From 1134a38584f2e84d7eb2a2de3fcc11ee2f280df5 Mon Sep 17 00:00:00 2001
From: Maciej Gibowicz <maciej.gibowicz@mudita.com>
Date: Tue, 7 Sep 2021 10:41:36 +0200
Subject: [PATCH] [EGD-4875] Add internal load resistor switching

To reduce the power consumption, we disconnect
internal load resistor
---
 module-bsp/board/linux/lpm/LinuxLPM.cpp       |  6 ++++++
 module-bsp/board/linux/lpm/LinuxLPM.h         |  3 +++
 module-bsp/board/rt1051/bsp/lpm/RT1051LPM.cpp | 10 ++++++++++
 module-bsp/board/rt1051/bsp/lpm/RT1051LPM.hpp |  3 +++
 module-bsp/bsp/lpm/bsp_lpm.hpp                |  3 +++
 module-sys/SystemManager/PowerManager.cpp     |  5 +++++
 6 files changed, 30 insertions(+)

diff --git a/module-bsp/board/linux/lpm/LinuxLPM.cpp b/module-bsp/board/linux/lpm/LinuxLPM.cpp
index 37073b4a2b0bdc350329ce73b0152b8ec30a0708..1f6b83b3ee56b5a99ec98246b0c4d661c3c231bb 100644
--- a/module-bsp/board/linux/lpm/LinuxLPM.cpp
+++ b/module-bsp/board/linux/lpm/LinuxLPM.cpp
@@ -45,4 +45,10 @@ namespace bsp
     void LinuxLPM::DisableDcdcPowerSaveMode()
     {}
 
+    void LinuxLPM::DisconnectInternalLoadResistor()
+    {}
+
+    void LinuxLPM::ConnectInternalLoadResistor()
+    {}
+
 } // namespace bsp
diff --git a/module-bsp/board/linux/lpm/LinuxLPM.h b/module-bsp/board/linux/lpm/LinuxLPM.h
index fe5f93b94fd3d0a371d66bb39c51b400e64ebf61..d8c8752d7c2e67a774ac648fc129ffbc7b225da2 100644
--- a/module-bsp/board/linux/lpm/LinuxLPM.h
+++ b/module-bsp/board/linux/lpm/LinuxLPM.h
@@ -22,6 +22,9 @@ namespace bsp
 
         void EnableDcdcPowerSaveMode() final;
         void DisableDcdcPowerSaveMode() final;
+
+        void DisconnectInternalLoadResistor() final;
+        void ConnectInternalLoadResistor() final;
     };
 
 } // namespace bsp
diff --git a/module-bsp/board/rt1051/bsp/lpm/RT1051LPM.cpp b/module-bsp/board/rt1051/bsp/lpm/RT1051LPM.cpp
index 9520c414ed5845484eb2be0e0af2bf724b694639..87e0a3174329d6e86d499732b957ef6bf2db617e 100644
--- a/module-bsp/board/rt1051/bsp/lpm/RT1051LPM.cpp
+++ b/module-bsp/board/rt1051/bsp/lpm/RT1051LPM.cpp
@@ -133,4 +133,14 @@ namespace bsp
         gpio_2->WritePin(static_cast<uint32_t>(BoardDefinitions::DCDC_INVERTER_MODE_PIN), 1);
     }
 
+    void RT1051LPM::DisconnectInternalLoadResistor()
+    {
+        DCDC->REG1 &= ~DCDC_REG1_REG_RLOAD_SW_MASK;
+    }
+
+    void RT1051LPM::ConnectInternalLoadResistor()
+    {
+        DCDC->REG1 |= DCDC_REG1_REG_RLOAD_SW_MASK;
+    }
+
 } // namespace bsp
diff --git a/module-bsp/board/rt1051/bsp/lpm/RT1051LPM.hpp b/module-bsp/board/rt1051/bsp/lpm/RT1051LPM.hpp
index 35e2b79eb17c170725baf972275a2c34ff9eb462..7bb3f208b116dd52dcd175e78561c14ba108f7f1 100644
--- a/module-bsp/board/rt1051/bsp/lpm/RT1051LPM.hpp
+++ b/module-bsp/board/rt1051/bsp/lpm/RT1051LPM.hpp
@@ -25,6 +25,9 @@ namespace bsp
         void EnableDcdcPowerSaveMode() final;
         void DisableDcdcPowerSaveMode() final;
 
+        void DisconnectInternalLoadResistor() final;
+        void ConnectInternalLoadResistor() final;
+
       private:
         std::shared_ptr<drivers::DriverGPIO> gpio_1;
         std::shared_ptr<drivers::DriverGPIO> gpio_2;
diff --git a/module-bsp/bsp/lpm/bsp_lpm.hpp b/module-bsp/bsp/lpm/bsp_lpm.hpp
index 56343e88f578cc5a9f23dd6f443cab5366424afc..850da968ff9b2c357ce82e459495c9fd347f1ad5 100644
--- a/module-bsp/bsp/lpm/bsp_lpm.hpp
+++ b/module-bsp/bsp/lpm/bsp_lpm.hpp
@@ -45,6 +45,9 @@ namespace bsp
         virtual void EnableDcdcPowerSaveMode()  = 0;
         virtual void DisableDcdcPowerSaveMode() = 0;
 
+        virtual void DisconnectInternalLoadResistor()  = 0;
+        virtual void ConnectInternalLoadResistor() = 0;
+
       protected:
         CpuFrequencyHz currentFrequency = CpuFrequencyHz::Level_6;
     };
diff --git a/module-sys/SystemManager/PowerManager.cpp b/module-sys/SystemManager/PowerManager.cpp
index 2f9fec3198e3edab00be8ccbc763ca6d965170fb..1158702ac7424bf1f1dfe1ddc08545eaa7043f83 100644
--- a/module-sys/SystemManager/PowerManager.cpp
+++ b/module-sys/SystemManager/PowerManager.cpp
@@ -120,6 +120,8 @@ namespace sys
         const auto freq = lowPowerControl->GetCurrentFrequencyLevel();
 
         if (freq == bsp::CpuFrequencyHz::Level_1) {
+            // connect internal the load resistor
+            lowPowerControl->ConnectInternalLoadResistor();
             // turn off power save mode for DCDC inverter
             lowPowerControl->DisableDcdcPowerSaveMode();
             // Switch DCDC to full throttle during oscillator switch
@@ -182,6 +184,9 @@ namespace sys
 
             // turn on power save mode for DCDC inverter
             lowPowerControl->EnableDcdcPowerSaveMode();
+
+            // disconnect internal the load resistor
+            lowPowerControl->DisconnectInternalLoadResistor();
         }
 
         isFrequencyLoweringInProgress = true;