EMC voltage for Mariko; Fix #60; Show battery & voltage info in overlay on Erista

- From previous analysis, EMC voltage is set before AMS loads on Mariko, and will not be set again or changed afterwards.

- sys-clk-OC will take care of setting emc voltage on Mariko once it loads.

- OS will not hang at boot as it always boots with EMC @ 1600 MHz.

Source/sys-clk-OC/common/include/cpp_util.hpp

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <utility>
+
+template<typename F>
+class ScopeGuard {
+public:
+    ScopeGuard(F&& f)
+     : f(f), engaged(true) {};
+
+    ~ScopeGuard() {
+        if (engaged)
+            f();
+    };
+
+    ScopeGuard(ScopeGuard&& rhs)
+     : f(std::move(rhs.f)) {};
+
+    void dismiss() { engaged = false; }
+
+private:
+    F f;
+    bool engaged;
+};
+
+struct MakeScopeExit {
+    template<typename F>
+    ScopeGuard<F> operator+=(F&& f) {
+        return ScopeGuard<F>(std::move(f));
+    };
+};
+
+#define STRING_CAT2(x, y) x##y
+#define STRING_CAT(x, y) STRING_CAT2(x, y)
+#define SCOPE_GUARD MakeScopeExit() += [&]() __attribute__((always_inline))
+#define SCOPE_EXIT auto STRING_CAT(scope_exit_, __LINE__) = SCOPE_GUARD

Source/sys-clk-OC/common/include/sysclk.h

@@ -11,6 +11,7 @@
 #pragma once
 
 #ifdef __cplusplus
+#include "cpp_util.hpp"
 extern "C" {
 #endif
 

Source/sys-clk-OC/common/include/sysclk/i2c.h

@@ -14,14 +14,34 @@ float I2c_Max17050_GetBatteryCurrent();
 
 const u8 MAX17050_CURRENT_REG = 0x0A;
 
-// Max77812 Mariko-specific buck converter
-typedef enum I2c_Max77812_Volt_Type {
+// Buck Converter
+typedef enum I2c_BuckConverter_Reg {
+    I2c_Max77620_SD1VOLT_REG = 0x16,
+    I2c_Max77621_VOLT_REG    = 0x00,
     I2c_Max77812_CPUVOLT_REG = 0x26,
     I2c_Max77812_GPUVOLT_REG = 0x23,
-    I2c_Max77812_MEMVOLT_REG = 0x25,
-} I2c_Max77812_Volt_Type;
+    I2c_Max77812_MEMVOLT_REG = 0x25, // Master 3 (GPU 1 + 2, DRAM 3, CPU 4)
+} I2c_BuckConverter_Reg;
 
-u32 I2c_Max77812_GetMVOUT(I2c_Max77812_Volt_Type type);
+typedef struct I2c_BuckConverter_Domain {
+    I2cDevice device;
+    I2c_BuckConverter_Reg reg;
+    u8 volt_mask;
+    u32 uv_step;
+    u32 uv_min;
+    u32 uv_max;
+    u8 por_val;
+} I2c_BuckConverter_Domain;
+
+const I2c_BuckConverter_Domain I2c_Erista_CPU  = { I2cDevice_Max77621Cpu,  I2c_Max77621_VOLT_REG,    0x7F,  6250, 606250, 1400000, };
+const I2c_BuckConverter_Domain I2c_Erista_GPU  = { I2cDevice_Max77621Gpu,  I2c_Max77621_VOLT_REG,    0x7F,  6250, 606250, 1400000, };
+const I2c_BuckConverter_Domain I2c_Erista_DRAM = { I2cDevice_Max77620Pmic, I2c_Max77620_SD1VOLT_REG, 0x7F, 12500, 600000, 1250000, };
+const I2c_BuckConverter_Domain I2c_Mariko_CPU  = { I2cDevice_Max77812_2,   I2c_Max77812_CPUVOLT_REG, 0xFF,  5000, 250000, 1525000, 0x78 };
+const I2c_BuckConverter_Domain I2c_Mariko_GPU  = { I2cDevice_Max77812_2,   I2c_Max77812_GPUVOLT_REG, 0xFF,  5000, 250000, 1525000, 0x78 };
+const I2c_BuckConverter_Domain I2c_Mariko_DRAM = { I2cDevice_Max77812_2,   I2c_Max77812_MEMVOLT_REG, 0xFF,  5000, 250000,  650000, 0x78 };
+
+u32 I2c_BuckConverter_GetMvOut(const I2c_BuckConverter_Domain* domain);
+Result I2c_BuckConverter_SetMvOut(const I2c_BuckConverter_Domain* domain, u32 mvolt);
 
 // Bq24193 Battery management
 u32 I2c_Bq24193_Convert_Raw_mA(u8 raw);

Source/sys-clk-OC/common/src/i2c.c

@@ -83,24 +83,58 @@ float I2c_Max17050_GetBatteryCurrent() {
     return (s16)val * (1.5625 / (SenseResistor * CGain));
 }
 
-u32 I2c_Max77812_GetMVOUT(I2c_Max77812_Volt_Type type) {
-    u8 reg = (u8)type;
+u32 I2c_BuckConverter_MultiplierToMvOut(const I2c_BuckConverter_Domain* domain, u8 multiplier) {
+    return (domain->uv_min + domain->uv_step * multiplier) / 1000;
+}
 
-    const u32 MIN_MV    = 250;
-    const u32 MV_STEP   = 5;
-    const u8  RESET_VAL = 0x78;
+u8 I2c_BuckConverter_MvOutToMultiplier(const I2c_BuckConverter_Domain* domain, u32 mvolt) {
+    u32 uvolt = mvolt * 1000;
+    if (uvolt < domain->uv_min)
+        uvolt = domain->uv_min;
+    if (uvolt > domain->uv_max)
+        uvolt = domain->uv_max;
 
-    u8 val = RESET_VAL;
-    // Retry 3 times if received RESET_VAL
+    return (uvolt - domain->uv_min) / domain->uv_step;
+}
+
+u32 I2c_BuckConverter_GetMvOut(const I2c_BuckConverter_Domain* domain) {
+    u8 val;
+    Result res;
+    // Retry 3 times if failed or received POR value
     for (int i = 0; i < 3; i++) {
-        if (I2cRead_OutU8(I2cDevice_Max77812_2, reg, &val))
-            return 0u;
-        if (val != RESET_VAL)
-            break;
-        svcSleepThread(10);
+        res = I2cRead_OutU8(domain->device, domain->reg, &val);
+        if (R_FAILED(res) || (domain->por_val && val == domain->por_val)) {
+            svcSleepThread(1000);
+            continue;
+        }
+        return I2c_BuckConverter_MultiplierToMvOut(domain, val & domain->volt_mask);
     }
+    return 0u;
+}
 
-    return val * MV_STEP + MIN_MV;
+Result I2c_BuckConverter_SetMvOut(const I2c_BuckConverter_Domain* domain, u32 mvolt) {
+    u8 val;
+    Result res = I2cRead_OutU8(domain->device, domain->reg, &val);
+    if (R_FAILED(res))
+        return res;
+
+    u8 multiplier = I2c_BuckConverter_MvOutToMultiplier(domain, mvolt);
+    val &= ~domain->volt_mask;
+    val |= multiplier & domain->volt_mask;
+
+    res = I2cSet_U8(domain->device, domain->reg, val);
+    if (R_FAILED(res))
+        return res;
+
+    svcSleepThread(1000);
+    u8 new_val;
+    res = I2cRead_OutU8(domain->device, domain->reg, &new_val);
+    if (R_FAILED(res))
+        return res;
+    if (new_val != val)
+        return -1;
+
+    return 0;
 }
 
 u8 I2c_Bq24193_Convert_mA_Raw(u32 ma) {