esp32: Replace esp.neopixel with machine.bitstream.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>

7 files changed, 110 insertions, 90 deletions

diff --git a/ports/esp32/espneopixel.c b/ports/esp32/espneopixel.c
deleted file mode 100644
index 0b9308e2c0..0000000000
--- a/ports/esp32/espneopixel.c
+++ /dev/null
@@ -1,74 +0,0 @@
-// Original version from https://github.com/adafruit/Adafruit_NeoPixel
-// Modifications by dpgeorge to support auto-CPU-frequency detection
-
-// This is a mash-up of the Due show() code + insights from Michael Miller's
-// ESP8266 work for the NeoPixelBus library: github.com/Makuna/NeoPixelBus
-// Needs to be a separate .c file to enforce ICACHE_RAM_ATTR execution.
-
-#include "py/mpconfig.h"
-#include "py/mphal.h"
-#include "modesp.h"
-
-void IRAM_ATTR esp_neopixel_write(uint8_t pin, uint8_t *pixels, uint32_t numBytes, uint8_t timing) {
-    uint8_t *p, *end, pix, mask;
-    uint32_t t, time0, time1, period, c, startTime, pinMask, gpio_reg_set, gpio_reg_clear;
-
-    #if !CONFIG_IDF_TARGET_ESP32C3
-    if (pin >= 32) {
-        pinMask = 1 << (pin - 32);
-        gpio_reg_set = GPIO_OUT1_W1TS_REG;
-        gpio_reg_clear = GPIO_OUT1_W1TC_REG;
-    } else
-    #endif
-    {
-        pinMask = 1 << pin;
-        gpio_reg_set = GPIO_OUT_W1TS_REG;
-        gpio_reg_clear = GPIO_OUT_W1TC_REG;
-    }
-    p = pixels;
-    end = p + numBytes;
-    pix = *p++;
-    mask = 0x80;
-    startTime = 0;
-
-    uint32_t fcpu = ets_get_cpu_frequency();
-
-    if (timing == 1) {
-        // 800 KHz
-        time0 = (fcpu * 350) / 1000; // 0.35us
-        time1 = (fcpu * 800) / 1000; // 0.8us
-        period = (fcpu * 1250) / 1000; // 1.25us per bit
-    } else {
-        // 400 KHz
-        time0 = (fcpu * 500) / 1000; // 0.5us
-        time1 = (fcpu * 1200) / 1000; // 1.2us
-        period = (fcpu * 2500) / 1000; // 2.5us per bit
-    }
-
-    uint32_t irq_state = mp_hal_quiet_timing_enter();
-    for (t = time0;; t = time0) {
-        if (pix & mask) {
-            t = time1;                                              // Bit high duration
-        }
-        while (((c = mp_hal_ticks_cpu()) - startTime) < period) {
-            ;                                                       // Wait for bit start
-        }
-        GPIO_REG_WRITE(gpio_reg_set, pinMask);                      // Set high
-        startTime = c;                                              // Save start time
-        while (((c = mp_hal_ticks_cpu()) - startTime) < t) {
-            ;                                                       // Wait high duration
-        }
-        GPIO_REG_WRITE(gpio_reg_clear, pinMask);                    // Set low
-        if (!(mask >>= 1)) {                                        // Next bit/byte
-            if (p >= end) {
-                break;
-            }
-            pix = *p++;
-            mask = 0x80;
-        }
-    }
-    while ((mp_hal_ticks_cpu() - startTime) < period) {
-        ;                                              // Wait for last bit
-    }
-    mp_hal_quiet_timing_exit(irq_state);
-}
diff --git a/ports/esp32/machine_bitstream.c b/ports/esp32/machine_bitstream.c
new file mode 100644
index 0000000000..a60fe1b1c5
--- /dev/null
+++ b/ports/esp32/machine_bitstream.c
@@ -0,0 +1,88 @@
+/*
+ * 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 a translation of the cycle counter implementation in ports/stm32/machine_bitstream.c.
+
+#include "py/mpconfig.h"
+#include "py/mphal.h"
+
+#if MICROPY_PY_MACHINE_BITSTREAM
+
+#define NS_TICKS_OVERHEAD (6)
+
+void IRAM_ATTR 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, gpio_reg_set, gpio_reg_clear;
+    #if !CONFIG_IDF_TARGET_ESP32C3
+    if (pin >= 32) {
+        pin_mask = 1 << (pin - 32);
+        gpio_reg_set = GPIO_OUT1_W1TS_REG;
+        gpio_reg_clear = GPIO_OUT1_W1TC_REG;
+    } else
+    #endif
+    {
+        pin_mask = 1 << pin;
+        gpio_reg_set = GPIO_OUT_W1TS_REG;
+        gpio_reg_clear = GPIO_OUT_W1TC_REG;
+    }
+
+    // Convert ns to cpu ticks [high_time_0, period_0, high_time_1, period_1].
+    uint32_t fcpu_mhz = ets_get_cpu_frequency();
+    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_reg_set, 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_reg_clear, 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
diff --git a/ports/esp32/main/CMakeLists.txt b/ports/esp32/main/CMakeLists.txt
index 1ca30b0cb9..0e7d6ff250 100644
--- a/ports/esp32/main/CMakeLists.txt
+++ b/ports/esp32/main/CMakeLists.txt
@@ -53,6 +53,7 @@ set(MICROPY_SOURCE_PORT
     ${PROJECT_DIR}/help.c
     ${PROJECT_DIR}/modutime.c
     ${PROJECT_DIR}/moduos.c
+    ${PROJECT_DIR}/machine_bitstream.c
     ${PROJECT_DIR}/machine_timer.c
     ${PROJECT_DIR}/machine_pin.c
     ${PROJECT_DIR}/machine_touchpad.c
@@ -74,7 +75,6 @@ set(MICROPY_SOURCE_PORT
     ${PROJECT_DIR}/esp32_rmt.c
     ${PROJECT_DIR}/esp32_ulp.c
     ${PROJECT_DIR}/modesp32.c
-    ${PROJECT_DIR}/espneopixel.c
     ${PROJECT_DIR}/machine_hw_spi.c
     ${PROJECT_DIR}/machine_wdt.c
     ${PROJECT_DIR}/mpthreadport.c
diff --git a/ports/esp32/modesp.c b/ports/esp32/modesp.c
index 59a261e8c2..8a7f025754 100644
--- a/ports/esp32/modesp.c
+++ b/ports/esp32/modesp.c
@@ -112,15 +112,6 @@ STATIC mp_obj_t esp_gpio_matrix_out(size_t n_args, const mp_obj_t *args) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(esp_gpio_matrix_out_obj, 4, 4, esp_gpio_matrix_out);
 
-STATIC mp_obj_t esp_neopixel_write_(mp_obj_t pin, mp_obj_t buf, mp_obj_t timing) {
-    mp_buffer_info_t bufinfo;
-    mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_READ);
-    esp_neopixel_write(mp_hal_get_pin_obj(pin),
-        (uint8_t *)bufinfo.buf, bufinfo.len, mp_obj_get_int(timing));
-    return mp_const_none;
-}
-STATIC MP_DEFINE_CONST_FUN_OBJ_3(esp_neopixel_write_obj, esp_neopixel_write_);
-
 STATIC const mp_rom_map_elem_t esp_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_esp) },
 
@@ -135,7 +126,6 @@ STATIC const mp_rom_map_elem_t esp_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_gpio_matrix_in), MP_ROM_PTR(&esp_gpio_matrix_in_obj) },
     { MP_ROM_QSTR(MP_QSTR_gpio_matrix_out), MP_ROM_PTR(&esp_gpio_matrix_out_obj) },
 
-    { MP_ROM_QSTR(MP_QSTR_neopixel_write), MP_ROM_PTR(&esp_neopixel_write_obj) },
     { MP_ROM_QSTR(MP_QSTR_dht_readinto), MP_ROM_PTR(&dht_readinto_obj) },
 
     // Constants for second arg of osdebug()
diff --git a/ports/esp32/modmachine.c b/ports/esp32/modmachine.c
index 34fe8600ae..5f94007d49 100644
--- a/ports/esp32/modmachine.c
+++ b/ports/esp32/modmachine.c
@@ -49,6 +49,7 @@
 #include "py/obj.h"
 #include "py/runtime.h"
 #include "shared/runtime/pyexec.h"
+#include "extmod/machine_bitstream.h"
 #include "extmod/machine_mem.h"
 #include "extmod/machine_signal.h"
 #include "extmod/machine_pulse.h"
@@ -271,7 +272,12 @@ STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_disable_irq), MP_ROM_PTR(&machine_disable_irq_obj) },
     { MP_ROM_QSTR(MP_QSTR_enable_irq), MP_ROM_PTR(&machine_enable_irq_obj) },
 
+    #if MICROPY_PY_MACHINE_BITSTREAM
+    { MP_ROM_QSTR(MP_QSTR_bitstream), MP_ROM_PTR(&machine_bitstream_obj) },
+    #endif
+    #if MICROPY_PY_MACHINE_PULSE
     { MP_ROM_QSTR(MP_QSTR_time_pulse_us), MP_ROM_PTR(&machine_time_pulse_us_obj) },
+    #endif
 
     { MP_ROM_QSTR(MP_QSTR_Timer), MP_ROM_PTR(&machine_timer_type) },
     { MP_ROM_QSTR(MP_QSTR_WDT), MP_ROM_PTR(&machine_wdt_type) },
diff --git a/ports/esp32/modules/neopixel.py b/ports/esp32/modules/neopixel.py
index f5c9193988..9ed5155c72 100644
--- a/ports/esp32/modules/neopixel.py
+++ b/ports/esp32/modules/neopixel.py
@@ -1,7 +1,12 @@
-# NeoPixel driver for MicroPython on ESP32
-# MIT license; Copyright (c) 2016 Damien P. George
+# NeoPixel driver for MicroPython
+# MIT license; Copyright (c) 2016 Damien P. George, 2021 Jim Mussared
 
-from esp import neopixel_write
+from micropython import const
+from machine import bitstream
+
+_BITSTREAM_TYPE_HIGH_LOW = const(0)
+_TIMING_WS2818_800 = (400, 850, 800, 450)
+_TIMING_WS2818_400 = (800, 1700, 1600, 900)
 
 
 class NeoPixel:
@@ -13,7 +18,11 @@ class NeoPixel:
         self.bpp = bpp
         self.buf = bytearray(n * bpp)
         self.pin.init(pin.OUT)
-        self.timing = timing
+        self.timing = (
+            (_TIMING_WS2818_800 if timing else _TIMING_WS2818_400)
+            if isinstance(timing, int)
+            else timing
+        )
 
     def __len__(self):
         return self.n
@@ -32,4 +41,4 @@ class NeoPixel:
             self[i] = color
 
     def write(self):
-        neopixel_write(self.pin, self.buf, self.timing)
+        bitstream(self.pin, _BITSTREAM_TYPE_HIGH_LOW, self.timing, self.buf)
diff --git a/ports/esp32/mpconfigport.h b/ports/esp32/mpconfigport.h
index a21c0d524d..057251fa49 100644
--- a/ports/esp32/mpconfigport.h
+++ b/ports/esp32/mpconfigport.h
@@ -156,6 +156,7 @@
 #define MICROPY_PY_OS_DUPTERM               (1)
 #define MICROPY_PY_MACHINE                  (1)
 #define MICROPY_PY_MACHINE_PIN_MAKE_NEW     mp_pin_make_new
+#define MICROPY_PY_MACHINE_BITSTREAM        (1)
 #define MICROPY_PY_MACHINE_PULSE            (1)
 #define MICROPY_PY_MACHINE_I2C              (1)
 #define MICROPY_PY_MACHINE_SPI              (1)