From: Ming Yu This driver supports Watchdog timer functionality for NCT6694 MFD device based on USB interface. Acked-by: Guenter Roeck Signed-off-by: Ming Yu --- Changes since version 13: 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 41aecd188d37..1a03b8603d16 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17822,6 +17822,7 @@ 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 +#include +#include +#include +#include +#include +#include + +#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 "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:nct6694-wdt"); -- 2.34.1