1 files changed, 60 insertions, 0 deletions
diff --git a/platforms/chibios/_wait.h b/platforms/chibios/_wait.h
new file mode 100644
index 0000000000..2f36c64a2e
--- /dev/null
+++ b/platforms/chibios/_wait.h
@@ -0,0 +1,60 @@
+/* Copyright 2021 QMK
+ *
+ * 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 3 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 <ch.h>
+#include <hal.h>
+
+/* chThdSleepX of zero maps to infinite - so we map to a tiny delay to still yield */
+#define wait_ms(ms)                     \
+    do {                                \
+        if (ms != 0) {                  \
+            chThdSleepMilliseconds(ms); \
+        } else {                        \
+            chThdSleepMicroseconds(1);  \
+        }                               \
+    } while (0)
+
+#ifdef WAIT_US_TIMER
+void wait_us(uint16_t duration);
+#else
+#    define wait_us(us)                     \
+        do {                                \
+            if (us != 0) {                  \
+                chThdSleepMicroseconds(us); \
+            } else {                        \
+                chThdSleepMicroseconds(1);  \
+            }                               \
+        } while (0)
+#endif
+
+#include "_wait.c"
+
+/* For GPIOs on ARM-based MCUs, the input pins are sampled by the clock of the bus
+ * to which the GPIO is connected.
+ * The connected buses differ depending on the various series of MCUs.
+ * And since the instruction execution clock of the CPU and the bus clock of GPIO are different,
+ * there is a delay of several clocks to read the change of the input signal.
+ *
+ * Define this delay with the GPIO_INPUT_PIN_DELAY macro.
+ * If the GPIO_INPUT_PIN_DELAY macro is not defined, the following default values will be used.
+ * (A fairly large value of 0.25 microseconds is set.)
+ */
+#ifndef GPIO_INPUT_PIN_DELAY
+#    define GPIO_INPUT_PIN_DELAY (CPU_CLOCK / 1000000L / 4)
+#endif
+
+#define waitInputPinDelay() wait_cpuclock(GPIO_INPUT_PIN_DELAY)