Diff: targets/TARGET_NUVOTON/TARGET_M451/sleep.c

Revision:

149:156823d33999

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_NUVOTON/TARGET_M451/sleep.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,118 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2015-2016 Nuvoton
+ *
+ * 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.
+ */
+
+#include "sleep_api.h"
+#include "serial_api.h"
+#include "lp_ticker_api.h"
+
+#if DEVICE_SLEEP
+
+#include "cmsis.h"
+#include "device.h"
+#include "objects.h"
+#include "PeripheralPins.h"
+
+void us_ticker_prepare_sleep(struct sleep_s *obj);
+void us_ticker_wakeup_from_sleep(struct sleep_s *obj);
+static void mbed_enter_sleep(struct sleep_s *obj);
+static void mbed_exit_sleep(struct sleep_s *obj);
+
+int serial_allow_powerdown(void);
+int spi_allow_powerdown(void);
+int i2c_allow_powerdown(void);
+int pwmout_allow_powerdown(void);
+
+/**
+ * Enter Idle mode.
+ */
+void sleep(void)
+{
+    struct sleep_s sleep_obj;
+    sleep_obj.powerdown = 0;
+    mbed_enter_sleep(&sleep_obj);
+    mbed_exit_sleep(&sleep_obj);
+}
+
+/**
+ * Enter Power-down mode while no peripheral is active; otherwise, enter Idle mode.
+ */
+void deepsleep(void)
+{
+    struct sleep_s sleep_obj;
+    sleep_obj.powerdown = 1;
+    mbed_enter_sleep(&sleep_obj);
+    mbed_exit_sleep(&sleep_obj);
+}
+
+
+void mbed_enter_sleep(struct sleep_s *obj)
+{
+    // Check if serial allows entering power-down mode
+    if (obj->powerdown) {
+        obj->powerdown = serial_allow_powerdown();
+    }
+    // Check if spi allows entering power-down mode
+    if (obj->powerdown) {
+        obj->powerdown = spi_allow_powerdown();
+    }
+    // Check if i2c allows entering power-down mode
+    if (obj->powerdown) {
+        obj->powerdown = i2c_allow_powerdown();
+    }
+    // Check if pwmout allows entering power-down mode
+    if (obj->powerdown) {
+        obj->powerdown = pwmout_allow_powerdown();
+    }
+    // TODO: Check if other peripherals allow entering power-down mode
+    
+    obj->start_us = lp_ticker_read();
+    // Let us_ticker prepare for power-down or reject it.
+    us_ticker_prepare_sleep(obj);
+    
+    // NOTE(STALE): To pass mbed-drivers test, timer requires to be fine-grained, so its implementation needs HIRC rather than LIRC/LXT as its clock source.
+    //       But as CLK_PowerDown()/CLK_Idle() is called, HIRC will be disabled and timer cannot keep counting and alarm. To overcome the dilemma, 
+    //       just make CPU halt and compromise power saving.
+    // NOTE: As CLK_PowerDown()/CLK_Idle() is called, HIRC/HXT will be disabled in normal mode, but not in ICE mode. This may cause confusion in development.
+
+    if (obj->powerdown) {   // Power-down mode (HIRC/HXT disabled, LIRC/LXT enabled)
+        SYS_UnlockReg();
+        CLK_PowerDown();
+        SYS_LockReg();
+    }
+    else {  // CPU halt mode (HIRC/HXT enabled, LIRC/LXT enabled)
+        SYS_UnlockReg();
+        CLK_Idle();
+        SYS_LockReg();
+    }
+    __NOP();
+    __NOP();
+    __NOP();
+    __NOP();
+    
+    obj->end_us = lp_ticker_read();
+    obj->period_us = (obj->end_us > obj->start_us) ? (obj->end_us - obj->start_us) : (uint32_t) ((uint64_t) obj->end_us + 0xFFFFFFFFu - obj->start_us);
+    // Let us_ticker recover from power-down.
+    us_ticker_wakeup_from_sleep(obj);
+}
+
+void mbed_exit_sleep(struct sleep_s *obj)
+{
+    // TODO: TO BE CONTINUED
+    
+    (void)obj;
+}
+
+#endif