drivers: power_domain: add nrfs_swext driver

Add power domain driver for nordic nrfs swext power domain.

Signed-off-by: Bjarki Arge Andreasen <bjarki.andreasen@nordicsemi.no>

Author: bjarki-andreasen

drivers/power_domain/CMakeLists.txt

@@ -7,4 +7,5 @@ zephyr_library_sources_ifdef(CONFIG_POWER_DOMAIN_GPIO power_domain_gpio.c)
 zephyr_library_sources_ifdef(CONFIG_POWER_DOMAIN_GPIO_MONITOR power_domain_gpio_monitor.c)
 zephyr_library_sources_ifdef(CONFIG_POWER_DOMAIN_INTEL_ADSP power_domain_intel_adsp.c)
 zephyr_library_sources_ifdef(CONFIG_POWER_DOMAIN_NXP_SCU power_domain_nxp_scu.c)
+zephyr_library_sources_ifdef(CONFIG_POWER_DOMAIN_NRFS_SWEXT power_domain_nrfs_swext.c)
 zephyr_library_sources_ifdef(CONFIG_POWER_DOMAIN_SOC_PM_STATE power_domain_soc_state_change.c)

drivers/power_domain/Kconfig

@@ -99,4 +99,6 @@ config POWER_DOMAIN_SOC_PM_STATE
 	  Generic power domain control to turn on/off devices when the
 	  PM subsystem transitions in and out certain power states.
 
+rsource "Kconfig.nrfs_swext"
+
 endif

drivers/power_domain/Kconfig.nrfs_swext

@@ -0,0 +1,9 @@
+# Copyright 2025 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+config POWER_DOMAIN_NRFS_SWEXT
+	bool "NRFS SWEXT power domain driver"
+	depends on DT_HAS_NORDIC_NRFS_SWEXT_ENABLED
+	depends on NRFS
+	depends on NRFS_SWEXT_SERVICE_ENABLED
+	default y

drivers/power_domain/power_domain_nrfs_swext.c

@@ -0,0 +1,162 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT nordic_nrfs_swext
+
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/pm/device.h>
+#include <zephyr/logging/log.h>
+
+#include <nrfs_swext.h>
+#include <nrfs_backend_ipc_service.h>
+
+LOG_MODULE_REGISTER(nrfs_swext, CONFIG_POWER_DOMAIN_LOG_LEVEL);
+
+BUILD_ASSERT(
+	DT_NUM_INST_STATUS_OKAY(DT_DRV_COMPAT) == 1,
+	"multiple instances not supported"
+);
+
+struct nrfs_swext_data {
+	struct k_sem evt_sem;
+	nrfs_swext_evt_type_t evt;
+};
+
+struct nrfs_swext_config {
+	uint16_t current_limit_ua;
+	bool enable_power_down_clamp;
+};
+
+static void nrfs_swext_driver_evt_handler(nrfs_swext_evt_t const *p_evt, void *context)
+{
+	struct nrfs_swext_data *dev_data = context;
+
+	LOG_DBG("evt %u", (uint32_t)p_evt->type);
+
+	if (p_evt->type == NRFS_SWEXT_EVT_OVERCURRENT) {
+		/* Overcurrent is an unrecoverable condition which requires hardware fix */
+		LOG_ERR("overcurrent");
+		k_panic();
+	};
+
+	dev_data->evt = p_evt->type;
+	k_sem_give(&dev_data->evt_sem);
+}
+
+static int nrfs_swext_driver_suspend(const struct device *dev)
+{
+	struct nrfs_swext_data *dev_data = dev->data;
+	const struct nrfs_swext_config *dev_config = dev->config;
+	nrfs_err_t err;
+	swext_pd_clamp_t pd_clamp = dev_config->enable_power_down_clamp
+				  ? SWEXT_PD_CLAMP_ENABLED
+				  : SWEXT_PD_CLAMP_DISABLED;
+
+	err = nrfs_swext_power_down(pd_clamp, dev_data);
+	if (err != NRFS_SUCCESS) {
+		LOG_ERR("failed to request power up");
+		return -ENODEV;
+	}
+
+	(void)k_sem_take(&dev_data->evt_sem, K_FOREVER);
+
+	if (dev_data->evt == NRFS_SWEXT_EVT_ENABLED) {
+		return 0;
+	}
+
+	LOG_ERR("power down request rejected");
+	return -EIO;
+}
+
+static int nrfs_swext_driver_resume(const struct device *dev)
+{
+	struct nrfs_swext_data *dev_data = dev->data;
+	const struct nrfs_swext_config *dev_config = dev->config;
+	nrfs_err_t err;
+	uint8_t load_current;
+
+	load_current = nrfs_swext_load_current_to_raw(dev_config->current_limit_ua);
+	err = nrfs_swext_power_up(load_current, dev_data);
+	if (err != NRFS_SUCCESS) {
+		LOG_ERR("failed to request power up");
+		return -ENODEV;
+	}
+
+	(void)k_sem_take(&dev_data->evt_sem, K_FOREVER);
+
+	if (dev_data->evt == NRFS_SWEXT_EVT_ENABLED) {
+		return 0;
+	}
+
+	LOG_ERR("power up request rejected");
+	return -EIO;
+}
+
+static int nrfs_swext_driver_pm_action(const struct device *dev, enum pm_device_action action)
+{
+	int ret;
+
+	switch (action) {
+	case PM_DEVICE_ACTION_SUSPEND:
+		ret = nrfs_swext_driver_suspend(dev);
+		break;
+
+	case PM_DEVICE_ACTION_RESUME:
+		ret = nrfs_swext_driver_resume(dev);
+		break;
+
+	default:
+		ret = -ENOTSUP;
+		break;
+	};
+
+	return ret;
+}
+
+static int nrfs_swext_driver_init(const struct device *dev)
+{
+	struct nrfs_swext_data *dev_data = dev->data;
+	nrfs_err_t err;
+
+	LOG_DBG("waiting for nrfs backend connected");
+	err = nrfs_backend_wait_for_connection(K_FOREVER);
+	if (err != NRFS_SUCCESS) {
+		LOG_ERR("nrfs backend not connected");
+		return -ENODEV;
+	}
+
+	err = nrfs_swext_init(nrfs_swext_driver_evt_handler);
+	if (err != NRFS_SUCCESS) {
+		LOG_ERR("failed to init swext service");
+		return -ENODEV;
+	}
+
+	k_sem_init(&dev_data->evt_sem, 0, 1);
+	return pm_device_driver_init(dev, nrfs_swext_driver_pm_action);
+}
+
+PM_DEVICE_DT_INST_DEFINE(0, power_domain_driver_pm_action);
+
+BUILD_ASSERT(DT_INST_PROP(0, max_current_ua) <= UINT16_MAX);
+BUILD_ASSERT(DT_INST_PROP(0, current_limit_ua) <= DT_INST_PROP(0, max_current_ua));
+
+static struct nrfs_swext_data data0;
+static const struct nrfs_swext_config config0 = {
+	.current_limit_ua = DT_INST_PROP(0, current_limit_ua),
+	.enable_power_down_clamp = DT_INST_PROP(0, power_down_clamp),
+};
+
+DEVICE_DT_INST_DEFINE(
+	0,
+	nrfs_swext_driver_init,
+	PM_DEVICE_DT_INST_GET(inst),
+	&data0,
+	&config0,
+	POST_KERNEL,
+	UTIL_INC(CONFIG_NRFS_BACKEND_IPC_SERVICE_INIT_PRIO),
+	NULL
+);