drivers: watchdog: Add Ambiq wdt driver

This commits add watchdog driver for Apollo4 SoCs

Signed-off-by: Mateusz Sierszulski <msierszulski@antmicro.com>

drivers/watchdog/CMakeLists.txt

@@ -38,6 +38,7 @@ zephyr_library_sources_ifdef(CONFIG_WDT_TI_TPS382X wdt_ti_tps382x.c)
 zephyr_library_sources_ifdef(CONFIG_WDT_XILINX_AXI wdt_xilinx_axi.c)
 zephyr_library_sources_ifdef(CONFIG_WDT_INFINEON_CAT1 wdt_ifx_cat1.c)
 zephyr_library_sources_ifdef(CONFIG_WDT_OPENTITAN wdt_opentitan.c)
+zephyr_library_sources_ifdef(CONFIG_WDT_AMBIQ wdt_ambiq.c)
 
 zephyr_library_sources_ifdef(CONFIG_WDT_DW wdt_dw.c wdt_dw_common.c)
 zephyr_library_sources_ifdef(CONFIG_WDT_INTEL_ADSP wdt_intel_adsp.c wdt_dw_common.c)

drivers/watchdog/Kconfig

@@ -116,4 +116,6 @@ source "drivers/watchdog/Kconfig.andes_atcwdt200"
 
 source "drivers/watchdog/Kconfig.nxp_fs26"
 
+source "drivers/watchdog/Kconfig.ambiq"
+
 endif # WATCHDOG

drivers/watchdog/Kconfig.ambiq

@@ -0,0 +1,14 @@
+# Ambiq SDK WDT
+#
+# Copyright (c) 2023 Antmicro <www.antmicro.com>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+config WDT_AMBIQ
+	bool "AMBIQ WDT driver"
+	default y
+	depends on DT_HAS_AMBIQ_WATCHDOG_ENABLED
+	select AMBIQ_HAL
+	select AMBIQ_HAL_USE_WDT
+	help
+	  Enable driver for Ambiq WDT.

drivers/watchdog/wdt_ambiq.c

@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2023 Antmicro <www.antmicro.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT ambiq_watchdog
+
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/watchdog.h>
+
+#include <errno.h>
+#include <am_mcu_apollo.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(wdt_ambiq, CONFIG_WDT_LOG_LEVEL);
+
+typedef void (*ambiq_wdt_cfg_func_t)(void);
+
+struct wdt_ambiq_config {
+	uint32_t base;
+	uint32_t irq_num;
+	uint8_t clk_freq;
+	ambiq_wdt_cfg_func_t cfg_func;
+};
+
+struct wdt_ambiq_data {
+	wdt_callback_t callback;
+	uint32_t timeout;
+	bool reset;
+};
+
+static void wdt_ambiq_isr(void *arg)
+{
+	const struct device *dev = (const struct device *)arg;
+	struct wdt_ambiq_data *data = dev->data;
+
+	uint32_t status;
+
+	am_hal_wdt_interrupt_status_get(AM_HAL_WDT_MCU, &status, false);
+	am_hal_wdt_interrupt_clear(AM_HAL_WDT_MCU, status);
+
+	if (data->callback) {
+		data->callback(dev, 0);
+	}
+}
+
+static int wdt_ambiq_setup(const struct device *dev, uint8_t options)
+{
+	const struct wdt_ambiq_config *dev_cfg = dev->config;
+	struct wdt_ambiq_data *data = dev->data;
+	am_hal_wdt_config_t cfg;
+
+	if (dev_cfg->clk_freq == 128) {
+		cfg.eClockSource = AM_HAL_WDT_128HZ;
+	} else if (dev_cfg->clk_freq == 16) {
+		cfg.eClockSource = AM_HAL_WDT_16HZ;
+	} else if (dev_cfg->clk_freq == 1) {
+		cfg.eClockSource = AM_HAL_WDT_1HZ;
+	}
+
+	cfg.bInterruptEnable = true;
+	cfg.ui32InterruptValue = data->timeout;
+	cfg.bResetEnable = data->reset;
+	cfg.ui32ResetValue = data->timeout;
+	cfg.bAlertOnDSPReset = false;
+
+	am_hal_wdt_config(AM_HAL_WDT_MCU, &cfg);
+	am_hal_wdt_interrupt_enable(AM_HAL_WDT_MCU, AM_HAL_WDT_INTERRUPT_MCU);
+	am_hal_wdt_start(AM_HAL_WDT_MCU, false);
+
+	return 0;
+}
+
+static int wdt_ambiq_disable(const struct device *dev)
+{
+	ARG_UNUSED(dev);
+
+	am_hal_wdt_stop(AM_HAL_WDT_MCU);
+
+	return 0;
+}
+
+static int wdt_ambiq_install_timeout(const struct device *dev, const struct wdt_timeout_cfg *cfg)
+{
+	const struct wdt_ambiq_config *dev_cfg = dev->config;
+	struct wdt_ambiq_data *data = dev->data;
+
+	if (cfg->window.min != 0U || cfg->window.max == 0U) {
+		return -EINVAL;
+	}
+
+	data->timeout = cfg->window.max / 1000 * dev_cfg->clk_freq;
+	data->callback = cfg->callback;
+
+	switch (cfg->flags) {
+	case WDT_FLAG_RESET_CPU_CORE:
+	case WDT_FLAG_RESET_SOC:
+		data->reset = true;
+		break;
+	case WDT_FLAG_RESET_NONE:
+		data->reset = false;
+		break;
+	default:
+		LOG_ERR("Unsupported watchdog config flag");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int wdt_ambiq_feed(const struct device *dev, int channel_id)
+{
+	ARG_UNUSED(dev);
+	ARG_UNUSED(channel_id);
+
+	am_hal_wdt_restart(AM_HAL_WDT_MCU);
+	LOG_DBG("Fed the watchdog");
+
+	return 0;
+}
+
+static int wdt_ambiq_init(const struct device *dev)
+{
+	const struct wdt_ambiq_config *dev_cfg = dev->config;
+
+	if (dev_cfg->clk_freq != 128 && dev_cfg->clk_freq != 16 && dev_cfg->clk_freq != 1) {
+		return -ENOTSUP;
+	}
+
+	NVIC_ClearPendingIRQ(dev_cfg->irq_num);
+
+	dev_cfg->cfg_func();
+
+	irq_enable(dev_cfg->irq_num);
+
+	return 0;
+}
+
+static const struct wdt_driver_api wdt_ambiq_driver_api = {
+	.setup = wdt_ambiq_setup,
+	.disable = wdt_ambiq_disable,
+	.install_timeout = wdt_ambiq_install_timeout,
+	.feed = wdt_ambiq_feed,
+};
+
+#define AMBIQ_WDT_INIT(n)                                                                          \
+	static struct wdt_ambiq_data wdt_ambiq_data##n;                                            \
+	static void ambiq_wdt_cfg_func_##n(void)                                                   \
+	{                                                                                          \
+                                                                                                   \
+		IRQ_CONNECT(DT_INST_IRQN(n), DT_INST_IRQ(n, priority), wdt_ambiq_isr,              \
+			    DEVICE_DT_INST_GET(n), 0);                                             \
+	};                                                                                         \
+	static const struct wdt_ambiq_config wdt_ambiq_config##n = {                               \
+		.base = DT_INST_REG_ADDR(n),                                                       \
+		.clk_freq = DT_INST_PROP(n, clock_frequency),                                      \
+		.irq_num = DT_INST_IRQN(n),                                                        \
+		.cfg_func = ambiq_wdt_cfg_func_##n};                                               \
+                                                                                                   \
+	DEVICE_DT_INST_DEFINE(n, wdt_ambiq_init, NULL, &wdt_ambiq_data##n, &wdt_ambiq_config##n,   \
+			      PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,                    \
+			      &wdt_ambiq_driver_api);
+
+DT_INST_FOREACH_STATUS_OKAY(AMBIQ_WDT_INIT)

dts/bindings/watchdog/ambiq,watchdog.yaml

@@ -0,0 +1,19 @@
+# Copyright (c) 2023 Antmicro <www.antmicro.com>
+# SPDX-License-Identifier: Apache-2.0
+
+description: Ambiq Watchdog
+
+compatible: "ambiq,watchdog"
+
+include: base.yaml
+
+properties:
+  reg:
+    required: true
+
+  clock-frequency:
+    type: int
+    required: true
+
+  interrupts:
+    required: true

modules/hal_ambiq/Kconfig

@@ -25,4 +25,9 @@ config AMBIQ_HAL_USE_TIMER
 	help
 	  Use the TIMER driver from Ambiq HAL
 
+config AMBIQ_HAL_USE_WDT
+	bool
+	help
+	  Use the WDT driver from Ambiq HAL
+
 endif # AMBIQ_HAL

west.yml

@@ -142,7 +142,7 @@ manifest:
       groups:
         - hal
     - name: hal_ambiq
-      revision: 5079b0096479a5630b91d38a891c2db1693faa2a
+      revision: fe158a4395ba80a9d46c6782e23c277149855a57
       path: modules/hal/ambiq
       groups:
         - hal