aarch64/raspberrypi: Add Watchdog Timer driver

bsps/aarch64/raspberrypi/include/bsp/raspberrypi.h

@@ -124,10 +124,12 @@
 #define BCM2711_PM_RSTC_DRCFG    0x00000003
 #define BCM2711_PM_RSTC_WRCFG    0x00000030
 #define BCM2711_PM_RSTC_WRCFG_FULL   0x00000020
+#define BCM2711_PM_RSTC_WRCFG_CLR    0xffffffcf
 #define BCM2711_PM_RSTC_SRCFG    0x00000300
 #define BCM2711_PM_RSTC_QRCFG    0x00003000
 #define BCM2711_PM_RSTC_FRCFG    0x00030000
 #define BCM2711_PM_RSTC_HRCFG    0x00300000
+#define BCM2711_PM_RSTC_RESET    0x00000102
 
 #define BCM2711_PM_RSTS          (BCM2711_PM_BASE + 0x20)
 #define BCM2711_PM_RSTS_HADDRQ   0x00000001
@@ -142,6 +144,7 @@
 #define BCM2711_PM_RSTS_HADPOR   0x00001000
 
 #define BCM2711_PM_WDOG          (BCM2711_PM_BASE + 0x24)
+#define BCM2711_PM_WDOG_MASK     0x000fffff
 
 /** @} */
 

bsps/aarch64/raspberrypi/include/bsp/watchdog.h

@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup RTEMSBSPsAArch64RaspberryPi
+ *
+ * @brief API of the Watchdog driver for the raspberrypi4 bsp in RTEMS.
+ */
+
+/*
+ * Copyright (C) 2024 Ning Yang
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef LIBBSP_AARCH64_RASPBERRYPI_BSP_RPI_WATCHDOG_H
+#define LIBBSP_AARCH64_RASPBERRYPI_BSP_RPI_WATCHDOG_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @note a brief example of expected usage.
+ *
+ * void raspberrypi_watchdog_example()
+ * {
+ *  raspberrypi_watchdog_init();
+ *  raspberrypi_watchdog_start(15000);
+ *
+ *  raspberrypi_watchdog_reload();
+ *  ...
+ *  raspberrypi_watchdog_reload();
+ *  
+ *  raspberrypi_watchdog_stop();
+ * }
+ * 
+ */
+
+/**
+ * @brief Initialize BSP watchdog routines.
+ */
+void raspberrypi_watchdog_init(void);
+
+/**
+ * @brief Turn on the watchdog / begin the counter at the desired value.
+ *
+ * @param timeout Watchdog timeout value in ms. 
+ *                The watchdog device has 20 bits of timeout, so it only 
+ *                supports a maximum of 15999 ms for its timeout. 
+ *                This value should be between 0 and 15999.
+ */
+void raspberrypi_watchdog_start(uint32_t timeout_ms);
+
+/**
+ * @brief Turn off the watchdog.
+ */
+void raspberrypi_watchdog_stop(void);
+
+/**
+ * @brief Reload watchdog.
+ */
+void raspberrypi_watchdog_reload(void);
+
+/**
+ * @brief Get the remaining time of the watchdog.
+ *        The return value is still valid when the watchdog has been stopped.
+ *
+ * @retval Watchdog remaining time in ms.
+ */
+uint32_t raspberrypi_watchdog_get_remaining_time(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

bsps/aarch64/raspberrypi/start/watchdog.c

@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup RTEMSBSPsAArch64RaspberryPi
+ *
+ * @brief Watchdog Driver
+ */
+
+/*
+ * Copyright (C) 2024 Ning Yang
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <bsp/raspberrypi.h>
+#include <bsp/watchdog.h>
+
+#define PM_WDOG BCM2835_REG(BCM2711_PM_WDOG)
+#define PM_RSTC BCM2835_REG(BCM2711_PM_RSTC)
+
+uint32_t raspberrypi_watchdog_timeout;
+
+void raspberrypi_watchdog_init()
+{
+  raspberrypi_watchdog_timeout = 0;
+}
+
+void raspberrypi_watchdog_start(uint32_t timeout_ms)
+{
+  raspberrypi_watchdog_timeout = timeout_ms;
+
+  PM_WDOG = BCM2711_PM_PASSWD_MAGIC |
+            ((timeout_ms * 65536 / 1000) & BCM2711_PM_WDOG_MASK);
+
+  PM_RSTC &= BCM2711_PM_RSTC_WRCFG_CLR;
+  PM_RSTC = (BCM2711_PM_PASSWD_MAGIC | BCM2711_PM_RSTC_WRCFG_FULL);
+}
+
+void raspberrypi_watchdog_stop()
+{
+  PM_RSTC = BCM2711_PM_PASSWD_MAGIC | BCM2711_PM_RSTC_RESET;
+}
+
+void raspberrypi_watchdog_reload()
+{
+  raspberrypi_watchdog_start(raspberrypi_watchdog_timeout);
+}
+
+uint32_t raspberrypi_watchdog_get_remaining_time()
+{
+  return (PM_WDOG & BCM2711_PM_WDOG_MASK)*1000/65536;
+}

spec/build/bsps/aarch64/raspberrypi/bspraspberrypi4.yml

@@ -57,6 +57,8 @@ links:
   uid: objgpio
 - role: build-dependency
   uid: objspi
+- role: build-dependency
+  uid: objwatchdog
 source:
 - bsps/aarch64/raspberrypi/console/console.c
 - bsps/aarch64/raspberrypi/start/bspstart.c

spec/build/bsps/aarch64/raspberrypi/objwatchdog.yml

@@ -0,0 +1,17 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+build-type: objects
+cflags: []
+copyrights:
+  - Copyright (C) 2024 Ning Yang
+cppflags: []
+cxxflags: []
+enabled-by: true
+includes: []
+install:
+  - destination: ${BSP_INCLUDEDIR}/bsp
+    source:
+      - bsps/aarch64/raspberrypi/include/bsp/watchdog.h
+links: []
+source:
+  - bsps/aarch64/raspberrypi/start/watchdog.c
+type: build