drivers: watchdog: Add shim for nrfx WDT driver

Changes add a translation layer to make nrfx WDT driver works
with Zephyr API.

Signed-off-by: Karol Lasończyk <karol.lasonczyk@nordicsemi.no>

drivers/watchdog/CMakeLists.txt

@@ -4,3 +4,4 @@ zephyr_sources_ifdef(CONFIG_WDOG_CMSDK_APB wdog_cmsdk_apb.c)
 zephyr_sources_ifdef(CONFIG_WDT_SAM wdt_sam.c)
 zephyr_sources_ifdef(CONFIG_WDT_ESP32 wdt_esp32.c)
 zephyr_sources_ifdef(CONFIG_WDT_SAM0 wdt_sam0.c)
+zephyr_sources_ifdef(CONFIG_WDT_NRFX wdt_nrfx.c)

drivers/watchdog/Kconfig

@@ -57,4 +57,6 @@ source "drivers/watchdog/Kconfig.esp32"
 
 source "drivers/watchdog/Kconfig.sam0"
 
+source "drivers/watchdog/Kconfig.nrfx"
+
 endif

drivers/watchdog/Kconfig.nrfx

@@ -0,0 +1,14 @@
+# Kconfig - nrfx WDT support
+#
+# Copyright (c) 2018, Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: Apache-2.0
+
+menuconfig WDT_NRFX
+	bool "nRF WDT nrfx driver"
+	depends on SOC_FAMILY_NRF && CLOCK_CONTROL_NRF5
+	select HAS_DTS_WDT
+	select NRFX_WDT
+	default n
+	help
+	  Enable support for nrfx WDT driver for nRF MCU series.

drivers/watchdog/wdt_nrfx.c

@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) 2018, Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <nrfx_wdt.h>
+#include <nrf_clock.h>
+#include <clock_control.h>
+#include <watchdog.h>
+
+#define SYS_LOG_DOMAIN "wdt_nrfx"
+#define SYS_LOG_LEVEL CONFIG_SYS_LOG_WDT_LEVEL
+#include <logging/sys_log.h>
+
+DEVICE_DECLARE(wdt_nrfx);
+
+/* Each activated and not reloaded channel can generate watchdog interrupt.
+ * Array m_callbacks provides storing callbacks for each channel.
+ */
+static wdt_callback_t m_callbacks[NRF_WDT_CHANNEL_NUMBER];
+
+/*
+ * The m_allocated_channels variable stores number of currently allocated
+ * and activated watchdog channels.
+ */
+static u8_t           m_allocated_channels;
+
+/*
+ * The m_timeout variable stores watchdog timeout value in millisecond units.
+ * It is used to check whether installing watchdog provide the same timeout
+ * value in the window configuration.
+ */
+static u32_t          m_timeout;
+
+
+static void wdt_event_handler(void)
+{
+	int i;
+
+	for (i = 0; i < m_allocated_channels ; ++i) {
+		if (nrf_wdt_request_status((nrf_wdt_rr_register_t)i)) {
+			if (m_callbacks[i]) {
+				m_callbacks[i](DEVICE_GET(wdt_nrfx), i);
+			}
+		}
+	}
+}
+
+static void wdt_nrf_isr(struct device *dev)
+{
+	ARG_UNUSED(dev);
+	/* We need to implement our own interrupt handler until nrfx one will
+	 * be fixed.
+	 * Clearing events also clears the reload register and has to be done
+	 * AFTER event handler.
+	 */
+	wdt_event_handler();
+	nrf_wdt_event_clear(NRF_WDT_EVENT_TIMEOUT);
+}
+
+static int wdt_nrf_setup(struct device *dev, u8_t options)
+{
+	nrfx_wdt_config_t config;
+	nrfx_err_t err_code;
+
+	ARG_UNUSED(dev);
+
+	if (!nrf_clock_lf_is_running()) {
+		return -ENOTSUP;
+	}
+
+	/* Activate all available options. Run in all cases. */
+	config.behaviour = NRF_WDT_BEHAVIOUR_RUN_SLEEP_HALT;
+
+	/* Deactivate running in sleep mode. */
+	if (options & WDT_OPT_PAUSE_IN_SLEEP) {
+		config.behaviour &= ~NRF_WDT_BEHAVIOUR_RUN_SLEEP;
+	}
+
+	/* Deactivate running when debugger is attached. */
+	if (options & WDT_OPT_PAUSE_HALTED_BY_DBG) {
+		config.behaviour &= ~NRF_WDT_BEHAVIOUR_RUN_HALT;
+	}
+
+	config.reload_value = m_timeout;
+
+	err_code = nrfx_wdt_init(&config, wdt_event_handler);
+	if (err_code != NRFX_SUCCESS) {
+		return -EBUSY;
+	}
+
+	IRQ_CONNECT(CONFIG_WDT_NRF_IRQ,
+		    CONFIG_WDT_NRF_IRQ_PRI, wdt_nrf_isr,
+		    DEVICE_GET(wdt_nrfx), 0);
+	irq_enable(CONFIG_WDT_NRF_IRQ);
+
+	nrfx_wdt_enable();
+
+	return 0;
+}
+
+static int wdt_nrf_disable(struct device *dev)
+{
+	/* Started watchdog cannot be stopped on nRF devices. */
+	ARG_UNUSED(dev);
+	return -EPERM;
+}
+
+static int wdt_nrf_install_timeout(struct device *dev,
+				   const struct wdt_timeout_cfg *cfg)
+{
+	nrfx_err_t err_code;
+	nrfx_wdt_channel_id channel_id;
+
+	ARG_UNUSED(dev);
+
+	if (cfg->flags != WDT_FLAG_RESET_SOC) {
+		return -ENOTSUP;
+	}
+
+	if (cfg->window.min != 0) {
+		return -EINVAL;
+	}
+
+	if (m_allocated_channels == 0) {
+		/* Save timeout value from first registered watchdog channel. */
+		m_timeout = cfg->window.max;
+	} else if (cfg->window.max != m_timeout) {
+		return -EINVAL;
+	}
+
+	err_code = nrfx_wdt_channel_alloc(&channel_id);
+
+	if (err_code == NRFX_ERROR_NO_MEM) {
+		return -ENOMEM;
+	}
+
+	if (cfg->callback != NULL) {
+		m_callbacks[channel_id] = cfg->callback;
+	}
+
+	m_allocated_channels++;
+	return channel_id;
+}
+
+static int wdt_nrf_feed(struct device *dev, int channel_id)
+{
+	ARG_UNUSED(dev);
+	if (channel_id > m_allocated_channels) {
+		return -EINVAL;
+	}
+
+	nrfx_wdt_channel_feed((nrfx_wdt_channel_id)channel_id);
+
+	return 0;
+}
+
+static void wdt_nrf_enable(struct device *dev)
+{
+	ARG_UNUSED(dev);
+	/* Deprecated function. No implementation needed. */
+	SYS_LOG_ERR("Function not implemented!");
+}
+
+static int wdt_nrf_set_config(struct device *dev, struct wdt_config *config)
+{
+	ARG_UNUSED(dev);
+	ARG_UNUSED(config);
+	/* Deprecated function. No implementation needed. */
+	SYS_LOG_ERR("Function not implemented!");
+	return 0;
+}
+
+static void wdt_nrf_get_config(struct device *dev, struct wdt_config *config)
+{
+	ARG_UNUSED(dev);
+	ARG_UNUSED(config);
+	/* Deprecated function. No implementation needed. */
+	SYS_LOG_ERR("Function not implemented!");
+}
+
+static void wdt_nrf_reload(struct device *dev)
+{
+	ARG_UNUSED(dev);
+	/* Deprecated function. No implementation needed. */
+	SYS_LOG_ERR("Function not implemented!");
+}
+
+static const struct wdt_driver_api wdt_nrf_api = {
+	.setup = wdt_nrf_setup,
+	.disable = wdt_nrf_disable,
+	.install_timeout = wdt_nrf_install_timeout,
+	.feed = wdt_nrf_feed,
+	.enable = wdt_nrf_enable,
+	.get_config = wdt_nrf_get_config,
+	.set_config = wdt_nrf_set_config,
+	.reload = wdt_nrf_reload,
+};
+
+static int init_wdt(struct device *dev)
+{
+	ARG_UNUSED(dev);
+	return 0;
+}
+
+DEVICE_AND_API_INIT(wdt_nrf, CONFIG_WDT_0_NAME, init_wdt,
+		    NULL, NULL, PRE_KERNEL_1,
+		    CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &wdt_nrf_api);

ext/hal/nordic/Kconfig

@@ -18,3 +18,6 @@ config NRFX_SPIM
 
 config NRFX_SPIS
 	bool
+
+config NRFX_WDT
+	bool

ext/hal/nordic/nrfx_config_nrf51.h

@@ -1504,8 +1504,8 @@
 
 // <e> NRFX_WDT_ENABLED - nrfx_wdt - WDT peripheral driver
 //==========================================================
-#ifndef NRFX_WDT_ENABLED
-#define NRFX_WDT_ENABLED 0
+#ifdef CONFIG_NRFX_WDT
+#define NRFX_WDT_ENABLED 1
 #endif
 // <o> NRFX_WDT_CONFIG_BEHAVIOUR  - WDT behavior in CPU SLEEP or HALT mode
 

ext/hal/nordic/nrfx_config_nrf52832.h

@@ -2806,8 +2806,8 @@
 
 // <e> NRFX_WDT_ENABLED - nrfx_wdt - WDT peripheral driver
 //==========================================================
-#ifndef NRFX_WDT_ENABLED
-#define NRFX_WDT_ENABLED 0
+#ifdef CONFIG_NRFX_WDT
+#define NRFX_WDT_ENABLED 1
 #endif
 // <o> NRFX_WDT_CONFIG_BEHAVIOUR  - WDT behavior in CPU SLEEP or HALT mode
 

ext/hal/nordic/nrfx_config_nrf52840.h

@@ -2901,8 +2901,8 @@
 
 // <e> NRFX_WDT_ENABLED - nrfx_wdt - WDT peripheral driver
 //==========================================================
-#ifndef NRFX_WDT_ENABLED
-#define NRFX_WDT_ENABLED 0
+#ifdef CONFIG_NRFX_WDT
+#define NRFX_WDT_ENABLED 1
 #endif
 // <o> NRFX_WDT_CONFIG_BEHAVIOUR  - WDT behavior in CPU SLEEP or HALT mode