Merge pull request #1408 from hathach/nrf52_pulsein

added pulsein using nrfx gpiote (gpio interrupt)

6 files changed, 226 insertions, 16 deletions

diff --git a/ports/nrf/Makefile b/ports/nrf/Makefile
index b8d186621..ca9583df7 100755
--- a/ports/nrf/Makefile
+++ b/ports/nrf/Makefile
@@ -101,6 +101,7 @@ SRC_NRFX = $(addprefix nrfx/,\
 	drivers/src/nrfx_timer.c \
 	drivers/src/nrfx_twim.c \
 	drivers/src/nrfx_uarte.c \
+	drivers/src/nrfx_gpiote.c \
 	)
 
 ifdef EXTERNAL_FLASH_DEVICES
diff --git a/ports/nrf/common-hal/neopixel_write/__init__.c b/ports/nrf/common-hal/neopixel_write/__init__.c
index c9da436b8..f810a44cc 100644
--- a/ports/nrf/common-hal/neopixel_write/__init__.c
+++ b/ports/nrf/common-hal/neopixel_write/__init__.c
@@ -141,7 +141,7 @@ void common_hal_neopixel_write (const digitalio_digitalinout_obj_t* digitalinout
         for ( uint16_t n = 0; n < numBytes; n++ ) {
             uint8_t pix = pixels[n];
 
-            for ( uint8_t mask = 0x80, i = 0; mask > 0; mask >>= 1, i++ ) {
+            for ( uint8_t mask = 0x80; mask > 0; mask >>= 1 ) {
                 pixels_pattern[pos] = (pix & mask) ? MAGIC_T1H : MAGIC_T0H;
                 pos++;
             }
diff --git a/ports/nrf/common-hal/pulseio/PulseIn.c b/ports/nrf/common-hal/pulseio/PulseIn.c
index 3d6d266af..6e5825af6 100644
--- a/ports/nrf/common-hal/pulseio/PulseIn.c
+++ b/ports/nrf/common-hal/pulseio/PulseIn.c
@@ -27,6 +27,7 @@
 #include "common-hal/pulseio/PulseIn.h"
 
 #include <stdint.h>
+#include <string.h>
 
 #include "py/mpconfig.h"
 #include "py/gc.h"
@@ -35,50 +36,247 @@
 #include "shared-bindings/microcontroller/__init__.h"
 #include "shared-bindings/pulseio/PulseIn.h"
 
+#include "tick.h"
+#include "nrfx_gpiote.h"
+
+// obj array to map pin -> self since nrfx hide the mapping
+static pulseio_pulsein_obj_t* _objs[GPIOTE_CH_NUM];
+
+// return index of the object in array
+static int _find_pulsein_obj(pulseio_pulsein_obj_t* obj) {
+    for(int i = 0; i < NRFX_ARRAY_SIZE(_objs); i++ ) {
+        if ( _objs[i] == obj) {
+            return i;
+        }
+    }
+
+    return -1;
+}
+
+static void _pulsein_handler(nrfx_gpiote_pin_t pin, nrf_gpiote_polarity_t action) {
+    // Grab the current time first.
+    uint32_t current_us;
+    uint64_t current_ms;
+    current_tick(&current_ms, &current_us);
+
+    // current_tick gives us the remaining us until the next tick but we want the number since the last ms.
+    current_us = 1000 - current_us;
+
+    pulseio_pulsein_obj_t* self = NULL;
+    for(int i = 0; i < NRFX_ARRAY_SIZE(_objs); i++ ) {
+        if ( _objs[i] && _objs[i]->pin == pin ) {
+            self = _objs[i];
+            break;
+        }
+    }
+    if ( !self ) return;
+
+    if (self->first_edge) {
+        // first pulse is opposite state from idle
+        bool state = nrf_gpio_pin_read(self->pin);
+        if ( self->idle_state != state ) {
+            self->first_edge = false;
+        }
+    }else {
+        uint32_t ms_diff = current_ms - self->last_ms;
+        uint16_t us_diff = current_us - self->last_us;
+        uint32_t total_diff = us_diff;
+
+        if (self->last_us > current_us) {
+            total_diff = 1000 + current_us - self->last_us;
+            if (ms_diff > 1) {
+                total_diff += (ms_diff - 1) * 1000;
+            }
+        } else {
+            total_diff += ms_diff * 1000;
+        }
+        uint16_t duration = 0xffff;
+        if (total_diff < duration) {
+            duration = total_diff;
+        }
+
+        uint16_t i = (self->start + self->len) % self->maxlen;
+        self->buffer[i] = duration;
+        if (self->len < self->maxlen) {
+            self->len++;
+        } else {
+            self->start++;
+        }
+    }
+
+    self->last_ms = current_ms;
+    self->last_us = current_us;
+}
+
 void pulsein_reset(void) {
+    if ( nrfx_gpiote_is_init() ) {
+        nrfx_gpiote_uninit();
+    }
+    nrfx_gpiote_init();
 
+    memset(_objs, 0, sizeof(_objs));
 }
 
 void common_hal_pulseio_pulsein_construct(pulseio_pulsein_obj_t* self, const mcu_pin_obj_t* pin, uint16_t maxlen, bool idle_state) {
-    mp_raise_NotImplementedError(NULL);
+    int idx = _find_pulsein_obj(NULL);
+    if ( idx < 0 ) {
+        mp_raise_NotImplementedError(NULL);
+    }
+    _objs[idx] = self;
+
+    self->buffer = (uint16_t *) m_malloc(maxlen * sizeof(uint16_t), false);
+    if (self->buffer == NULL) {
+        mp_raise_msg_varg(&mp_type_MemoryError, translate("Failed to allocate RX buffer of %d bytes"), maxlen * sizeof(uint16_t));
+    }
+
+    self->pin = pin->number;
+    self->maxlen = maxlen;
+    self->idle_state = idle_state;
+    self->start = 0;
+    self->len = 0;
+    self->first_edge = true;
+    self->paused = false;
+    self->last_us = 0;
+    self->last_ms = 0;
+
+    claim_pin(pin);
+
+    nrfx_gpiote_in_config_t cfg = {
+        .sense = NRF_GPIOTE_POLARITY_TOGGLE,
+        .pull = NRF_GPIO_PIN_NOPULL, // idle_state ? NRF_GPIO_PIN_PULLDOWN : NRF_GPIO_PIN_PULLUP,
+        .is_watcher = false, // nrf_gpio_cfg_watcher vs nrf_gpio_cfg_input
+        .hi_accuracy = true,
+        .skip_gpio_setup = false
+    };
+    nrfx_gpiote_in_init(self->pin, &cfg, _pulsein_handler);
+    nrfx_gpiote_in_event_enable(self->pin, true);
 }
 
 bool common_hal_pulseio_pulsein_deinited(pulseio_pulsein_obj_t* self) {
-  return 1;
+  return self->pin == NO_PIN;
 }
 
 void common_hal_pulseio_pulsein_deinit(pulseio_pulsein_obj_t* self) {
+    if (common_hal_pulseio_pulsein_deinited(self)) {
+        return;
+    }
+
+    nrfx_gpiote_in_event_disable(self->pin);
+    nrfx_gpiote_in_uninit(self->pin);
+
+    // mark local array as invalid
+    int idx = _find_pulsein_obj(self);
+    if ( idx < 0 ) {
+        mp_raise_NotImplementedError(NULL);
+    }
+    _objs[idx] = NULL;
 
+    reset_pin_number(self->pin);
+    self->pin = NO_PIN;
 }
 
 void common_hal_pulseio_pulsein_pause(pulseio_pulsein_obj_t* self) {
-
+    nrfx_gpiote_in_event_disable(self->pin);
+    self->paused = true;
 }
 
 void common_hal_pulseio_pulsein_resume(pulseio_pulsein_obj_t* self, uint16_t trigger_duration) {
+    // Make sure we're paused.
+    if ( !self->paused ) {
+        common_hal_pulseio_pulsein_pause(self);
+    }
+
+    // Send the trigger pulse.
+    if (trigger_duration > 0) {
+        nrfx_gpiote_in_uninit(self->pin);
+
+        nrf_gpio_cfg_output(self->pin);
+        nrf_gpio_pin_write(self->pin, !self->idle_state);
+        common_hal_mcu_delay_us((uint32_t)trigger_duration);
+        nrf_gpio_pin_write(self->pin, self->idle_state);
+
+        nrfx_gpiote_in_config_t cfg = {
+            .sense = NRF_GPIOTE_POLARITY_TOGGLE,
+            .pull = NRF_GPIO_PIN_NOPULL, // idle_state ? NRF_GPIO_PIN_PULLDOWN : NRF_GPIO_PIN_PULLUP,
+            .is_watcher = false, // nrf_gpio_cfg_watcher vs nrf_gpio_cfg_input
+            .hi_accuracy = true,
+            .skip_gpio_setup = false
+        };
+        nrfx_gpiote_in_init(self->pin, &cfg, _pulsein_handler);
+    }
+
+    self->first_edge = true;
+    self->paused = false;
+    self->last_ms = 0;
+    self->last_us = 0;
 
+    nrfx_gpiote_in_event_enable(self->pin, true);
 }
 
 void common_hal_pulseio_pulsein_clear(pulseio_pulsein_obj_t* self) {
+    if ( !self->paused ) {
+        nrfx_gpiote_in_event_disable(self->pin);
+    }
 
+    self->start = 0;
+    self->len = 0;
+
+    if ( !self->paused ) {
+        nrfx_gpiote_in_event_enable(self->pin, true);
+    }
+}
+
+uint16_t common_hal_pulseio_pulsein_get_item(pulseio_pulsein_obj_t* self, int16_t index) {
+    if ( !self->paused ) {
+        nrfx_gpiote_in_event_disable(self->pin);
+    }
+
+    if (index < 0) {
+        index += self->len;
+    }
+    if (index < 0 || index >= self->len) {
+        if ( !self->paused ) {
+            nrfx_gpiote_in_event_enable(self->pin, true);
+        }
+        mp_raise_IndexError(translate("index out of range"));
+    }
+    uint16_t value = self->buffer[(self->start + index) % self->maxlen];
+
+    if ( !self->paused ) {
+        nrfx_gpiote_in_event_enable(self->pin, true);
+    }
+
+    return value;
 }
 
 uint16_t common_hal_pulseio_pulsein_popleft(pulseio_pulsein_obj_t* self) {
-  return 0;
+    if (self->len == 0) {
+        mp_raise_IndexError(translate("pop from an empty PulseIn"));
+    }
+
+    if ( !self->paused ) {
+        nrfx_gpiote_in_event_disable(self->pin);
+    }
+
+    uint16_t value = self->buffer[self->start];
+    self->start = (self->start + 1) % self->maxlen;
+    self->len--;
+
+    if ( !self->paused ) {
+        nrfx_gpiote_in_event_enable(self->pin, true);
+    }
+
+    return value;
 }
 
 uint16_t common_hal_pulseio_pulsein_get_maxlen(pulseio_pulsein_obj_t* self) {
-    return 0xadaf;
+    return self->maxlen;
 }
 
 bool common_hal_pulseio_pulsein_get_paused(pulseio_pulsein_obj_t* self) {
-    return false;
+    return self->paused;
 }
 
 uint16_t common_hal_pulseio_pulsein_get_len(pulseio_pulsein_obj_t* self) {
-    return 0xadaf;
-}
-
-uint16_t common_hal_pulseio_pulsein_get_item(pulseio_pulsein_obj_t* self, int16_t index) {
-  return 0xadaf;
+    return self->len;
 }
diff --git a/ports/nrf/common-hal/pulseio/PulseIn.h b/ports/nrf/common-hal/pulseio/PulseIn.h
index 666f5a164..4b2c6eee3 100644
--- a/ports/nrf/common-hal/pulseio/PulseIn.h
+++ b/ports/nrf/common-hal/pulseio/PulseIn.h
@@ -33,15 +33,19 @@
 
 typedef struct {
     mp_obj_base_t base;
-    uint8_t channel;
+
     uint8_t pin;
+    bool idle_state;
+    bool paused;
+    volatile bool first_edge;
+
     uint16_t* buffer;
     uint16_t maxlen;
-    bool idle_state;
+
     volatile uint16_t start;
     volatile uint16_t len;
-    volatile bool first_edge;
-    uint16_t ticks_per_ms;
+    volatile uint16_t last_us;
+    volatile uint64_t last_ms;
 } pulseio_pulsein_obj_t;
 
 void pulsein_reset(void);
diff --git a/ports/nrf/nrfx_config.h b/ports/nrf/nrfx_config.h
index 1d3085e2b..8676bd7f8 100644
--- a/ports/nrf/nrfx_config.h
+++ b/ports/nrf/nrfx_config.h
@@ -84,4 +84,9 @@
 
 #define NRFX_TIMER_DEFAULT_CONFIG_IRQ_PRIORITY 7
 
+// GPIO interrupt
+#define NRFX_GPIOTE_ENABLED 1
+#define NRFX_GPIOTE_CONFIG_NUM_OF_LOW_POWER_EVENTS 1
+#define NRFX_GPIOTE_CONFIG_IRQ_PRIORITY 7
+
 #endif // NRFX_CONFIG_H__
diff --git a/ports/nrf/supervisor/port.c b/ports/nrf/supervisor/port.c
index ece5bae29..2e25c7d15 100644
--- a/ports/nrf/supervisor/port.c
+++ b/ports/nrf/supervisor/port.c
@@ -42,6 +42,7 @@
 #include "common-hal/busio/SPI.h"
 #include "common-hal/pulseio/PWMOut.h"
 #include "common-hal/pulseio/PulseOut.h"
+#include "common-hal/pulseio/PulseIn.h"
 #include "tick.h"
 
 static void power_warning_handler(void) {
@@ -84,6 +85,7 @@ void reset_port(void) {
     spi_reset();
     pwmout_reset();
     pulseout_reset();
+    pulsein_reset();
     timers_reset();
 
     reset_all_pins();