Add HighResClock and LowPowerClock

Author: kjbracey

drivers/HighResClock.h

@@ -0,0 +1,80 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2019 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MBED_HIGHRESCLOCK_H
+#define MBED_HIGHRESCLOCK_H
+
+#include <chrono>
+#include "hal/us_ticker_api.h"
+#include "platform/mbed_power_mgmt.h"
+
+namespace mbed {
+/**
+ * \defgroup drivers_HighResClock HighResClock class
+ * \ingroup drivers-public-api-ticker
+ * @{
+ */
+
+/**
+ * A C++11 Clock representing the HAL us_ticker.
+ *
+ * The high resolution clock will pause whenever deep sleep is entered.
+ *
+ * Lock and unlock methods are provided to control deep sleep to keep the
+ * clock running. LowPowerClock provides the same methods as dummies to support
+ * generic code that works with either clock.
+ *
+ * Locks and unlocks are passed to the deep sleep manager, so are reference counted.
+ *
+ * The lock and unlock methods mean this is a C++11 BasicLockable class,
+ * so scoped_lock<HighResClock> or unique_lock<HighResClock> could be used to
+ * manage ownership and guarantee balanced unlocking.
+ *
+ * @note To avoid the need to worry about locking, consider using the Timer, Ticker or
+ *       Timeout classes, which lock automatically and only whenever they are active
+ */
+class HighResClock {
+public:
+    /* duration is C++11 standard microseconds, so representation will be 64-bit signed integer */
+    using duration = std::chrono::microseconds;
+    using rep = duration::rep;
+    using period = duration::period;
+    using time_point = std::chrono::time_point<HighResClock>;
+    static const bool is_steady = false;
+
+    /** Read the current time */
+    static time_point now()
+    {
+        return time_point{duration{ticker_read_us(get_us_ticker_data())}};
+    }
+
+    /** Lock the clock to ensure it stays running */
+    static void lock()
+    {
+        sleep_manager_lock_deep_sleep();
+    }
+
+    /** Unlock the clock, allowing it to stop during power saving */
+    static void unlock()
+    {
+        sleep_manager_unlock_deep_sleep();
+    }
+};
+
+/** @}*/
+
+}
+#endif /* MBED_HIGHRESCLOCK_H */

drivers/LowPowerClock.h

@@ -0,0 +1,66 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2019 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MBED_LOWPOWERCLOCK_H
+#define MBED_LOWPOWERCLOCK_H
+
+#include <chrono>
+#include "hal/lp_ticker_api.h"
+
+namespace mbed {
+/**
+ * \defgroup drivers_LowPowerClock LowPowerClock class
+ * \ingroup drivers-public-api-ticker
+ * @{
+ */
+
+/**
+ * A C++11 Clock representing the HAL lp_ticker.
+ *
+ * Dummy lock/unlock methods are provided to have the same generic API
+ * as UnlockedHighPowerClock. No action is required as the lp_ticker
+ * runs continuously.
+ */
+class LowPowerClock {
+public:
+    /* duration is C++11 standard microseconds, so representation will be 64-bit signed integer */
+    using duration = std::chrono::microseconds;
+    using rep = duration::rep;
+    using period = duration::period;
+    using time_point = std::chrono::time_point<LowPowerClock>;
+    static const bool is_steady = true;
+
+    /** Read the current time */
+    static time_point now()
+    {
+        return time_point{duration{ticker_read_us(get_lp_ticker_data())}};
+    }
+
+    /** Lock the clock to ensure it stays running; dummy for API compatibility with HighResClock */
+    static void lock()
+    {
+    }
+
+    /** Unlock the clock, allowing it to stop during power saving; dummy for API compatibility with HighResClock */
+    static void unlock()
+    {
+    }
+};
+
+/** @}*/
+
+}
+#endif /* MBED_LOWPOWERCLOCK_H */

mbed.h

@@ -76,9 +76,11 @@
 
 // mbed Internal components
 #include "drivers/ResetReason.h"
+#include "drivers/HighResClock.h"
 #include "drivers/Timer.h"
 #include "drivers/Ticker.h"
 #include "drivers/Timeout.h"
+#include "drivers/LowPowerClock.h"
 #include "drivers/LowPowerTimeout.h"
 #include "drivers/LowPowerTicker.h"
 #include "drivers/LowPowerTimer.h"