Move gpio wait logic to wait.h (#12067)

3 files changed, 145 insertions, 0 deletions

diff --git a/tmk_core/common/chibios/_wait.h b/tmk_core/common/chibios/_wait.h
new file mode 100644
index 0000000000..5bface53e1
--- /dev/null
+++ b/tmk_core/common/chibios/_wait.h
@@ -0,0 +1,55 @@
+/* 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>
+
+/* 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)
+#define wait_us(us)                     \
+    do {                                \
+        if (us != 0) {                  \
+            chThdSleepMicroseconds(us); \
+        } else {                        \
+            chThdSleepMicroseconds(1);  \
+        }                               \
+    } while (0)
+
+/* 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.)
+ */
+
+#include "wait.c"
+
+#ifndef GPIO_INPUT_PIN_DELAY
+#    define GPIO_INPUT_PIN_DELAY (STM32_SYSCLK / 1000000L / 4)
+#endif
+
+#define waitInputPinDelay() wait_cpuclock(GPIO_INPUT_PIN_DELAY)
diff --git a/tmk_core/common/chibios/chibios_config.h b/tmk_core/common/chibios/chibios_config.h
index bebf026de7..9a66ac3174 100644
--- a/tmk_core/common/chibios/chibios_config.h
+++ b/tmk_core/common/chibios/chibios_config.h
@@ -30,4 +30,5 @@
 #    define USE_I2CV1
 #    define USE_I2CV1_CONTRIB  // for some reason a bunch of ChibiOS-Contrib boards only have clock_speed
 #    define USE_GPIOV1
+#    define STM32_SYSCLK KINETIS_SYSCLK_FREQUENCY
 #endif
diff --git a/tmk_core/common/chibios/wait.c b/tmk_core/common/chibios/wait.c
new file mode 100644
index 0000000000..c6270fd95e
--- /dev/null
+++ b/tmk_core/common/chibios/wait.c
@@ -0,0 +1,89 @@
+/* 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/>.
+ */
+
+#ifndef __OPTIMIZE__
+#    pragma message "Compiler optimizations disabled; wait_cpuclock() won't work as designed"
+#endif
+
+#define CLOCK_DELAY_NOP8 "nop\n\t nop\n\t nop\n\t nop\n\t   nop\n\t nop\n\t nop\n\t nop\n\t"
+
+__attribute__((always_inline)) static inline void wait_cpuclock(unsigned int n) { /* n: 1..135 */
+    /* The argument n must be a constant expression.
+     * That way, compiler optimization will remove unnecessary code. */
+    if (n < 1) {
+        return;
+    }
+    if (n > 8) {
+        unsigned int n8 = n / 8;
+        n               = n - n8 * 8;
+        switch (n8) {
+            case 16:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 15:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 14:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 13:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 12:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 11:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 10:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 9:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 8:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 7:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 6:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 5:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 4:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 3:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 2:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 1:
+                asm volatile(CLOCK_DELAY_NOP8::: "memory");
+            case 0:
+                break;
+        }
+    }
+    switch (n) {
+        case 8:
+            asm volatile("nop" ::: "memory");
+        case 7:
+            asm volatile("nop" ::: "memory");
+        case 6:
+            asm volatile("nop" ::: "memory");
+        case 5:
+            asm volatile("nop" ::: "memory");
+        case 4:
+            asm volatile("nop" ::: "memory");
+        case 3:
+            asm volatile("nop" ::: "memory");
+        case 2:
+            asm volatile("nop" ::: "memory");
+        case 1:
+            asm volatile("nop" ::: "memory");
+        case 0:
+            break;
+    }
+}
\ No newline at end of file