From 9b7be8b88f6c14eb13dbe73179d29fdd25fe8b28 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@siemens.com>
Date: Tue, 2 Mar 2021 18:05:27 +0100
Subject: [PATCH 01/13] rework encoder pin handling for split keyboards

---
 quantum/encoder.c | 115 ++++++++++++++++++++++++++++------------------
 1 file changed, 71 insertions(+), 44 deletions(-)

diff --git a/quantum/encoder.c b/quantum/encoder.c
index 2ed64c1e3074..97619518da7c 100644
--- a/quantum/encoder.c
+++ b/quantum/encoder.c
@@ -31,11 +31,39 @@
 #    error "No encoder pads defined by ENCODERS_PAD_A and ENCODERS_PAD_B"
 #endif
 
-#define NUMBER_OF_ENCODERS (sizeof(encoders_pad_a) / sizeof(pin_t))
-static pin_t encoders_pad_a[] = ENCODERS_PAD_A;
-static pin_t encoders_pad_b[] = ENCODERS_PAD_B;
-#ifdef ENCODER_RESOLUTIONS
-static uint8_t encoder_resolutions[] = ENCODER_RESOLUTIONS;
+#ifdef SPLIT_KEYBOARD
+    #ifndef ENCODERS_PAD_A_RIGHT
+    #   define ENCODERS_PAD_A_RIGHT ENCODERS_PAD_A
+    #endif
+
+    #ifndef ENCODERS_PAD_B_RIGHT
+    #   define ENCODERS_PAD_B_RIGHT ENCODERS_PAD_B
+    #endif
+
+    #if defined(ENCODER_RESOLUTIONS) && !defined(ENCODER_RESOLUTIONS_RIGHT)
+    #   define ENCODER_RESOLUTIONS_RIGHT ENCODER_RESOLUTIONS
+    #endif
+
+#   define NUMBER_OF_ENCODERS ((sizeof(encoders_pad_a) + sizeof(encoders_pad_a_right)) / sizeof(pin_t))
+#   define NUMBER_OF_ENCODERS_LEFT (sizeof(encoders_pad_a) / sizeof(pin_t))
+#   define NUMBER_OF_ENCODERS_RIGHT (sizeof(encoders_pad_a_right) / sizeof(pin_t))
+    static pin_t encoders_pad_a[] = ENCODERS_PAD_A;
+    static pin_t encoders_pad_b[] = ENCODERS_PAD_B;
+	#ifdef ENCODER_RESOLUTIONS
+		static uint8_t encoder_resolutions[] = ENCODER_RESOLUTIONS;
+	#endif
+    static pin_t encoders_pad_a_right[] = ENCODERS_PAD_A_RIGHT;
+    static pin_t encoders_pad_b_right[] = ENCODERS_PAD_B_RIGHT;
+    #ifdef ENCODER_RESOLUTIONS_RIGHT
+		static uint8_t encoder_resolutions_right[] = ENCODER_RESOLUTIONS_RIGHT;
+	#endif
+#else
+#   define NUMBER_OF_ENCODERS (sizeof(encoders_pad_a) / sizeof(pin_t))
+    static pin_t encoders_pad_a[] = ENCODERS_PAD_A;
+    static pin_t encoders_pad_b[] = ENCODERS_PAD_B;
+	#ifdef ENCODER_RESOLUTIONS
+		static uint8_t encoder_resolutions[] = ENCODER_RESOLUTIONS;
+	#endif
 #endif
 
 #ifndef ENCODER_DIRECTION_FLIP
@@ -50,96 +78,95 @@ static int8_t encoder_LUT[] = {0, -1, 1, 0, 1, 0, 0, -1, -1, 0, 0, 1, 0, 1, -1,
 static uint8_t encoder_state[NUMBER_OF_ENCODERS]  = {0};
 static int8_t  encoder_pulses[NUMBER_OF_ENCODERS] = {0};
 
-#ifdef SPLIT_KEYBOARD
-// right half encoders come over as second set of encoders
-static uint8_t encoder_value[NUMBER_OF_ENCODERS * 2] = {0};
-// row offsets for each hand
-static uint8_t thisHand, thatHand;
-#else
 static uint8_t encoder_value[NUMBER_OF_ENCODERS] = {0};
-#endif
 
 __attribute__((weak)) void encoder_update_user(int8_t index, bool clockwise) {}
 
 __attribute__((weak)) void encoder_update_kb(int8_t index, bool clockwise) { encoder_update_user(index, clockwise); }
 
-void encoder_init(void) {
-#if defined(SPLIT_KEYBOARD) && defined(ENCODERS_PAD_A_RIGHT) && defined(ENCODERS_PAD_B_RIGHT)
-    if (!isLeftHand) {
-        const pin_t encoders_pad_a_right[] = ENCODERS_PAD_A_RIGHT;
-        const pin_t encoders_pad_b_right[] = ENCODERS_PAD_B_RIGHT;
-#    if defined(ENCODER_RESOLUTIONS_RIGHT)
-        const uint8_t encoder_resolutions_right[] = ENCODER_RESOLUTIONS_RIGHT;
-#    endif
-        for (uint8_t i = 0; i < NUMBER_OF_ENCODERS; i++) {
-            encoders_pad_a[i] = encoders_pad_a_right[i];
-            encoders_pad_b[i] = encoders_pad_b_right[i];
-#    if defined(ENCODER_RESOLUTIONS_RIGHT)
-            encoder_resolutions[i] = encoder_resolutions_right[i];
-#    endif
-        }
-    }
+#ifdef SPLIT_KEYBOARD
+    // row offsets for each hand
+    static uint8_t thisHand, thatHand;
 #endif
 
+void encoder_init(void) {
+#ifndef SPLIT_KEYBOARD
     for (int i = 0; i < NUMBER_OF_ENCODERS; i++) {
         setPinInputHigh(encoders_pad_a[i]);
         setPinInputHigh(encoders_pad_b[i]);
 
         encoder_state[i] = (readPin(encoders_pad_a[i]) << 0) | (readPin(encoders_pad_b[i]) << 1);
     }
-
-#ifdef SPLIT_KEYBOARD
-    thisHand = isLeftHand ? 0 : NUMBER_OF_ENCODERS;
+#else
+    thisHand = is_keyboard_left() ? 0 : NUMBER_OF_ENCODERS_LEFT;
+    thisHandNum = is_keyboard_left() ? NUMBER_OF_ENCODERS_LEFT : NUMBER_OF_ENCODERS_RIGHT;
     thatHand = NUMBER_OF_ENCODERS - thisHand;
+
+    pin_t pad_a[] = is_keyboard_left() ? encoders_pad_a : encoders_pad_a_right;
+    pin_t pad_b[] = is_keyboard_left() ? encoders_pad_b : encoders_pad_b_right;
+    
+    for (int i = 0; i < thisHandNum; i++) {
+        setPinInputHigh(pad_a[i]);
+        setPinInputHigh(pad_b[i]);
+
+        encoder_state[thisHand + i] = (readPin(pad_a[i]) << 0) | (readPin(pad_b[i]) << 1);
+    }
 #endif
+
 }
 
 static bool encoder_update(int8_t index, uint8_t state) {
     bool    changed = false;
-    uint8_t i       = index;
-
+    
 #ifdef ENCODER_RESOLUTIONS
-    int8_t resolution = encoder_resolutions[i];
+    int8_t resolution = is_keyboard_left() ? encoder_resolutions[index] : encoder_resolutions_right[index - NUMBER_OF_ENCODERS_LEFT];
 #else
     int8_t resolution = ENCODER_RESOLUTION;
 #endif
-
-#ifdef SPLIT_KEYBOARD
-    index += thisHand;
-#endif
-    encoder_pulses[i] += encoder_LUT[state & 0xF];
-    if (encoder_pulses[i] >= resolution) {
+    encoder_pulses[index] += encoder_LUT[state & 0xF];
+    if (encoder_pulses[index] >= resolution) {
         encoder_value[index]++;
         changed = true;
         encoder_update_kb(index, ENCODER_COUNTER_CLOCKWISE);
     }
-    if (encoder_pulses[i] <= -resolution) {  // direction is arbitrary here, but this clockwise
+    if (encoder_pulses[index] <= -resolution) {  // direction is arbitrary here, but this clockwise
         encoder_value[index]--;
         changed = true;
         encoder_update_kb(index, ENCODER_CLOCKWISE);
     }
-    encoder_pulses[i] %= resolution;
+    encoder_pulses[index] %= resolution;
     return changed;
 }
 
 bool encoder_read(void) {
     bool changed = false;
+#ifndef SPLIT_KEYBOARD
     for (uint8_t i = 0; i < NUMBER_OF_ENCODERS; i++) {
         encoder_state[i] <<= 2;
         encoder_state[i] |= (readPin(encoders_pad_a[i]) << 0) | (readPin(encoders_pad_b[i]) << 1);
         changed |= encoder_update(i, encoder_state[i]);
     }
+#else
+    pin_t pad_a[] = is_keyboard_left() ? encoders_pad_a : encoders_pad_a_right;
+    pin_t pad_b[] = is_keyboard_left() ? encoders_pad_b : encoders_pad_b_right;
+
+    for (uint8_t i = 0; i < thisHandNum; i++) {
+        encoder_state[thisHand + i] <<= 2;
+        encoder_state[thisHand + i] |= (readPin(pad_a[i]) << 0) | (readPin(pad_b[i]) << 1);
+        changed |= encoder_update(thisHand + i, encoder_state[thisHand + i]);
+    }
+#endif
     return changed;
 }
 
 #ifdef SPLIT_KEYBOARD
 void last_encoder_activity_trigger(void);
 
-void encoder_state_raw(uint8_t* slave_state) { memcpy(slave_state, &encoder_value[thisHand], sizeof(uint8_t) * NUMBER_OF_ENCODERS); }
+void encoder_state_raw(uint8_t* slave_state) { memcpy(slave_state, &encoder_value[thisHand], sizeof(uint8_t) * thisHandNum); }
 
 void encoder_update_raw(uint8_t* slave_state) {
     bool changed = false;
-    for (uint8_t i = 0; i < NUMBER_OF_ENCODERS; i++) {
+    for (uint8_t i = 0; i < NUMBER_OF_ENCODERS - thisHandNum; i++) {
         uint8_t index = i + thatHand;
         int8_t  delta = slave_state[i] - encoder_value[index];
         while (delta > 0) {

From c31e643f3c53b5171f46596d2c8e5911905e3089 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@siemens.com>
Date: Tue, 2 Mar 2021 20:05:43 +0100
Subject: [PATCH 02/13] simplify encoder code

---
 quantum/encoder.c | 73 +++++++++++++++++++++++------------------------
 1 file changed, 36 insertions(+), 37 deletions(-)

diff --git a/quantum/encoder.c b/quantum/encoder.c
index 97619518da7c..05113ca9eae7 100644
--- a/quantum/encoder.c
+++ b/quantum/encoder.c
@@ -27,11 +27,12 @@
 #    define ENCODER_RESOLUTION 4
 #endif
 
-#if !defined(ENCODERS_PAD_A) || !defined(ENCODERS_PAD_B)
-#    error "No encoder pads defined by ENCODERS_PAD_A and ENCODERS_PAD_B"
+#if (!defined(ENCODERS_PAD_A) || !defined(ENCODERS_PAD_B)) && (!defined(ENCODERS_PAD_A) || !defined(ENCODERS_PAD_B))
+#    error "No encoder pads defined by ENCODERS_PAD_A and ENCODERS_PAD_B or ENCODERS_PAD_A_RIGHT and ENCODERS_PAD_B_RIGHT"
 #endif
 
 #ifdef SPLIT_KEYBOARD
+    // if no pads for right half are defined, we assume the keyboard is symmetric (i.e. same pads)
     #ifndef ENCODERS_PAD_A_RIGHT
     #   define ENCODERS_PAD_A_RIGHT ENCODERS_PAD_A
     #endif
@@ -84,34 +85,43 @@ __attribute__((weak)) void encoder_update_user(int8_t index, bool clockwise) {}
 
 __attribute__((weak)) void encoder_update_kb(int8_t index, bool clockwise) { encoder_update_user(index, clockwise); }
 
+// number of encoders connected to this controller
+static uint8_t numEncodersHere;
+// index of the first encoder connected to this controller (only for right halves, this will be nonzero)
+static uint8_t firstEncoderHere;
 #ifdef SPLIT_KEYBOARD
-    // row offsets for each hand
-    static uint8_t thisHand, thatHand;
+    // index of the first encoder connected to the other half
+    static uint8_t firstEncoderThere;
 #endif
 
 void encoder_init(void) {
 #ifndef SPLIT_KEYBOARD
-    for (int i = 0; i < NUMBER_OF_ENCODERS; i++) {
-        setPinInputHigh(encoders_pad_a[i]);
-        setPinInputHigh(encoders_pad_b[i]);
-
-        encoder_state[i] = (readPin(encoders_pad_a[i]) << 0) | (readPin(encoders_pad_b[i]) << 1);
-    }
+    numEncodersHere = NUMBER_OF_ENCODERS;
+    pin_t pad_a[] = encoders_pad_a;
+    pin_t pad_b[] = encoders_pad_b;
+    firstEncoderHere = 0;
 #else
-    thisHand = is_keyboard_left() ? 0 : NUMBER_OF_ENCODERS_LEFT;
-    thisHandNum = is_keyboard_left() ? NUMBER_OF_ENCODERS_LEFT : NUMBER_OF_ENCODERS_RIGHT;
-    thatHand = NUMBER_OF_ENCODERS - thisHand;
-
-    pin_t pad_a[] = is_keyboard_left() ? encoders_pad_a : encoders_pad_a_right;
-    pin_t pad_b[] = is_keyboard_left() ? encoders_pad_b : encoders_pad_b_right;
+    if (is_keyboard_left()) {
+        numEncodersHere = NUMBER_OF_ENCODERS_LEFT;
+        pin_t pad_a[] = encoders_pad_a;
+        pin_t pad_b[] = encoders_pad_b;
+        firstEncoderHere = 0;
+        firstEncoderThere = NUMBER_OF_ENCODERS_LEFT;
+    } else {
+        numEncodersHere = NUMBER_OF_ENCODERS_RIGHT;
+        pin_t pad_a[] = encoders_pad_a_right;
+        pin_t pad_b[] = encoders_pad_b_right;
+        firstEncoderHere = NUMBER_OF_ENCODERS_LEFT;
+        firstEncoderThere = 0;
+    }
+#endif
     
-    for (int i = 0; i < thisHandNum; i++) {
+    for (int i = 0; i < numEncodersHere; i++) {
         setPinInputHigh(pad_a[i]);
         setPinInputHigh(pad_b[i]);
 
-        encoder_state[thisHand + i] = (readPin(pad_a[i]) << 0) | (readPin(pad_b[i]) << 1);
+        encoder_state[firstEncoderHere + i] = (readPin(pad_a[i]) << 0) | (readPin(pad_b[i]) << 1);
     }
-#endif
 
 }
 
@@ -140,34 +150,23 @@ static bool encoder_update(int8_t index, uint8_t state) {
 
 bool encoder_read(void) {
     bool changed = false;
-#ifndef SPLIT_KEYBOARD
-    for (uint8_t i = 0; i < NUMBER_OF_ENCODERS; i++) {
-        encoder_state[i] <<= 2;
-        encoder_state[i] |= (readPin(encoders_pad_a[i]) << 0) | (readPin(encoders_pad_b[i]) << 1);
-        changed |= encoder_update(i, encoder_state[i]);
+    for (uint8_t i = 0; i < numEncodersHere; i++) {
+        encoder_state[firstEncoderHere + i] <<= 2;
+        encoder_state[firstEncoderHere + i] |= (readPin(pad_a[i]) << 0) | (readPin(pad_b[i]) << 1);
+        changed |= encoder_update(firstEncoderHere + i, encoder_state[firstEncoderHere + i]);
     }
-#else
-    pin_t pad_a[] = is_keyboard_left() ? encoders_pad_a : encoders_pad_a_right;
-    pin_t pad_b[] = is_keyboard_left() ? encoders_pad_b : encoders_pad_b_right;
-
-    for (uint8_t i = 0; i < thisHandNum; i++) {
-        encoder_state[thisHand + i] <<= 2;
-        encoder_state[thisHand + i] |= (readPin(pad_a[i]) << 0) | (readPin(pad_b[i]) << 1);
-        changed |= encoder_update(thisHand + i, encoder_state[thisHand + i]);
-    }
-#endif
     return changed;
 }
 
 #ifdef SPLIT_KEYBOARD
 void last_encoder_activity_trigger(void);
 
-void encoder_state_raw(uint8_t* slave_state) { memcpy(slave_state, &encoder_value[thisHand], sizeof(uint8_t) * thisHandNum); }
+void encoder_state_raw(uint8_t* slave_state) { memcpy(slave_state, &encoder_value[firstEncoderHere], sizeof(uint8_t) * numEncodersHere); }
 
 void encoder_update_raw(uint8_t* slave_state) {
     bool changed = false;
-    for (uint8_t i = 0; i < NUMBER_OF_ENCODERS - thisHandNum; i++) {
-        uint8_t index = i + thatHand;
+    for (uint8_t i = 0; i < NUMBER_OF_ENCODERS - numEncodersHere; i++) {
+        uint8_t index = firstEncoderThere + i;
         int8_t  delta = slave_state[i] - encoder_value[index];
         while (delta > 0) {
             delta--;

From 20f003f750667509cb3e7dbb3aa0f8acc03ae473 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@gmail.com>
Date: Tue, 2 Mar 2021 21:13:34 +0100
Subject: [PATCH 03/13] fixes and align resolutions

---
 quantum/encoder.c | 46 ++++++++++++++++++++++++----------------------
 1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/quantum/encoder.c b/quantum/encoder.c
index 05113ca9eae7..a93c217a6cce 100644
--- a/quantum/encoder.c
+++ b/quantum/encoder.c
@@ -31,16 +31,23 @@
 #    error "No encoder pads defined by ENCODERS_PAD_A and ENCODERS_PAD_B or ENCODERS_PAD_A_RIGHT and ENCODERS_PAD_B_RIGHT"
 #endif
 
-#ifdef SPLIT_KEYBOARD
+// on split keyboards, these are the pads and resolutions for the left half
+static pin_t encoders_pad_a[] = ENCODERS_PAD_A;
+static pin_t encoders_pad_b[] = ENCODERS_PAD_B;
+#ifdef ENCODER_RESOLUTIONS
+    static uint8_t encoder_resolutions[] = ENCODER_RESOLUTIONS;
+#endif
+
+#ifndef SPLIT_KEYBOARD
+#   define NUMBER_OF_ENCODERS (sizeof(encoders_pad_a) / sizeof(pin_t))
+#else
     // if no pads for right half are defined, we assume the keyboard is symmetric (i.e. same pads)
     #ifndef ENCODERS_PAD_A_RIGHT
     #   define ENCODERS_PAD_A_RIGHT ENCODERS_PAD_A
     #endif
-
     #ifndef ENCODERS_PAD_B_RIGHT
     #   define ENCODERS_PAD_B_RIGHT ENCODERS_PAD_B
     #endif
-
     #if defined(ENCODER_RESOLUTIONS) && !defined(ENCODER_RESOLUTIONS_RIGHT)
     #   define ENCODER_RESOLUTIONS_RIGHT ENCODER_RESOLUTIONS
     #endif
@@ -48,23 +55,11 @@
 #   define NUMBER_OF_ENCODERS ((sizeof(encoders_pad_a) + sizeof(encoders_pad_a_right)) / sizeof(pin_t))
 #   define NUMBER_OF_ENCODERS_LEFT (sizeof(encoders_pad_a) / sizeof(pin_t))
 #   define NUMBER_OF_ENCODERS_RIGHT (sizeof(encoders_pad_a_right) / sizeof(pin_t))
-    static pin_t encoders_pad_a[] = ENCODERS_PAD_A;
-    static pin_t encoders_pad_b[] = ENCODERS_PAD_B;
-	#ifdef ENCODER_RESOLUTIONS
-		static uint8_t encoder_resolutions[] = ENCODER_RESOLUTIONS;
-	#endif
     static pin_t encoders_pad_a_right[] = ENCODERS_PAD_A_RIGHT;
     static pin_t encoders_pad_b_right[] = ENCODERS_PAD_B_RIGHT;
     #ifdef ENCODER_RESOLUTIONS_RIGHT
 		static uint8_t encoder_resolutions_right[] = ENCODER_RESOLUTIONS_RIGHT;
 	#endif
-#else
-#   define NUMBER_OF_ENCODERS (sizeof(encoders_pad_a) / sizeof(pin_t))
-    static pin_t encoders_pad_a[] = ENCODERS_PAD_A;
-    static pin_t encoders_pad_b[] = ENCODERS_PAD_B;
-	#ifdef ENCODER_RESOLUTIONS
-		static uint8_t encoder_resolutions[] = ENCODER_RESOLUTIONS;
-	#endif
 #endif
 
 #ifndef ENCODER_DIRECTION_FLIP
@@ -93,24 +88,27 @@ static uint8_t firstEncoderHere;
     // index of the first encoder connected to the other half
     static uint8_t firstEncoderThere;
 #endif
+// the pads for this controller
+static pin_t *pad_a;
+static pin_t *pad_b;
 
 void encoder_init(void) {
 #ifndef SPLIT_KEYBOARD
     numEncodersHere = NUMBER_OF_ENCODERS;
-    pin_t pad_a[] = encoders_pad_a;
-    pin_t pad_b[] = encoders_pad_b;
+    pad_a = encoders_pad_a;
+    pad_b = encoders_pad_b;
     firstEncoderHere = 0;
 #else
     if (is_keyboard_left()) {
         numEncodersHere = NUMBER_OF_ENCODERS_LEFT;
-        pin_t pad_a[] = encoders_pad_a;
-        pin_t pad_b[] = encoders_pad_b;
+        pad_a = encoders_pad_a;
+        pad_b = encoders_pad_b;
         firstEncoderHere = 0;
         firstEncoderThere = NUMBER_OF_ENCODERS_LEFT;
     } else {
         numEncodersHere = NUMBER_OF_ENCODERS_RIGHT;
-        pin_t pad_a[] = encoders_pad_a_right;
-        pin_t pad_b[] = encoders_pad_b_right;
+        pad_a = encoders_pad_a_right;
+        pad_b = encoders_pad_b_right;
         firstEncoderHere = NUMBER_OF_ENCODERS_LEFT;
         firstEncoderThere = 0;
     }
@@ -129,7 +127,11 @@ static bool encoder_update(int8_t index, uint8_t state) {
     bool    changed = false;
     
 #ifdef ENCODER_RESOLUTIONS
-    int8_t resolution = is_keyboard_left() ? encoder_resolutions[index] : encoder_resolutions_right[index - NUMBER_OF_ENCODERS_LEFT];
+    #ifndef SPLIT_KEYBOARD
+        int8_t resolution = encoder_resolutions[index];
+    #else
+        int8_t resolution = is_keyboard_left() ? encoder_resolutions[index] : encoder_resolutions_right[index - NUMBER_OF_ENCODERS_LEFT];
+    #endif
 #else
     int8_t resolution = ENCODER_RESOLUTION;
 #endif

From 629009203972b17f98affd4ca20f7dc271293333 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@gmail.com>
Date: Tue, 2 Mar 2021 22:13:25 +0100
Subject: [PATCH 04/13] update docs

---
 docs/feature_encoders.md | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/docs/feature_encoders.md b/docs/feature_encoders.md
index e2cafdac48e8..23e3695f6686 100644
--- a/docs/feature_encoders.md
+++ b/docs/feature_encoders.md
@@ -40,7 +40,9 @@ It can also be defined per-encoder, by instead defining:
 
 ## Split Keyboards
 
-If you are using different pinouts for the encoders on each half of a split keyboard, you can define the pinout (and optionally, resolutions) for the right half like this:
+The above is enough for split keyboards that are symmetrical, i.e. the halves have the same number of encoders and they are on the same pins.
+If the halves are not symmetrical, you can define the pinout (and optionally, resolutions) of the right half separately.
+The left half will use the definitions above.
 
 ```c
 #define ENCODERS_PAD_A_RIGHT { encoder1a, encoder2a }
@@ -48,6 +50,17 @@ If you are using different pinouts for the encoders on each half of a split keyb
 #define ENCODER_RESOLUTIONS_RIGHT { 2, 4 }
 ```
 
+If only the right half has encoders, you must still define an empty array for the left pads (and resolutions, if you define `ENCODER_RESOLUTIONS_RIGHT`).
+
+```c
+#define ENCODERS_PAD_A {  }
+#define ENCODERS_PAD_B {  }
+#define ENCODER_RESOLUTIONS {  }
+#define ENCODERS_PAD_A_RIGHT { encoder1a, encoder2a }
+#define ENCODERS_PAD_B_RIGHT { encoder1b, encoder2b }
+#define ENCODER_RESOLUTIONS_RIGHT { 2, 4 }
+```
+
 ## Callbacks
 
 The callback functions can be inserted into your `<keyboard>.c`:

From 91ae2741adc930a7756e24d1ef4f07b9b6eb26f5 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@gmail.com>
Date: Wed, 3 Mar 2021 17:03:28 -0800
Subject: [PATCH 05/13] fix formating of encoder.c with clang-format

---
 quantum/encoder.c | 89 +++++++++++++++++++++++------------------------
 1 file changed, 44 insertions(+), 45 deletions(-)

diff --git a/quantum/encoder.c b/quantum/encoder.c
index a93c217a6cce..eb21710a2a65 100644
--- a/quantum/encoder.c
+++ b/quantum/encoder.c
@@ -35,31 +35,31 @@
 static pin_t encoders_pad_a[] = ENCODERS_PAD_A;
 static pin_t encoders_pad_b[] = ENCODERS_PAD_B;
 #ifdef ENCODER_RESOLUTIONS
-    static uint8_t encoder_resolutions[] = ENCODER_RESOLUTIONS;
+static uint8_t encoder_resolutions[] = ENCODER_RESOLUTIONS;
 #endif
 
 #ifndef SPLIT_KEYBOARD
-#   define NUMBER_OF_ENCODERS (sizeof(encoders_pad_a) / sizeof(pin_t))
+#    define NUMBER_OF_ENCODERS (sizeof(encoders_pad_a) / sizeof(pin_t))
 #else
-    // if no pads for right half are defined, we assume the keyboard is symmetric (i.e. same pads)
-    #ifndef ENCODERS_PAD_A_RIGHT
-    #   define ENCODERS_PAD_A_RIGHT ENCODERS_PAD_A
-    #endif
-    #ifndef ENCODERS_PAD_B_RIGHT
-    #   define ENCODERS_PAD_B_RIGHT ENCODERS_PAD_B
-    #endif
-    #if defined(ENCODER_RESOLUTIONS) && !defined(ENCODER_RESOLUTIONS_RIGHT)
-    #   define ENCODER_RESOLUTIONS_RIGHT ENCODER_RESOLUTIONS
-    #endif
-
-#   define NUMBER_OF_ENCODERS ((sizeof(encoders_pad_a) + sizeof(encoders_pad_a_right)) / sizeof(pin_t))
-#   define NUMBER_OF_ENCODERS_LEFT (sizeof(encoders_pad_a) / sizeof(pin_t))
-#   define NUMBER_OF_ENCODERS_RIGHT (sizeof(encoders_pad_a_right) / sizeof(pin_t))
-    static pin_t encoders_pad_a_right[] = ENCODERS_PAD_A_RIGHT;
-    static pin_t encoders_pad_b_right[] = ENCODERS_PAD_B_RIGHT;
-    #ifdef ENCODER_RESOLUTIONS_RIGHT
-		static uint8_t encoder_resolutions_right[] = ENCODER_RESOLUTIONS_RIGHT;
-	#endif
+// if no pads for right half are defined, we assume the keyboard is symmetric (i.e. same pads)
+#    ifndef ENCODERS_PAD_A_RIGHT
+#        define ENCODERS_PAD_A_RIGHT ENCODERS_PAD_A
+#    endif
+#    ifndef ENCODERS_PAD_B_RIGHT
+#        define ENCODERS_PAD_B_RIGHT ENCODERS_PAD_B
+#    endif
+#    if defined(ENCODER_RESOLUTIONS) && !defined(ENCODER_RESOLUTIONS_RIGHT)
+#        define ENCODER_RESOLUTIONS_RIGHT ENCODER_RESOLUTIONS
+#    endif
+
+#    define NUMBER_OF_ENCODERS ((sizeof(encoders_pad_a) + sizeof(encoders_pad_a_right)) / sizeof(pin_t))
+#    define NUMBER_OF_ENCODERS_LEFT (sizeof(encoders_pad_a) / sizeof(pin_t))
+#    define NUMBER_OF_ENCODERS_RIGHT (sizeof(encoders_pad_a_right) / sizeof(pin_t))
+static pin_t   encoders_pad_a_right[]      = ENCODERS_PAD_A_RIGHT;
+static pin_t   encoders_pad_b_right[]      = ENCODERS_PAD_B_RIGHT;
+#    ifdef ENCODER_RESOLUTIONS_RIGHT
+static uint8_t encoder_resolutions_right[] = ENCODER_RESOLUTIONS_RIGHT;
+#    endif
 #endif
 
 #ifndef ENCODER_DIRECTION_FLIP
@@ -85,53 +85,52 @@ static uint8_t numEncodersHere;
 // index of the first encoder connected to this controller (only for right halves, this will be nonzero)
 static uint8_t firstEncoderHere;
 #ifdef SPLIT_KEYBOARD
-    // index of the first encoder connected to the other half
-    static uint8_t firstEncoderThere;
+// index of the first encoder connected to the other half
+static uint8_t firstEncoderThere;
 #endif
 // the pads for this controller
-static pin_t *pad_a;
-static pin_t *pad_b;
+static pin_t* pad_a;
+static pin_t* pad_b;
 
 void encoder_init(void) {
 #ifndef SPLIT_KEYBOARD
-    numEncodersHere = NUMBER_OF_ENCODERS;
-    pad_a = encoders_pad_a;
-    pad_b = encoders_pad_b;
+    numEncodersHere  = NUMBER_OF_ENCODERS;
+    pad_a            = encoders_pad_a;
+    pad_b            = encoders_pad_b;
     firstEncoderHere = 0;
 #else
     if (is_keyboard_left()) {
-        numEncodersHere = NUMBER_OF_ENCODERS_LEFT;
-        pad_a = encoders_pad_a;
-        pad_b = encoders_pad_b;
-        firstEncoderHere = 0;
+        numEncodersHere   = NUMBER_OF_ENCODERS_LEFT;
+        pad_a             = encoders_pad_a;
+        pad_b             = encoders_pad_b;
+        firstEncoderHere  = 0;
         firstEncoderThere = NUMBER_OF_ENCODERS_LEFT;
     } else {
-        numEncodersHere = NUMBER_OF_ENCODERS_RIGHT;
-        pad_a = encoders_pad_a_right;
-        pad_b = encoders_pad_b_right;
-        firstEncoderHere = NUMBER_OF_ENCODERS_LEFT;
+        numEncodersHere   = NUMBER_OF_ENCODERS_RIGHT;
+        pad_a             = encoders_pad_a_right;
+        pad_b             = encoders_pad_b_right;
+        firstEncoderHere  = NUMBER_OF_ENCODERS_LEFT;
         firstEncoderThere = 0;
     }
 #endif
-    
+
     for (int i = 0; i < numEncodersHere; i++) {
         setPinInputHigh(pad_a[i]);
         setPinInputHigh(pad_b[i]);
 
         encoder_state[firstEncoderHere + i] = (readPin(pad_a[i]) << 0) | (readPin(pad_b[i]) << 1);
     }
-
 }
 
 static bool encoder_update(int8_t index, uint8_t state) {
-    bool    changed = false;
-    
+    bool changed = false;
+
 #ifdef ENCODER_RESOLUTIONS
-    #ifndef SPLIT_KEYBOARD
-        int8_t resolution = encoder_resolutions[index];
-    #else
-        int8_t resolution = is_keyboard_left() ? encoder_resolutions[index] : encoder_resolutions_right[index - NUMBER_OF_ENCODERS_LEFT];
-    #endif
+#    ifndef SPLIT_KEYBOARD
+    int8_t resolution = encoder_resolutions[index];
+#    else
+    int8_t resolution = is_keyboard_left() ? encoder_resolutions[index] : encoder_resolutions_right[index - NUMBER_OF_ENCODERS_LEFT];
+#    endif
 #else
     int8_t resolution = ENCODER_RESOLUTION;
 #endif

From 8f2f14fdec1be4ec3a404a89f0f3819350fb6386 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@gmail.com>
Date: Thu, 4 Mar 2021 12:46:54 -0800
Subject: [PATCH 06/13] replace include of quantum.h in encoder.h

---
 quantum/encoder.c | 4 ++--
 quantum/encoder.h | 4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/quantum/encoder.c b/quantum/encoder.c
index eb21710a2a65..cee2c8f78c3a 100644
--- a/quantum/encoder.c
+++ b/quantum/encoder.c
@@ -99,7 +99,7 @@ void encoder_init(void) {
     pad_b            = encoders_pad_b;
     firstEncoderHere = 0;
 #else
-    if (is_keyboard_left()) {
+    if (isLeftHand) {
         numEncodersHere   = NUMBER_OF_ENCODERS_LEFT;
         pad_a             = encoders_pad_a;
         pad_b             = encoders_pad_b;
@@ -129,7 +129,7 @@ static bool encoder_update(int8_t index, uint8_t state) {
 #    ifndef SPLIT_KEYBOARD
     int8_t resolution = encoder_resolutions[index];
 #    else
-    int8_t resolution = is_keyboard_left() ? encoder_resolutions[index] : encoder_resolutions_right[index - NUMBER_OF_ENCODERS_LEFT];
+    int8_t resolution = isLeftHand ? encoder_resolutions[index] : encoder_resolutions_right[index - NUMBER_OF_ENCODERS_LEFT];
 #    endif
 #else
     int8_t resolution = ENCODER_RESOLUTION;
diff --git a/quantum/encoder.h b/quantum/encoder.h
index db6f220da4a4..71089625e03e 100644
--- a/quantum/encoder.h
+++ b/quantum/encoder.h
@@ -17,7 +17,9 @@
 
 #pragma once
 
-#include "quantum.h"
+#include <stdbool.h>
+#include <stdint.h>
+#include <gpio.h>
 
 void encoder_init(void);
 bool encoder_read(void);

From f283d0f0a41eb139d393fd3614a148e1ac829243 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@gmail.com>
Date: Thu, 4 Mar 2021 15:07:30 -0800
Subject: [PATCH 07/13] fix transport buffer size for encoders

---
 quantum/split_common/transport.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/quantum/split_common/transport.c b/quantum/split_common/transport.c
index 27a1c0d3a426..646f2f1b2424 100644
--- a/quantum/split_common/transport.c
+++ b/quantum/split_common/transport.c
@@ -18,8 +18,17 @@
 
 #ifdef ENCODER_ENABLE
 #    include "encoder.h"
-static pin_t encoders_pad[] = ENCODERS_PAD_A;
-#    define NUMBER_OF_ENCODERS (sizeof(encoders_pad) / sizeof(pin_t))
+// if no pads for right half are defined, we assume the keyboard is symmetric (i.e. same pads)
+#    ifndef ENCODERS_PAD_A_RIGHT
+#        define ENCODERS_PAD_A_RIGHT ENCODERS_PAD_A
+#    endif
+#    ifndef ENCODERS_PAD_B_RIGHT
+#        define ENCODERS_PAD_B_RIGHT ENCODERS_PAD_B
+#    endif
+#    define NUMBER_OF_ENCODERS ((sizeof(encoders_pad_a) + sizeof(encoders_pad_a_right)) / sizeof(pin_t))
+// only needed to calculate number of encoders / size of buffer
+static pin_t encoders_pad_a[]       = ENCODERS_PAD_A;
+static pin_t encoders_pad_a_right[] = ENCODERS_PAD_A_RIGHT;
 #endif
 
 #if defined(RGB_MATRIX_ENABLE) && defined(RGB_MATRIX_SPLIT)

From b8f157b857a4d8edfedf48851095d678b199d2c0 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@gmail.com>
Date: Fri, 5 Mar 2021 13:05:55 -0800
Subject: [PATCH 08/13] add unit tests for encoders

---
 build_test.mk                                 |   1 +
 quantum/encoder.c                             |  13 +-
 quantum/encoder.h                             |   1 -
 quantum/encoder/tests/encoder_tests.cpp       | 130 ++++++++++++++++++
 quantum/encoder/tests/encoder_tests_split.cpp | 129 +++++++++++++++++
 quantum/encoder/tests/mock.c                  |  21 +++
 quantum/encoder/tests/mock.h                  |  22 +++
 quantum/encoder/tests/mock_split.c            |  23 ++++
 quantum/encoder/tests/mock_split.h            |  28 ++++
 quantum/encoder/tests/rules.mk                |  13 ++
 quantum/encoder/tests/testlist.mk             |   3 +
 testlist.mk                                   |   1 +
 12 files changed, 382 insertions(+), 3 deletions(-)
 create mode 100644 quantum/encoder/tests/encoder_tests.cpp
 create mode 100644 quantum/encoder/tests/encoder_tests_split.cpp
 create mode 100644 quantum/encoder/tests/mock.c
 create mode 100644 quantum/encoder/tests/mock.h
 create mode 100644 quantum/encoder/tests/mock_split.c
 create mode 100644 quantum/encoder/tests/mock_split.h
 create mode 100644 quantum/encoder/tests/rules.mk
 create mode 100644 quantum/encoder/tests/testlist.mk

diff --git a/build_test.mk b/build_test.mk
index 77c4265f9371..e857be26e164 100644
--- a/build_test.mk
+++ b/build_test.mk
@@ -51,6 +51,7 @@ include common_features.mk
 include $(TMK_PATH)/common.mk
 include $(QUANTUM_PATH)/sequencer/tests/rules.mk
 include $(QUANTUM_PATH)/serial_link/tests/rules.mk
+include $(QUANTUM_PATH)/encoder/tests/rules.mk
 ifneq ($(filter $(FULL_TESTS),$(TEST)),)
 include build_full_test.mk
 endif
diff --git a/quantum/encoder.c b/quantum/encoder.c
index cee2c8f78c3a..92153a65c057 100644
--- a/quantum/encoder.c
+++ b/quantum/encoder.c
@@ -16,8 +16,17 @@
  */
 
 #include "encoder.h"
-#ifdef SPLIT_KEYBOARD
-#    include "split_util.h"
+
+// this is for unit testing
+#if defined(ENCODER_MOCK_SINGLE)
+#    include "encoder/tests/mock.h"
+#elif defined(ENCODER_MOCK_SPLIT)
+#    include "encoder/tests/mock_split.h"
+#else
+#    include <gpio.h>
+#    ifdef SPLIT_KEYBOARD
+#        include "split_util.h"
+#    endif
 #endif
 
 // for memcpy
diff --git a/quantum/encoder.h b/quantum/encoder.h
index 71089625e03e..d5cfa4d26f8f 100644
--- a/quantum/encoder.h
+++ b/quantum/encoder.h
@@ -19,7 +19,6 @@
 
 #include <stdbool.h>
 #include <stdint.h>
-#include <gpio.h>
 
 void encoder_init(void);
 bool encoder_read(void);
diff --git a/quantum/encoder/tests/encoder_tests.cpp b/quantum/encoder/tests/encoder_tests.cpp
new file mode 100644
index 000000000000..b118352c30a5
--- /dev/null
+++ b/quantum/encoder/tests/encoder_tests.cpp
@@ -0,0 +1,130 @@
+
+#include "gtest/gtest.h"
+#include "gmock/gmock.h"
+#include <vector>
+#include <algorithm>
+#include <stdio.h>
+
+extern "C" {
+    #include "encoder.h"
+    #include "encoder/tests/mock.h"
+}
+
+struct update {
+    int8_t index;
+    bool clockwise;
+};
+
+uint8_t uidx = 0;
+update updates[32];
+
+void encoder_update_kb(int8_t index, bool clockwise) {
+    updates[uidx % 32] = {index, clockwise};
+    uidx++;
+}
+
+bool setAndRead(pin_t pin, bool val) {
+    setPin(pin, val);
+    return encoder_read();
+}
+
+class EncoderTest : public ::testing::Test {
+
+};
+
+TEST_F(EncoderTest, TestInit) {
+    uidx = 0;
+    encoder_init();
+    EXPECT_EQ(pinIsInputHigh[0], true);
+    EXPECT_EQ(pinIsInputHigh[1], true);
+    EXPECT_EQ(uidx, 0);
+}
+
+TEST_F(EncoderTest, TestOneClockwise) {
+    uidx = 0;
+    encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(0, false);
+    setAndRead(1, false);
+    setAndRead(0, true);
+    setAndRead(1, true);
+
+    EXPECT_EQ(uidx, 1);
+    EXPECT_EQ(updates[0].index, 0);
+    EXPECT_EQ(updates[0].clockwise, true);
+}
+
+TEST_F(EncoderTest, TestOneCounterClockwise) {
+    uidx = 0;
+    encoder_init();
+    setAndRead(1, false);
+    setAndRead(0, false);
+    setAndRead(1, true);
+    setAndRead(0, true);
+
+    EXPECT_EQ(uidx, 1);
+    EXPECT_EQ(updates[0].index, 0);
+    EXPECT_EQ(updates[0].clockwise, false);
+}
+
+TEST_F(EncoderTest, TestTwoClockwiseOneCC) {
+    uidx = 0;
+    encoder_init();
+    setAndRead(0, false);
+    setAndRead(1, false);
+    setAndRead(0, true);
+    setAndRead(1, true);
+    setAndRead(0, false);
+    setAndRead(1, false);
+    setAndRead(0, true);
+    setAndRead(1, true);
+    setAndRead(1, false);
+    setAndRead(0, false);
+    setAndRead(1, true);
+    setAndRead(0, true);
+
+    EXPECT_EQ(uidx, 3);
+    EXPECT_EQ(updates[0].index, 0);
+    EXPECT_EQ(updates[0].clockwise, true);
+    EXPECT_EQ(updates[1].index, 0);
+    EXPECT_EQ(updates[1].clockwise, true);
+    EXPECT_EQ(updates[2].index, 0);
+    EXPECT_EQ(updates[2].clockwise, false);
+}
+
+TEST_F(EncoderTest, TestNoEarly) {
+    uidx = 0;
+    encoder_init();
+    // send 3 pulses. with resolution 4, that's not enough for a step.
+    setAndRead(0, false);
+    setAndRead(1, false);
+    setAndRead(0, true);
+    EXPECT_EQ(uidx, 0);
+    // now send last pulse
+    setAndRead(1, true);
+    EXPECT_EQ(uidx, 1);
+    EXPECT_EQ(updates[0].index, 0);
+    EXPECT_EQ(updates[0].clockwise, true);
+}
+
+TEST_F(EncoderTest, TestHalfway) {
+    uidx = 0;
+    encoder_init();
+    // go halfway
+    setAndRead(0, false);
+    setAndRead(1, false);
+    EXPECT_EQ(uidx, 0);
+    // back off
+    setAndRead(1, true);
+    setAndRead(0, true);
+    EXPECT_EQ(uidx, 0);
+    // go all the way
+    setAndRead(0, false);
+    setAndRead(1, false);
+    setAndRead(0, true);
+    setAndRead(1, true);
+    // should result in 1 update
+    EXPECT_EQ(uidx, 1);
+    EXPECT_EQ(updates[0].index, 0);
+    EXPECT_EQ(updates[0].clockwise, true);
+}
diff --git a/quantum/encoder/tests/encoder_tests_split.cpp b/quantum/encoder/tests/encoder_tests_split.cpp
new file mode 100644
index 000000000000..1680387d3c59
--- /dev/null
+++ b/quantum/encoder/tests/encoder_tests_split.cpp
@@ -0,0 +1,129 @@
+
+#include "gtest/gtest.h"
+#include "gmock/gmock.h"
+#include <vector>
+#include <algorithm>
+#include <stdio.h>
+
+extern "C" {
+    #include "encoder.h"
+    #include "encoder/tests/mock_split.h"
+}
+
+struct update {
+    int8_t index;
+    bool clockwise;
+};
+
+uint8_t uidx = 0;
+update updates[32];
+
+bool isLeftHand;
+
+void encoder_update_kb(int8_t index, bool clockwise) {
+    if (!isLeftHand) {
+        // this method has no effect on slave half
+        printf("ignoring update on right hand (%d,%s)\n", index, clockwise ? "CW" : "CC");
+        return;
+    }
+    updates[uidx % 32] = {index, clockwise};
+    uidx++;
+}
+
+bool setAndRead(pin_t pin, bool val) {
+    setPin(pin, val);
+    return encoder_read();
+}
+
+class EncoderTest : public ::testing::Test {
+    protected:
+    void SetUp() override {
+        uidx = 0;
+        for (int i = 0; i < 32; i++) {
+            pinIsInputHigh[i] = 0;
+            pins[i] = 0;
+        }
+    }
+};
+
+TEST_F(EncoderTest, TestInitLeft) {
+    isLeftHand = true;
+    encoder_init();
+    EXPECT_EQ(pinIsInputHigh[0], true);
+    EXPECT_EQ(pinIsInputHigh[1], true);
+    EXPECT_EQ(pinIsInputHigh[2], false);
+    EXPECT_EQ(pinIsInputHigh[3], false);
+    EXPECT_EQ(uidx, 0);
+}
+
+TEST_F(EncoderTest, TestInitRight) {
+    isLeftHand = false;
+    encoder_init();
+    EXPECT_EQ(pinIsInputHigh[0], false);
+    EXPECT_EQ(pinIsInputHigh[1], false);
+    EXPECT_EQ(pinIsInputHigh[2], true);
+    EXPECT_EQ(pinIsInputHigh[3], true);
+    EXPECT_EQ(uidx, 0);
+}
+
+TEST_F(EncoderTest, TestOneClockwiseLeft) {
+    isLeftHand = true;
+    encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(0, false);
+    setAndRead(1, false);
+    setAndRead(0, true);
+    setAndRead(1, true);
+
+    EXPECT_EQ(uidx, 1);
+    EXPECT_EQ(updates[0].index, 0);
+    EXPECT_EQ(updates[0].clockwise, true);
+}
+
+TEST_F(EncoderTest, TestOneClockwiseRightSent) {
+    isLeftHand = false;
+    encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(2, false);
+    setAndRead(3, false);
+    setAndRead(2, true);
+    setAndRead(3, true);
+
+    uint8_t slave_state[2] = {0};
+    encoder_state_raw(slave_state);
+
+    EXPECT_EQ((int8_t) slave_state[0], -1);
+}
+
+/* this test will not work after the previous test.
+ * this is due to encoder_value[1] already being set to -1 when simulating the right half.
+ * When we now receive this update acting as the left half, there is no change.
+ * This is hard to mock, as the static values inside encoder.c normally exist twice, once on each half,
+ * but here, they only exist once.
+ */
+
+// TEST_F(EncoderTest, TestOneClockwiseRightReceived) {
+//     isLeftHand = true;
+//     encoder_init();
+
+
+//     uint8_t slave_state[2] = {255, 0};
+//     encoder_update_raw(slave_state);
+
+//     EXPECT_EQ(uidx, 1);
+//     EXPECT_EQ(updates[0].index, 1);
+//     EXPECT_EQ(updates[0].clockwise, true);
+// }
+
+TEST_F(EncoderTest, TestOneCounterClockwiseRightReceived) {
+    isLeftHand = true;
+    encoder_init();
+
+
+    uint8_t slave_state[2] = {0, 0};
+    encoder_update_raw(slave_state);
+
+    EXPECT_EQ(uidx, 1);
+    EXPECT_EQ(updates[0].index, 1);
+    EXPECT_EQ(updates[0].clockwise, false);
+}
diff --git a/quantum/encoder/tests/mock.c b/quantum/encoder/tests/mock.c
new file mode 100644
index 000000000000..4c3c11e6f87e
--- /dev/null
+++ b/quantum/encoder/tests/mock.c
@@ -0,0 +1,21 @@
+
+#include "mock.h"
+
+bool pins[32] = {0};
+bool pinIsInputHigh[32] = {0};
+
+uint8_t mockSetPinInputHigh(pin_t pin) {
+    // dprintf("Setting pin %d input high.", pin);
+    pins[pin] = true;
+    pinIsInputHigh[pin] = true;
+    return 0;
+}
+
+bool mockReadPin(pin_t pin) {
+    return pins[pin];
+}
+
+bool setPin(pin_t pin, bool val) {
+    pins[pin] = val;
+    return val;
+}
diff --git a/quantum/encoder/tests/mock.h b/quantum/encoder/tests/mock.h
new file mode 100644
index 000000000000..311ab3745913
--- /dev/null
+++ b/quantum/encoder/tests/mock.h
@@ -0,0 +1,22 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/* Here, "pins" from 0 to 31 are allowed. */
+#define ENCODERS_PAD_A { 0 }
+#define ENCODERS_PAD_B { 1 }
+
+typedef uint8_t pin_t;
+
+extern bool pins[];
+extern bool pinIsInputHigh[];
+
+#define setPinInputHigh(pin) (mockSetPinInputHigh(pin))
+#define readPin(pin) (mockReadPin(pin))
+
+uint8_t mockSetPinInputHigh(pin_t pin);
+
+bool mockReadPin(pin_t pin);
+
+bool setPin(pin_t pin, bool val);
diff --git a/quantum/encoder/tests/mock_split.c b/quantum/encoder/tests/mock_split.c
new file mode 100644
index 000000000000..42e0cc209fab
--- /dev/null
+++ b/quantum/encoder/tests/mock_split.c
@@ -0,0 +1,23 @@
+
+#include "mock_split.h"
+
+bool pins[32] = {0};
+bool pinIsInputHigh[32] = {0};
+
+uint8_t mockSetPinInputHigh(pin_t pin) {
+    // dprintf("Setting pin %d input high.", pin);
+    pins[pin] = true;
+    pinIsInputHigh[pin] = true;
+    return 0;
+}
+
+bool mockReadPin(pin_t pin) {
+    return pins[pin];
+}
+
+bool setPin(pin_t pin, bool val) {
+    pins[pin] = val;
+    return val;
+}
+
+void last_encoder_activity_trigger(void) {}
diff --git a/quantum/encoder/tests/mock_split.h b/quantum/encoder/tests/mock_split.h
new file mode 100644
index 000000000000..845103836482
--- /dev/null
+++ b/quantum/encoder/tests/mock_split.h
@@ -0,0 +1,28 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#define SPLIT_KEYBOARD
+/* Here, "pins" from 0 to 31 are allowed. */
+#define ENCODERS_PAD_A { 0 }
+#define ENCODERS_PAD_B { 1 }
+#define ENCODERS_PAD_A_RIGHT { 2 }
+#define ENCODERS_PAD_B_RIGHT { 3 }
+
+typedef uint8_t pin_t;
+extern bool isLeftHand;
+void encoder_state_raw(uint8_t* slave_state);
+void encoder_update_raw(uint8_t* slave_state);
+
+extern bool pins[];
+extern bool pinIsInputHigh[];
+
+#define setPinInputHigh(pin) (mockSetPinInputHigh(pin))
+#define readPin(pin) (mockReadPin(pin))
+
+uint8_t mockSetPinInputHigh(pin_t pin);
+
+bool mockReadPin(pin_t pin);
+
+bool setPin(pin_t pin, bool val);
diff --git a/quantum/encoder/tests/rules.mk b/quantum/encoder/tests/rules.mk
new file mode 100644
index 000000000000..b826ce3aedec
--- /dev/null
+++ b/quantum/encoder/tests/rules.mk
@@ -0,0 +1,13 @@
+encoder_DEFS := -DENCODER_MOCK_SINGLE
+
+encoder_SRC := \
+	$(QUANTUM_PATH)/encoder/tests/mock.c \
+	$(QUANTUM_PATH)/encoder/tests/encoder_tests.cpp \
+	$(QUANTUM_PATH)/encoder.c
+
+encoder_split_DEFS := -DENCODER_MOCK_SPLIT
+
+encoder_split_SRC := \
+	$(QUANTUM_PATH)/encoder/tests/mock_split.c \
+	$(QUANTUM_PATH)/encoder/tests/encoder_tests_split.cpp \
+	$(QUANTUM_PATH)/encoder.c
diff --git a/quantum/encoder/tests/testlist.mk b/quantum/encoder/tests/testlist.mk
new file mode 100644
index 000000000000..1be9f4a0548e
--- /dev/null
+++ b/quantum/encoder/tests/testlist.mk
@@ -0,0 +1,3 @@
+TEST_LIST += \
+	encoder \
+	encoder_split
diff --git a/testlist.mk b/testlist.mk
index 0d7609b9f071..80d76bd9af28 100644
--- a/testlist.mk
+++ b/testlist.mk
@@ -3,6 +3,7 @@ FULL_TESTS := $(TEST_LIST)
 
 include $(ROOT_DIR)/quantum/sequencer/tests/testlist.mk
 include $(ROOT_DIR)/quantum/serial_link/tests/testlist.mk
+include $(ROOT_DIR)/quantum/encoder/tests/testlist.mk
 
 define VALIDATE_TEST_LIST
     ifneq ($1,)

From 32599a45f9982daf6982e0d350d4265ca25fe118 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@gmail.com>
Date: Thu, 30 Sep 2021 23:50:40 +0200
Subject: [PATCH 09/13] format encoder tests

---
 quantum/encoder/tests/encoder_tests.cpp       | 12 +++++-------
 quantum/encoder/tests/encoder_tests_split.cpp | 16 +++++++---------
 quantum/encoder/tests/mock.c                  |  8 +++-----
 quantum/encoder/tests/mock.h                  |  6 ++++--
 quantum/encoder/tests/mock_split.c            |  8 +++-----
 quantum/encoder/tests/mock_split.h            | 18 +++++++++++-------
 6 files changed, 33 insertions(+), 35 deletions(-)

diff --git a/quantum/encoder/tests/encoder_tests.cpp b/quantum/encoder/tests/encoder_tests.cpp
index b118352c30a5..ac4037929796 100644
--- a/quantum/encoder/tests/encoder_tests.cpp
+++ b/quantum/encoder/tests/encoder_tests.cpp
@@ -6,17 +6,17 @@
 #include <stdio.h>
 
 extern "C" {
-    #include "encoder.h"
-    #include "encoder/tests/mock.h"
+#include "encoder.h"
+#include "encoder/tests/mock.h"
 }
 
 struct update {
     int8_t index;
-    bool clockwise;
+    bool   clockwise;
 };
 
 uint8_t uidx = 0;
-update updates[32];
+update  updates[32];
 
 void encoder_update_kb(int8_t index, bool clockwise) {
     updates[uidx % 32] = {index, clockwise};
@@ -28,9 +28,7 @@ bool setAndRead(pin_t pin, bool val) {
     return encoder_read();
 }
 
-class EncoderTest : public ::testing::Test {
-
-};
+class EncoderTest : public ::testing::Test {};
 
 TEST_F(EncoderTest, TestInit) {
     uidx = 0;
diff --git a/quantum/encoder/tests/encoder_tests_split.cpp b/quantum/encoder/tests/encoder_tests_split.cpp
index 1680387d3c59..a8aa5520a05d 100644
--- a/quantum/encoder/tests/encoder_tests_split.cpp
+++ b/quantum/encoder/tests/encoder_tests_split.cpp
@@ -6,17 +6,17 @@
 #include <stdio.h>
 
 extern "C" {
-    #include "encoder.h"
-    #include "encoder/tests/mock_split.h"
+#include "encoder.h"
+#include "encoder/tests/mock_split.h"
 }
 
 struct update {
     int8_t index;
-    bool clockwise;
+    bool   clockwise;
 };
 
 uint8_t uidx = 0;
-update updates[32];
+update  updates[32];
 
 bool isLeftHand;
 
@@ -36,12 +36,12 @@ bool setAndRead(pin_t pin, bool val) {
 }
 
 class EncoderTest : public ::testing::Test {
-    protected:
+   protected:
     void SetUp() override {
         uidx = 0;
         for (int i = 0; i < 32; i++) {
             pinIsInputHigh[i] = 0;
-            pins[i] = 0;
+            pins[i]           = 0;
         }
     }
 };
@@ -92,7 +92,7 @@ TEST_F(EncoderTest, TestOneClockwiseRightSent) {
     uint8_t slave_state[2] = {0};
     encoder_state_raw(slave_state);
 
-    EXPECT_EQ((int8_t) slave_state[0], -1);
+    EXPECT_EQ((int8_t)slave_state[0], -1);
 }
 
 /* this test will not work after the previous test.
@@ -106,7 +106,6 @@ TEST_F(EncoderTest, TestOneClockwiseRightSent) {
 //     isLeftHand = true;
 //     encoder_init();
 
-
 //     uint8_t slave_state[2] = {255, 0};
 //     encoder_update_raw(slave_state);
 
@@ -119,7 +118,6 @@ TEST_F(EncoderTest, TestOneCounterClockwiseRightReceived) {
     isLeftHand = true;
     encoder_init();
 
-
     uint8_t slave_state[2] = {0, 0};
     encoder_update_raw(slave_state);
 
diff --git a/quantum/encoder/tests/mock.c b/quantum/encoder/tests/mock.c
index 4c3c11e6f87e..10a2fce7fbc4 100644
--- a/quantum/encoder/tests/mock.c
+++ b/quantum/encoder/tests/mock.c
@@ -1,19 +1,17 @@
 
 #include "mock.h"
 
-bool pins[32] = {0};
+bool pins[32]           = {0};
 bool pinIsInputHigh[32] = {0};
 
 uint8_t mockSetPinInputHigh(pin_t pin) {
     // dprintf("Setting pin %d input high.", pin);
-    pins[pin] = true;
+    pins[pin]           = true;
     pinIsInputHigh[pin] = true;
     return 0;
 }
 
-bool mockReadPin(pin_t pin) {
-    return pins[pin];
-}
+bool mockReadPin(pin_t pin) { return pins[pin]; }
 
 bool setPin(pin_t pin, bool val) {
     pins[pin] = val;
diff --git a/quantum/encoder/tests/mock.h b/quantum/encoder/tests/mock.h
index 311ab3745913..9877aca02cc7 100644
--- a/quantum/encoder/tests/mock.h
+++ b/quantum/encoder/tests/mock.h
@@ -4,8 +4,10 @@
 #include <stdbool.h>
 
 /* Here, "pins" from 0 to 31 are allowed. */
-#define ENCODERS_PAD_A { 0 }
-#define ENCODERS_PAD_B { 1 }
+#define ENCODERS_PAD_A \
+    { 0 }
+#define ENCODERS_PAD_B \
+    { 1 }
 
 typedef uint8_t pin_t;
 
diff --git a/quantum/encoder/tests/mock_split.c b/quantum/encoder/tests/mock_split.c
index 42e0cc209fab..f4650a01fb00 100644
--- a/quantum/encoder/tests/mock_split.c
+++ b/quantum/encoder/tests/mock_split.c
@@ -1,19 +1,17 @@
 
 #include "mock_split.h"
 
-bool pins[32] = {0};
+bool pins[32]           = {0};
 bool pinIsInputHigh[32] = {0};
 
 uint8_t mockSetPinInputHigh(pin_t pin) {
     // dprintf("Setting pin %d input high.", pin);
-    pins[pin] = true;
+    pins[pin]           = true;
     pinIsInputHigh[pin] = true;
     return 0;
 }
 
-bool mockReadPin(pin_t pin) {
-    return pins[pin];
-}
+bool mockReadPin(pin_t pin) { return pins[pin]; }
 
 bool setPin(pin_t pin, bool val) {
     pins[pin] = val;
diff --git a/quantum/encoder/tests/mock_split.h b/quantum/encoder/tests/mock_split.h
index 845103836482..53f144ce5e7d 100644
--- a/quantum/encoder/tests/mock_split.h
+++ b/quantum/encoder/tests/mock_split.h
@@ -5,15 +5,19 @@
 
 #define SPLIT_KEYBOARD
 /* Here, "pins" from 0 to 31 are allowed. */
-#define ENCODERS_PAD_A { 0 }
-#define ENCODERS_PAD_B { 1 }
-#define ENCODERS_PAD_A_RIGHT { 2 }
-#define ENCODERS_PAD_B_RIGHT { 3 }
+#define ENCODERS_PAD_A \
+    { 0 }
+#define ENCODERS_PAD_B \
+    { 1 }
+#define ENCODERS_PAD_A_RIGHT \
+    { 2 }
+#define ENCODERS_PAD_B_RIGHT \
+    { 3 }
 
 typedef uint8_t pin_t;
-extern bool isLeftHand;
-void encoder_state_raw(uint8_t* slave_state);
-void encoder_update_raw(uint8_t* slave_state);
+extern bool     isLeftHand;
+void            encoder_state_raw(uint8_t* slave_state);
+void            encoder_update_raw(uint8_t* slave_state);
 
 extern bool pins[];
 extern bool pinIsInputHigh[];

From 8213db23d4ad0afabc75b95c90ba2307a8dfe1e6 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@gmail.com>
Date: Fri, 1 Oct 2021 00:25:44 +0200
Subject: [PATCH 10/13] reapply transport buffer size fix after transport was
 refactored

---
 quantum/split_common/transport.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/quantum/split_common/transport.h b/quantum/split_common/transport.h
index 1d4f6ed0cd86..ab65ff56db6c 100644
--- a/quantum/split_common/transport.h
+++ b/quantum/split_common/transport.h
@@ -42,7 +42,11 @@ bool transport_execute_transaction(int8_t id, const void *initiator2target_buf,
 
 #ifdef ENCODER_ENABLE
 #    include "encoder.h"
-#    define NUMBER_OF_ENCODERS (sizeof((pin_t[])ENCODERS_PAD_A) / sizeof(pin_t))
+// if no pads for right half are defined, we assume the keyboard is symmetric (i.e. same pads)
+#    ifndef ENCODERS_PAD_A_RIGHT
+#        define ENCODERS_PAD_A_RIGHT ENCODERS_PAD_A
+#    endif
+#    define NUMBER_OF_ENCODERS ((sizeof((pin_t[])ENCODERS_PAD_A) + (sizeof((pin_t[])ENCODERS_PAD_A_RIGHT)) / sizeof(pin_t))
 #endif  // ENCODER_ENABLE
 
 #ifdef BACKLIGHT_ENABLE

From 15b1c51a0d628080dcc7333e1ad7896d2ea4ddf8 Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@gmail.com>
Date: Wed, 3 Nov 2021 17:29:54 +0100
Subject: [PATCH 11/13] add license header to encoder test files

---
 quantum/encoder/tests/encoder_tests.cpp       | 15 +++++++++++++++
 quantum/encoder/tests/encoder_tests_split.cpp | 15 +++++++++++++++
 quantum/encoder/tests/mock.c                  | 15 +++++++++++++++
 quantum/encoder/tests/mock.h                  | 16 ++++++++++++++++
 quantum/encoder/tests/mock_split.c            | 15 +++++++++++++++
 quantum/encoder/tests/mock_split.h            | 16 ++++++++++++++++
 6 files changed, 92 insertions(+)

diff --git a/quantum/encoder/tests/encoder_tests.cpp b/quantum/encoder/tests/encoder_tests.cpp
index ac4037929796..1b2ac1a231ed 100644
--- a/quantum/encoder/tests/encoder_tests.cpp
+++ b/quantum/encoder/tests/encoder_tests.cpp
@@ -1,3 +1,18 @@
+/* Copyright 2021 Balz Guenat
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 
 #include "gtest/gtest.h"
 #include "gmock/gmock.h"
diff --git a/quantum/encoder/tests/encoder_tests_split.cpp b/quantum/encoder/tests/encoder_tests_split.cpp
index a8aa5520a05d..320d2655e574 100644
--- a/quantum/encoder/tests/encoder_tests_split.cpp
+++ b/quantum/encoder/tests/encoder_tests_split.cpp
@@ -1,3 +1,18 @@
+/* Copyright 2021 Balz Guenat
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 
 #include "gtest/gtest.h"
 #include "gmock/gmock.h"
diff --git a/quantum/encoder/tests/mock.c b/quantum/encoder/tests/mock.c
index 10a2fce7fbc4..d0506a938f7b 100644
--- a/quantum/encoder/tests/mock.c
+++ b/quantum/encoder/tests/mock.c
@@ -1,3 +1,18 @@
+/* Copyright 2021 Balz Guenat
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 
 #include "mock.h"
 
diff --git a/quantum/encoder/tests/mock.h b/quantum/encoder/tests/mock.h
index 9877aca02cc7..dbc25a084618 100644
--- a/quantum/encoder/tests/mock.h
+++ b/quantum/encoder/tests/mock.h
@@ -1,3 +1,19 @@
+/* Copyright 2021 Balz Guenat
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <stdint.h>
diff --git a/quantum/encoder/tests/mock_split.c b/quantum/encoder/tests/mock_split.c
index f4650a01fb00..68bf3af59929 100644
--- a/quantum/encoder/tests/mock_split.c
+++ b/quantum/encoder/tests/mock_split.c
@@ -1,3 +1,18 @@
+/* Copyright 2021 Balz Guenat
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
 
 #include "mock_split.h"
 
diff --git a/quantum/encoder/tests/mock_split.h b/quantum/encoder/tests/mock_split.h
index 53f144ce5e7d..0ae62652f97f 100644
--- a/quantum/encoder/tests/mock_split.h
+++ b/quantum/encoder/tests/mock_split.h
@@ -1,3 +1,19 @@
+/* Copyright 2021 Balz Guenat
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <stdint.h>

From d545e986eb02239cf5a32f07d9510eaee3f48842 Mon Sep 17 00:00:00 2001
From: Nick Brassel <nick@tzarc.org>
Date: Sat, 20 Nov 2021 08:36:01 +1100
Subject: [PATCH 12/13] Fix overall test execution, tests are failing.

---
 build_test.mk | 1 -
 1 file changed, 1 deletion(-)

diff --git a/build_test.mk b/build_test.mk
index 44fade25294d..36cb7936edd6 100644
--- a/build_test.mk
+++ b/build_test.mk
@@ -25,7 +25,6 @@ GTEST_INTERNAL_INC :=\
 
 $(GTEST_OUTPUT)_SRC :=\
 	googletest/src/gtest-all.cc\
-	googletest/src/gtest_main.cc\
 	googlemock/src/gmock-all.cc
 
 $(GTEST_OUTPUT)_DEFS :=

From 1d9e349beb1c28c84c39b183b29ad5b9760504ff Mon Sep 17 00:00:00 2001
From: Balz Guenat <balz.guenat@gmail.com>
Date: Sat, 20 Nov 2021 13:05:34 +0100
Subject: [PATCH 13/13] fix encoder tests

---
 quantum/encoder/tests/encoder_tests.cpp       | 3 ++-
 quantum/encoder/tests/encoder_tests_split.cpp | 5 +++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/quantum/encoder/tests/encoder_tests.cpp b/quantum/encoder/tests/encoder_tests.cpp
index 1b2ac1a231ed..1888fdab8d08 100644
--- a/quantum/encoder/tests/encoder_tests.cpp
+++ b/quantum/encoder/tests/encoder_tests.cpp
@@ -33,9 +33,10 @@ struct update {
 uint8_t uidx = 0;
 update  updates[32];
 
-void encoder_update_kb(int8_t index, bool clockwise) {
+bool encoder_update_kb(uint8_t index, bool clockwise) {
     updates[uidx % 32] = {index, clockwise};
     uidx++;
+    return true;
 }
 
 bool setAndRead(pin_t pin, bool val) {
diff --git a/quantum/encoder/tests/encoder_tests_split.cpp b/quantum/encoder/tests/encoder_tests_split.cpp
index 320d2655e574..25e52c83f9d6 100644
--- a/quantum/encoder/tests/encoder_tests_split.cpp
+++ b/quantum/encoder/tests/encoder_tests_split.cpp
@@ -35,14 +35,15 @@ update  updates[32];
 
 bool isLeftHand;
 
-void encoder_update_kb(int8_t index, bool clockwise) {
+bool encoder_update_kb(uint8_t index, bool clockwise) {
     if (!isLeftHand) {
         // this method has no effect on slave half
         printf("ignoring update on right hand (%d,%s)\n", index, clockwise ? "CW" : "CC");
-        return;
+        return true;
     }
     updates[uidx % 32] = {index, clockwise};
     uidx++;
+    return true;
 }
 
 bool setAndRead(pin_t pin, bool val) {