Add Dip Switch as a core feature (#6140)

* Add Dip Switches as a core feature

* Add documentation for Dip Switch feature

* Update Preonic Rev3 to use new feature and remove custom matrix

* Apply suggestions from code review

Co-Authored-By: noroadsleft <18669334+noroadsleft@users.noreply.github.com>

* Remove custom matrix line completely

Rather than just disabling it

Co-Authored-By: fauxpark <fauxpark@gmail.com>

* DIP changes

Co-Authored-By: fauxpark <fauxpark@gmail.com>

* Use better check for DIP Switch configuration

* Add to show features

* Add bitmask callback for dip switch

* Fix OLKB Boards dip switch config

* Update docs to include bitmask example

* Fix comments/documentation

Co-Authored-By: fauxpark <fauxpark@gmail.com>

* Fix issues with docs and use example from @tuzonghua

* Fix wording

Co-Authored-By: fauxpark <fauxpark@gmail.com>

* Fix example to use proper formatting

Bad, BAAAAAAD drashna!!!

* Handle dip switch initialization better

1 files changed, 90 insertions, 0 deletions

diff --git a/docs/feature_dip_switch.md b/docs/feature_dip_switch.md
new file mode 100644
index 0000000000..bce47fed88
--- /dev/null
+++ b/docs/feature_dip_switch.md
@@ -0,0 +1,90 @@
+# DIP Switches
+
+DIP switches are supported by adding this to your `rules.mk`:
+
+    DIP_SWITCH_ENABLE = yes
+
+and this to your `config.h`:
+
+```c
+#define DIP_SWITCH_PINS { B14, A15, A10, B9 }
+```
+
+## Callbacks
+
+The callback functions can be inserted into your `<keyboard>.c`:
+
+```c
+void dip_switch_update_kb(uint8_t index, bool active) { 
+    dip_switch_update_user(index, active); 
+}
+```
+
+
+or `keymap.c`:
+
+```c
+void dip_switch_update_user(uint8_t index, bool active) { 
+    switch (index) {
+        case 0:
+            if(active) { audio_on(); } else { audio_off(); }
+            break;
+        case 1:
+            if(active) { clicky_on(); } else { clicky_off(); }
+            break;
+        case 2:
+            if(active) { music_on(); } else { music_off(); }
+            break;
+        case 3:
+            if (active) {
+                #ifdef AUDIO_ENABLE
+                    PLAY_SONG(plover_song);
+                #endif
+                layer_on(_PLOVER);
+            } else {
+                #ifdef AUDIO_ENABLE
+                    PLAY_SONG(plover_gb_song);
+                #endif
+                layer_off(_PLOVER);
+            }
+            break;
+    }
+}
+```
+
+Additionally, we support bit mask functions which allow for more complex handling. 
+
+
+```c
+void dip_switch_update_mask_kb(uint32_t state) { 
+    dip_switch_update_mask_user(state); 
+}
+```
+
+
+or `keymap.c`:
+
+```c
+void dip_switch_update_mask_user(uint32_t state) { 
+    if (state & (1UL<<0) && state & (1UL<<1)) {
+        layer_on(_ADJUST); // C on esc
+    } else {
+        layer_off(_ADJUST);
+    }
+    if (state & (1UL<<0)) {
+        layer_on(_TEST_A); // A on ESC
+    } else {
+        layer_off(_TEST_A);
+    }
+    if (state & (1UL<<1)) {
+        layer_on(_TEST_B); // B on esc
+    } else {
+        layer_off(_TEST_B);
+    }
+}
+```
+
+
+## Hardware
+
+One side of the DIP switch should be wired directly to the pin on the MCU, and the other side to ground.  It should not matter which side is connected to which, as it should be functionally the same.