add linuxJoystick input module (#10970)

* add linuxJoystick input module

* close epollfd to avoid leaks

bin/config-dist.yaml

@@ -173,6 +173,16 @@ Input:
 
 #  KeyboardDevice: /dev/input/by-id/usb-_Raspberry_Pi_Internal_Keyboard-event-kbd
 
+### Configure device for USB gamepad/joystick input (evdev). The D-pad drives
+### Up/Down/Left/Right; buttons are mapped below. Find button codes with `evtest`.
+#  JoystickDevice: /dev/input/by-id/usb-0079_USB_Gamepad-event-joystick
+### Map evdev button codes (hex or decimal) to actions. Omit to use built-in
+### defaults (select=0x121, cancel=0x122). Actions: select, cancel, back, up,
+### down, left, right, user.
+#  JoystickButtons:
+#    select: 0x122
+#    cancel: 0x121
+
 ### Standard User Button Config
 #  UserButton: 6
 
@@ -199,13 +209,11 @@ Webserver:
 #  SSLKey: /etc/meshtasticd/ssl/private_key.pem # Path to SSL Key, generated if not present
 #  SSLCert: /etc/meshtasticd/ssl/certificate.pem # Path to SSL Certificate, generated if not present
 
-
 HostMetrics:
 #  ReportInterval: 30 # Interval in minutes between HostMetrics report packets, or 0 for disabled
 #  Channel: 0 # channel to send Host Metrics over. Defaults to the primary channel.
 #  UserStringCommand: cat /sys/firmware/devicetree/base/serial-number # Command to execute, to send the results as the userString
 
-
 Config:
 #  DisplayMode: TWOCOLOR # uncomment to force BaseUI
 #  DisplayMode: COLOR # uncomment to force MUI

src/Power.cpp

@@ -37,6 +37,7 @@
 #if defined(ARCH_PORTDUINO)
 #include "api/WiFiServerAPI.h"
 #include "input/LinuxInputImpl.h"
+#include "input/LinuxJoystick.h"
 #endif
 
 // Working USB detection for powered/charging states on the RAK platform
@@ -860,6 +861,8 @@ void Power::reboot()
 #ifdef __linux__
     if (aLinuxInputImpl)
         aLinuxInputImpl->deInit();
+    if (aLinuxJoystick)
+        aLinuxJoystick->deInit();
 #endif
     SPI.end();
     Wire.end();

src/input/InputBroker.cpp

@@ -10,6 +10,7 @@
 
 #if ARCH_PORTDUINO
 #include "input/LinuxInputImpl.h"
+#include "input/LinuxJoystick.h"
 #include "input/SeesawRotary.h"
 #include "platform/portduino/PortduinoGlue.h"
 #endif
@@ -430,6 +431,9 @@ void InputBroker::Init()
         // Linux evdev keyboard input only - macOS has no <linux/input.h>.
         aLinuxInputImpl = new LinuxInputImpl();
         aLinuxInputImpl->init();
+        // Linux evdev gamepad/joystick input (D-pad + confirm/cancel buttons).
+        aLinuxJoystick = new LinuxJoystick("LinuxJoystick");
+        aLinuxJoystick->init();
 #endif
     }
 #endif

src/input/LinuxInput.cpp

@@ -25,8 +25,14 @@ LinuxInput::LinuxInput(const char *name) : concurrency::OSThread(name)
 
 void LinuxInput::deInit()
 {
+    // reboot() on native does execv() in-place, which only closes O_CLOEXEC fds.
+    // Close both descriptors here so we don't leak one per restart.
     if (fd >= 0)
         close(fd);
+    if (epollfd >= 0)
+        close(epollfd);
+    fd = -1;
+    epollfd = -1;
 }
 
 int32_t LinuxInput::runOnce()
@@ -35,14 +41,14 @@ int32_t LinuxInput::runOnce()
     if (firstTime) {
         if (portduino_config.keyboardDevice == "")
             return disable();
-        fd = open(portduino_config.keyboardDevice.c_str(), O_RDWR);
+        fd = open(portduino_config.keyboardDevice.c_str(), O_RDWR | O_CLOEXEC);
         if (fd < 0)
             return disable();
         ret = ioctl(fd, EVIOCGRAB, (void *)1);
         if (ret != 0)
             return disable();
 
-        epollfd = epoll_create1(0);
+        epollfd = epoll_create1(EPOLL_CLOEXEC);
         assert(epollfd >= 0);
 
         ev.events = EPOLLIN;

src/input/LinuxInput.h

@@ -44,7 +44,7 @@ class LinuxInput : public Observable<const InputEvent *>, public concurrency::OS
     int fd = -1;
     int ret;
     uint8_t report[8];
-    int epollfd;
+    int epollfd = -1;
     struct epoll_event ev;
     uint8_t modifiers = 0;
     std::map<int, char> keymap{

src/input/LinuxJoystick.cpp

@@ -0,0 +1,159 @@
+#include "configuration.h"
+#if ARCH_PORTDUINO && defined(__linux__)
+#include "InputBroker.h"
+#include "LinuxJoystick.h"
+#include "platform/portduino/PortduinoGlue.h"
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+LinuxJoystick *aLinuxJoystick;
+
+LinuxJoystick::LinuxJoystick(const char *name) : concurrency::OSThread(name)
+{
+    this->_originName = name;
+}
+
+// Translate a config.yaml action name into a broker event. Returns INPUT_BROKER_NONE
+// for unknown names so a typo simply leaves that button unmapped.
+static input_broker_event joystickActionToEvent(const std::string &action)
+{
+    if (action == "select")
+        return INPUT_BROKER_SELECT;
+    if (action == "cancel")
+        return INPUT_BROKER_CANCEL;
+    if (action == "back")
+        return INPUT_BROKER_BACK;
+    if (action == "up")
+        return INPUT_BROKER_UP;
+    if (action == "down")
+        return INPUT_BROKER_DOWN;
+    if (action == "left")
+        return INPUT_BROKER_LEFT;
+    if (action == "right")
+        return INPUT_BROKER_RIGHT;
+    if (action == "user" || action == "userpress")
+        return INPUT_BROKER_USER_PRESS;
+    return INPUT_BROKER_NONE;
+}
+
+void LinuxJoystick::init()
+{
+    if (portduino_config.joystickButtons.empty()) {
+        // No config override: fall back to the built-in defaults.
+        buttonMap[JOY_BTN_A] = INPUT_BROKER_SELECT;
+        buttonMap[JOY_BTN_B] = INPUT_BROKER_CANCEL;
+    } else {
+        for (const auto &button : portduino_config.joystickButtons) {
+            input_broker_event event = joystickActionToEvent(button.second);
+            if (event != INPUT_BROKER_NONE)
+                buttonMap[button.first] = event;
+        }
+    }
+    inputBroker->registerSource(this);
+}
+
+void LinuxJoystick::deInit()
+{
+    // reboot() on native does execv() in-place, which only closes O_CLOEXEC fds.
+    // Close both descriptors here so we don't leak one per restart.
+    if (fd >= 0)
+        close(fd);
+    if (epollfd >= 0)
+        close(epollfd);
+    fd = -1;
+    epollfd = -1;
+}
+
+// Bucket a raw axis value into a direction zone: -1 (min edge), 0 (center), +1 (max edge).
+static int axisZone(int value)
+{
+    if (value <= JOY_AXIS_LOW)
+        return -1;
+    if (value >= JOY_AXIS_HIGH)
+        return 1;
+    return 0;
+}
+
+int32_t LinuxJoystick::runOnce()
+{
+    if (firstTime) {
+        if (portduino_config.joystickDevice == "")
+            return disable();
+        fd = open(portduino_config.joystickDevice.c_str(), O_RDWR | O_CLOEXEC);
+        if (fd < 0)
+            return disable();
+        if (ioctl(fd, EVIOCGRAB, (void *)1) != 0)
+            return disable();
+
+        epollfd = epoll_create1(EPOLL_CLOEXEC);
+        assert(epollfd >= 0);
+
+        ev.events = EPOLLIN;
+        ev.data.fd = fd;
+        if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev)) {
+            perror("joystick: unable to epoll add");
+            return disable();
+        }
+        // This is the first time the OSThread library has called this function, so do port setup
+        firstTime = false;
+    }
+
+    int nfds = epoll_wait(epollfd, events, JOY_MAX_EVENTS, 1);
+    if (nfds < 0) {
+        perror("joystick: epoll_wait failed");
+        return disable();
+    } else if (nfds == 0) {
+        return 50;
+    }
+
+    for (int i = 0; i < nfds; i++) {
+        struct input_event evs[64];
+        int rd = read(events[i].data.fd, evs, sizeof(evs));
+        if (rd < (signed int)sizeof(struct input_event))
+            continue;
+        for (int j = 0; j < rd / ((signed int)sizeof(struct input_event)); j++) {
+            InputEvent e = {};
+            e.inputEvent = INPUT_BROKER_NONE;
+            e.source = this->_originName;
+            e.kbchar = 0;
+            unsigned int type = evs[j].type;
+            unsigned int code = evs[j].code;
+            int value = evs[j].value;
+
+            if (type == EV_ABS) {
+                // D-pad reports as ABS_X / ABS_Y with digital 0 / 127 / 255 values.
+                // Emit exactly once when an axis crosses from center to an edge.
+                if (code == ABS_X) {
+                    int zone = axisZone(value);
+                    if (zone != axisZone(lastX) && zone != 0)
+                        e.inputEvent = (zone < 0) ? INPUT_BROKER_LEFT : INPUT_BROKER_RIGHT;
+                    lastX = value;
+                } else if (code == ABS_Y) {
+                    int zone = axisZone(value);
+                    if (zone != axisZone(lastY) && zone != 0)
+                        e.inputEvent = (zone < 0) ? INPUT_BROKER_UP : INPUT_BROKER_DOWN;
+                    lastY = value;
+                }
+            } else if (type == EV_KEY && value == 1) {
+                // Look up the configured action for this button; unmapped buttons are ignored.
+                auto mapped = buttonMap.find(code);
+                if (mapped != buttonMap.end())
+                    e.inputEvent = mapped->second;
+            }
+
+            if (e.inputEvent != INPUT_BROKER_NONE) {
+                LOG_DEBUG("joystick: %s event %d", this->_originName, e.inputEvent);
+                this->notifyObservers(&e);
+            }
+        }
+    }
+
+    return 50; // Poll every 50msec
+}
+
+#endif

src/input/LinuxJoystick.h

@@ -0,0 +1,51 @@
+#pragma once
+// Linux evdev gamepad/joystick input. Only compiled on Linux portduino targets;
+// macOS / non-Linux builds have no <linux/input.h> or epoll. Unlike LinuxInput
+// (keyboard, EV_KEY only) this decodes the D-pad from EV_ABS axes as well.
+#if ARCH_PORTDUINO && defined(__linux__)
+#include "InputBroker.h"
+#include "concurrency/OSThread.h"
+#include <linux/input.h>
+#include <map>
+#include <stdint.h>
+#include <sys/epoll.h>
+
+#define JOY_MAX_EVENTS 10
+
+// Default button map when config.yaml has no [Input] JoystickButtons override.
+// Codes confirmed by evdev capture on a 0079:0011 "USB Gamepad".
+#define JOY_BTN_A BTN_THUMB  // 0x121 -> INPUT_BROKER_SELECT
+#define JOY_BTN_B BTN_THUMB2 // 0x122 -> INPUT_BROKER_CANCEL
+#define JOY_AXIS_CENTER 127  // D-pad resting value
+#define JOY_AXIS_LOW 64      // below this -> "min" edge (0)
+#define JOY_AXIS_HIGH 192    // above this -> "max" edge (255)
+
+class LinuxJoystick : public Observable<const InputEvent *>, public concurrency::OSThread
+{
+  public:
+    explicit LinuxJoystick(const char *name);
+    void init();   // Registers this source with the InputBroker
+    void deInit(); // Strictly for cleanly "rebooting" the binary on native
+
+  protected:
+    virtual int32_t runOnce() override;
+
+  private:
+    const char *_originName;
+    bool firstTime = true;
+
+    // evdev button code -> broker event, built from config (or defaults) in init().
+    std::map<int, input_broker_event> buttonMap;
+
+    struct epoll_event events[JOY_MAX_EVENTS];
+    struct epoll_event ev;
+    int fd = -1;
+    int epollfd = -1;
+
+    // Latch the last emitted axis position so a held direction fires exactly
+    // once (on the transition away from center), not a continuous stream.
+    int lastX = JOY_AXIS_CENTER;
+    int lastY = JOY_AXIS_CENTER;
+};
+extern LinuxJoystick *aLinuxJoystick;
+#endif

src/platform/portduino/PortduinoGlue.cpp

@@ -1038,6 +1038,25 @@ bool loadConfig(const char *configPath)
         if (yamlConfig["Input"]) {
             portduino_config.keyboardDevice = (yamlConfig["Input"]["KeyboardDevice"]).as<std::string>("");
             portduino_config.pointerDevice = (yamlConfig["Input"]["PointerDevice"]).as<std::string>("");
+            portduino_config.joystickDevice = (yamlConfig["Input"]["JoystickDevice"]).as<std::string>("");
+            if (yamlConfig["Input"]["JoystickButtons"]) {
+                // action name -> evdev button code (hex like 0x122 or decimal); stored inverted
+                // as code -> lowercase action name for the driver to look up per keypress.
+                for (const auto &button : yamlConfig["Input"]["JoystickButtons"]) {
+                    std::string action = button.first.as<std::string>("");
+                    for (auto &c : action)
+                        c = tolower(c);
+                    int code = 0;
+                    try {
+                        // base 0 accepts hex (0x122) or decimal; a malformed value just skips this entry.
+                        code = std::stoi(button.second.as<std::string>(""), nullptr, 0);
+                    } catch (const std::exception &) {
+                        code = 0;
+                    }
+                    if (code != 0 && action != "")
+                        portduino_config.joystickButtons[code] = action;
+                }
+            }
 
             readGPIOFromYaml(yamlConfig["Input"]["User"], portduino_config.userButtonPin);
             readGPIOFromYaml(yamlConfig["Input"]["TrackballUp"], portduino_config.tbUpPin);

src/platform/portduino/PortduinoGlue.h

@@ -160,6 +160,11 @@ extern struct portduino_config_struct {
     // Input
     std::string keyboardDevice = "";
     std::string pointerDevice = "";
+    std::string joystickDevice = "";
+    // Joystick/gamepad button map: evdev button code -> lowercase action name
+    // ("select", "cancel", "back", "up", "down", "left", "right", "user").
+    // Empty means the LinuxJoystick driver uses its built-in defaults.
+    std::map<int, std::string> joystickButtons;
     int tbDirection;
     pinMapping userButtonPin = {"Input", "User"};
     pinMapping tbUpPin = {"Input", "TrackballUp"};
@@ -458,6 +463,14 @@ extern struct portduino_config_struct {
             out << YAML::Key << "KeyboardDevice" << YAML::Value << keyboardDevice;
         if (pointerDevice != "")
             out << YAML::Key << "PointerDevice" << YAML::Value << pointerDevice;
+        if (joystickDevice != "")
+            out << YAML::Key << "JoystickDevice" << YAML::Value << joystickDevice;
+        if (!joystickButtons.empty()) {
+            out << YAML::Key << "JoystickButtons" << YAML::Value << YAML::BeginMap;
+            for (const auto &button : joystickButtons)
+                out << YAML::Key << button.second << YAML::Value << button.first;
+            out << YAML::EndMap;
+        }
 
         for (const auto *input_pin : all_pins) {
             if (input_pin->config_section == "Input" && input_pin->enabled) {