Huawei MateBook E Camera (GalaxyCore GC5024 on Intel IPU3)

Linux kernel driver and userspace integration for the front-facing camera of the HUAWEI MateBook E (Kaby Lake, Intel IPU3 ImgU / TPS68470 PMIC).

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Status: Fully Working

• Hardware ISP Acceleration: Powered by Intel IPU3 ImgU via libcamera and PipeWire.
• Zero Heavy CPU Usage: Near 0% CPU consumption during streaming (unlike software ISP / CPU debayer).
• Auto Exposure (AE) & Auto White Balance (AWB): Real-time hardware tuning handled by IPU3 IPA algorithms with display Gamma 2.2 and tuned BLC.
• Resolution:
  • 1080p (1920x1080) @ ~30 fps (Default Viewfinder / Webcam mode).
  • 720p (1280x720) @ ~45 fps.
  • Full 5MP (2592x1944) still raw capture support.
• Desktop Application Compatibility: Works out-of-the-box in GNOME Camera (Snapshot), Chromium / Chrome, Firefox, OBS Studio, Cheese, and WebRTC video conferencing.

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Hardware Specifications

Item	Value	Source
Model	Huawei MateBook E (BL-W09 / BL-W19 / Kaby Lake)	DMI HUAWEI / HUAWEI MateBook E
Sensor	GalaxyCore GC5024 (Chip ID 0x5024)	ACPI GCTI5024, hardware verified
Location	Built-in Front Camera (定焦 / Fixed Focus)	ACPI SSDB + hardware
I2C Bus	0x37 on I2C2 (\_SB.PCI0.I2C2)	ACPI _CRS
Data Lanes	2 MIPI CSI-2 lanes @ 420 MHz link frequency	ACPI SSDB
MCLK	19.2 MHz	ACPI SSDB + tps68470 PLL
Native Resolution	2592 x 1944 (5 MP, 10-bit Bayer BGGR, 1.4µm pixel)	Vendor spec / Hardware registers
PMIC	TI TPS68470 (INT3472) at I2C2:0x4c	ACPI
Sensor Reset	tps68470-gpio line 9 (s_resetn, active low)	Hardware verified
PMIC Clock	PLLCTL = 0xD0, then PLL enable bit	clk-tps68470.c

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What Mainline Was Missing

On stock kernels, the Intel IPU3 capture nodes exist but fail with VIDIOC_STREAMON returned -1 (Link has been severed) because:

1. No gc5024 sensor driver in mainline Linux (drivers/media/i2c/).
2. Missing TPS68470 board data for Huawei MateBook E, so int3472-tps68470 bails out with No board-data found for this model, failing to power the sensor rails or clock.
3. Missing GCTI5024 entry in ipu-bridge, preventing the ACPI camera graph from connecting to the CIO2 receiver.
4. Missing GC5024 definitions in libcamera, so IPU3 hardware ISP would reject the camera without sensor properties and tuning YAML.

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Architecture

This repository provides two ways to use the camera:

1. Modern Hardware ISP Stack (Recommended)

GC5024 Sensor -> CIO2 (MIPI CSI-2) -> IPU3 ImgU (Hardware ISP)
                                              |
                                       libcamera (IPA AE/AWB)
                                              |
                                    PipeWire / WirePlumber
                                              |
                        GNOME Camera / Browsers / Video Apps

• CPU Usage: ~0%
• Quality: Hardware demosaicing, AE/AWB hardware stats, Gamma 2.2 correction.

2. Standalone Software ISP Stack (Fallback / Testing)

GC5024 Sensor -> CIO2 -> /dev/video0 -> gc5024-camera (userspace) -> v4l2loopback (/dev/video20)

• Useful for headless environments or manual raw capture testing.

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Installation & Setup

Prerequisites

For Arch Linux / Manjaro:

sudo pacman -S --needed dkms linux-headers base-devel libcamera pipewire-libcamera gst-plugin-libcamera

For Ubuntu / Debian / Fedora: Ensure kernel headers, DKMS, and libcamera with PipeWire plugins are installed.

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Step 1: Install Kernel Drivers via DKMS

Run the install script as your normal user (uses sudo internally):

./tools/install.sh

This will automatically:

1. Install gc5024 sensor driver as a DKMS module (/extra/gc5024.ko).
2. Install patched ipu-bridge and intel_skl_int3472_tps68470 modules as DKMS.
3. Configure module loading and options in /etc/modprobe.d/ and /etc/modules-load.d/.

Verify that the sensor is detected:

dmesg | grep -E "gc5024|ipu-bridge"
# Output should show:
# ipu-bridge: Found supported sensor GCTI5024:00
# gc5024 2-0037: Identified GC5024 sensor (chip id 0x5024)

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Step 2: Build & Install libcamera with IPU3 GC5024 Support

Run the helper script:

./tools/setup_libcamera.sh

This will:

• Clone libcamera.
• Apply patches/0003-libcamera-add-GalaxyCore-GC5024-support.patch.
• Build and install libcamera with IPU3 pipeline and signed IPA module.
• Install the tuning configuration to /usr/share/libcamera/ipa/ipu3/gc5024.yaml.

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Step 3: Test the Camera

Verify with cam:

cam -c 1 -I

You should see:

Using camera \_SB_.PCI0.I2C2.CAM1 as cam0
0: 1920x1080-NV12

Launch GNOME Camera (Snapshot), Firefox, or Chrome — the camera will be recognized as "Built-in Front Camera" streaming at 1080p 30fps.

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Repository Structure

├── src/
│   ├── gc5024.c                 # Linux V4L2 subdev sensor driver
│   ├── gc5024_regs.h            # GC5024 register map definitions
│   └── Makefile                 # Kernel kbuild file
├── patches/
│   ├── 0001-media-ipu-bridge-add-GalaxyCore-GC5024-sensor.patch
│   ├── 0002-platform-x86-int3472-add-Huawei-MateBook-E-board-data.patch
│   └── 0003-libcamera-add-GalaxyCore-GC5024-support.patch
├── tuning/
│   └── ipu3/gc5024.yaml         # libcamera IPU3 IPA tuning profile
├── dkms/                        # DKMS packaging configs
├── tools/
│   ├── install.sh               # DKMS kernel driver installer
│   ├── setup_libcamera.sh       # Automated libcamera IPU3 builder
│   ├── probe_gpios.sh           # Hardware diagnostic script for TPS68470
│   ├── test_capture.sh          # Raw frame capture test
│   └── raw2png.py               # Software Bayer to PNG converter
├── apps/
│   └── gc5024-camera.c          # Standalone fallback userspace ISP
└── docs/                        # Hardware documentation and register tables

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Technical Details

Power Sequencing & Timing

1. PLLCTL = 0xD0: Configures external capacitor 5 << 4 and crystal oscillator 1 << 7, followed by PLL enable bit. Without this, no 19.2 MHz MCLK is produced.
2. s_resetn (GPIO 9): The sensor is held in active-low reset until SGPO bit 2 is driven high.
3. Power Rails:
   • dvdd (CORE) = 1.2 V
   • avdd (ANA) = 2.8152 V
   • dovdd (VIO / VSIO) = 1.8 V
4. The rails and MCLK must stabilize before reset is deasserted, otherwise the sensor NAKs on the I2C bus.

Sensor Windowing Modes

The GC5024 supports native windowing without scaling:

• 1080p Mode: 1952x1096 window cropped to 1920x1080 @ 31.5 fps.
• 720p Mode: 1312x736 window cropped to 1280x720 @ 45.9 fps.
• Vertical Blanking: P0:0x07/0x08 controls VB (not VTS). Correct configuration prevents frame rate halving.

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License

• Kernel modules and patches: GPL-2.0
• libcamera tuning files and userspace scripts: MIT / CC0-1.0