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package com.diozero.internal.board.raspberrypi;

/*
 * #%L
 * Organisation: diozero
 * Project:      Device I/O Zero - Core
 * Filename:     RaspberryPiMmapGpio.java  
 * 
 * This file is part of the diozero project. More information about this project
 * can be found at http://www.diozero.com/
 * %%
 * Copyright (C) 2016 - 2021 diozero
 * %%
 * 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.
 * #L%
 */

import java.nio.ByteOrder;

import com.diozero.api.DeviceMode;
import com.diozero.api.GpioPullUpDown;
import com.diozero.internal.spi.MmapGpioInterface;
import com.diozero.util.MmapIntBuffer;
import com.diozero.util.SleepUtil;

@SuppressWarnings("unused")
public class RaspberryPiMmapGpio implements MmapGpioInterface {
	// #define GPIO_BASE  (pi_peri_phys + 0x00200000)
	// #define PCM_BASE   (pi_peri_phys + 0x00203000)
	// #define SPI_BASE   (pi_peri_phys + 0x00204000)
	// #define PWM_BASE   (pi_peri_phys + 0x0020C000)
	
	private static final String GPIOMEM_DEVICE = "/dev/gpiomem";
	// private static final int GPIOMEM_LEN = 0xB4;
	private static final int GPIOMEM_LEN = 4096;

	// From BCM2835 data-sheet, p.91
	private static final byte GPFSEL_OFFSET = 0x00 >> 2;
	private static final byte GPSET_OFFSET = 0x1c >> 2;
	private static final byte GPCLR_OFFSET = 0x28 >> 2;
	private static final byte GPLEV_OFFSET = 0x34 >> 2;
	private static final byte GPEDS_OFFSET = 0x40 >> 2;
	private static final byte GPREN_OFFSET = 0x4c >> 2;
	private static final byte GPFEN_OFFSET = 0x58 >> 2;
	private static final byte GPHEN_OFFSET = 0x64 >> 2;
	private static final byte GPLEN_OFFSET = 0x70 >> 2;
	private static final byte GPAREN_OFFSET = 0x7c >> 2;
	private static final byte GPAFEN_OFFSET = 0x88 >> 2;
	private static final byte GPPUD_OFFSET = 0x94 >> 2;
	private static final byte GPPUDCLK_OFFSET = 0x98 >> 2;

	// Offset to the GPIO Set registers for each GPIO pin
	private static final byte[] GPIO_TO_GPSET = { 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
			7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
			8, 8, 8, 8, 8 };
	// Offset to the GPIO Clear registers for each GPIO pin
	private static final byte[] GPIO_TO_GPCLR = { 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
			10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
			11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11 };
	// Offset to the GPIO Input level registers for each GPIO pin
	private static final byte[] GPIO_TO_GPLEV = { 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
			13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
			14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14 };

	/* BCM2711 has different pulls */
	private static final int GPPUPPDN0 = 57;
	private static final int GPPUPPDN1 = 58;
	private static final int GPPUPPDN2 = 59;
	private static final int GPPUPPDN3 = 60;

	// GPIO Pin pull up/down register
	private static final byte GPPUD = 37;
	// Offset to the Pull Up Down Clock register
	private static byte[] GPIO_TO_PUDCLK = { 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38,
			38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39,
			39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39, 39 };

	private static final int PI_2711_PUD_OFF = 0;
	private static final int PI_2711_PUD_DOWN = 2;
	private static final int PI_2711_PUD_UP = 1;

	private static final int PI_28XX_PUD_OFF = 0;
	private static final int PI_28XX_PUD_DOWN = 1;
	private static final int PI_28XX_PUD_UP = 2;

	private boolean initialised;
	private boolean piIs2711;
	private MmapIntBuffer mmapIntBuffer;

	public RaspberryPiMmapGpio(boolean piIs2711) {
		this.piIs2711 = piIs2711;
	}

	@Override
	public synchronized void initialise() {
		if (!initialised) {
			// Note /dev/gpiomem device ignores any offset and always grants access to the
			// GPIO register area
			mmapIntBuffer = new MmapIntBuffer(GPIOMEM_DEVICE, 0, GPIOMEM_LEN, ByteOrder.LITTLE_ENDIAN);

			initialised = true;
		}
	}

	@Override
	public synchronized void close() {
		if (initialised) {
			mmapIntBuffer.close();
			mmapIntBuffer = null;
		}
	}

	/**
	 * Returns the function of a GPIO: 0=input, 1=output, 4=alt0
	 * 
	 * @param gpio GPIO number
	 * @return GPIO mode (0 - INPUT, 1 - OUTPUT)
	 */
	@Override
	public DeviceMode getMode(int gpio) {
		int reg = gpio / 10;
		int shift = (gpio % 10) * 3;

		switch (mmapIntBuffer.getShiftRight(reg, shift, 7)) {
		case 0:
			return DeviceMode.DIGITAL_INPUT;
		case 1:
			return DeviceMode.DIGITAL_OUTPUT;
		default:
			return DeviceMode.UNKNOWN;
		}
	}

	@Override
	public void setMode(int gpio, DeviceMode mode) {
		int reg = gpio / 10;
		int shift = (gpio % 10) * 3;

		/*-
		 * Pi modes:
		 * #define PI_INPUT  0
		 * #define PI_OUTPUT 1
		 * #define PI_ALT0   4
		 * #define PI_ALT1   5
		 * #define PI_ALT2   6
		 * #define PI_ALT3   7
		 * #define PI_ALT4   3
		 * #define PI_ALT5   2
		 */
		switch (mode) {
		case DIGITAL_INPUT:
			mmapIntBuffer.put(reg, mmapIntBuffer.get(reg) & ~(7 << shift));
			break;
		case DIGITAL_OUTPUT:
			mmapIntBuffer.put(reg, mmapIntBuffer.get(reg) & ~(7 << shift) | (1 << shift));
			break;
		default:
			throw new IllegalArgumentException("Invalid GPIO mode " + mode + " for pin " + gpio);
		}
	}

	@Override
	public void setPullUpDown(int gpio, GpioPullUpDown pud) {
		// See pigpio: https://github.com/joan2937/pigpio/blob/master/pigpio.c#L8880
		int shift = (gpio & 0xf) << 1;

		if (piIs2711) {
			int pull;
			switch (pud) {
			case PULL_UP:
				pull = PI_2711_PUD_UP;
				break;
			case PULL_DOWN:
				pull = PI_2711_PUD_DOWN;
				break;
			case NONE:
			default:
				pull = PI_2711_PUD_OFF;
				break;
			}

			/*-
			 * 
			bits = *(gpioReg + GPPUPPDN0 + (gpio>>4));
			bits &= ~(3 << shift);
			bits |= (pull << shift);
			*(gpioReg + GPPUPPDN0 + (gpio>>4)) = bits;
			*/
			int bits = mmapIntBuffer.get(GPPUPPDN0 + (gpio >> 4));
			bits &= ~(3 << shift);
			bits |= (pull << shift);
			mmapIntBuffer.put(GPPUPPDN0 + (gpio >> 4), bits);
		} else {
			int pull;
			switch (pud) {
			case PULL_UP:
				pull = PI_28XX_PUD_UP;
				break;
			case PULL_DOWN:
				pull = PI_28XX_PUD_DOWN;
				break;
			case NONE:
			default:
				pull = PI_28XX_PUD_OFF;
				break;
			}

			/*-
			#define BANK (gpio >> 5)
			#define BIT  (1 << (gpio & 0x1F))
			*(gpioReg + GPPUD) = pud;
			myGpioDelay(1);
			*(gpioReg + GPPUDCLK0 + BANK) = BIT;
			myGpioDelay(1);
			*(gpioReg + GPPUD) = 0;
			*(gpioReg + GPPUDCLK0 + BANK) = 0;
			*/
			mmapIntBuffer.put(GPPUD, pull);
			SleepUtil.busySleep(1_000);
			mmapIntBuffer.put(GPIO_TO_PUDCLK[gpio], 1 << (gpio & 0x1F));
			SleepUtil.busySleep(1_000);
			mmapIntBuffer.put(GPPUD, 0);
			mmapIntBuffer.put(GPIO_TO_PUDCLK[gpio], 0);
		}
	}

	@Override
	public boolean gpioRead(int gpio) {
		// return (gpioReg.get(GPLEV0 + (gpio >> 5)) & (1 << (gpio & 0x1F))) != 0;
		// return (mmapIntBuffer.get(GPIO_TO_GPLEV[gpio]) & (1 << (gpio & 0x1F))) != 0;
		return mmapIntBuffer.get(GPIO_TO_GPLEV[gpio], 1 << (gpio & 0x1F)) != 0;
	}

	@Override
	public void gpioWrite(int gpio, boolean value) {
		if (value) {
			// pigpio
			// gpioReg.put(GPSET0 + gpio >> 5, 1 << (gpio & 0x1F));
			// wiringPi
			mmapIntBuffer.put(GPIO_TO_GPSET[gpio], 1 << (gpio & 0x1F));
		} else {
			// pigpio
			// gpioReg.put(GPCLR0 + gpio >> 5, 1 << (gpio & 0x1F));
			// wiringPi
			mmapIntBuffer.put(GPIO_TO_GPCLR[gpio], 1 << (gpio & 0x1F));
		}
	}

	@SuppressWarnings("boxing")
	public static void main(String[] args) {
		boolean PI_OFF = false;
		boolean PI_ON = true;

		try (RaspberryPiMmapGpio mmap = new RaspberryPiMmapGpio(false)) {
			mmap.initialise();

			int gpio = 12;
			for (int i = 0; i < 10; i++) {
				mmap.setMode(gpio, DeviceMode.DIGITAL_INPUT);
				System.out.format("Mode for GPIO# %d: %s, value: %b. (Mode should be %s)%n", gpio, mmap.getMode(gpio),
						mmap.gpioRead(gpio), DeviceMode.DIGITAL_INPUT);
				mmap.setMode(gpio, DeviceMode.DIGITAL_OUTPUT);
				System.out.format("Mode for GPIO# %d: %s, value: %b. (Mode should be %s)%n", gpio, mmap.getMode(gpio),
						mmap.gpioRead(gpio), DeviceMode.DIGITAL_OUTPUT);
				mmap.gpioWrite(gpio, PI_ON);
				System.out.format("Mode for GPIO# %d: %s, value: %b. (Value should be %b)%n", gpio, mmap.getMode(gpio),
						mmap.gpioRead(gpio), PI_ON);
				SleepUtil.sleepSeconds(1);
				mmap.gpioWrite(gpio, PI_OFF);
				System.out.format("Mode for GPIO# %d: %s, value: %b. (Value should be %b)%n", gpio, mmap.getMode(gpio),
						mmap.gpioRead(gpio), PI_OFF);
				SleepUtil.sleepSeconds(1);
			}
		}
	}
}




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