Stop the us_ticker timer before deepsleep

A running timer will block DeepSleep, which would normally be
good because we don't want the timer to accidentally lose counts.
We don't care about that for us_ticker (If we're requesting deepsleep
the upper layers already determined that they are okay with that),
so explicitly stop the us_ticker timer before we go to sleep and
start it back up afterwards.

Author: Kyle Kearney

targets/TARGET_Cypress/TARGET_PSOC6/cy_sleep_api.c

@@ -19,21 +19,30 @@
 
 #include "cmsis.h"
 #include "device.h"
-#include "cy_syspm.h"
+#include "cyhal_syspm.h"
+#include "cy_us_ticker.h"
 
 #if DEVICE_SLEEP
 
 void hal_sleep(void)
 {
-    Cy_SysPm_CpuEnterSleep(CY_SYSPM_WAIT_FOR_INTERRUPT);
+    cyhal_syspm_sleep();
 }
 
 void hal_deepsleep(void)
 {
 #if DEVICE_LPTICKER
-    Cy_SysPm_CpuEnterDeepSleep(CY_SYSPM_WAIT_FOR_INTERRUPT);
+    // A running timer will block DeepSleep, which would normally be
+    // good because we don't want the timer to accidentally
+    // lose counts. We don't care about that for us_ticker
+    // (If we're requesting deepsleep the upper layers already determined
+    // that they are okay with that), so explicitly stop the us_ticker
+    // timer before we go to sleep and start it back up afterwards.
+    cy_us_ticker_stop();
+    cyhal_syspm_deepsleep();
+    cy_us_ticker_start();
 #else
-    Cy_SysPm_CpuEnterSleep(CY_SYSPM_WAIT_FOR_INTERRUPT);
+    cyhal_syspm_sleep();
 #endif /* DEVICE_LPTICKER */
 }
 

targets/TARGET_Cypress/TARGET_PSOC6/cy_us_ticker.h

@@ -0,0 +1,37 @@
+/*
+ * mbed Microcontroller Library
+ * Copyright (c) 2017-2018 Future Electronics
+ * Copyright (c) 2019, Arm Limited and affiliates.
+ * 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_CY_US_TICKER_H
+#define MBED_CY_US_TICKER_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Starts the us_ticker. */
+void cy_us_ticker_start();
+
+/** Stops the us_ticker. */
+void cy_us_ticker_stop();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // MBED_CY_US_TICKER_H

targets/TARGET_Cypress/TARGET_PSOC6/cy_us_ticker_api.c

@@ -17,6 +17,7 @@
 #include "cmsis.h"
 #include "us_ticker_api.h"
 #include "mbed_error.h"
+#include "cy_us_ticker.h"
 #include "cyhal_timer.h"
 #include "cy_tcpwm_counter.h"
 
@@ -51,6 +52,16 @@ static void cy_us_ticker_irq_handler(MBED_UNUSED void *arg, MBED_UNUSED cyhal_ti
     us_ticker_irq_handler();
 }
 
+void cy_us_ticker_start()
+{
+    cyhal_timer_start(&cy_us_timer);
+}
+
+void cy_us_ticker_stop()
+{
+    cyhal_timer_stop(&cy_us_timer);
+}
+
 void us_ticker_init(void)
 {
     if (!cy_us_ticker_initialized) {