8 files changed, 91 insertions(+), 1 deletions(-)

M changelog.md
M module-bsp/board/linux/lpm/LinuxLPM.cpp
M module-bsp/board/linux/lpm/LinuxLPM.h
M module-bsp/board/rt1051/bsp/lpm/RT1051LPM.cpp
M module-bsp/board/rt1051/bsp/lpm/RT1051LPM.hpp
M module-bsp/bsp/lpm/bsp_lpm.cpp
M module-bsp/bsp/lpm/bsp_lpm.hpp
M module-sys/SystemManager/PowerManager.cpp

@@ 17,6 17,7 @@
 * Add custom repeat window for the alarm application.
 * Add GUI for custom MMI messages.
 * Add CPU frequency shift mechanism to save power.
+* Add oscillator clock switching mechanisms.
 
 ### Fixed
 

@@ 24,4 24,9 @@ namespace bsp
     {
         currentFrequency = freq;
     }
+
+    void LinuxLPM::SwitchOscillatorSource(bsp::LowPowerMode::OscillatorSource source)
+    {
+        currentOscSource = source;
+    }
 } // namespace bsp

@@ 16,6 16,7 @@ namespace bsp
         int32_t PowerOff() override final;
         int32_t Reboot() override final;
         void SetCpuFrequency(CpuFrequency freq) final;
+        void SwitchOscillatorSource(OscillatorSource source) final;
     };
 
 } // namespace bsp

@@ 7,6 7,8 @@
 #include "log/log.hpp"
 #include "bsp/BoardDefinitions.hpp"
 #include "bsp/watchdog/watchdog.hpp"
+#include <fsl_clock.h>
+#include <fsl_dcdc.h>
 
 namespace bsp
 {


@@ 66,4 68,45 @@ namespace bsp
         }
         LOG_INFO("CPU frequency changed to %lu", CLOCK_GetFreq(kCLOCK_CpuClk));
     }
+
+    void RT1051LPM::SwitchOscillatorSource(bsp::LowPowerMode::OscillatorSource source)
+    {
+        if (source == bsp::LowPowerMode::OscillatorSource::Internal) {
+            if (IsClockEnabled(kCLOCK_Lpuart1) || IsClockEnabled(kCLOCK_Lpuart2) || IsClockEnabled(kCLOCK_Lpuart3) ||
+                IsClockEnabled(kCLOCK_Lpuart4) || IsClockEnabled(kCLOCK_Lpuart5) || IsClockEnabled(kCLOCK_Lpuart6) ||
+                IsClockEnabled(kCLOCK_Lpuart7) || IsClockEnabled(kCLOCK_Lpuart8)) {
+                return;
+            }
+
+            /// Switch DCDC to use DCDC internal OSC
+            DCDC_SetClockSource(DCDC, kDCDC_ClockInternalOsc);
+            /// Switch clock source to internal RC
+            CLOCK_SwitchOsc(kCLOCK_RcOsc);
+            CLOCK_DeinitExternalClk();
+            /// Wait CCM operation finishes
+            while (CCM->CDHIPR != 0) {}
+        }
+        else if (source == bsp::LowPowerMode::OscillatorSource::External) {
+            CLOCK_InitExternalClk(0);
+            /// Switch DCDC to use DCDC external OSC
+            DCDC_SetClockSource(DCDC, kDCDC_ClockExternalOsc);
+            /// Switch clock source to external OSC.
+            CLOCK_SwitchOsc(kCLOCK_XtalOsc);
+            /// Wait CCM operation finishes
+            while (CCM->CDHIPR != 0) {}
+            /// Set Oscillator ready counter value.
+            CCM->CCR = (CCM->CCR & (~CCM_CCR_OSCNT_MASK)) | CCM_CCR_OSCNT(bsp::OscillatorReadyCounterValue);
+        }
+
+        currentOscSource = source;
+    }
+
+    bool RT1051LPM::IsClockEnabled(clock_ip_name_t name) const noexcept
+    {
+        const auto index = static_cast<uint32_t>(name) >> CCM_TupleShift;
+        const auto shift = static_cast<uint32_t>(name) & CCM_TupleMask;
+
+        return ((*reinterpret_cast<volatile uint32_t *>(&CCM->CCGR0 + index)) & (ClockNeededRunWaitMode << shift));
+    }
+
 } // namespace bsp

@@ 7,9 7,14 @@
 #include "bsp/lpm/bsp_lpm.hpp"
 #include "drivers/gpio/DriverGPIO.hpp"
 #include "CpuFreqLPM.hpp"
+#include <fsl_clock.h>
 
 namespace bsp
 {
+    inline constexpr uint8_t OscillatorReadyCounterValue{127};
+    inline constexpr uint8_t CCM_TupleShift{8};
+    inline constexpr uint8_t CCM_TupleMask{0x1F};
+    inline constexpr uint32_t ClockNeededRunWaitMode{3};
 
     class RT1051LPM : public LowPowerMode
     {


@@ 18,8 23,11 @@ namespace bsp
         int32_t PowerOff() override final;
         int32_t Reboot() override final;
         void SetCpuFrequency(CpuFrequency freq) final;
+        void SwitchOscillatorSource(OscillatorSource source) final;
 
       private:
+        [[nodiscard]] bool IsClockEnabled(clock_ip_name_t name) const noexcept;
+
         std::shared_ptr<drivers::DriverGPIO> gpio;
         std::unique_ptr<bsp::CpuFreqLPM> CpuFreq;
     };

@@ 30,4 30,9 @@ namespace bsp{
     {
     	return currentFrequency;
     }
+
+    LowPowerMode::OscillatorSource LowPowerMode::GetCurrentOscillatorSource() const noexcept
+    {
+    	return currentOscSource;
+    }
 }

@@ 18,6 18,11 @@ namespace bsp {
             Level_5, // 264 MHz
             Level_6  // 528 MHz
         };
+        enum class OscillatorSource
+        {
+            External,
+            Internal
+        };
 
         LowPowerMode()          = default;
         virtual ~LowPowerMode() = default;


@@ 26,11 31,16 @@ namespace bsp {
 
         virtual int32_t PowerOff() = 0;
         virtual int32_t Reboot() = 0;
+
         virtual void SetCpuFrequency(CpuFrequency freq) = 0;
         [[nodiscard]] CpuFrequency GetCurrentFrequency() const noexcept;
 
+        virtual void SwitchOscillatorSource(OscillatorSource source) = 0;
+        [[nodiscard]] OscillatorSource GetCurrentOscillatorSource() const noexcept;
+
     protected:
         CpuFrequency currentFrequency = CpuFrequency::Level_6;
+        OscillatorSource currentOscSource = OscillatorSource::External;
     };
 } // namespace bsp
 

@@ 53,7 53,16 @@ namespace sys
 
     void PowerManager::IncreaseCpuFrequency() const
     {
-        bsp::LowPowerMode::CpuFrequency freq = lowPowerControl->GetCurrentFrequency();
+        const auto freq      = lowPowerControl->GetCurrentFrequency();
+        const auto oscSource = lowPowerControl->GetCurrentOscillatorSource();
+
+        /// switch osc source first
+        if (freq == bsp::LowPowerMode::CpuFrequency::Level_1 &&
+            oscSource == bsp::LowPowerMode::OscillatorSource::Internal) {
+            lowPowerControl->SwitchOscillatorSource(bsp::LowPowerMode::OscillatorSource::External);
+        }
+
+        /// then increase frequency
         if (freq < bsp::LowPowerMode::CpuFrequency::Level_6) {
             lowPowerControl->SetCpuFrequency(bsp::LowPowerMode::CpuFrequency::Level_6);
         }


@@ 62,6 71,7 @@ namespace sys
     void PowerManager::DecreaseCpuFrequency() const
     {
         const auto freq = lowPowerControl->GetCurrentFrequency();
+        const auto oscSource = lowPowerControl->GetCurrentOscillatorSource();
         auto level      = bsp::LowPowerMode::CpuFrequency::Level_1;
 
         switch (freq) {


@@ 84,9 94,16 @@ namespace sys
             break;
         }
 
+        /// decrease frequency first
         if (level != freq) {
             lowPowerControl->SetCpuFrequency(level);
         }
+
+        /// then switch osc source
+        if (level == bsp::LowPowerMode::CpuFrequency::Level_1 &&
+            oscSource == bsp::LowPowerMode::OscillatorSource::External) {
+            lowPowerControl->SwitchOscillatorSource(bsp::LowPowerMode::OscillatorSource::Internal);
+        }
     }
 
     void PowerManager::ResetFrequencyShiftCounter()