Add pcewing Speedo v3 keymap (#18118)

* Add pcewing Speedo v3 keymap

* Add readme and code quality improvements

1 files changed, 68 insertions, 0 deletions

diff --git a/users/pcewing/key_repeater.h b/users/pcewing/key_repeater.h
new file mode 100644
index 0000000000..30b7f748ff
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+++ b/users/pcewing/key_repeater.h
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+/*
+ * Copyright 2022 Paul Ewing
+ *
+ * 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
+
+// The key_repeater_config_t type holds user configurable options set when
+// allocating a new key repeater.
+struct key_repeater_config_t {
+    // The key code that will be repeatedly registered
+    int key;
+
+    // The minimum amount of time to press down the key when registered
+    const uint32_t key_duration_min;
+
+    // The maximum amount of time to press down the key when registered
+    const uint32_t key_duration_max;
+
+    // The minimum amount of time to wait between registering key presses
+    const uint32_t wait_duration_min;
+
+    // The maximum amount of time to wait between registering key presses
+    const uint32_t wait_duration_max;
+};
+
+// The key_repeater_t type represents a key repeater. This is similar to the
+// "Rapid fire" feature on many game controllers. The intention behind this is
+// to periodically send a key code while the user is pressing a key.
+//
+// The duration of the key press as well as the time between key presses is
+// slightly randomized by design. This is to simulate more realistic human
+// behavior. By setting the minimum and maximum duration fields to the same
+// value in the configuration, this randomization can be disabled.
+//
+// This type is intentionally opaque to avoid the user setting internal fields
+// directly. It must be allocated and destroyed using the kr_new() and
+// kr_free() functions respectively.
+struct key_repeater_t;
+
+// Allocate a new key repeater.
+struct key_repeater_t* kr_new(struct key_repeater_config_t* cfg);
+
+// Release an allocated key repeater.
+void kr_free(struct key_repeater_t** kr);
+
+// Enable the key repeater such that it will start periodically registering the
+// configured key code.
+void kr_enable(struct key_repeater_t* kr);
+
+// Disable the key repeater such that it will stop periodically registering the
+// configured key code.
+void kr_disable(struct key_repeater_t* kr);
+
+// Poll the key repeater to execute, tyically called from matrix_scan_user().
+void kr_poll(struct key_repeater_t* kr);