Implement Mariko-style MRF for erista

There is heavy code duplication because I'm lazy, but loader needs to be
refactored anyway at some point and this "works" for now.

Source/Atmosphere/stratosphere/loader/source/oc/erista/calculate_timings_erista.cpp

@@ -18,8 +18,80 @@
 
 namespace ams::ldr::hoc::pcv::erista {
 
-    void CalculateTimings(double tCK_avg) {
-        tR2W    = FLOOR(FLOOR((5.0 / tCK_avg) + ((FLOOR(48.0 / WL) - 0.478) * 3.0)) / 1.501) + RL - (C.t6_tRTW * 3) + finetRTW;
+    void SwitchLatency(volatile u32 &latency, u32 index, u32 latencyStep) {
+        latency += index * latencyStep;
+    }
+
+    static s32 GetMaxLatencyIndex(volatile u32 *latencyArray, u32 latencySize) {
+        s32 maxIndex = -1;
+        for (u32 i = 0; i < latencySize; ++i) {
+            if (latencyArray[i]) {
+                maxIndex = i;
+            }
+        }
+
+        return maxIndex;
+    }
+
+    void AutoLatency(volatile u32 &latency, u32 freq, u32 latencyStep) {
+        if (freq > 1600'000 && freq <= 1866'000) { /* 1866tRWL */
+            latency += latencyStep * 2;
+        } else { /* 2133tRWL */
+            latency += latencyStep * 3;
+        }
+    }
+
+    void HandleLatency(u32 freq, volatile u32 &latency, volatile u32 *latencyArray, u32 indexMax, u32 latencyStep) {
+        for (u32 i = 0; i <= indexMax; ++i) {
+            if (latencyArray[i] != 0 && freq <= latencyArray[i]) {
+                SwitchLatency(latency, i, latencyStep);
+                return;
+            }
+        }
+
+        SwitchLatency(latency, indexMax, latencyStep);
+    }
+
+    void HandleLatency(u32 freq) {
+        static s32 rlIndexMax = GetMaxLatencyIndex(C.readLatency, std::size(C.readLatency));
+        static s32 wlIndexMax = GetMaxLatencyIndex(C.writeLatency, std::size(C.writeLatency));
+        constexpr u32 ReadLatencyStep  = 4;
+        constexpr u32 WriteLatencyStep = 2;
+        bool autoLatencyRead = false, autoLatencyWrite = false;
+
+        if (rlIndexMax == -1) {
+            AutoLatency(RL, freq, ReadLatencyStep);
+            autoLatencyRead = true;
+        }
+
+        if (wlIndexMax == -1) {
+            AutoLatency(WL, freq, WriteLatencyStep);
+            autoLatencyWrite = true;
+        }
+
+        if (autoLatencyRead && autoLatencyWrite) {
+            return;
+        }
+
+        if (!autoLatencyRead) {
+            HandleLatency(freq, RL, C.readLatency, rlIndexMax, ReadLatencyStep);
+        }
+
+        if (!autoLatencyWrite) {
+            HandleLatency(freq, WL, C.writeLatency, wlIndexMax, WriteLatencyStep);
+        }
+    }
+
+    void CalculateTimings(double tCK_avg, u32 freq) {
+        RL = RL_1331;
+        WL = WL_1331;
+
+        HandleLatency(freq);
+
+        tR2P = CEIL((RL * 0.426) - 2.0);
+        tR2W = FLOOR(FLOOR((5.0 / tCK_avg) + ((FLOOR(48.0 / WL) - 0.478) * 3.0)) / 1.501) + RL - (C.t6_tRTW * 3) + finetRTW;
+
+        tW2P    = (CEIL(WL * 1.7303) * 2) - 5;
         tWTPDEN = CEIL(((1.803 / tCK_avg) + MAX(RL + (2.694 / tCK_avg), static_cast<double>(tW2P))) + (BL / 2));
         tW2R    = FLOOR(MAX((5.020 / tCK_avg) + 1.130, WL - MAX(-CEIL(0.258 * (WL - RL)), 1.964)) * 1.964) + WL - CEIL(tWTR / tCK_avg) + finetWTR;
 

Source/Atmosphere/stratosphere/loader/source/oc/erista/calculate_timings_erista.hpp

@@ -18,6 +18,6 @@
 
 namespace ams::ldr::hoc::pcv::erista {
 
-    void CalculateTimings(double tCK_avg);
+    void CalculateTimings(double tCK_avg, u32 freq);
 
 }