0049-RP2040-add-pwm-driver.patch

From 5d47e3a8f6ae9c24c3e335d9f656373c9283f5cc Mon Sep 17 00:00:00 2001
From: Martino Facchin <m.facchin@arduino.cc>
Date: Tue, 23 Feb 2021 16:48:23 +0100
Subject: [PATCH 49/87] RP2040: add pwm driver

---
 .../TARGET_RP2040/objects.h                   |   9 +
 .../TARGET_RP2040/pwmout_api.c                | 198 ++++++++++++++++++
 targets/targets.json                          |   1 +
 3 files changed, 208 insertions(+)
 create mode 100644 targets/TARGET_RASPBERRYPI/TARGET_RP2040/pwmout_api.c

diff --git a/targets/TARGET_RASPBERRYPI/TARGET_RP2040/objects.h b/targets/TARGET_RASPBERRYPI/TARGET_RP2040/objects.h
index 061cee5908..5e5f2f0d6a 100644
--- a/targets/TARGET_RASPBERRYPI/TARGET_RP2040/objects.h
+++ b/targets/TARGET_RASPBERRYPI/TARGET_RP2040/objects.h
@@ -101,6 +101,15 @@ struct spi_s {
     spi_inst_t * dev;
 };
 
+struct pwmout_s {
+    PinName pin;
+    uint8_t slice;
+    uint8_t channel;
+    uint16_t period;
+    float percent;
+    pwm_config cfg;
+};
+
 struct flash_s {
 	/*  nothing to be stored for now */
 	uint32_t dummy;
diff --git a/targets/TARGET_RASPBERRYPI/TARGET_RP2040/pwmout_api.c b/targets/TARGET_RASPBERRYPI/TARGET_RP2040/pwmout_api.c
new file mode 100644
index 0000000000..5f5d847995
--- /dev/null
+++ b/targets/TARGET_RASPBERRYPI/TARGET_RP2040/pwmout_api.c
@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2018 Nordic Semiconductor ASA
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright notice, this list
+ *      of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form, except as embedded into a Nordic Semiconductor ASA
+ *      integrated circuit in a product or a software update for such product, must reproduce
+ *      the above copyright notice, this list of conditions and the following disclaimer in
+ *      the documentation and/or other materials provided with the distribution.
+ *
+ *   3. Neither the name of Nordic Semiconductor ASA nor the names of its contributors may be
+ *      used to endorse or promote products derived from this software without specific prior
+ *      written permission.
+ *
+ *   4. This software, with or without modification, must only be used with a
+ *      Nordic Semiconductor ASA integrated circuit.
+ *
+ *   5. Any software provided in binary or object form under this license must not be reverse
+ *      engineered, decompiled, modified and/or disassembled.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#if DEVICE_PWMOUT
+
+#include "hal/pwmout_api.h"
+#include "PeripheralPins.h"
+#include "pinmap.h"
+#include "hardware/pwm.h"
+#include "hardware/clocks.h"
+
+const uint count_top = 1000;
+
+/** Initialize the pwm out peripheral and configure the pin
+ *
+ * Parameter obj The pwmout object to initialize
+ * Parameter pin The pwmout pin to initialize
+ */
+void pwmout_init(pwmout_t *obj, PinName pin)
+{
+    MBED_ASSERT(obj);
+
+    /* Populate PWM object with default values. */
+    obj->slice = pwm_gpio_to_slice_num(pin);
+    obj->channel = pwm_gpio_to_channel(pin);
+    obj->pin = pin;
+    obj->period = 0;
+    obj->percent = 0.5f;
+
+    obj->cfg = pwm_get_default_config();
+    pwm_config_set_wrap(&(obj->cfg), count_top);
+
+    pwm_init(obj->slice, &(obj->cfg), false);
+    gpio_set_function(pin, GPIO_FUNC_PWM);
+}
+
+/** Deinitialize the pwmout object
+ *
+ * Parameter obj The pwmout object
+ */
+void pwmout_free(pwmout_t *obj)
+{
+    MBED_ASSERT(obj);
+    pwm_set_enabled(obj->slice, false);
+}
+
+/** Set the output duty-cycle in range <0.0f, 1.0f>
+ *
+ * pulse 0.0f represents 0 percentage, 1.0f represents 100 percent.
+ * Parameter obj     The pwmout object
+ * Parameter percent The floating-point percentage number
+ */
+void pwmout_write(pwmout_t *obj, float percent)
+{
+    obj->percent = percent;
+    pwm_set_gpio_level(obj->pin, percent * (count_top + 1));
+}
+
+/** Read the current float-point output duty-cycle
+ *
+ * Parameter obj The pwmout object
+ * Return A floating-point output duty-cycle
+ */
+float pwmout_read(pwmout_t *obj)
+{
+    /* Return percentage stored in object instead of calculating the value.
+     * This prevents floating point rounding errors.
+     */
+    return obj->percent;
+}
+
+/** Set the PWM period specified in seconds, keeping the duty cycle the same
+ *
+ * Periods smaller than microseconds (the lowest resolution) are set to zero.
+ * Parameter obj     The pwmout object
+ * Parameter seconds The floating-point seconds period
+ */
+void pwmout_period(pwmout_t *obj, float period)
+{
+    /* Set new period. */
+    pwmout_period_us(obj, period * 1000000);
+}
+
+/** Set the PWM period specified in miliseconds, keeping the duty cycle the same
+ *
+ * Parameter obj The pwmout object
+ * Parameter ms  The milisecond period
+ */
+void pwmout_period_ms(pwmout_t *obj, int period)
+{
+    /* Set new period. */
+    pwmout_period_us(obj, period * 1000);
+}
+
+/** Set the PWM period specified in microseconds, keeping the duty cycle the same
+ *
+ * Parameter obj The pwmout object
+ * Parameter us  The microsecond period
+ */
+void pwmout_period_us(pwmout_t *obj, int period)
+{
+    obj->period = period;
+
+    // min_period should be 8us
+    uint32_t min_period = 1000000 * count_top / clock_get_hz(clk_sys);
+
+    pwm_config_set_clkdiv(&(obj->cfg), (float)period / (float)min_period);
+    pwm_init(obj->slice, &(obj->cfg), false);
+}
+
+int pwmout_read_period_us(pwmout_t *obj)
+{
+    return obj->period;
+}
+
+/** Set the PWM pulsewidth specified in seconds, keeping the period the same.
+ *
+ * Parameter obj     The pwmout object
+ * Parameter seconds The floating-point pulsewidth in seconds
+ */
+void pwmout_pulsewidth(pwmout_t *obj, float pulse)
+{
+    pwmout_pulsewidth_us(obj, pulse * 1000000);
+}
+
+/** Set the PWM pulsewidth specified in miliseconds, keeping the period the same.
+ *
+ * Parameter obj The pwmout object
+ * Parameter ms  The floating-point pulsewidth in miliseconds
+ */
+void pwmout_pulsewidth_ms(pwmout_t *obj, int pulse)
+{
+    pwmout_pulsewidth_us(obj, pulse * 1000);
+}
+
+/** Set the PWM pulsewidth specified in microseconds, keeping the period the same.
+ *
+ * Parameter obj The pwmout object
+ * Parameter us  The floating-point pulsewidth in microseconds
+ */
+void pwmout_pulsewidth_us(pwmout_t *obj, int pulse)
+{
+    /* Cap pulsewidth to period. */
+    if (pulse > obj->period) {
+        pulse = obj->period;
+    }
+
+    obj->percent = (float) pulse / (float) obj->period;
+
+    /* Restart instance with new values. */
+    pwmout_write(obj, obj->percent);
+}
+
+int pwmout_read_pulsewidth_us(pwmout_t *obj) {
+    return (obj->period) * (obj->percent);
+}
+
+const PinMap *pwmout_pinmap()
+{
+    return PinMap_PWM_OUT;
+}
+
+#endif // DEVICE_PWMOUT
diff --git a/targets/targets.json b/targets/targets.json
index e2a2543952..f2f7095861 100644
--- a/targets/targets.json
+++ b/targets/targets.json
@@ -8380,6 +8380,7 @@
             "I2C",
             "PORT_IN",
             "PORT_OUT",
+            "PWMOUT",
             "SERIAL",
             "SPI",
             "USBDEVICE"
-- 
2.30.2