From 9b8a95a1de0dc18f2bb5e7e7a5a291ea900c76da Mon Sep 17 00:00:00 2001
From: TuxSH <1922548+TuxSH@users.noreply.github.com>
Date: Sat, 19 Oct 2024 23:53:44 +0200
Subject: [PATCH] Fix volume override for applets (i2s2/csnd)

This feature repurposes the functionality used for the camera shutter sound.
As such, it interferes with it:
    - shutter volume is set to the override instead of its default 100% value
    - due to implementation details, having the shutter sound effect play will
      make this feature stop working until the volume override is reapplied by
      going back to this menu

Closes #2072
---
 sysmodules/rosalina/source/menus/sysconfig.c | 59 +++++++++++++++-----
 1 file changed, 45 insertions(+), 14 deletions(-)

diff --git a/sysmodules/rosalina/source/menus/sysconfig.c b/sysmodules/rosalina/source/menus/sysconfig.c
index fdb1b079..7569fc76 100644
--- a/sysmodules/rosalina/source/menus/sysconfig.c
+++ b/sysmodules/rosalina/source/menus/sysconfig.c
@@ -389,24 +389,55 @@ void SysConfigMenu_ToggleCardIfPower(void)
 
 static Result SysConfigMenu_ApplyVolumeOverride(void)
 {
-    // Credit: profi200
-    u8 tmp;
+    // This feature repurposes the functionality used for the camera shutter sound.
+    // As such, it interferes with it:
+    //     - shutter volume is set to the override instead of its default 100% value
+    //     - due to implementation details, having the shutter sound effect play will
+    //       make this feature stop working until the volume override is reapplied by
+    //       going back to this menu
+
+    // Original credit: profi200
+
+    u8 i2s1Mux;
+    u8 i2s2Mux;
     Result res = cdcChkInit();
 
-    if (R_SUCCEEDED(res)) res = CDCCHK_ReadRegisters2(0, 116, &tmp, 1); // CDC_REG_VOL_MICDET_PIN_SAR_ADC
-    if (currVolumeSliderOverride >= 0)
-        tmp &= ~0x80;
-    else
-        tmp |= 0x80;
-    if (R_SUCCEEDED(res)) res = CDCCHK_WriteRegisters2(0, 116, &tmp, 1);
+    if (R_SUCCEEDED(res)) res = CDCCHK_ReadRegisters2(0,  116, &i2s1Mux, 1); // used for shutter sound in TWL mode, and all GBA/DSi/3DS application
+    if (R_SUCCEEDED(res)) res = CDCCHK_ReadRegisters2(100, 49, &i2s2Mux, 1); // used for shutter sound in CTR mode and CTR mode library applets
 
-    if (currVolumeSliderOverride >= 0) {
-        s8 calculated = -128 + (((float)currVolumeSliderOverride/100.f) * 108);
-        if (calculated > -20)
-            res = -1; // Just in case
-        s8 volumes[2] = {calculated, calculated}; // Volume in 0.5 dB steps. -128 (muted) to 48. Do not go above -20 (100%).
-        if (R_SUCCEEDED(res)) res = CDCCHK_WriteRegisters2(0, 65, volumes, 2); // CDC_REG_DAC_L_VOLUME_CTRL, CDC_REG_DAC_R_VOLUME_CTRL
+    if (currVolumeSliderOverride >= 0)
+    {
+        i2s1Mux &= ~0x80;
+        i2s2Mux |=  0x20;
     }
+    else
+    {
+        i2s1Mux |=  0x80;
+        i2s2Mux &= ~0x20;
+    }
+
+    s8 i2s1Volume;
+    s8 i2s2Volume;
+    if (currVolumeSliderOverride >= 0)
+    {
+        i2s1Volume = -128 + (((float)currVolumeSliderOverride/100.f) * 108);
+        i2s2Volume = i2s1Volume;
+    }
+    else
+    {
+        // Restore shutter sound volumes. This sould be sourced from cfg,
+        // however the values are the same everwhere
+        i2s1Volume =  -3; // -1.5 dB (115.7%, only used by TWL applications when taking photos)
+        i2s2Volume = -20; // -10 dB  (100%)
+    }
+
+    // Write volume overrides values before writing to the pinmux registers
+    if (R_SUCCEEDED(res)) res = CDCCHK_WriteRegisters2(0, 65, &i2s1Volume, 1); // CDC_REG_DAC_L_VOLUME_CTRL
+    if (R_SUCCEEDED(res)) res = CDCCHK_WriteRegisters2(0, 66, &i2s1Volume, 1); // CDC_REG_DAC_R_VOLUME_CTRL
+    if (R_SUCCEEDED(res)) res = CDCCHK_WriteRegisters2(100, 123, &i2s2Volume, 1);
+
+    if (R_SUCCEEDED(res)) res = CDCCHK_WriteRegisters2(0, 116, &i2s1Mux, 1);
+    if (R_SUCCEEDED(res)) res = CDCCHK_WriteRegisters2(100, 49, &i2s2Mux, 1);
 
     cdcChkExit();
     return res;