drivers: watchdog: npm2100: Add driver for npm2100 pmic

Add watchdog driver for npm2100 pmic.

This pmic has one timer that can be used for multiple functions,
including a watchdog that can reset or power-cycle connected devices.

Signed-off-by: Audun Korneliussen <audun.korneliussen@nordicsemi.no>

drivers/watchdog/CMakeLists.txt

@@ -26,6 +26,7 @@ zephyr_library_sources_ifdef(CONFIG_WDT_MCUX_WDOG32 wdt_mcux_wdog32.c)
 zephyr_library_sources_ifdef(CONFIG_WDT_MCUX_WWDT wdt_mcux_wwdt.c)
 zephyr_library_sources_ifdef(CONFIG_WDT_NPCX wdt_npcx.c)
 zephyr_library_sources_ifdef(CONFIG_WDT_NPM1300 wdt_npm1300.c)
+zephyr_library_sources_ifdef(CONFIG_WDT_NPM2100 wdt_npm2100.c)
 zephyr_library_sources_ifdef(CONFIG_WDT_NPM6001 wdt_npm6001.c)
 zephyr_library_sources_ifdef(CONFIG_WDT_NRFX wdt_nrfx.c)
 zephyr_library_sources_ifdef(CONFIG_WDT_RPI_PICO wdt_rpi_pico.c)

drivers/watchdog/Kconfig

@@ -96,6 +96,8 @@ source "drivers/watchdog/Kconfig.gd32"
 
 source "drivers/watchdog/Kconfig.npm1300"
 
+source "drivers/watchdog/Kconfig.npm2100"
+
 source "drivers/watchdog/Kconfig.npm6001"
 
 source "drivers/watchdog/Kconfig.nxp_s32"

drivers/watchdog/Kconfig.npm2100

@@ -0,0 +1,19 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+config WDT_NPM2100
+	bool "nPM2100 Watchdog driver"
+	default y
+	depends on DT_HAS_NORDIC_NPM2100_WDT_ENABLED
+	select I2C
+	select MFD
+	help
+	  Enable nPM2100 Watchdog driver
+
+config WDT_NPM2100_INIT_PRIORITY
+	int "nPM2100 Watchdog driver initialization priority"
+	depends on WDT_NPM2100
+	default 85
+	help
+	  Initialization priority for the nPM2100 Watchdog driver.
+	  It must be greater than GPIO_NPM2100_INIT_PRIORITY.

drivers/watchdog/wdt_npm2100.c

@@ -0,0 +1,146 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT nordic_npm2100_wdt
+
+#include <errno.h>
+
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/drivers/watchdog.h>
+#include <zephyr/drivers/mfd/npm2100.h>
+
+#define TIMER_TASKS_START 0xB0U
+#define TIMER_TASKS_STOP  0xB1U
+#define TIMER_TASKS_KICK  0xB2U
+#define TIMER_CONFIG      0xB3U
+#define TIMER_TARGET_HI   0xB4U
+#define TIMER_TARGET_MID  0xB5U
+#define TIMER_TARGET_LO   0xB6U
+#define TIMER_STATUS      0xB7U
+#define TIMER_BOOT_MON    0xB8U
+
+struct wdt_npm2100_config {
+	const struct device *mfd;
+	struct i2c_dt_spec i2c;
+};
+
+struct wdt_npm2100_data {
+	bool timeout_valid;
+};
+
+static int wdt_npm2100_setup(const struct device *dev, uint8_t options)
+{
+	const struct wdt_npm2100_config *config = dev->config;
+	struct wdt_npm2100_data *data = dev->data;
+
+	if (!data->timeout_valid) {
+		return -EINVAL;
+	}
+
+	return mfd_npm2100_start_timer(config->mfd);
+}
+
+static int wdt_npm2100_disable(const struct device *dev)
+{
+	const struct wdt_npm2100_config *config = dev->config;
+	struct wdt_npm2100_data *data = dev->data;
+	int ret;
+
+	ret = i2c_reg_write_byte_dt(&config->i2c, TIMER_TASKS_STOP, 1U);
+	if (ret < 0) {
+		return ret;
+	}
+
+	data->timeout_valid = false;
+
+	return 0;
+}
+
+static int wdt_npm2100_install_timeout(const struct device *dev,
+				       const struct wdt_timeout_cfg *timeout)
+{
+	const struct wdt_npm2100_config *config = dev->config;
+	struct wdt_npm2100_data *data = dev->data;
+	uint8_t mode;
+	int ret;
+
+	if (data->timeout_valid) {
+		return -ENOMEM;
+	}
+
+	if (timeout->window.min != 0U) {
+		return -EINVAL;
+	}
+
+	switch (timeout->flags & WDT_FLAG_RESET_MASK) {
+	case WDT_FLAG_RESET_NONE:
+		/* Watchdog expiry causes event only, and does not reset */
+		mode = NPM2100_TIMER_MODE_GENERAL_PURPOSE;
+		break;
+	case WDT_FLAG_RESET_CPU_CORE:
+		/* Watchdog expiry asserts reset output */
+		mode = NPM2100_TIMER_MODE_WDT_RESET;
+		break;
+	case WDT_FLAG_RESET_SOC:
+		/* Watchdog expiry causes full power cycle */
+		mode = NPM2100_TIMER_MODE_WDT_POWER_CYCLE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = mfd_npm2100_set_timer(config->mfd, timeout->window.max, mode);
+	if (ret < 0) {
+		return ret;
+	}
+
+	data->timeout_valid = true;
+
+	return 0;
+}
+
+static int wdt_npm2100_feed(const struct device *dev, int channel_id)
+{
+	const struct wdt_npm2100_config *config = dev->config;
+
+	if (channel_id != 0) {
+		return -EINVAL;
+	}
+
+	return i2c_reg_write_byte_dt(&config->i2c, TIMER_TASKS_KICK, 1U);
+}
+
+static DEVICE_API(wdt, wdt_npm2100_api) = {
+	.setup = wdt_npm2100_setup,
+	.disable = wdt_npm2100_disable,
+	.install_timeout = wdt_npm2100_install_timeout,
+	.feed = wdt_npm2100_feed,
+};
+
+static int wdt_npm2100_init(const struct device *dev)
+{
+	const struct wdt_npm2100_config *config = dev->config;
+
+	if (!i2c_is_ready_dt(&config->i2c)) {
+		return -ENODEV;
+	}
+
+	/* Disable boot monitor */
+	return wdt_npm2100_disable(dev);
+}
+
+#define WDT_NPM2100_DEFINE(n)                                                                      \
+	static struct wdt_npm2100_data data##n;                                                    \
+                                                                                                   \
+	static const struct wdt_npm2100_config config##n = {                                       \
+		.mfd = DEVICE_DT_GET(DT_INST_PARENT(n)),                                           \
+		.i2c = I2C_DT_SPEC_GET(DT_INST_PARENT(n)),                                         \
+	};                                                                                         \
+                                                                                                   \
+	DEVICE_DT_INST_DEFINE(n, &wdt_npm2100_init, NULL, &data##n, &config##n, POST_KERNEL,       \
+			      CONFIG_WDT_NPM2100_INIT_PRIORITY, &wdt_npm2100_api);
+
+DT_INST_FOREACH_STATUS_OKAY(WDT_NPM2100_DEFINE)

dts/bindings/watchdog/nordic,npm2100-wdt.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+description: nPM2100 Watchdog
+
+compatible: "nordic,npm2100-wdt"
+
+include: base.yaml

tests/drivers/build_all/watchdog/i2c_devices.overlay

@@ -32,6 +32,15 @@
 					compatible = "nordic,npm6001-wdt";
 				};
 			};
+
+			npm2100_pmic: pmic@1 {
+				compatible = "nordic,npm2100";
+				reg = <0x1>;
+
+				npm2100_wdt: watchdog {
+					compatible = "nordic,npm2100-wdt";
+				};
+			};
 		};
 	};
 };