Do not load keylayout if required kernel module is missing

Some key layouts require the presence of a specific kernel module. If
the kernel module is not present, the layout should not be loaded.

In this CL, we add an option to specify which kernel modules / configs
are needed inside the kl file.

Bug: 228005926
Test: atest libinput_tests
Change-Id: I0d2ab6298bd41df6dc56120bf0385e10da6c3bfe
Merged-In: I0d2ab6298bd41df6dc56120bf0385e10da6c3bfe

1 files changed, 26 insertions, 13 deletions

diff --git a/libs/input/Keyboard.cpp b/libs/input/Keyboard.cpp
index f0895b32ef..c3f5151fd1 100644
--- a/libs/input/Keyboard.cpp
+++ b/libs/input/Keyboard.cpp
@@ -20,16 +20,23 @@
 #include <unistd.h>
 #include <limits.h>
 
-#include <input/Keyboard.h>
+#include <input/InputDevice.h>
 #include <input/InputEventLabels.h>
-#include <input/KeyLayoutMap.h>
 #include <input/KeyCharacterMap.h>
-#include <input/InputDevice.h>
+#include <input/KeyLayoutMap.h>
+#include <input/Keyboard.h>
+#include <log/log.h>
 #include <utils/Errors.h>
-#include <utils/Log.h>
 
 namespace android {
 
+static std::string getPath(const InputDeviceIdentifier& deviceIdentifier, const std::string& name,
+                           InputDeviceConfigurationFileType type) {
+    return name.empty()
+            ? getInputDeviceConfigurationFilePathByDeviceIdentifier(deviceIdentifier, type)
+            : getInputDeviceConfigurationFilePathByName(name, type);
+}
+
 // --- KeyMap ---
 
 KeyMap::KeyMap() {
@@ -111,11 +118,25 @@ status_t KeyMap::loadKeyLayout(const InputDeviceIdentifier& deviceIdentifier,
     }
 
     base::Result<std::shared_ptr<KeyLayoutMap>> ret = KeyLayoutMap::load(path);
+    if (ret.ok()) {
+        keyLayoutMap = *ret;
+        keyLayoutFile = path;
+        return OK;
+    }
+
+    // Try to load fallback layout if the regular layout could not be loaded due to missing
+    // kernel modules
+    std::string fallbackPath(
+            getInputDeviceConfigurationFilePathByDeviceIdentifier(deviceIdentifier,
+                                                                  InputDeviceConfigurationFileType::
+                                                                          KEY_LAYOUT,
+                                                                  "_fallback"));
+    ret = KeyLayoutMap::load(fallbackPath);
     if (!ret.ok()) {
         return ret.error().code();
     }
     keyLayoutMap = *ret;
-    keyLayoutFile = path;
+    keyLayoutFile = fallbackPath;
     return OK;
 }
 
@@ -137,14 +158,6 @@ status_t KeyMap::loadKeyCharacterMap(const InputDeviceIdentifier& deviceIdentifi
     return OK;
 }
 
-std::string KeyMap::getPath(const InputDeviceIdentifier& deviceIdentifier,
-        const std::string& name, InputDeviceConfigurationFileType type) {
-    return name.empty()
-            ? getInputDeviceConfigurationFilePathByDeviceIdentifier(deviceIdentifier, type)
-            : getInputDeviceConfigurationFilePathByName(name, type);
-}
-
-
 // --- Global functions ---
 
 bool isKeyboardSpecialFunction(const PropertyMap* config) {