1 files changed, 76 insertions, 0 deletions
diff --git a/ports/esp8266/machine_bitstream.c b/ports/esp8266/machine_bitstream.c
new file mode 100644
index 0000000000..bc16aea44d
--- /dev/null
+++ b/ports/esp8266/machine_bitstream.c
@@ -0,0 +1,76 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Jim Mussared
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+// This is slightly modified from the implementation in ports/esp32/machine_bitstream.c.
+
+#include "py/mpconfig.h"
+#include "py/mphal.h"
+
+#if MICROPY_PY_MACHINE_BITSTREAM
+
+#define NS_TICKS_OVERHEAD (8)
+
+void machine_bitstream_high_low(mp_hal_pin_obj_t pin, uint32_t *timing_ns, const uint8_t *buf, size_t len) {
+    uint32_t pin_mask = 1 << pin;
+
+    // Convert ns to cpu ticks [high_time_0, period_0, high_time_1, period_1].
+    uint32_t fcpu_mhz = system_get_cpu_freq();
+    for (size_t i = 0; i < 4; ++i) {
+        timing_ns[i] = fcpu_mhz * timing_ns[i] / 1000;
+        if (timing_ns[i] > NS_TICKS_OVERHEAD) {
+            timing_ns[i] -= NS_TICKS_OVERHEAD;
+        }
+        if (i % 2 == 1) {
+            // Convert low_time to period (i.e. add high_time).
+            timing_ns[i] += timing_ns[i - 1];
+        }
+    }
+
+    uint32_t irq_state = mp_hal_quiet_timing_enter();
+
+    for (size_t i = 0; i < len; ++i) {
+        uint8_t b = buf[i];
+        for (size_t j = 0; j < 8; ++j) {
+            GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, pin_mask);
+            uint32_t start_ticks = mp_hal_ticks_cpu();
+            uint32_t *t = &timing_ns[b >> 6 & 2];
+            uint32_t end_ticks = start_ticks + t[0];
+            while (mp_hal_ticks_cpu() - start_ticks < t[0]) {
+                ;
+            }
+            GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, pin_mask);
+            b <<= 1;
+            end_ticks += t[1];
+            while (mp_hal_ticks_cpu() - start_ticks < t[1]) {
+                ;
+            }
+        }
+    }
+
+    mp_hal_quiet_timing_exit(irq_state);
+}
+
+#endif // MICROPY_PY_MACHINE_BITSTREAM