Samsung Galaxy Tab 10.1 (samsung-p4wifi)

From postmarketOS
Revision as of 13:01, 7 March 2019 by Decatf (talk | contribs) (Fix Accelerometer heading)
Jump to navigation Jump to search
Samsung Galaxy Tab 10.1
Xcfe4 running on Samsung Galaxy Tab 10.1 (p4wifi)
Xcfe4 running on Samsung Galaxy Tab 10.1 (p4wifi)
Manufacturer Samsung
Name Galaxy Tab 10.1
Codename samsung-p4wifi
Released 2011
Category testing
Original software Android 3.1 Honeycomb
Chipset Nvidia Tegra 2
CPU 1Ghz ARM Cortex-A9
GPU Tegra 2
Display 1280×800
Storage 16/32 GB
Memory 1GB
Architecture armhf
Unixbench Whet/Dhry score 424.5
USB Networking
3D Acceleration
Mobile data


  • decatf


  • decatf


postmarketOS for the Samsung Galaxy Tab 10.1 runs on mainline Linux kernel fork. The kernel uses both mainline and forward ported drivers. Some peripherals are using mainline device driver where applicable. Some peripherals which are not working on or don't have mainline drivers are using drivers forward ported from the stock 3.1.10 kernel.

How to enter flash mode

Press and hold Power + Volume Down buttons


  1. Init pmbootstrap
    $ pmbootstrap init
    Choose 'samsung-p4wifi' as target device.
  2. Start the build process
    $ pmbootstrap build linux-samsung-p4wifi
    $ pmbootstrap build device-samsung-p4wifi
    $ pmbootstrap install --no-fde
  3. Enter flash (download) mode
  4. Flash the kernel and system images
    $ pmbootstrap flasher flash_kernel
    $ pmbootstrap flasher flash_rootfs


The battery in this device is the max17042. A tear down of the (nearly) identical Galaxy Tab 8.9 reveals that the charger is max8903.

Differences between mainline and downstream drivers:

The downstream kernel provides an early implementation of a driver for the max17042 battery. The implementation of the battery and charger driver are split across p4_battery.c and max17042_battery.c. The downstream charger driver implements additional logic to handle charge full and low battery events which may affect the health of the battery. The implementation details are not clear but the overall functionality appears to dynamically tune the full charge value. The mainline driver does not have this sort of functionality. The downstream driver reports the current in milliamp whereas the mainline driver is in microamp.

The max8903 datasheet shows that there are separate GPIOs for USB and DC power connectors. This device has one connect GPIO for both USB and DC mode. The type of connector is determined by reading the usb-sel GPIOs. It's unclear which piece of hardware the usb-sel is coming from (max8903 / tegra soc / 30-pin connector ???).


The reverse engineer grate-driver provides 2D (EXA) acceleration on X11. There is minimal 3D implementation which is not complete enough to run the Wayland compositor.

Usability of desktop environments:

  • Xfce4 and Mate desktop will run on 2D acceleration.
  • Wayland desktops will only work with software rendering backends.
  • Hildon requires an OpenGL backend.
    • As of cogl 1.22.2 the clutter/cogl backend requires stencil buffers (EGL_STENCIL_SIZE). This not implemented in the grate-driver.

Video Decoding

Video Decoder Engine (VDE) was added to mainline kernel v4.16. The grate-driver includes hardware h264 decoding with libvdpau-tegra.

The vdpau driver does not support h264 videos encoded with:

  • weighted prediction

Sample video that can be decoded with hardware acceleration:

$ mpv --hwdec=vdpau
Using hardware decoding (vdpau).
VO: [vdpau] 1280x720 vdpau[yuv420p]


Audio output through headphone and speakers are working. Audio input through the built-in microphone and headset microphone are working.

The ALSA UCM config files were previously generated using the xml2ucm tool. The mixer_paths.xml and p4wifi.config.xml can be found in this github gist.

$ stack exec -- xml2ucm -m mixer_paths.xml -c p4wifi-config.xml -o examples

As of pmaports!254 the ALSA UCM config files were created based the wm8994 datasheet and the downstream driver coding of the mixer.


The wifi chip in this device is the Broadcom BCM4330 B1 revision. There is a B2 revision which is much more common. The only distinguishing factor is the firmware. Only the B1 firmware will work on this device. The most common BCM4330 firmware found from various sources (such as linux-firmware) is for the B2 revision.

Cellular Modem

The xmm6260 modem was used in quite a few Samsung Android devices from the same era as this tablet. The Samsung Galaxy Tab 10.1 3G (p4) and Samsung Galaxy Tab 10.1 from T-Mobile (p4tmo) are otherwise identical to the WiFi only version of the tablet (p4wifi). The cellular modem is connected via an internal USB interface called USB HSIC. The mainline Tegra USB driver does not implement this functionality. Much of the work in enabling the cellular stack would involve adding USB HSIC support to the mainline USB driver.


The bcm4330 Bluetooth module is supported by the mainline kernel and Bluez 5 stack.

Install bluetooth service:

$ apk add bluez
$ rc-update add bluetooth default
$ rc-service bluetooth start

Pair a Bluetooth device:

$ bluetoothctl
$ power on
$ scan on
$ connect XX:XX:XX:XX:XX:XX
$ scan off


The following instructions will play audio to a Bluetooth headset.

Install PulseAudio:

$ apk add pulseaudio pulseaudio-bluez pulseaudio-utils

Start PulseAudio:

$ pulseaudio --daemonize

Check that the Bluetooth audio profiles are working in bluetoothctl:

$ show
Controller XX:XX:XX:XX:XX:XX (public)
        Name: BlueZ 5.49
        Alias: BlueZ 5.49
        Class: 0x000c0000
        Powered: yes
        Discoverable: no
        Pairable: yes
        UUID: Headset AG                (00001112-0000-1000-8000-00805f9b34fb)
        UUID: Generic Attribute Profile (00001801-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control        (0000110e-0000-1000-8000-00805f9b34fb)
        UUID: Generic Access Profile    (00001800-0000-1000-8000-00805f9b34fb)
        UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)
        UUID: Audio Source              (0000110a-0000-1000-8000-00805f9b34fb)
        UUID: Audio Sink                (0000110b-0000-1000-8000-00805f9b34fb)
        UUID: Headset                   (00001108-0000-1000-8000-00805f9b34fb)
        Modalias: usb:v1D6Bp0246d0531
        Discovering: no

Play an audio file through a Bluetooth headset:

$ paplay audio.wav


The kxt9f accelerometer driver works pending device tree patches being merged into upstream. There requires a user space daemon such as iio-sensor-proxy to read the sensor data.

Other Information

Hardware Information & Mainline Driver Status

The Linux mainlining effort contains drivers forward ported from the stock Samsung Linux 3.1.10 kernel which shipped with the device. Some peripheral devices have been transitioned over to the mainline driver. Other drivers are not in the mainline kernel or the device is not compatible with the mainline driver.

Peripheral Type Hardware Mainline Driver
Accelerometer kxtf91
Ambient light sensor bh1721fvc Y
Analog Digital Converter stmpe811 Y
Audio wm8994 Y
Battery max17042 Y
Camera s5k5ccgx (front)
s5k6bbgx (back)
Charger max8903 Y
Compass ak8975c2
CPU Temperature Sensor nct1008 Y
Display Panel cmc623 P
GPS bcm4751 P
GPU tegra host1x Y
Gyroscope mpu3050 Y
HDMI Connector sii92343
Touch Digitizer mxt1386 Y
Vibration Motor isa1200 P
Voltage Regulators tps6586x Y
Wifi / Bluetooth bcm4330 Y
3G Modem xmm6260 -
3.5mm Jack sec_jack P
30-pin accessory port unknown -


1: kxt9f driver exists in mainline. The driver needs support device tree bindings.
2: ak8975 driver exists in mainline. The device id for ak8975c needs to be added to the driver. I (decatf) can't test it because the compass seems to report nonsense data. The compass on my tablet might be broken.
3: sii9234 driver exists in mainline. Requires someone with an MHL cable to implement / test it.

Mainline Driver Status Legend
Code Meaning
Y Mainline driver
P Forward ported driver
- No driver -- driver has not been forward ported

See also