->wdt_cmd, "WDTS", 4);
> +	cmd->reserved = 0;
> +
> +	return nct6694_write_msg(data->nct6694, &cmd_hd, cmd);
> +}
> +
> +static int nct6694_wdt_set_timeout(struct watchdog_device *wdev,
> +				   unsigned int new_timeout)
> +{
> +	int ret;
> +
> +	ret = nct6694_wdt_setting(wdev, new_timeout, NCT6694_ACTION_GPO,
> +				  wdev->pretimeout, NCT6694_ACTION_GPO);
> +	if (ret)
> +		return ret;
> +
> +	wdev->timeout = new_timeout;
> +
> +	return 0;
> +}
> +
> +static int nct6694_wdt_set_pretimeout(struct watchdog_device *wdev,
> +				      unsigned int new_pretimeout)
> +{
> +	int ret;
> +
> +	ret = nct6694_wdt_setting(wdev, wdev->timeout, NCT6694_ACTION_GPO,
> +				  new_pretimeout, NCT6694_ACTION_GPO);
> +	if (ret)
> +		return ret;
> +
> +	wdev->pretimeout = new_pretimeout;
> +
> +	return 0;
> +}
> +
> +static unsigned int nct6694_wdt_get_time(struct watchdog_device *wdev)
> +{
> +	struct nct6694_wdt_data *data = watchdog_get_drvdata(wdev);
> +	struct nct6694_wdt_setup *setup = &data->msg->setup;
> +	const struct nct6694_cmd_header cmd_hd = {
> +		.mod = NCT6694_WDT_MOD,
> +		.cmd = NCT6694_WDT_SETUP,
> +		.sel = NCT6694_WDT_SETUP_SEL(data->wdev_idx),
> +		.len = cpu_to_le16(sizeof(*setup))
> +	};
> +	unsigned int timeleft_ms;
> +	int ret;
> +
> +	ret = nct6694_read_msg(data->nct6694, &cmd_hd, setup);
> +	if (ret)
> +		return 0;
> +
> +	timeleft_ms = le32_to_cpu(setup->countdown);
> +
> +	return timeleft_ms / 1000;
> +}
> +
> +static const struct watchdog_info nct6694_wdt_info = {
> +	.options = WDIOF_SETTIMEOUT	|
> +		   WDIOF_KEEPALIVEPING	|
> +		   WDIOF_MAGICCLOSE	|
> +		   WDIOF_PRETIMEOUT,
> +	.identity = DEVICE_NAME,
> +};
> +
> +static const struct watchdog_ops nct6694_wdt_ops = {
> +	.owner = THIS_MODULE,
> +	.start = nct6694_wdt_start,
> +	.stop = nct6694_wdt_stop,
> +	.set_timeout = nct6694_wdt_set_timeout,
> +	.set_pretimeout = nct6694_wdt_set_pretimeout,
> +	.get_timeleft = nct6694_wdt_get_time,
> +	.ping = nct6694_wdt_ping,
> +};
> +
> +static void nct6694_wdt_ida_free(void *d)
> +{
> +	struct nct6694_wdt_data *data = d;
> +	struct nct6694 *nct6694 = data->nct6694;
> +
> +	ida_free(&nct6694->wdt_ida, data->wdev_idx);
> +}
> +
> +static int nct6694_wdt_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct nct6694 *nct6694 = dev_get_drvdata(dev->parent);
> +	struct nct6694_wdt_data *data;
> +	struct watchdog_device *wdev;
> +	int ret;
> +
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->msg = devm_kzalloc(dev, sizeof(union nct6694_wdt_msg),
> +				 GFP_KERNEL);
> +	if (!data->msg)
> +		return -ENOMEM;
> +
> +	data->dev = dev;
> +	data->nct6694 = nct6694;
> +
> +	ret = ida_alloc(&nct6694->wdt_ida, GFP_KERNEL);
> +	if (ret < 0)
> +		return ret;
> +	data->wdev_idx = ret;
> +
> +	ret = devm_add_action_or_reset(dev, nct6694_wdt_ida_free, data);
> +	if (ret)
> +		return ret;
> +
> +	wdev = &data->wdev;
> +	wdev->info = &nct6694_wdt_info;
> +	wdev->ops = &nct6694_wdt_ops;
> +	wdev->timeout = timeout[data->wdev_idx];
> +	wdev->pretimeout = pretimeout[data->wdev_idx];
> +	if (timeout[data->wdev_idx] < pretimeout[data->wdev_idx]) {
> +		dev_warn(data->dev, "pretimeout < timeout. Setting to zero\n");
> +		wdev->pretimeout = 0;
> +	}
> +
> +	wdev->min_timeout = 1;
> +	wdev->max_timeout = 255;
> +
> +	platform_set_drvdata(pdev, data);
> +
> +	watchdog_set_drvdata(&data->wdev, data);
> +	watchdog_set_nowayout(&data->wdev, nowayout);
> +	watchdog_stop_on_reboot(&data->wdev);
> +
> +	return devm_watchdog_register_device(dev, &data->wdev);
> +}
> +
> +static struct platform_driver nct6694_wdt_driver = {
> +	.driver = {
> +		.name	= DEVICE_NAME,
> +	},
> +	.probe		= nct6694_wdt_probe,
> +};
> +
> +module_platform_driver(nct6694_wdt_driver);
> +
> +MODULE_DESCRIPTION("USB-WDT driver for NCT6694");
> +MODULE_AUTHOR("Ming Yu <tmyu0@nuvoton.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:nct6694-wdt");
> -- 
> 2.34.1
>