Merge pull request #2681 from phire/evdev-stable

Linux: Add an evdev based controller backend, to replace SDL.

1 files changed, 270 insertions, 0 deletions

diff --git a/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp b/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp
new file mode 100644
index 0000000000..9b31da73c4
--- /dev/null
+++ b/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp
@@ -0,0 +1,270 @@
+// Copyright 2015 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <libudev.h>
+#include <unistd.h>
+
+#include "Common/Logging/Log.h"
+#include "InputCommon/ControllerInterface/evdev/evdev.h"
+
+
+namespace ciface
+{
+namespace evdev
+{
+
+void Init(std::vector<Core::Device*> &controllerDevices)
+{
+	int num_controllers = 0;
+
+	// We use Udev to find any devices. In the future this will allow for hotplugging.
+	// But for now it is essentially iterating over /dev/input/event0 to event31. However if the
+	// naming scheme is ever updated in the future, this *should* be forwards compatable.
+
+	struct udev* udev = udev_new();
+	_assert_msg_(PAD, udev != 0, "Couldn't initilize libudev.");
+
+	// List all input devices
+	udev_enumerate* enumerate = udev_enumerate_new(udev);
+	udev_enumerate_add_match_subsystem(enumerate, "input");
+	udev_enumerate_scan_devices(enumerate);
+	udev_list_entry* devices = udev_enumerate_get_list_entry(enumerate);
+
+	// Iterate over all input devices
+	udev_list_entry* dev_list_entry;
+	udev_list_entry_foreach(dev_list_entry, devices)
+	{
+		const char* path = udev_list_entry_get_name(dev_list_entry);
+
+		udev_device* dev = udev_device_new_from_syspath(udev, path);
+
+		const char* devnode = udev_device_get_devnode(dev);
+		// We only care about devices which we have read/write access to.
+		if (access(devnode, W_OK) == 0)
+		{
+			// Unfortunately udev gives us no way to filter out the non event device interfaces.
+			// So we open it and see if it works with evdev ioctls or not.
+			evdevDevice* input = new evdevDevice(devnode, num_controllers);
+
+			if (input->IsInteresting())
+			{
+				controllerDevices.push_back(input);
+				num_controllers++;
+			}
+			else
+			{
+				// Either it wasn't a evdev device, or it didn't have at least 8 buttons or two axis.
+				delete input;
+			}
+		}
+		udev_device_unref(dev);
+	}
+	udev_enumerate_unref(enumerate);
+	udev_unref(udev);
+}
+
+evdevDevice::evdevDevice(const std::string &devnode, int id) : m_devfile(devnode), m_id(id)
+{
+	// The device file will be read on one of the main threads, so we open in non-blocking mode.
+	m_fd = open(devnode.c_str(), O_RDWR|O_NONBLOCK);
+	int ret = libevdev_new_from_fd(m_fd, &m_dev);
+
+	if (ret != 0)
+	{
+		// This useally fails because the device node isn't an evdev device, such as /dev/input/js0
+		m_initialized = false;
+		close(m_fd);
+		return;
+	}
+
+	m_name = libevdev_get_name(m_dev);
+
+	// Controller buttons (and keyboard keys)
+	int num_buttons = 0;
+	for (int key = 0; key < KEY_MAX; key++)
+		if (libevdev_has_event_code(m_dev, EV_KEY, key))
+			AddInput(new Button(num_buttons++, key, m_dev));
+
+	// Absolute axis (thumbsticks)
+	int num_axis = 0;
+	for (int axis = 0; axis < 0x100; axis++)
+		if (libevdev_has_event_code(m_dev, EV_ABS, axis))
+		{
+			AddAnalogInputs(new Axis(num_axis, axis, false, m_dev),
+			                new Axis(num_axis, axis, true, m_dev));
+			num_axis++;
+		}
+
+	// Force feedback
+	if (libevdev_has_event_code(m_dev, EV_FF, FF_PERIODIC))
+	{
+		for (auto type : {FF_SINE, FF_SQUARE, FF_TRIANGLE, FF_SAW_UP, FF_SAW_DOWN})
+			if (libevdev_has_event_code(m_dev, EV_FF, type))
+				AddOutput(new ForceFeedback(type, m_dev));
+	}
+	if (libevdev_has_event_code(m_dev, EV_FF, FF_RUMBLE))
+	{
+		AddOutput(new ForceFeedback(FF_RUMBLE, m_dev));
+	}
+
+	// TODO: Add leds as output devices
+
+	m_initialized = true;
+	m_interesting = num_axis >= 2 || num_buttons >= 8;
+}
+
+evdevDevice::~evdevDevice()
+{
+	if (m_initialized)
+	{
+		libevdev_free(m_dev);
+		close(m_fd);
+	}
+}
+
+void evdevDevice::UpdateInput()
+{
+	// Run through all evdev events
+	// libevdev will keep track of the actual controller state internally which can be queried
+	// later with libevdev_fetch_event_value()
+	input_event ev;
+	int rc = LIBEVDEV_READ_STATUS_SUCCESS;
+	do
+	{
+		if (rc == LIBEVDEV_READ_STATUS_SYNC)
+			rc = libevdev_next_event(m_dev, LIBEVDEV_READ_FLAG_SYNC, &ev);
+		else
+			rc = libevdev_next_event(m_dev, LIBEVDEV_READ_FLAG_NORMAL, &ev);
+	} while (rc >= 0);
+}
+
+
+std::string evdevDevice::Button::GetName() const
+{
+	// Buttons below 0x100 are mostly keyboard keys, and the names make sense
+	if (m_code < 0x100)
+	{
+		const char* name = libevdev_event_code_get_name(EV_KEY, m_code);
+		if (name)
+			return std::string(name);
+	}
+	// But controllers use codes above 0x100, and the standard label often doesn't match.
+	// We are better off with Button 0 and so on.
+	return "Button " + std::to_string(m_index);
+}
+
+ControlState evdevDevice::Button::GetState() const
+{
+	int value = 0;
+	libevdev_fetch_event_value(m_dev, EV_KEY, m_code, &value);
+	return value;
+}
+
+evdevDevice::Axis::Axis(u8 index, u16 code, bool upper, libevdev* dev) :
+	m_code(code), m_index(index), m_upper(upper), m_dev(dev)
+{
+	m_min = libevdev_get_abs_minimum(m_dev, m_code);
+	m_range = libevdev_get_abs_maximum(m_dev, m_code) + abs(m_min);
+}
+
+std::string evdevDevice::Axis::GetName() const
+{
+	return "Axis " + std::to_string(m_index) + (m_upper ? "+" : "-");
+}
+
+ControlState evdevDevice::Axis::GetState() const
+{
+	int value = 0;
+	libevdev_fetch_event_value(m_dev, EV_ABS, m_code, &value);
+
+	// Value from 0.0 to 1.0
+	ControlState fvalue = double(value - m_min) / double(m_range);
+
+	// Split into two axis, each covering half the range from 0.0 to 1.0
+	if (m_upper)
+		return std::max(0.0, fvalue - 0.5) * 2.0;
+	else
+		return (0.5 - std::min(0.5, fvalue)) * 2.0;
+}
+
+std::string evdevDevice::ForceFeedback::GetName() const
+{
+	// We have some default names.
+	switch (m_type)
+	{
+	case FF_SINE:
+		return "Sine";
+	case FF_TRIANGLE:
+		return "Triangle";
+	case FF_SQUARE:
+		return "Square";
+	case FF_RUMBLE:
+		return "LeftRight";
+	default:
+		{
+			const char* name = libevdev_event_code_get_name(EV_FF, m_type);
+			if (name)
+				return std::string(name);
+			return "Unknown";
+		}
+	}
+}
+
+void evdevDevice::ForceFeedback::SetState(ControlState state)
+{
+	// libevdev doesn't have nice helpers for forcefeedback
+	// we will use the file descriptors directly.
+
+	if (state > 0) // Upload and start an effect.
+	{
+		ff_effect effect;
+
+		effect.id = -1;
+		effect.direction = 0; // down
+		effect.replay.length = 500; // 500ms
+		effect.replay.delay = 0;
+		effect.trigger.button = 0; // don't trigger on button press
+		effect.trigger.interval = 0;
+
+		// This is the the interface that XInput uses, with 2 motors of differing sizes/frequencies that
+		// are controlled seperatally
+		if (m_type == FF_RUMBLE)
+		{
+			effect.type = FF_RUMBLE;
+			// max ranges tuned to 'feel' similar in magnitude to triangle/sine on xbox360 controller
+			effect.u.rumble.strong_magnitude = u16(state * 0x4000);
+			effect.u.rumble.weak_magnitude = u16(state * 0xFFFF);
+		}
+		else // FF_PERIODIC, a more generic interface.
+		{
+			effect.type = FF_PERIODIC;
+			effect.u.periodic.waveform = m_type;
+			effect.u.periodic.phase = 0x7fff; // 180 degrees
+			effect.u.periodic.offset = 0;
+			effect.u.periodic.period = 10;
+			effect.u.periodic.magnitude = s16(state * 0x7FFF);
+			effect.u.periodic.envelope.attack_length = 0; // no attack
+			effect.u.periodic.envelope.attack_level = 0;
+			effect.u.periodic.envelope.fade_length = 0;
+			effect.u.periodic.envelope.fade_level = 0;
+		}
+
+		ioctl(m_fd, EVIOCSFF, &effect);
+		m_id = effect.id;
+
+		input_event play;
+		play.type = EV_FF;
+		play.code = m_id;
+		play.value = 1;
+
+		write(m_fd, (const void*) &play, sizeof(play));
+	}
+	else if (m_id != -1)  // delete the effect (which also stops it)
+	{
+		ioctl(m_id, EVIOCRMFF, m_id);
+	}
+}
+
+}
+}