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EmilioCBenEmilioCBen
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drivers: watchdog: Added Driver for the EWM
Added a driver for the External Watchdog Driver Signed-off-by: Emilio Benavente <[email protected]>
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‎drivers/watchdog/CMakeLists.txt

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Original file line numberDiff line numberDiff line change
@@ -57,5 +57,6 @@ zephyr_library_sources_ifdef(CONFIG_WDT_ANDES_ATCWDT200 wdt_andes_atcwdt200.c)
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zephyr_library_sources_ifdef(CONFIG_WDT_NXP_FS26 wdt_nxp_fs26.c)
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zephyr_library_sources_ifdef(CONFIG_WDT_SHELL wdt_shell.c)
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zephyr_library_sources_ifdef(CONFIG_WDT_RENESAS_RA wdt_renesas_ra.c)
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zephyr_library_sources_ifdef(CONFIG_WDT_NXP_EWM wdt_nxp_ewm.c)
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zephyr_library_sources_ifdef(CONFIG_USERSPACE wdt_handlers.c)

‎drivers/watchdog/Kconfig

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Original file line numberDiff line numberDiff line change
@@ -149,4 +149,6 @@ source "drivers/watchdog/Kconfig.rts5912"
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source "drivers/watchdog/Kconfig.renesas_ra"
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source "drivers/watchdog/Kconfig.nxp_ewm"
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endif # WATCHDOG

‎drivers/watchdog/Kconfig.nxp_ewm

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# Copyright 2025 NXP
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# SPDX-License-Identifier: Apache-2.0
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config WDT_NXP_EWM
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bool "NXP EWM driver"
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default y
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depends on DT_HAS_NXP_EWM_ENABLED
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help
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Enable the nxp ewm driver.

‎drivers/watchdog/wdt_nxp_ewm.c

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/*
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*
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* Copyright 2025 NXP
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#define DT_DRV_COMPAT nxp_ewm
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#include <zephyr/drivers/watchdog.h>
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#include <zephyr/irq.h>
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#include <fsl_clock.h>
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#define LOG_LEVEL CONFIG_WDT_LOG_LEVEL
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#include <zephyr/logging/log.h>
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LOG_MODULE_REGISTER(wdt_nxp_ewm);
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#define NXP_EWM_FEED_MAGIC_NUMBER 0x2CB4
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#define NXP_EWM_MAX_TIMEOUT_WINDOW 0xFE
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struct nxp_ewm_config {
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EWM_Type *base;
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void (*irq_config_func)(const struct device *dev);
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bool is_input_enabled;
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bool is_input_active_high;
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uint8_t clk_divider;
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};
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struct nxp_ewm_data {
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struct wdt_timeout_cfg timeout_cfg;
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bool is_watchdog_setup;
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};
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static int nxp_ewm_setup(const struct device *dev, uint8_t options)
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{
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const struct nxp_ewm_config *config = dev->config;
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struct nxp_ewm_data *data = dev->data;
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EWM_Type *base = config->base;
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if (!data->is_watchdog_setup) {
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if (options) {
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/* Unable to halt counter during debugging */
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return -ENOTSUP;
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}
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data->is_watchdog_setup = true;
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base->CMPL = EWM_CMPL_COMPAREL(data->timeout_cfg.window.min);
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base->CMPH = EWM_CMPH_COMPAREH(data->timeout_cfg.window.max);
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/*
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* base->CTRL should be the last thing touched due to
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* the small watchdog window time.
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* After this write, only the INTEN bit is writable until reset.
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*
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* EWM_CTRL_INTEN enables the interrupt signal
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* EWM_CTRL_EWMEN enables the watchdog.
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*/
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base->CTRL |= EWM_CTRL_INEN(config->is_input_enabled) |
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EWM_CTRL_ASSIN(config->is_input_active_high) |
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EWM_CTRL_INTEN(1) | EWM_CTRL_EWMEN(1);
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return 0;
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}
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/* Watchdog cannot be re-configured after enabled. */
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return -EBUSY;
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}
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static int nxp_ewm_disable(const struct device *dev)
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{
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struct nxp_ewm_data *data = dev->data;
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if (!data->is_watchdog_setup) {
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return -EFAULT;
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}
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return -EPERM;
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}
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static int nxp_ewm_install_timeout(const struct device *dev,
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const struct wdt_timeout_cfg *cfg)
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{
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struct nxp_ewm_data *data = dev->data;
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if (!data->is_watchdog_setup) {
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if (cfg && cfg->window.max <= NXP_EWM_MAX_TIMEOUT_WINDOW &&
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cfg->window.min <= cfg->window.max &&
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cfg->window.max > 0 &&
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cfg->window.min >= 0) {
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data->timeout_cfg.window = cfg->window;
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} else {
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return -EINVAL;
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}
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#if defined(CONFIG_WDT_MULTISTAGE)
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if (cfg->next) {
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return -EINVAL;
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}
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#endif
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if (cfg->callback) {
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data->timeout_cfg.callback = cfg->callback;
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}
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if (cfg->flags) {
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return -ENOTSUP;
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}
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return 0;
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}
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/* Only one watchdog timeout is available */
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return -ENOMEM;
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}
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static int nxp_ewm_feed(const struct device *dev, int channel_id)
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{
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ARG_UNUSED(channel_id);
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const struct nxp_ewm_config *config = dev->config;
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EWM_Type *base = config->base;
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unsigned int key = irq_lock();
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base->SERV = EWM_SERV_SERVICE(NXP_EWM_FEED_MAGIC_NUMBER);
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base->SERV = EWM_SERV_SERVICE(NXP_EWM_FEED_MAGIC_NUMBER >> 8);
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irq_unlock(key);
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return 0;
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}
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static void nxp_ewm_isr(const struct device *dev)
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{
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const struct nxp_ewm_config *config = dev->config;
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struct nxp_ewm_data *data = dev->data;
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EWM_Type *base = config->base;
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base->CTRL &= (~EWM_CTRL_INTEN_MASK);
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if (data->timeout_cfg.callback) {
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data->timeout_cfg.callback(dev, 0);
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}
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if (data->timeout_cfg.flags) {
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}
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}
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static int nxp_ewm_init(const struct device *dev)
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{
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const struct nxp_ewm_config *config = dev->config;
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EWM_Type *base = config->base;
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if (config->clk_divider >= 0 && config->clk_divider <= 0xFF) {
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base->CLKPRESCALER = EWM_CLKPRESCALER_CLK_DIV(config->clk_divider);
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}
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config->irq_config_func(dev);
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return 0;
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}
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static DEVICE_API(wdt, nxp_ewm_api) = {
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.setup = nxp_ewm_setup,
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.disable = nxp_ewm_disable,
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.install_timeout = nxp_ewm_install_timeout,
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.feed = nxp_ewm_feed,
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};
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#define WDT_EWM_INIT(n) \
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static void nxp_ewm_config_func_##n(const struct device *dev); \
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\
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static const struct nxp_ewm_config nxp_ewm_config_##n = { \
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.base = (EWM_Type *)DT_INST_REG_ADDR(n), \
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.irq_config_func = nxp_ewm_config_func_##n, \
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.is_input_enabled = DT_INST_PROP(n, input_trigger_en), \
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.is_input_active_high = \
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DT_INST_PROP(n, input_trigger_active_high), \
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.clk_divider = DT_INST_PROP(n, clk_divider), \
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}; \
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\
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static struct nxp_ewm_data nxp_ewm_data_##n; \
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\
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DEVICE_DT_INST_DEFINE(n, \
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nxp_ewm_init, \
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NULL, \
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&nxp_ewm_data_##n, &nxp_ewm_config_##n, \
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POST_KERNEL, \
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CONFIG_KERNEL_INIT_PRIORITY_DEVICE, \
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&nxp_ewm_api); \
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\
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static void nxp_ewm_config_func_##n(const struct device *dev) \
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{ \
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ARG_UNUSED(dev); \
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\
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IRQ_CONNECT(DT_INST_IRQN(n), \
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DT_INST_IRQ(n, priority), \
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nxp_ewm_isr, DEVICE_DT_INST_GET(n), 0); \
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\
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irq_enable(DT_INST_IRQN(n)); \
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}
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DT_INST_FOREACH_STATUS_OKAY(WDT_EWM_INIT)

‎dts/bindings/watchdog/nxp,ewm.yaml

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@@ -0,0 +1,32 @@
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# Copyright 2025 NXP
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# SPDX-License-Identifier: Apache-2.0
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description: NXP External Watchdog Monitor
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compatible: "nxp,ewm"
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include: base.yaml
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properties:
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reg:
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required: true
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interrupts:
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required: true
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clk-divider:
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type: int
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description: Watchdog clock divider
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required: true
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input_trigger_en:
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type: boolean
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description: |
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When enabled the ewm_in signal can be used
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to assert the ewm.
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input_trigger_active_high:
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type: boolean
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description: |
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When enabled the ewm_in signal is active high.
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The ewm_in signal is active low otherwise.

‎soc/nxp/mcx/mcxw/soc.c

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@@ -188,6 +188,10 @@ __weak void clock_init(void)
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if (DT_NODE_HAS_COMPAT_STATUS(adc0, nxp_lpadc, okay)) {
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CLOCK_EnableClock(kCLOCK_Lpadc0);
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}
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if (DT_NODE_HAS_COMPAT_STATUS(DT_NODELABEL(ewm0), nxp_ewm, okay)) {
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CLOCK_EnableClock(kCLOCK_Ewm0);
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}
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}
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static void vbat_init(void)

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