Samsung Galaxy Tab 3 8.0 (samsung-lt01)

Features
Flashing	Works
USB Networking	Works
Internal storage	Works
SD card	Works
Battery	Works
Screen	Partial
Touchscreen	Works
Multimedia
3D Acceleration	Works
Audio	Works
Camera	Broken
IR TX	Broken
Connectivity
WiFi	Works
Bluetooth	Works
GPS	Broken
Miscellaneous
FDE
USB OTG	Works
HDMI/DP
Sensors
Accelerometer	Works
Magnetometer	Broken
Ambient Light	Works
Hall Effect	Works

Samsung Galaxy Tab 3 8.0
	; Photo of the Galaxy Tab 3 8.0 running postmarketOS
Manufacturer	Samsung
Name	Galaxy Tab 3 8.0
Codename	samsung-lt01
Model	SM-T310, SM-T311, SM-T315
Released	2013
Type	tablet
Hardware
Chipset	Samsung Exynos 4212 Dual
CPU	Dual-core 1.5 GHz Cortex-A9
GPU	Mali-400MP4
Display	800x1280
Storage	16GB
Memory	1.5GB
Architecture	armv7
Software
Original software	Android
Original version	4.2.2
FOSS bootloader	no
postmarketOS
Category	testing
Pre-built images	no
Mainline	yes
postmarketOS kernel	6.10.0
Unixbench Whet/Dhry score	638.8

Maintainer(s)

knuxify

Users owning this device

Knuxify (Notes: SM-T310, 2x, mainlined!)
Lordkaczuha (Notes: (SM-T310) 2x one cracked but touch works other doesn't accept touch inputs afaikt. also have plenty of replacement parts if anybody wants some lol.)

How to enter flash mode

Enter download mode by holding down the Power and Volume down keys simultaneously until the download mode warning screen shows up, then press Volume up to dismiss the warning. (Holding down the home button is not necessary on this tablet, unlike on other Samsung devices.)

Installation

See Installation/Using pmbootstrap. This section contains the device-specific information related to installing with pmbootstrap.

In pmbootstrap init, select samsung-lt01 as the device. You will be prompted to select a variant:

wifi for the SM-T310;
3g for the SM-T311;
lte for the SM-T315.

Flashing

To flash the image to the device, enter download mode by holding down the Power and Volume down keys simultaneously until the download mode warning screen shows up, then press Volume up to dismiss the warning.

First, flash the kernel:

$ pmbootstrap flasher flash_kernel

The device will reboot; boot it back into download move with the above key combination.

Then, flash the rootfs. To flash to the userdata partition (recommended as it has more space, but will wipe your Android data!):

$ pmbootstrap flasher flash_rootfs --partition USERDATA

If you want to flash the rootfs to the system partition, drop --partition USERDATA from the above command.

Upgrading from old `samsung-lt01wifi` device package

WARNING: This procedure is untested. It's preferable to re-install the OS from scratch if you plan to use the mainline kernel.

In the command line, run:

# apk add device-samsung-lt01 device-samsung-lt01-kernel-wifi linux-postmarketos-exynos4 device-samsung-lt01-nonfree-firmware

This should automatically reflash the boot image; if not, you may need to go through pmbootstrap installation, then run pmbootstrap flasher flash_kernel.

Reboot the device, then run:

# apk del device-samsung-lt01wifi linux-samsung-lt01wifi firmware-samsung-lt01wifi

Parts and their status

If the DRM driver crashes (screen gets stuck, lines start to get blurry/dimmer), power off the device immediately as leaving it on WILL (temporarily) damage your display! Usually the damage goes away after anywhere from a few minutes to about half an hour, but it's better to be safe.

Current issues:

RAM is limited to 1GB due to some weird quirks in how the later RAM is treated by the downstream kernel
Backlight forgets settings after suspend, resulting in choppy brightness changes
In Phosh, moving the mouse cursor around in landscape mode will cause the DRM driver to crash ("vblank wait timed out")
On one of my tablets, the screen sometimes has weird black lines on it; usually fixes itself on panel restart. Need to figure out if this is a hardware issue or if it could be worked around (the display seems to behave weirdly on startup too, maybe it's just the hardware...)
OTG works, but peripheral mode might not work after switching to OTG (if you see messages about DWC gadget init after plugging in an OTG cable, it will likely not work). This is yet to be fixed.
When plugging in headphones, the "media" key is detected to be pressed, causing a media player to be launched. (TODO, maybe it should be remapped to play/pause?)

For the status of all components, see the tables below:

Element type	Element	Works?	Notes
Chipset	Exynos 4212	Y
Graphics	Mali-400MP4	Y
Charging IC	max77693	Y	Supported in mainline.
Audio	WM1811	Y	Speaker and headphone jack works, internal mic works (but peaks - TODO).
PMIC	S5M8767	Y	Supported in mainline
Fuel gauge	MAX17050	Y	Supported by MAX17042 driver
Touchscreen	MELFAS MMS252	Y	Pretty much identical to the other Melfas touchscreens in mainline. Using mms114 compatible for now. Both touchscreen and touch keys work.
Buttons	gpio-keys	Y	Volume up/down, power and home button.
WiFi, Bluetooth	BCM4334	Y	Driver in mainline.
Display	S6D7AA0 LSL080AL02	P	Driver in kernel fork. See also: Blog post about getting the display working. Moderate to heavy glitching on some tablets, pending investigation.
Backlight	LP8556TMX	Y	PWM-controlled backlight controller. Seems to have a weird issue where setting it to 100% causes the backlight to shut down (though this is lazily worked around in my fork). Also seems to forget ROM settings after suspend.
Camera	Sony ISX012 and Siliconfile SR130PC20		Both aren't in mainline
IR	ABOV Semiconductor MC96FR332AUB		The kernel option is IR_REMOCON_MC96, but REMOCON just seems to be Samsung's designation for remote controllers (given that they use it in part numbers for their TV remotes). The Kconfig description says it's a Micom(ABOV) device (Micom seems to be a generic term for microcontrollers). It's an 8-bit microcontroller, programmed with a custom firmware bundled in the kernel as `drivers/irda/irda_fw.h`. Chip markings say ABOV 332AUB 1427. Also used on the GT-N8000. Official site/datasheet for what seems to be the same model, datasheet mirror. WIP work in my kernel tree, IR led lights up but does not actually work as a remote - wrong configuration or driver bug?
MHL	sii9244		sii9234 driver seems to initialize fine, can't test because I don't own a dock; currently disabled, since this is the same chip as in the S3 and likely suffers from the same issues (phosh not starting up with dock unplugged)
Modem	XMM6262 (3G), Qualcomm ??? (LTE)		XMM6262 seems to be supported by replicant but isn't yet in mainline; Qualcomm modem might be MDM9615, since that's what the S3 4G uses; didn't check the code to make sure
GPS	BCM47521		No clue about mainline support, seems to be unsupported

Sensors

Shared

Element type	Element	Works?	Notes
Hall effect/flip cover sensor	gpio-keys	Y	Simple sensor connected via GPIO.
Accelerometer	STMicroelectronics K2DH	Y	Seems to be compatible with LIS2DH12
Magnetometer	YAS532	P	Enabled in DTS and seems to be detected, but the values don't seem to make much sense? TODO

WiFi

Element type	Element	Works?	Notes
Light sensor	CM3323	Y	Driver in mainline

3G/LTE

Element type	Element	Works?	Notes
"Grip sensor"?	AD semiconductor ASP01		Appears to be a "Capacitive Touch/Proximity Sensor"; datasheet. Not 100% sure what this is used for.
Proximity sensor	CM36653		Not in mainline; likely similar to CM36651