envmanager: Attempt to autodetect device id

Attempt to use `/sys/firmware/devicetree/base/compatible` to autodetect
the device id for device profiles. This approach is described here: https://phosh.mobi/posts/notch-support/#the-compatibles-string

devices/README.md

@@ -7,17 +7,29 @@ This folder is where device-specific information is set.
 
 ### Usage as a distro
 
-As a distribution, you can ship the device preset with the image by installing a file.
+As a distribution, you can ship the device preset with the image by installing a file if the device id isn't autodetected.
 
 In `/etc/xdg/plasmamobilerc`, write:
 
 ```toml
 [Device]
-device=oneplus-enchilada # replace with the device id
+device=oneplus,enchilada # replace with the device id
 ```
 
 This should be a file name that exists in `/usr/share/plasma-mobile-device-presets` (which are the files in the `configs` folder).
 
+### Auto-detecting device names
+
+Envmanager reads `/sys/firmware/devicetree/base/compatible` to try to autodetect the device id.
+
+Use this command to determine your device's id:
+
+```
+$ sed -z 's/$/\n/' /sys/firmware/devicetree/base/compatible
+oneplus,enchilada
+qcom,sdm845
+```
+
 ### Adding a new device config
 
 See [spec.conf](spec.conf) for more details on the specification. If a setting is omitted in the file, then the system will use the default value.
@@ -28,5 +40,5 @@ In order to test your changes, install the file to `/usr/share/plasma-mobile-dev
 
 ```
 $ plasma-mobile-envmanager --apply-settings
-$ plasmashell --replace
+$ plasmashell -p org.kde.plasma.mobileshell --replace
 ```

envmanager/devicepresets.cpp

@@ -20,17 +20,6 @@ DevicePresets::DevicePresets(QObject *parent)
 {
 }
 
-void setKey(KConfigGroup &fallbackGroup, KConfigGroup &fromGroup, KConfigGroup &toGroup, QString fromKey, QString toKey)
-{
-    if (fromGroup.hasKey(fromKey)) {
-        toGroup.writeEntry(toKey, fromGroup.readEntry(fromKey), KConfigGroup::Notify);
-    } else if (fallbackGroup.hasKey(fromKey)) {
-        toGroup.writeEntry(toKey, fallbackGroup.readEntry(fromKey), KConfigGroup::Notify);
-    } else {
-        toGroup.deleteEntry(toKey, KConfigGroup::Notify);
-    }
-}
-
 void DevicePresets::initialize()
 {
     // Open mobile config to read from all locations (/etc/xdg/plasmamobilerc, ~/.config/plasmamobilerc, etc.)
@@ -40,21 +29,36 @@ void DevicePresets::initialize()
     // Read device id
     const QString device = deviceGroup.readEntry(u"device"_s, {});
 
-    QString presetFile = QStandardPaths::locate(QStandardPaths::GenericDataLocation, u"plasma-mobile-device-presets/"_s + device + ".conf");
-    if (!QFile{presetFile}.exists()) {
-        presetFile = QStandardPaths::locate(QStandardPaths::GenericDataLocation, u"plasma-mobile-device-presets/default.conf"_s);
-        if (!QFile{presetFile}.exists()) {
-            qWarning() << "Failed to find any device preset file";
-            return;
+    QString presetFile = QStandardPaths::locate(QStandardPaths::GenericDataLocation, u"plasma-mobile-device-presets/default.conf"_s);
+
+    // Loop over detected devices and see if file exists
+    QString candidatePresetFile;
+    for (const QString &detectedDevice : detectDeviceString()) {
+        candidatePresetFile = QStandardPaths::locate(QStandardPaths::GenericDataLocation, u"plasma-mobile-device-presets/"_s + detectedDevice + ".conf");
+        if (!candidatePresetFile.isEmpty()) {
+            presetFile = candidatePresetFile;
+            break;
         }
     }
 
-    // Open preset file /usr/share/plasma-mobile-device-presets/device.conf
-    auto presetConfig = KSharedConfig::openConfig(QFileInfo{presetFile}.absoluteFilePath(), KConfig::SimpleConfig);
-    if (!presetConfig) {
+    // Config-specified device has highest priority
+    candidatePresetFile = QStandardPaths::locate(QStandardPaths::GenericDataLocation, u"plasma-mobile-device-presets/"_s + device + ".conf");
+    if (!candidatePresetFile.isEmpty()) {
+        presetFile = candidatePresetFile;
+    } else if (!device.isEmpty()) {
+        qWarning() << "Failed to find device preset file for" << device << "as defined in config";
+    }
+
+    if (QFile{presetFile}.exists()) {
+        qDebug() << "Using device preset file at" << presetFile;
+    } else {
+        qDebug() << "No device preset file could be found.";
         return;
     }
 
+    // Open preset file /usr/share/plasma-mobile-device-presets/[device].conf
+    auto presetConfig = KSharedConfig::openConfig(QFileInfo{presetFile}.absoluteFilePath(), KConfig::SimpleConfig);
+
     // Write presets to ~/.config/plasma-mobile/plasmamobilerc
     // This is then read by components/mobileshellstate (PanelSettingsDBusObjectManager)
     auto presetPanelsGroup = KConfigGroup{presetConfig, u"Panels"_s};
@@ -86,3 +90,41 @@ void DevicePresets::initialize()
 
     m_mobileConfig->sync();
 }
+
+void DevicePresets::setKey(KConfigGroup &fallbackGroup, KConfigGroup &fromGroup, KConfigGroup &toGroup, const QString &fromKey, const QString &toKey)
+{
+    if (fromGroup.hasKey(fromKey)) {
+        toGroup.writeEntry(toKey, fromGroup.readEntry(fromKey), KConfigGroup::Notify);
+    } else if (fallbackGroup.hasKey(fromKey)) {
+        toGroup.writeEntry(toKey, fallbackGroup.readEntry(fromKey), KConfigGroup::Notify);
+    } else {
+        toGroup.deleteEntry(toKey, KConfigGroup::Notify);
+    }
+}
+
+QStringList DevicePresets::detectDeviceString()
+{
+    // On some systems, this file contains an identifier for the device
+    QFile deviceinfoFile{u"/sys/firmware/devicetree/base/compatible"_s};
+    if (!deviceinfoFile.exists()) {
+        return {};
+    }
+
+    if (!deviceinfoFile.open(QIODevice::ReadOnly)) {
+        return {};
+    }
+
+    QByteArray data = deviceinfoFile.readAll();
+    deviceinfoFile.close();
+
+    // Split by null bytes and convert to QStringList
+    QStringList result;
+    const QList<QByteArray> parts = data.split('\0');
+    for (const QByteArray &part : parts) {
+        if (!part.isEmpty()) {
+            result.append(QString::fromUtf8(part));
+        }
+    }
+
+    return result;
+}

envmanager/devicepresets.h

@@ -1,6 +1,8 @@
 // SPDX-FileCopyrightText: 2025 Devin Lin <devin@kde.org>
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#pragma once
+
 #include <QObject>
 
 #include <KConfigGroup>
@@ -16,5 +18,8 @@ public:
     void initialize();
 
 private:
+    void setKey(KConfigGroup &fallbackGroup, KConfigGroup &fromGroup, KConfigGroup &toGroup, const QString &fromKey, const QString &toKey);
+    QStringList detectDeviceString();
+
     KSharedConfig::Ptr m_mobileConfig;
 };