[rp] PIO with compile-time assembler

examples/rp_pico/pio_ws2812/main.cpp

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+/*
+ * Copyright (c) 2016, Sascha Schade
+ * Copyright (c) 2017, Niklas Hauser
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+// ----------------------------------------------------------------------------
+
+#include <modm/board.hpp>
+using namespace Board;
+
+/* from https://github.com/raspberrypi/pico-examples/blob/master/pio/ws2812/ws2812.pio */
+
+// constants WS2812
+// static constexpr uint32_t T0H = 350; // ns
+// static constexpr uint32_t T0L = 800;
+// static constexpr uint32_t T1H = 700;
+// static constexpr uint32_t T1L = 600;
+
+// constants WS2812B
+static constexpr uint32_t T0H = 400; // ns
+static constexpr uint32_t T0L = 850;
+static constexpr uint32_t T1H = 850;
+static constexpr uint32_t T1L = 400;
+
+static constexpr uint32_t TimeScale = 50;
+
+static constexpr uint32_t TH_Common = T0H/TimeScale;
+static constexpr uint32_t TH_Add = (T1H-T0H)/TimeScale;
+static constexpr uint32_t TL_Common = T1L/TimeScale;
+static constexpr uint32_t TL_Add = (T0L-T1L)/TimeScale;
+
+static constexpr uint32_t T3 = 12;//
+
+// labels
+struct bitloop {};
+struct do_one {};
+struct do_zero {};
+
+
+/*
+.wrap_target
+bitloop:
+    out x, 1       side 0 [T3 - 1] ; Side-set still takes place when instruction stalls
+    jmp !x do_zero side 1 [T1 - 1] ; Branch on the bit we shifted out. Positive pulse
+do_one:
+    jmp  bitloop   side 1 [T2 - 1] ; Continue driving high, for a long pulse
+do_zero:
+    nop            side 0 [T2 - 1] ; Or drive low, for a short pulse
+.wrap
+*/
+// PIO program
+static constexpr auto pio_prog = modm::platform::PIOProgram::begin()
+	.sideset<1>()
+	.wrapTarget()
+	.label<bitloop>()
+		.instr(pio::Out().x<1>()				.side<0>().delay<TL_Common-1>())
+		.instr(pio::Jmp().not_x().to<do_zero>()	.side<1>().delay<TH_Common-1>())
+	.label<do_one>()
+		.instr(pio::Jmp().to<bitloop>()			.side<1>().delay<TH_Add-1>())
+	.label<do_zero>()
+		.instr(pio::Nop()						.side<0>().delay<TL_Add-1>())
+	.wrap()
+	.end();
+
+
+struct HW
+{
+	using PIO = modm::platform::Pio0;
+	using PIO_SM = PIO::StateMachine<0>;
+	using DataGpio = modm::platform::GpioOutput23;
+};
+
+static inline void write(uint32_t d) {
+	while (HW::PIO_SM::txFifoFull()) {__NOP();}
+	HW::PIO_SM::write(d << 8);
+}
+
+int
+main()
+{
+
+
+	Board::initialize();
+
+	HW::DataGpio::setOutput(Gpio::OutputType::PushPull, Gpio::SlewRate::Fast);
+	HW::DataGpio::setDriveStrength(Gpio::DriveStrength::mA_12);
+
+	auto pio_prog_offset = HW::PIO::addProgram(pio_prog);
+
+	HW::PIO::connect<HW::DataGpio::Pad>();
+
+	HW::PIO_SM::addOutput<HW::DataGpio>();
+
+	HW::PIO_SM::config()
+		.setup(pio_prog_offset,pio_prog)
+		.setSidesetPins<HW::DataGpio,1,false,false>()
+		.setFifoJoinTx()
+		.setOutShift<false,true,24>()
+		.setFrequency<Board::SystemClock,1000000000/TimeScale>()
+		.init(pio_prog_offset+pio_prog.getOffset<bitloop>());
+
+	HW::PIO_SM::setEnabled(true);
+
+	constexpr auto delay_val = 5ms;
+
+	while (true)
+	{
+		uint32_t clr = 0;
+		while (clr!=0xff0000) {
+			clr = clr + 0x010000;
+			write(clr);
+			modm::delay(delay_val);
+		}
+		while (clr!=0x000000) {
+			clr = clr - 0x010000;
+			write(clr);
+			modm::delay(delay_val);
+		}
+		while (clr!=0x00ff00) {
+			clr = clr + 0x000100;
+			write(clr);
+			modm::delay(delay_val);
+		}
+		while (clr!=0x000000) {
+			clr = clr - 0x000100;
+			write(clr);
+			modm::delay(delay_val);
+		}
+		while (clr!=0x0000ff) {
+			clr = clr + 0x000001;
+			write(clr);
+			modm::delay(delay_val);
+		}
+		while (clr!=0x000000) {
+			clr = clr - 0x000001;
+			write(clr);
+			modm::delay(delay_val);
+		}
+
+	}
+
+	return 0;
+}

examples/rp_pico/pio_ws2812/project.xml

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+<library>
+  <extends>modm:rp-pico</extends>
+  <options>
+    <option name="modm:build:build.path">../../../build/rp_pico/pio_ws2812</option>
+  </options>
+  <modules>
+    <module>modm:build:scons</module>
+    <module>modm:platform:pio:0</module>
+  </modules>
+</library>

src/modm/platform/pio/rp/module.lb

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+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2024, Andrey Kunitsyn
+#
+# This file is part of the modm project.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+# -----------------------------------------------------------------------------
+
+
+class Instance(Module):
+    def __init__(self, instance):
+        self.instance = instance
+
+    def init(self, module):
+        module.name = str(self.instance)
+        module.description = "PIO {} instance".format(self.instance)
+
+    def prepare(self, module, options):
+        return True
+
+    def build(self, env):
+        properties = {
+            "id": self.instance,
+        }
+        env.substitutions = properties
+        env.outbasepath = "modm/src/modm/platform/pio"
+
+        env.template("pio.hpp.in", "pio_{}.hpp".format(self.instance))
+        env.template("pio.cpp.in", "pio_{}.cpp".format(self.instance))
+
+
+
+def init(module):
+    module.name = ":platform:pio"
+    module.description = "Programmable IO block (PIO)"
+
+def prepare(module, options):
+    device = options[":target"]
+    if not device.has_driver("pio:rp*"):
+        return False
+
+    module.depends(
+        ":platform:gpio",
+        ":platform:clockgen",
+        ":architecture:interrupt")
+
+    for instance in listify(device.get_driver("pio")["instance"]):
+        module.add_submodule(Instance(instance))
+
+    return True
+
+def build(env):
+    env.outbasepath = "modm/src/modm/platform/pio"
+    env.copy("pio_asm.hpp")
+    env.copy("pio_program.hpp")
+    env.copy("pio_sm.hpp")
+    pass

src/modm/platform/pio/rp/pio.cpp.in

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+/*
+ * Copyright (c) 2022, Andrey Kunitsyn
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+// ----------------------------------------------------------------------------
+
+#include <modm/architecture/driver/atomic/queue.hpp>
+#include <modm/architecture/interface/atomic_lock.hpp>
+#include <modm/architecture/interface/interrupt.hpp>
+#include <modm/platform/core/resets.hpp>
+
+#include "../device.hpp"
+
+#include "pio_{{ id }}.hpp"
+
+// ----------------------------------------------------------------------------
+
+namespace modm::platform
+{
+    uint32_t Pio{{ id }}::used_instruction_space = 0;
+}
+
+
+
+// ----------------------------------------------------------------------------
+MODM_ISR(PIO{{ id }}_IRQ_0)
+{
+
+}
+
+MODM_ISR(PIO{{ id }}_IRQ_1)
+{
+
+}

src/modm/platform/pio/rp/pio.hpp.in

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+/*
+ * Copyright (c) 2022, Andrey Kunitsyn
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+// ----------------------------------------------------------------------------
+
+#pragma once
+
+#include <modm/architecture/interface/peripheral.hpp>
+#include <modm/platform/core/peripherals.hpp>
+#include <modm/platform/gpio/connector.hpp>
+#include <modm/math/algorithm/prescaler.hpp>
+
+#include "pio_program.hpp"
+#include "pio_sm.hpp"
+#include <hardware/structs/pio.h>
+
+namespace modm::platform
+{
+
+
+    /**
+     * Programmable IO block (PIO)
+     *
+     * @ingroup	modm_platform_pio
+     * @author		Andrey Kunitsyn
+     */
+    class Pio{{ id }} : public ::modm::PeripheralDriver
+    {
+    	static inline pio_hw_t& pio() { return *pio{{ id }}_hw; }
+
+        static uint32_t used_instruction_space;
+        static int findOffset(const PIOProgram& prg) {
+            uint32_t program_mask = (1u << prg.length) - 1;
+            if (prg.origin >= 0) {
+                if (prg.origin > 32 - prg.length) return -1;
+                return used_instruction_space & (program_mask << prg.origin) ? -1 : prg.origin;
+            } else {
+                // work down from the top always
+                for (int i = 32 - prg.length; i >= 0; i--) {
+                    if ((used_instruction_space & (program_mask << static_cast<unsigned int>(i)))==0) {
+                        return i;
+                    }
+                }
+                return -1;
+            }
+        }
+        static void addProgramAtOffset(size_t offset,const PIOProgram& prg) {
+            for (uint8_t i = 0; i < prg.length; ++i) {
+                auto& instr = prg.instructions[i];
+                pio().instr_mem[offset + i] = instr.store(offset);
+            }
+            uint32_t program_mask = (1u << prg.length) - 1;
+            used_instruction_space |= program_mask << offset;
+        }
+
+        template <typename Pio,size_t SM>
+        friend class pio::StateMachine;
+
+    public:
+        static constexpr Peripheral peripherial = Peripheral::Pio{{ id }};
+        template <size_t SM>
+        class StateMachine : public modm::platform::pio::StateMachine<Pio{{ id }},SM> {};
+
+        template< class... Signals >
+        static void
+        connect()
+        {
+            using Connector = GpioConnector<peripherial, Signals...>;
+            Connector::connect();
+        }
+
+        template< class Pin >
+        static void connectPin() {
+            using Connector = GpioConnector<peripherial, typename Pin::Pad>;
+            Connector::connect();
+        }
+
+        template <typename Program>
+        static size_t addProgram(const Program& prg_data) {
+            auto prg = PIOProgram::get(prg_data);
+            auto offset = findOffset(prg);
+            if (offset < 0) {
+                return offset;
+            }
+            auto res = static_cast<size_t>(offset);
+            addProgramAtOffset(res,prg);
+            return res;
+        }
+    };
+
+}	// namespace modm::platform
+