From 7929efec0d4e2990c77d71a195701450601f0734 Mon Sep 17 00:00:00 2001
From: Siddharth Purohit <siddharthbharatpurohit@gmail.com>
Date: Sun, 31 May 2020 17:50:46 +0530
Subject: [PATCH] HAL_ChibiOS: add EventSource HAL

---
 libraries/AP_HAL_ChibiOS/EventSource.cpp | 34 ++++++++++++++++++++++++
 libraries/AP_HAL_ChibiOS/EventSource.h   | 25 +++++++++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 libraries/AP_HAL_ChibiOS/EventSource.cpp
 create mode 100644 libraries/AP_HAL_ChibiOS/EventSource.h

diff --git a/libraries/AP_HAL_ChibiOS/EventSource.cpp b/libraries/AP_HAL_ChibiOS/EventSource.cpp
new file mode 100644
index 00000000000..7409baba0f3
--- /dev/null
+++ b/libraries/AP_HAL_ChibiOS/EventSource.cpp
@@ -0,0 +1,34 @@
+#include "EventSource.h"
+#include <AP_HAL/AP_HAL.h>
+
+using namespace ChibiOS;
+
+#if CH_CFG_USE_EVENTS == TRUE
+
+bool EventSource::wait(uint64_t duration, AP_HAL::EventHandle *evt_handle)
+{
+    chibios_rt::EventListener evt_listener;
+    eventmask_t evt_mask = evt_handle->get_evt_mask();
+    msg_t ret = msg_t();
+    ch_evt_src_.registerMask(&evt_listener, evt_mask);
+    if (duration == 0) {
+        ret = chEvtWaitAnyTimeout(evt_mask, TIME_IMMEDIATE);
+    } else {
+        ret = chEvtWaitAnyTimeout(evt_mask, chTimeUS2I(duration));
+    }
+    ch_evt_src_.unregister(&evt_listener);
+    return ret == MSG_OK;
+}
+
+void EventSource::signal(uint32_t evt_mask)
+{
+    ch_evt_src_.broadcastFlags(evt_mask);
+}
+
+void EventSource::signalI(uint32_t evt_mask)
+{
+    chSysLockFromISR();
+    ch_evt_src_.broadcastFlagsI(evt_mask);
+    chSysUnlockFromISR();
+}
+#endif
diff --git a/libraries/AP_HAL_ChibiOS/EventSource.h b/libraries/AP_HAL_ChibiOS/EventSource.h
new file mode 100644
index 00000000000..a3b497b9313
--- /dev/null
+++ b/libraries/AP_HAL_ChibiOS/EventSource.h
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <stdint.h>
+#include <AP_HAL/AP_HAL_Boards.h>
+#include <AP_HAL/AP_HAL_Macros.h>
+#include <AP_HAL/EventHandle.h>
+#include "AP_HAL_ChibiOS_Namespace.h"
+#include <ch.hpp>
+
+#if CH_CFG_USE_EVENTS == TRUE
+class ChibiOS::EventSource : public AP_HAL::EventSource {
+    // Single event source to be shared across multiple users
+    chibios_rt::EventSource ch_evt_src_;
+
+public:
+    // generate event from thread context
+    void signal(uint32_t evt_mask) override;
+
+    // generate event from interrupt context
+    void signalI(uint32_t evt_mask) override;
+
+    // Wait on an Event handle, method for internal use by EventHandle
+    bool wait(uint64_t duration, AP_HAL::EventHandle* evt_handle) override;
+};
+#endif