feature: Add basic EDID reading, writing, and patching capabilities

app/edidtools/patching_tools_linux.go

@@ -0,0 +1,127 @@
+//go:build linux
+// +build linux
+
+package edidtools
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/charmbracelet/log"
+)
+
+// Attempts to fetch the EDID firmware for any supported XR glasses device
+func FetchXRGlassEDID(allowUnsupportedDevices bool) (*DisplayMetadata, error) {
+	// Implementation goes here
+	pciDeviceCommand, err := exec.Command("lspci").Output()
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to execute lspci command: %w", err)
+	}
+
+	pciDevices := strings.Split(string(pciDeviceCommand), "\n")
+	pciDevices = pciDevices[:len(pciDevices)-1]
+
+	vgaDevices := []string{}
+
+	for _, pciDevice := range pciDevices {
+		if strings.Contains(pciDevice, "VGA compatible controller:") {
+			vgaDevices = append(vgaDevices, pciDevice[:strings.Index(pciDevice, " ")])
+		}
+	}
+
+	for _, vgaDevice := range vgaDevices {
+		cardDevices, err := os.ReadDir("/sys/devices/pci0000:00/0000:" + vgaDevice + "/drm/")
+
+		if err != nil {
+			return nil, fmt.Errorf("failed to read directory for device '%s': %w", vgaDevice, err)
+		}
+
+		for _, cardDevice := range cardDevices {
+			if !strings.Contains(cardDevice.Name(), "card") {
+				continue
+			}
+
+			monitors, err := os.ReadDir("/sys/devices/pci0000:00/0000:" + vgaDevice + "/drm/" + cardDevice.Name())
+
+			if err != nil {
+				return nil, fmt.Errorf("failed to read directory for card device '%s': %w", cardDevice.Name(), err)
+			}
+
+			for _, monitor := range monitors {
+				if !strings.Contains(monitor.Name(), cardDevice.Name()) {
+					continue
+				}
+
+				rawEDIDFile, err := os.ReadFile("/sys/devices/pci0000:00/0000:" + vgaDevice + "/drm/" + cardDevice.Name() + "/" + monitor.Name() + "/edid")
+
+				if err != nil {
+					return nil, fmt.Errorf("failed to read EDID file for monitor '%s': %w", monitor.Name(), err)
+				}
+
+				if len(rawEDIDFile) == 0 {
+					continue
+				}
+
+				parsedEDID, err := ParseEDID(rawEDIDFile, allowUnsupportedDevices)
+
+				if err != nil {
+					if !strings.HasPrefix(err.Error(), "failed to match manufacturer for monitor vendor") {
+						log.Warnf("Failed to parse EDID for monitor '%s': %s", monitor.Name(), err.Error())
+					}
+				} else {
+					parsedEDID.LinuxDRMCard = cardDevice.Name()
+					parsedEDID.LinuxDRMConnector = strings.Replace(cardDevice.Name(), cardDevice.Name()+"-", "", 1)
+
+					return parsedEDID, nil
+				}
+			}
+		}
+	}
+
+	return nil, fmt.Errorf("could not find supported device! Check if the XR device is plugged in. If it is plugged in and working correctly, check the README or open an issue.")
+}
+
+// Loads custom firmware for a supported XR glass device
+func LoadCustomEDIDFirmware(displayMetadata *DisplayMetadata, edidFirmware []byte) error {
+	if displayMetadata.LinuxDRMCard == "" || displayMetadata.LinuxDRMConnector == "" {
+		return fmt.Errorf("missing Linux DRM card or connector information")
+	}
+
+	drmFile, err := os.Open("/sys/kernel/debug/dri/" + strings.Replace(displayMetadata.LinuxDRMCard, "card", "", 1) + "/" + displayMetadata.LinuxDRMConnector + "/edid_override")
+
+	if err != nil {
+		return fmt.Errorf("failed to open EDID override file for monitor '%s': %w", displayMetadata.LinuxDRMConnector, err)
+	}
+
+	defer drmFile.Close()
+
+	if _, err := drmFile.Write(edidFirmware); err != nil {
+		return fmt.Errorf("failed to write EDID firmware for monitor '%s': %w", displayMetadata.LinuxDRMConnector, err)
+	}
+
+	return nil
+}
+
+// Unloads custom firmware for a supported XR glass device
+func UnloadCustomEDIDFirmware(displayMetadata *DisplayMetadata) error {
+	if displayMetadata.LinuxDRMCard == "" || displayMetadata.LinuxDRMConnector == "" {
+		return fmt.Errorf("missing Linux DRM card or connector information")
+	}
+
+	drmFile, err := os.Open("/sys/kernel/debug/dri/" + strings.Replace(displayMetadata.LinuxDRMCard, "card", "", 1) + "/" + displayMetadata.LinuxDRMConnector + "/edid_override")
+
+	if err != nil {
+		return fmt.Errorf("failed to open EDID override file for monitor '%s': %w", displayMetadata.LinuxDRMConnector, err)
+	}
+
+	defer drmFile.Close()
+
+	if _, err := drmFile.Write([]byte("reset")); err != nil {
+		return fmt.Errorf("failed to unload EDID firmware for monitor '%s': %w", displayMetadata.LinuxDRMConnector, err)
+	}
+
+	return nil
+}