1 files changed, 134 insertions, 0 deletions
diff --git a/circuitpython/ports/raspberrypi/common-hal/pulseio/PulseOut.c b/circuitpython/ports/raspberrypi/common-hal/pulseio/PulseOut.c
new file mode 100644
index 0000000..7704fdf
--- /dev/null
+++ b/circuitpython/ports/raspberrypi/common-hal/pulseio/PulseOut.c
@@ -0,0 +1,134 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Dave Putz for Adafruit Industries
+ *
+ * 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 "common-hal/pulseio/PulseOut.h"
+
+#include <stdint.h>
+#include "mpconfigport.h"
+#include "py/runtime.h"
+#include "shared-bindings/pulseio/PulseOut.h"
+#include "shared-bindings/pwmio/PWMOut.h"
+#include "shared-bindings/microcontroller/__init__.h"
+#include "common-hal/pwmio/PWMOut.h"
+#include "supervisor/shared/translate.h"
+#include "src/rp2040/hardware_structs/include/hardware/structs/pwm.h"
+#include "src/rp2_common/hardware_gpio/include/hardware/gpio.h"
+#include "src/rp2_common/hardware_pwm/include/hardware/pwm.h"
+#include "src/common/pico_time/include/pico/time.h"
+
+volatile alarm_id_t cur_alarm = 0;
+
+static void pulse_finish(pulseio_pulseout_obj_t *self) {
+    self->pulse_index++;
+    // Turn pwm pin off by switching the GPIO mux to SIO (the cpu manual
+    // control).
+    if (self->pulse_index >= self->pulse_length) {
+        gpio_set_function(self->pin, GPIO_FUNC_SIO);
+        return;
+    }
+    if (self->pulse_index % 2 == 0) {
+        gpio_set_function(self->pin, GPIO_FUNC_PWM);
+    } else {
+        gpio_set_function(self->pin, GPIO_FUNC_SIO);
+    }
+    uint64_t delay = self->pulse_buffer[self->pulse_index];
+    if (delay < self->min_pulse) {
+        delay = self->min_pulse;
+    }
+    cur_alarm = 0;
+    // if the alarm cannot be set, try again with a longer delay
+    while (cur_alarm == 0) {
+        cur_alarm = add_alarm_in_us(delay, pulseout_interrupt_handler, self, false);
+        delay = delay + 1;
+    }
+}
+
+int64_t pulseout_interrupt_handler(alarm_id_t id, void *user_data) {
+    pulse_finish(user_data);
+    return 0;
+}
+
+void pulseout_reset() {
+}
+
+void common_hal_pulseio_pulseout_construct(pulseio_pulseout_obj_t *self,
+    const mcu_pin_obj_t *pin,
+    uint32_t frequency,
+    uint16_t duty_cycle) {
+
+    pwmout_result_t result = common_hal_pwmio_pwmout_construct(
+        &self->carrier, pin, 0, frequency, false);
+    // This will raise an exception and not return if needed.
+    common_hal_pwmio_pwmout_raise_error(result);
+
+    // Disable gpio output before we set the duty cycle.
+    gpio_put(pin->number, false);
+    gpio_set_dir(pin->number, GPIO_OUT);
+    gpio_set_function(pin->number, GPIO_FUNC_SIO);
+    common_hal_pwmio_pwmout_set_duty_cycle(&self->carrier, duty_cycle);
+
+    self->pin = pin->number;
+    self->slice = self->carrier.slice;
+    self->min_pulse = (1000000 / self->carrier.actual_frequency);
+}
+
+bool common_hal_pulseio_pulseout_deinited(pulseio_pulseout_obj_t *self) {
+    return self->pin == NO_PIN;
+}
+
+void common_hal_pulseio_pulseout_deinit(pulseio_pulseout_obj_t *self) {
+    if (common_hal_pulseio_pulseout_deinited(self)) {
+        return;
+    }
+    gpio_set_dir(self->pin, GPIO_IN);
+    common_hal_pwmio_pwmout_deinit(&self->carrier);
+    self->pin = NO_PIN;
+}
+
+void common_hal_pulseio_pulseout_send(pulseio_pulseout_obj_t *self, uint16_t *pulses, uint16_t length) {
+    self->pulse_buffer = pulses;
+    self->pulse_index = 0;
+    self->pulse_length = length;
+
+    // Turn on the signal by connecting the PWM to the outside pin.
+    gpio_set_function(self->pin, GPIO_FUNC_PWM);
+    uint64_t delay = self->pulse_buffer[0];
+    if (delay < self->min_pulse) {
+        delay = self->min_pulse;
+    }
+    cur_alarm = 0;
+    // if the alarm cannot be set, try again with a longer delay
+    while (cur_alarm == 0) {
+        cur_alarm = add_alarm_in_us(delay, pulseout_interrupt_handler, self, false);
+        delay = delay + 1;
+    }
+
+    while (self->pulse_index < length) {
+        // Do other things while we wait. The interrupts will handle sending the
+        // signal.
+        RUN_BACKGROUND_TASKS;
+    }
+}