From c4917cdabd97c016a46b6193e93b274573d94193 Mon Sep 17 00:00:00 2001
From: microDev <70126934+microDev1@users.noreply.github.com>
Date: Mon, 16 Nov 2020 00:11:00 +0530
Subject: [PATCH 1/7] frequencyio implementation for esp32s2

---
 .../common-hal/frequencyio/FrequencyIn.c      | 158 ++++++++++++++++++
 .../common-hal/frequencyio/FrequencyIn.h      |  43 +++++
 .../esp32s2/common-hal/frequencyio/__init__.c |   1 +
 ports/esp32s2/mpconfigport.mk                 |   2 +-
 4 files changed, 203 insertions(+), 1 deletion(-)
 create mode 100644 ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
 create mode 100644 ports/esp32s2/common-hal/frequencyio/FrequencyIn.h
 create mode 100644 ports/esp32s2/common-hal/frequencyio/__init__.c

diff --git a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
new file mode 100644
index 0000000000..fce1d34d87
--- /dev/null
+++ b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
@@ -0,0 +1,158 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 microDev
+ *
+ * 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.
+ */
+
+#include "shared-bindings/frequencyio/FrequencyIn.h"
+
+#include <stdint.h>
+
+#include "py/runtime.h"
+
+#include "supervisor/shared/tick.h"
+#include "shared-bindings/time/__init__.h"
+
+#include "common-hal/microcontroller/Pin.h"
+
+static void frequencyin_interrupt_handler(void *self_in) {
+    frequencyio_frequencyin_obj_t* self = self_in;
+    // get counter value
+    int16_t count;
+    pcnt_get_counter_value(self->unit, &count);
+    self->frequency = count / 2.0 / self->capture_period;
+
+    // reset counter
+    pcnt_counter_clear(self->unit);
+}
+
+static void init_timer(frequencyio_frequencyin_obj_t* self, uint16_t capture_period) {
+    // Prepare configuration for the timer module
+    timer_config_t config = {
+        .alarm_en = true,
+        .counter_en = false,
+        .intr_type = TIMER_INTR_LEVEL,
+        .counter_dir = TIMER_COUNT_UP,
+        .auto_reload = true,
+        .divider = 80            // 1 us per tick
+    };
+
+    // Initialize timer module
+    timer_init(TIMER_GROUP_0, TIMER_0, &config);
+    timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
+    timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, capture_period * 1000000);
+    timer_enable_intr(TIMER_GROUP_0, TIMER_0);
+    timer_isr_register(TIMER_GROUP_0, TIMER_0, &frequencyin_interrupt_handler, (void *)self, 0, &self->handle);
+
+    // Start timer
+    timer_start(TIMER_GROUP_0, TIMER_0);
+}
+
+void common_hal_frequencyio_frequencyin_construct(frequencyio_frequencyin_obj_t* self,
+        const mcu_pin_obj_t* pin, const uint16_t capture_period) {
+    if ((capture_period == 0) || (capture_period > 500)) {
+        mp_raise_ValueError(translate("Invalid capture period. Valid range: 1 - 500"));
+    }
+
+    // Prepare configuration for the PCNT unit
+    const pcnt_config_t pcnt_config = {
+        // Set PCNT input signal and control GPIOs
+        .pulse_gpio_num = pin->number,
+        .ctrl_gpio_num = PCNT_PIN_NOT_USED,
+        .channel = PCNT_CHANNEL_0,
+        .lctrl_mode = PCNT_MODE_DISABLE,
+        .hctrl_mode = PCNT_MODE_KEEP,
+        .pos_mode = PCNT_COUNT_INC,  // count both rising and falling edges
+        .neg_mode = PCNT_COUNT_INC,
+        .counter_h_lim = 0,
+        .counter_l_lim = 0,
+    };
+
+    // Initialize PCNT unit
+    const int8_t unit = peripherals_pcnt_init(pcnt_config);
+    if (unit == -1) {
+        mp_raise_RuntimeError(translate("All PCNT units in use"));
+    }
+
+    // set the GPIO back to high-impedance, as pcnt_unit_config sets it as pull-up
+    gpio_set_pull_mode(pin->number, GPIO_FLOATING);
+
+    // initialize timer
+    init_timer(self, capture_period);
+
+    self->pin = pin->number;
+    self->unit = (pcnt_unit_t)unit;
+    self->capture_period = capture_period;
+
+    claim_pin(pin);
+}
+
+bool common_hal_frequencyio_frequencyin_deinited(frequencyio_frequencyin_obj_t* self) {
+    return self->unit == PCNT_UNIT_MAX;
+}
+
+void common_hal_frequencyio_frequencyin_deinit(frequencyio_frequencyin_obj_t* self) {
+    if (common_hal_frequencyio_frequencyin_deinited(self)) {
+        return;
+    }
+    reset_pin_number(self->pin);
+    peripherals_pcnt_deinit(&self->unit);
+    if (self->handle) {
+        timer_deinit(TIMER_GROUP_0, TIMER_0);
+        esp_intr_free(self->handle);
+        self->handle = NULL;
+    }
+}
+
+uint32_t common_hal_frequencyio_frequencyin_get_item(frequencyio_frequencyin_obj_t* self) {
+    return (1000 / (self->capture_period / self->frequency));
+}
+
+void common_hal_frequencyio_frequencyin_pause(frequencyio_frequencyin_obj_t* self) {
+    pcnt_counter_pause(self->unit);
+    timer_pause(TIMER_GROUP_0, TIMER_0);
+}
+
+void common_hal_frequencyio_frequencyin_resume(frequencyio_frequencyin_obj_t* self) {
+    pcnt_counter_resume(self->unit);
+    timer_start(TIMER_GROUP_0, TIMER_0);
+}
+
+void common_hal_frequencyio_frequencyin_clear(frequencyio_frequencyin_obj_t* self) {
+    self->frequency = 0;
+    pcnt_counter_clear(self->unit);
+    timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
+}
+
+uint16_t common_hal_frequencyio_frequencyin_get_capture_period(frequencyio_frequencyin_obj_t *self) {
+    return self->capture_period;
+}
+
+void common_hal_frequencyio_frequencyin_set_capture_period(frequencyio_frequencyin_obj_t *self, uint16_t capture_period) {
+    if ((capture_period == 0) || (capture_period > 500)) {
+        mp_raise_ValueError(translate("Invalid capture period. Valid range: 1 - 500"));
+    }
+    self->capture_period = capture_period;
+    common_hal_frequencyio_frequencyin_clear(self);
+    timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, capture_period * 1000000);
+}
diff --git a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h
new file mode 100644
index 0000000000..01e617d13a
--- /dev/null
+++ b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h
@@ -0,0 +1,43 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 microDev
+ *
+ * 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.
+ */
+
+#ifndef MICROPY_INCLUDED_ESP32S2_COMMON_HAL_FREQUENCYIO_FREQUENCYIN_H
+#define MICROPY_INCLUDED_ESP32S2_COMMON_HAL_FREQUENCYIO_FREQUENCYIN_H
+
+#include "py/obj.h"
+#include "driver/timer.h"
+#include "peripherals/pcnt.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    pcnt_unit_t unit;
+    intr_handle_t handle;
+    uint8_t pin;
+    uint32_t frequency;
+    uint16_t capture_period;
+} frequencyio_frequencyin_obj_t;
+
+#endif // MICROPY_INCLUDED_ESP32S2_COMMON_HAL_FREQUENCYIO_FREQUENCYIN_H
diff --git a/ports/esp32s2/common-hal/frequencyio/__init__.c b/ports/esp32s2/common-hal/frequencyio/__init__.c
new file mode 100644
index 0000000000..487814bd07
--- /dev/null
+++ b/ports/esp32s2/common-hal/frequencyio/__init__.c
@@ -0,0 +1 @@
+// No ferquencyio module functions.
diff --git a/ports/esp32s2/mpconfigport.mk b/ports/esp32s2/mpconfigport.mk
index 4579b95ab6..a84965a6a1 100644
--- a/ports/esp32s2/mpconfigport.mk
+++ b/ports/esp32s2/mpconfigport.mk
@@ -18,7 +18,7 @@ CIRCUITPY_AUDIOBUSIO = 0
 CIRCUITPY_AUDIOIO = 0
 CIRCUITPY_CANIO = 1
 CIRCUITPY_COUNTIO = 1
-CIRCUITPY_FREQUENCYIO = 0
+CIRCUITPY_FREQUENCYIO = 1
 CIRCUITPY_I2CPERIPHERAL = 0
 CIRCUITPY_ROTARYIO = 1
 CIRCUITPY_NVM = 0

From 2bec02738fb7eacaaea710bd448b98a418eb2693 Mon Sep 17 00:00:00 2001
From: microDev <70126934+microDev1@users.noreply.github.com>
Date: Mon, 16 Nov 2020 11:44:11 +0530
Subject: [PATCH 2/7] move interrupt handler to iram

---
 ports/esp32s2/common-hal/frequencyio/FrequencyIn.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
index fce1d34d87..ec7ebb21ac 100644
--- a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
+++ b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
@@ -35,7 +35,7 @@
 
 #include "common-hal/microcontroller/Pin.h"
 
-static void frequencyin_interrupt_handler(void *self_in) {
+static void IRAM_ATTR frequencyin_interrupt_handler(void *self_in) {
     frequencyio_frequencyin_obj_t* self = self_in;
     // get counter value
     int16_t count;
@@ -44,6 +44,10 @@ static void frequencyin_interrupt_handler(void *self_in) {
 
     // reset counter
     pcnt_counter_clear(self->unit);
+
+    // reset interrupt
+    TIMERG0.int_clr.t0 = 1;
+    TIMERG0.hw_timer[0].config.alarm_en = 1;
 }
 
 static void init_timer(frequencyio_frequencyin_obj_t* self, uint16_t capture_period) {
@@ -62,7 +66,7 @@ static void init_timer(frequencyio_frequencyin_obj_t* self, uint16_t capture_per
     timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
     timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, capture_period * 1000000);
     timer_enable_intr(TIMER_GROUP_0, TIMER_0);
-    timer_isr_register(TIMER_GROUP_0, TIMER_0, &frequencyin_interrupt_handler, (void *)self, 0, &self->handle);
+    timer_isr_register(TIMER_GROUP_0, TIMER_0, frequencyin_interrupt_handler, (void *)self, ESP_INTR_FLAG_IRAM, &self->handle);
 
     // Start timer
     timer_start(TIMER_GROUP_0, TIMER_0);

From f2824f6a68b3d326e0f4a137880e08147a0074d2 Mon Sep 17 00:00:00 2001
From: microDev <70126934+microDev1@users.noreply.github.com>
Date: Mon, 16 Nov 2020 12:55:55 +0530
Subject: [PATCH 3/7] update frequency measurement

---
 ports/esp32s2/common-hal/frequencyio/FrequencyIn.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
index ec7ebb21ac..bdbe782add 100644
--- a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
+++ b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
@@ -84,12 +84,9 @@ void common_hal_frequencyio_frequencyin_construct(frequencyio_frequencyin_obj_t*
         .pulse_gpio_num = pin->number,
         .ctrl_gpio_num = PCNT_PIN_NOT_USED,
         .channel = PCNT_CHANNEL_0,
-        .lctrl_mode = PCNT_MODE_DISABLE,
-        .hctrl_mode = PCNT_MODE_KEEP,
+        // What to do on the positive / negative edge of pulse input?
         .pos_mode = PCNT_COUNT_INC,  // count both rising and falling edges
         .neg_mode = PCNT_COUNT_INC,
-        .counter_h_lim = 0,
-        .counter_l_lim = 0,
     };
 
     // Initialize PCNT unit
@@ -129,7 +126,7 @@ void common_hal_frequencyio_frequencyin_deinit(frequencyio_frequencyin_obj_t* se
 }
 
 uint32_t common_hal_frequencyio_frequencyin_get_item(frequencyio_frequencyin_obj_t* self) {
-    return (1000 / (self->capture_period / self->frequency));
+    return self->frequency;
 }
 
 void common_hal_frequencyio_frequencyin_pause(frequencyio_frequencyin_obj_t* self) {

From 18e463cca538ed80f03ce9eda0e2ff757f1ba8f4 Mon Sep 17 00:00:00 2001
From: microDev <70126934+microDev1@users.noreply.github.com>
Date: Mon, 16 Nov 2020 23:32:22 +0530
Subject: [PATCH 4/7] add pcnt overflow handler & clean-up

---
 .../common-hal/frequencyio/FrequencyIn.c      | 91 +++++++++++--------
 .../common-hal/frequencyio/FrequencyIn.h      |  3 +-
 2 files changed, 57 insertions(+), 37 deletions(-)

diff --git a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
index bdbe782add..20d744139d 100644
--- a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
+++ b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
@@ -26,16 +26,21 @@
 
 #include "shared-bindings/frequencyio/FrequencyIn.h"
 
-#include <stdint.h>
-
 #include "py/runtime.h"
 
-#include "supervisor/shared/tick.h"
-#include "shared-bindings/time/__init__.h"
+static void IRAM_ATTR pcnt_overflow_handler(void *self_in) {
+    frequencyio_frequencyin_obj_t* self = self_in;
+    // reset counter
+    pcnt_counter_clear(self->unit);
 
-#include "common-hal/microcontroller/Pin.h"
+    // increase multiplier
+    self->multiplier++;
 
-static void IRAM_ATTR frequencyin_interrupt_handler(void *self_in) {
+    // reset interrupt
+    PCNT.int_clr.val = BIT(self->unit);
+}
+
+static void IRAM_ATTR timer_interrupt_handler(void *self_in) {
     frequencyio_frequencyin_obj_t* self = self_in;
     // get counter value
     int16_t count;
@@ -50,9 +55,41 @@ static void IRAM_ATTR frequencyin_interrupt_handler(void *self_in) {
     TIMERG0.hw_timer[0].config.alarm_en = 1;
 }
 
-static void init_timer(frequencyio_frequencyin_obj_t* self, uint16_t capture_period) {
+static void init_pcnt(frequencyio_frequencyin_obj_t* self) {
+    // Prepare configuration for the PCNT unit
+    const pcnt_config_t pcnt_config = {
+        // Set PCNT input signal and control GPIOs
+        .pulse_gpio_num = self->pin,
+        .ctrl_gpio_num = PCNT_PIN_NOT_USED,
+        .channel = PCNT_CHANNEL_0,
+        // What to do on the positive / negative edge of pulse input?
+        .pos_mode = PCNT_COUNT_INC,  // count both rising and falling edges
+        .neg_mode = PCNT_COUNT_INC,
+        // Set counter limit
+        .counter_h_lim = INT16_MAX,
+        .counter_l_lim = 0,
+    };
+
+    // Initialize PCNT unit
+    const int8_t unit = peripherals_pcnt_init(pcnt_config);
+    if (unit == -1) {
+        mp_raise_RuntimeError(translate("All PCNT units in use"));
+    }
+
+    // set the GPIO back to high-impedance, as pcnt_unit_config sets it as pull-up
+    gpio_set_pull_mode(self->pin, GPIO_FLOATING);
+
+    self->unit = (pcnt_unit_t)unit;
+
+    // enable pcnt interrupt
+    pcnt_event_enable(self->unit, PCNT_EVT_H_LIM);
+    pcnt_isr_register(pcnt_overflow_handler, (void *)self, ESP_INTR_FLAG_IRAM, &self->handle);
+    pcnt_intr_enable(self->unit);
+}
+
+static void init_timer(frequencyio_frequencyin_obj_t* self) {
     // Prepare configuration for the timer module
-    timer_config_t config = {
+    const timer_config_t config = {
         .alarm_en = true,
         .counter_en = false,
         .intr_type = TIMER_INTR_LEVEL,
@@ -64,9 +101,9 @@ static void init_timer(frequencyio_frequencyin_obj_t* self, uint16_t capture_per
     // Initialize timer module
     timer_init(TIMER_GROUP_0, TIMER_0, &config);
     timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
-    timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, capture_period * 1000000);
+    timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, self->capture_period * 1000000);
+    timer_isr_register(TIMER_GROUP_0, TIMER_0, timer_interrupt_handler, (void *)self, ESP_INTR_FLAG_IRAM, &self->handle);
     timer_enable_intr(TIMER_GROUP_0, TIMER_0);
-    timer_isr_register(TIMER_GROUP_0, TIMER_0, frequencyin_interrupt_handler, (void *)self, ESP_INTR_FLAG_IRAM, &self->handle);
 
     // Start timer
     timer_start(TIMER_GROUP_0, TIMER_0);
@@ -78,33 +115,15 @@ void common_hal_frequencyio_frequencyin_construct(frequencyio_frequencyin_obj_t*
         mp_raise_ValueError(translate("Invalid capture period. Valid range: 1 - 500"));
     }
 
-    // Prepare configuration for the PCNT unit
-    const pcnt_config_t pcnt_config = {
-        // Set PCNT input signal and control GPIOs
-        .pulse_gpio_num = pin->number,
-        .ctrl_gpio_num = PCNT_PIN_NOT_USED,
-        .channel = PCNT_CHANNEL_0,
-        // What to do on the positive / negative edge of pulse input?
-        .pos_mode = PCNT_COUNT_INC,  // count both rising and falling edges
-        .neg_mode = PCNT_COUNT_INC,
-    };
-
-    // Initialize PCNT unit
-    const int8_t unit = peripherals_pcnt_init(pcnt_config);
-    if (unit == -1) {
-        mp_raise_RuntimeError(translate("All PCNT units in use"));
-    }
-
-    // set the GPIO back to high-impedance, as pcnt_unit_config sets it as pull-up
-    gpio_set_pull_mode(pin->number, GPIO_FLOATING);
-
-    // initialize timer
-    init_timer(self, capture_period);
-
     self->pin = pin->number;
-    self->unit = (pcnt_unit_t)unit;
+    self->handle = NULL;
+    self->multiplier = 0;
     self->capture_period = capture_period;
 
+    // initialize pcnt and timer
+    init_pcnt(self);
+    init_timer(self);
+
     claim_pin(pin);
 }
 
@@ -118,15 +137,15 @@ void common_hal_frequencyio_frequencyin_deinit(frequencyio_frequencyin_obj_t* se
     }
     reset_pin_number(self->pin);
     peripherals_pcnt_deinit(&self->unit);
+    timer_deinit(TIMER_GROUP_0, TIMER_0);
     if (self->handle) {
-        timer_deinit(TIMER_GROUP_0, TIMER_0);
         esp_intr_free(self->handle);
         self->handle = NULL;
     }
 }
 
 uint32_t common_hal_frequencyio_frequencyin_get_item(frequencyio_frequencyin_obj_t* self) {
-    return self->frequency;
+    return (self->frequency + (self->multiplier * INT16_MAX));
 }
 
 void common_hal_frequencyio_frequencyin_pause(frequencyio_frequencyin_obj_t* self) {
diff --git a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h
index 01e617d13a..ce3bf8f2f9 100644
--- a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h
+++ b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h
@@ -36,7 +36,8 @@ typedef struct {
     pcnt_unit_t unit;
     intr_handle_t handle;
     uint8_t pin;
-    uint32_t frequency;
+    uint8_t multiplier;
+    uint16_t frequency;
     uint16_t capture_period;
 } frequencyio_frequencyin_obj_t;
 

From ff987e7496152c3175608570d90f36753b4c4670 Mon Sep 17 00:00:00 2001
From: microDev <70126934+microDev1@users.noreply.github.com>
Date: Wed, 18 Nov 2020 12:16:14 +0530
Subject: [PATCH 5/7] add timer peripheral

---
 ports/esp32s2/Makefile            |  1 +
 ports/esp32s2/peripherals/timer.c | 73 +++++++++++++++++++++++++++++++
 ports/esp32s2/peripherals/timer.h | 41 +++++++++++++++++
 ports/esp32s2/supervisor/port.c   | 23 ++++++----
 4 files changed, 129 insertions(+), 9 deletions(-)
 create mode 100644 ports/esp32s2/peripherals/timer.c
 create mode 100644 ports/esp32s2/peripherals/timer.h

diff --git a/ports/esp32s2/Makefile b/ports/esp32s2/Makefile
index 55d6e91d44..931e4d0639 100644
--- a/ports/esp32s2/Makefile
+++ b/ports/esp32s2/Makefile
@@ -188,6 +188,7 @@ SRC_C += \
 	lib/utils/pyexec.c \
 	lib/utils/stdout_helpers.c \
 	lib/utils/sys_stdio_mphal.c \
+	peripherals/timer.c \
 	peripherals/pcnt.c \
 	peripherals/pins.c \
 	peripherals/rmt.c \
diff --git a/ports/esp32s2/peripherals/timer.c b/ports/esp32s2/peripherals/timer.c
new file mode 100644
index 0000000000..3aee33dc50
--- /dev/null
+++ b/ports/esp32s2/peripherals/timer.c
@@ -0,0 +1,73 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 microDev
+ *
+ * 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.
+ */
+
+#include "peripherals/timer.h"
+
+#define TIMER_FREE 1
+#define TIMER_BUSY 0
+
+static uint8_t timer_state[2][2];
+
+void peripherals_timer_reset(void) {
+    timer_index_t timer;
+    for (uint8_t i = 0; i < 2; i++) {
+        for (uint8_t j = 0; j < 2; j++) {
+            if (timer_state[i][j] == TIMER_BUSY) {
+                timer.idx = (timer_idx_t)j;
+                timer.group = (timer_group_t)i;
+                timer_state[i][j] = TIMER_FREE;
+                peripherals_timer_deinit(&timer);
+            }
+        }
+    }
+}
+
+void peripherals_timer_init(const timer_config_t * config, timer_index_t * timer) {
+    // get free timer
+    for (uint8_t i = 0; i < 2; i++) {
+        for (uint8_t j = 0; j < 2; j++) {
+            if (timer_state[i][j] == TIMER_FREE) {
+                timer->idx = (timer_idx_t)j;
+                timer->group = (timer_group_t)i;
+                timer_state[i][j] = TIMER_BUSY;
+                goto init_timer;
+            } else if (i == 1 && j == 1) {
+                timer->idx = TIMER_MAX;
+                timer->group = TIMER_GROUP_MAX;
+                return;
+            }
+        }
+    }
+
+init_timer:
+    // initialize timer module
+    timer_init(timer->group, timer->idx, config);
+    timer_set_counter_value(timer->group, timer->idx, 0);
+}
+
+void peripherals_timer_deinit(timer_index_t * timer) {
+    timer_deinit(timer->group, timer->idx);
+}
diff --git a/ports/esp32s2/peripherals/timer.h b/ports/esp32s2/peripherals/timer.h
new file mode 100644
index 0000000000..8c9ebd91c9
--- /dev/null
+++ b/ports/esp32s2/peripherals/timer.h
@@ -0,0 +1,41 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 microDev
+ *
+ * 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.
+ */
+
+#ifndef MICROPY_INCLUDED_ESP32S2_PERIPHERALS_TIMER_HANDLER_H
+#define MICROPY_INCLUDED_ESP32S2_PERIPHERALS_TIMER_HANDLER_H
+
+#include "driver/timer.h"
+
+typedef struct {
+    timer_idx_t idx;
+    timer_group_t group;
+} timer_index_t;
+
+extern void peripherals_timer_init(const timer_config_t * config, timer_index_t * timer);
+extern void peripherals_timer_deinit(timer_index_t * timer);
+extern void peripherals_timer_reset(void);
+
+#endif  // MICROPY_INCLUDED_ESP32S2_PERIPHERALS_TIMER_HANDLER_H
diff --git a/ports/esp32s2/supervisor/port.c b/ports/esp32s2/supervisor/port.c
index ef032c4a76..4bf792516d 100644
--- a/ports/esp32s2/supervisor/port.c
+++ b/ports/esp32s2/supervisor/port.c
@@ -50,6 +50,7 @@
 
 #include "peripherals/rmt.h"
 #include "peripherals/pcnt.h"
+#include "peripherals/timer.h"
 #include "components/heap/include/esp_heap_caps.h"
 #include "components/soc/soc/esp32s2/include/soc/cache_memory.h"
 
@@ -103,15 +104,6 @@ void reset_port(void) {
     analogout_reset();
 #endif
 
-#if CIRCUITPY_PULSEIO
-    esp32s2_peripherals_rmt_reset();
-    pulsein_reset();
-#endif
-
-#if CIRCUITPY_PWMIO
-    pwmout_reset();
-#endif
-
 #if CIRCUITPY_BUSIO
     i2c_reset();
     spi_reset();
@@ -122,6 +114,19 @@ void reset_port(void) {
     peripherals_pcnt_reset();
 #endif
 
+#if CIRCUITPY_FREQUENCYIO
+    peripherals_timer_reset();
+#endif
+
+#if CIRCUITPY_PULSEIO
+    esp32s2_peripherals_rmt_reset();
+    pulsein_reset();
+#endif
+
+#if CIRCUITPY_PWMIO
+    pwmout_reset();
+#endif
+
 #if CIRCUITPY_RTC
     rtc_reset();
 #endif

From c457d373e18a5bcadec44e0815bea8b9beb30a97 Mon Sep 17 00:00:00 2001
From: microDev <70126934+microDev1@users.noreply.github.com>
Date: Wed, 18 Nov 2020 12:24:48 +0530
Subject: [PATCH 6/7] update init_timer & frequency calculation

---
 .../common-hal/frequencyio/FrequencyIn.c      | 55 ++++++++++++-------
 .../common-hal/frequencyio/FrequencyIn.h      |  5 +-
 2 files changed, 38 insertions(+), 22 deletions(-)

diff --git a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
index 20d744139d..12d612abb0 100644
--- a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
+++ b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.c
@@ -29,7 +29,7 @@
 #include "py/runtime.h"
 
 static void IRAM_ATTR pcnt_overflow_handler(void *self_in) {
-    frequencyio_frequencyin_obj_t* self = self_in;
+    frequencyio_frequencyin_obj_t * self = self_in;
     // reset counter
     pcnt_counter_clear(self->unit);
 
@@ -41,18 +41,26 @@ static void IRAM_ATTR pcnt_overflow_handler(void *self_in) {
 }
 
 static void IRAM_ATTR timer_interrupt_handler(void *self_in) {
-    frequencyio_frequencyin_obj_t* self = self_in;
+    frequencyio_frequencyin_obj_t * self = self_in;
     // get counter value
     int16_t count;
     pcnt_get_counter_value(self->unit, &count);
-    self->frequency = count / 2.0 / self->capture_period;
+    self->frequency = ((count / 2.0) + (self->multiplier * INT16_MAX / 4.0)) / (self->capture_period);
+
+    // reset multiplier
+    self->multiplier = 0;
 
     // reset counter
     pcnt_counter_clear(self->unit);
 
     // reset interrupt
-    TIMERG0.int_clr.t0 = 1;
-    TIMERG0.hw_timer[0].config.alarm_en = 1;
+    timg_dev_t *device = self->timer.group ? &(TIMERG1) : &(TIMERG0);
+    if (self->timer.idx) {
+        device->int_clr.t1 = 1;
+    } else {
+        device->int_clr.t0 = 1;
+    }
+    device->hw_timer[self->timer.idx].config.alarm_en = 1;
 }
 
 static void init_pcnt(frequencyio_frequencyin_obj_t* self) {
@@ -70,7 +78,7 @@ static void init_pcnt(frequencyio_frequencyin_obj_t* self) {
         .counter_l_lim = 0,
     };
 
-    // Initialize PCNT unit
+    // initialize PCNT
     const int8_t unit = peripherals_pcnt_init(pcnt_config);
     if (unit == -1) {
         mp_raise_RuntimeError(translate("All PCNT units in use"));
@@ -98,15 +106,22 @@ static void init_timer(frequencyio_frequencyin_obj_t* self) {
         .divider = 80            // 1 us per tick
     };
 
-    // Initialize timer module
-    timer_init(TIMER_GROUP_0, TIMER_0, &config);
-    timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
-    timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, self->capture_period * 1000000);
-    timer_isr_register(TIMER_GROUP_0, TIMER_0, timer_interrupt_handler, (void *)self, ESP_INTR_FLAG_IRAM, &self->handle);
-    timer_enable_intr(TIMER_GROUP_0, TIMER_0);
+    // initialize Timer
+    peripherals_timer_init(&config, &self->timer);
+    if (self->timer.idx == TIMER_MAX || self->timer.group == TIMER_GROUP_MAX) {
+        mp_raise_RuntimeError(translate("All timers in use"));
+    }
 
-    // Start timer
-    timer_start(TIMER_GROUP_0, TIMER_0);
+    timer_idx_t idx = self->timer.idx;
+    timer_group_t group = self->timer.group;
+
+    // enable timer interrupt
+    timer_set_alarm_value(group, idx, self->capture_period * 1000000);
+    timer_isr_register(group, idx, timer_interrupt_handler, (void *)self, ESP_INTR_FLAG_IRAM, &self->handle);
+    timer_enable_intr(group, idx);
+
+    // start timer
+    timer_start(self->timer.group, self->timer.idx);
 }
 
 void common_hal_frequencyio_frequencyin_construct(frequencyio_frequencyin_obj_t* self,
@@ -137,7 +152,7 @@ void common_hal_frequencyio_frequencyin_deinit(frequencyio_frequencyin_obj_t* se
     }
     reset_pin_number(self->pin);
     peripherals_pcnt_deinit(&self->unit);
-    timer_deinit(TIMER_GROUP_0, TIMER_0);
+    peripherals_timer_deinit(&self->timer);
     if (self->handle) {
         esp_intr_free(self->handle);
         self->handle = NULL;
@@ -145,23 +160,23 @@ void common_hal_frequencyio_frequencyin_deinit(frequencyio_frequencyin_obj_t* se
 }
 
 uint32_t common_hal_frequencyio_frequencyin_get_item(frequencyio_frequencyin_obj_t* self) {
-    return (self->frequency + (self->multiplier * INT16_MAX));
+    return self->frequency;
 }
 
 void common_hal_frequencyio_frequencyin_pause(frequencyio_frequencyin_obj_t* self) {
     pcnt_counter_pause(self->unit);
-    timer_pause(TIMER_GROUP_0, TIMER_0);
+    timer_pause(self->timer.group, self->timer.idx);
 }
 
 void common_hal_frequencyio_frequencyin_resume(frequencyio_frequencyin_obj_t* self) {
     pcnt_counter_resume(self->unit);
-    timer_start(TIMER_GROUP_0, TIMER_0);
+    timer_start(self->timer.group, self->timer.idx);
 }
 
 void common_hal_frequencyio_frequencyin_clear(frequencyio_frequencyin_obj_t* self) {
     self->frequency = 0;
     pcnt_counter_clear(self->unit);
-    timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
+    timer_set_counter_value(self->timer.group, self->timer.idx, 0);
 }
 
 uint16_t common_hal_frequencyio_frequencyin_get_capture_period(frequencyio_frequencyin_obj_t *self) {
@@ -174,5 +189,5 @@ void common_hal_frequencyio_frequencyin_set_capture_period(frequencyio_frequency
     }
     self->capture_period = capture_period;
     common_hal_frequencyio_frequencyin_clear(self);
-    timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, capture_period * 1000000);
+    timer_set_alarm_value(self->timer.group, self->timer.idx, capture_period * 1000000);
 }
diff --git a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h
index ce3bf8f2f9..cf9d2ae538 100644
--- a/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h
+++ b/ports/esp32s2/common-hal/frequencyio/FrequencyIn.h
@@ -28,16 +28,17 @@
 #define MICROPY_INCLUDED_ESP32S2_COMMON_HAL_FREQUENCYIO_FREQUENCYIN_H
 
 #include "py/obj.h"
-#include "driver/timer.h"
 #include "peripherals/pcnt.h"
+#include "peripherals/timer.h"
 
 typedef struct {
     mp_obj_base_t base;
     pcnt_unit_t unit;
+    timer_index_t timer;
     intr_handle_t handle;
     uint8_t pin;
     uint8_t multiplier;
-    uint16_t frequency;
+    uint32_t frequency;
     uint16_t capture_period;
 } frequencyio_frequencyin_obj_t;
 

From f3b5ca5f01058cb1d50be09838bc55b22d3aae69 Mon Sep 17 00:00:00 2001
From: microDev <70126934+microDev1@users.noreply.github.com>
Date: Sun, 22 Nov 2020 19:20:21 +0530
Subject: [PATCH 7/7] replace goto with conditional break

---
 ports/esp32s2/peripherals/timer.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/ports/esp32s2/peripherals/timer.c b/ports/esp32s2/peripherals/timer.c
index 3aee33dc50..0ae1403874 100644
--- a/ports/esp32s2/peripherals/timer.c
+++ b/ports/esp32s2/peripherals/timer.c
@@ -46,6 +46,8 @@ void peripherals_timer_reset(void) {
 }
 
 void peripherals_timer_init(const timer_config_t * config, timer_index_t * timer) {
+    bool break_loop = false;
+
     // get free timer
     for (uint8_t i = 0; i < 2; i++) {
         for (uint8_t j = 0; j < 2; j++) {
@@ -53,16 +55,17 @@ void peripherals_timer_init(const timer_config_t * config, timer_index_t * timer
                 timer->idx = (timer_idx_t)j;
                 timer->group = (timer_group_t)i;
                 timer_state[i][j] = TIMER_BUSY;
-                goto init_timer;
+                break_loop = true;
+                break;
             } else if (i == 1 && j == 1) {
                 timer->idx = TIMER_MAX;
                 timer->group = TIMER_GROUP_MAX;
                 return;
             }
         }
+        if (break_loop) {break;}
     }
 
-init_timer:
     // initialize timer module
     timer_init(timer->group, timer->idx, config);
     timer_set_counter_value(timer->group, timer->idx, 0);