[PR #1825] xfree86: add null input driver

PR: https://github.com/X11Libre/xserver/pull/1825

hw/xfree86/drivers/input/meson.build

@@ -1,3 +1,7 @@
 if get_option('xf86-input-inputtest')
     subdir('inputtest')
 endif
+
+if get_option('xf86-input-null')
+    subdir('null')
+endif

hw/xfree86/drivers/input/null/meson.build

@@ -0,0 +1,18 @@
+nullinputdrv_srcs = [
+    'null.c',
+]
+
+shared_module(
+    'nullinput_drv',
+    nullinputdrv_srcs,
+    name_prefix: '',
+
+    include_directories: [inc, xorg_inc],
+    c_args: xorg_c_args,
+    dependencies: [common_dep],
+
+    install: true,
+    install_dir: join_paths(module_abi_dir, 'input'),
+
+    link_with: xserver_exec,
+)

hw/xfree86/drivers/input/null/null.c

@@ -0,0 +1,103 @@
+#include <xorg-config.h>
+
+#include <exevents.h>
+#include <xserver-properties.h>
+
+#include <xorgVersion.h>
+#include <xf86Xinput.h>
+
+/* dummy needed, so that clients don't get BadValue error
+   when trying to ring the bell. */
+static void nullinput_bell(int percent, DeviceIntPtr pDev, void *ctrl, int unused) { }
+
+/* dummy needed, because no NULL protection here yet */
+static void nullinput_keyctrl(DeviceIntPtr pDev, KeybdCtrl *ctrl) { }
+
+/* dummy needed, because no NULL protection here yet */
+static void nullinput_pointer(DeviceIntPtr dev, PtrCtrl *ctrl) { }
+
+static int nullinput_device_init(DeviceIntPtr dev)
+{
+    Atom axes_labels[2] = {
+        XIGetKnownProperty(AXIS_LABEL_PROP_ABS_X),
+        XIGetKnownProperty(AXIS_LABEL_PROP_ABS_Y)
+    };
+
+    Atom btn_labels[3] = {
+        XIGetKnownProperty(BTN_LABEL_PROP_BTN_LEFT),
+        XIGetKnownProperty(BTN_LABEL_PROP_BTN_MIDDLE),
+        XIGetKnownProperty(BTN_LABEL_PROP_BTN_RIGHT)
+    };
+
+    unsigned char map[4] = { 0, 1, 2, 3 };
+
+    dev->public.on = FALSE;
+
+    if (!InitButtonClassDeviceStruct(dev, sizeof(map)-1, btn_labels, map))
+        return !Success;
+
+    if (InitKeyboardDeviceStruct(dev, NULL, nullinput_bell, nullinput_keyctrl))
+        return !Success;
+
+    if (!InitValuatorClassDeviceStruct(dev, 2, axes_labels, 0, Absolute))
+        return !Success;
+
+    if (!InitPtrFeedbackClassDeviceStruct(dev, nullinput_pointer))
+        return !Success;
+
+    return Success;
+}
+
+static int nullinput_device_control(DeviceIntPtr dev, int what)
+{
+    switch (what)
+    {
+        case DEVICE_INIT:
+            return nullinput_device_init(dev);
+
+        case DEVICE_ON:
+            dev->public.on = TRUE;
+            return Success;
+
+        case DEVICE_OFF:
+        case DEVICE_CLOSE:
+            dev->public.on = FALSE;
+            return Success;
+    }
+    return BadValue;
+}
+
+static int nullinput_preinit(InputDriverPtr drv, InputInfoPtr pInfo, int flags)
+{
+    pInfo->type_name = "null";
+    pInfo->device_control = nullinput_device_control;
+    pInfo->fd = -1;
+    return Success;
+}
+
+static void nullinput_uninit(InputDriverPtr drv,InputInfoPtr pInfo, int flags)
+{
+    pInfo->dev->public.on = FALSE;
+}
+
+InputDriverRec NullInput = {
+    .driverVersion = 1,
+    .driverName    = "null",
+    .PreInit       = nullinput_preinit,
+    .UnInit        = nullinput_uninit,
+};
+
+static void* nullinput_setup(void *mod, void *opt, int *errmaj, int *errmin)
+{
+    xf86AddInputDriver(&NullInput, mod, 0);
+    return mod;
+}
+
+XF86_MODULE_DATA_INPUT(
+    nullinput,
+    nullinput_setup,
+    NULL,
+    "nullinput",
+    XORG_VERSION_MAJOR,
+    XORG_VERSION_MINOR,
+    XORG_VERSION_PATCH);

meson_options.txt

@@ -157,6 +157,8 @@ option('docs-pdf', type: 'combo', choices: ['true', 'false', 'auto'], value: 'au
 # optional xfree86 DDX drivers
 option('xf86-input-inputtest', type: 'boolean', value: true,
        description: 'Test input driver support on XLibre')
+option('xf86-input-null', type: 'boolean', value: true,
+       description: 'Null input driver')
 
 # legacy nvidia driver quirks
 option('legacy_nvidia_padding', type: 'boolean', value: false,