Samsung Galaxy Tab A 9.7 2015 (samsung-gt510)

Features
Flashing	Works
USB Networking	Works
Internal storage
SD card
Battery	Partial
Screen	Works
Touchscreen	Works
Multimedia
3D Acceleration	Works
Audio	Works
Camera
Camera Flash
Connectivity
WiFi	Works
Bluetooth	Works
GPS	Works
Modem
Calls	Partial
SMS	Works
Mobile data	Works
Miscellaneous
FDE	Works
USB OTG
HDMI/DP
Sensors
Accelerometer	Works
Magnetometer
Ambient Light	Works
Proximity
Hall Effect	Works
Haptics

Samsung Galaxy Tab A 9.7 (2015)
	; Samsung Galaxy Tab A 9.7 WiFi (2015)
Manufacturer	Samsung
Name	Galaxy Tab A 9.7 (2015)
Codename	samsung-gt510
Released	2015
Type	tablet
Hardware
Chipset	Qualcomm Snapdragon 410 (MSM8916)
CPU	Quad-core 1.2 GHz Cortex-A53
GPU	Qualcomm Adreno 306
Display	768x1024 (XGA) PLS
Storage	16GB
Memory	2GB
Architecture	aarch64
Software
Original software	Android
Original version	7.1.1 (Linux 3.10.49)
postmarketOS
Category	community
Pre-built images	yes
postmarketOS kernel	Mainline
Unixbench Whet/Dhry score	904.0

Samsung Galaxy Tab A (2015) is a series of devices based on Qualcomm Snapdragon 410 SoC which has great mainline Linux support.

This page should generally apply to any 9.7 inch variant of the device (WiFi, LTE, with and without the pen support). Note that those variants may have different amount of RAM. For 8.0 inch variants see Samsung Galaxy Tab A 8.0.

Variant differences

The device has multiple variants, the main differences in the features are shown in the table below:

Feature	WIFI	LTE	Notes
GPS	Partial	Works	WiFi variant needs investigation. Modem support is not enabled for the WiFi variant at this time.
Mobile data	Unavailable	Works
SMS	Unavailable	Works
Calls	Unavailable	Partial	See "Known Issues" below for call audio.

Contributors

jja2000
TravMurav
Minecrell (and others from the msm8916-mainline team)

Maintainer(s)

TravMurav
jja2000

Users owning this device

Fell (Notes: pmOS)
Grimler
Jja2000 (Notes: Contributed, I have two of these now)
Lebedinets (Notes: SM-T555)
QC8086 (Notes: WiFi)
Roboe (Notes: (second hand) SM-P550 16GB (gt5note10wifi); broken S-Pen tip; running pmOS stable with lk2nd bootloader (flipped touch by the Y-axis after loading unofficial TWRP, .-.))
Russanandres (Notes: PMOS)
Samcday
TravMurav (Notes: SM-T555 (LTE variant))
UxAmadeus

How to enter flash mode

Download mode: When turned off hold Power + Volume Up + Home

lk2nd Fastboot: When turned off hold Power + Volume Down

Installation

lk2nd is a secondary bootloader that provides a standard fastboot interface, which can be used to boot postmarketOS without Android boot flashed or pmbootstrap flasher flash_kernel.

Download lk2nd-msm8916.img from Releases page on Github.
Boot your phone to bootloader (Odin/Download) mode by holding Volume Down and Home while powering up.
Follow lk2nd instructions to install lk2nd. Basically flash it to the boot partition (heimdall flash --BOOT lk2nd-msm8916.img)
Follow Qualcomm_Snapdragon_410/412_(MSM8916)#Installation to install postmarketOS.

Note: Enter lk2nd fastboot mode by pressing only Volume Down + Power (without Home). Pressing Home additionally will bring you to the Samsung Download mode.

Known Issues

Charger driver is not present at this time, but bootloader seem to enable it if the device was turned on by plugging the cable in. You can check if the device charges by reading the value from /sys/class/power_supply/max170xx_battery/current_now
Phone calls audio on LTE variants may be only available via headphones output at this time.
Due to a bug (?) in DSI driver, Brightness change DSI commands sent to the panel result in de-sync of the video data and produce some visual artifacts. To remove the artifacts simply turn the display off and on. You may want to make sure that automatic brightness control is disabled.

Mainline Kernel Status

Table of components in the device

Component	Model	Mainline kernel driver	Status
RGB LED	?	?	Doesn't exist in hardware?
MicroUSB	-	Yes	Working in kernel fork (Only Peripheral mode)
eMMC	(Android lists) Toshiba 400073	Yes	Working in kernel fork
Battery/Charging/Fuelgauge	MAX77849	?	Fuel-Gauge works with mainline driver, charger may work unconfigured.
Volume/Power/Home keys	GPIO	Yes	Working in kernel fork
Capacitive keys	Part of Atmel Touchscreen	No	Needs driver changes
Accelerometer	STMicroelectronics K2HH	Yes, supported in kernel fork	Same as matisseve, should work without trouble
Light Sensor	Capella Micro CM3323	Yes
Display	Samsung S6D7AA0 LTL101AT01	Yes	Working in kernel fork
Backlight IC	Texas Instruments lp8558	Not strictly needed	Brightness is set through DSI, PWM signal goes to lp8558 (results in artifacts as DSI commands desync the video data)
Audio	PM8916/MAX98357A	Yes	Audio over headset and mic work. Speakers are powered by external amp (MAX98357A or similar).
Touch Screen	Atmel MXT 1664T	Yes	Working in kernel fork
USB Switch / MUIC	Part of MAX77849	?	?
Proximity sensor	Semtech SX9500	Yes	Working in kernel fork, proximity sensor on the front
GPU	Adreno 306	Yes	Working in kernel fork
Wi-Fi	WNC3660B	Yes	Working in kernel fork, Using the WCN3660B compatible
Bluetooth	WCN3660B	Yes	Working in kernel fork, Using the WCN3660B compatible
GPS	qcom hexagon modem	In userspace	Part of modem DSP: Can be handled by ModemManager or gpsd. LTE variant should work, WiFi variant need investigation.
Front camera	Siliconfile Technologies Inc. SR200PC20	No	Not sure, but there's a datasheet
Main camera	Siliconfile Technologies Inc. SR544	No	Old v4l2 patch for unrelated hardware, may be adaptable to current Mainline

Running some diagnostics programs on Android will likely point out some more info about sensors and any other specifications. At some point I (jja2000) will switch around to Android for a bit to fill in the table. If anyone reading this finds some driver for any of the missing parts let me know on Matrix and if possible edit the table itself.

WiFi variant

The WiFi variant gt510wifi (model number SM-T550, 1.5/16GB) is APQ8016 (at least according to /proc/cpuinfo under adb on the OEM device). As mentioned above, the WiFi variant is currently packaged as a feature-limited version of MSM8916, rather than as a feature-rich version of APQ8016 (e.g., arrow-db410c). The sparse sensor suite agrees with that given in the table above, namely K2HH, CM3323, SX9500.

The flash mode access differs from above (or there is simply a typo above [unverified]),

Recovery mode: When turned off hold Power + Volume Up + Home

Download/odin mode: When turned off hold Power + Volume Down + Home

GPS

For overview, see MSM8916#Modem.

gt510wifi:~$ apk info|grep rproc
soc-qcom-msm8916-rproc-all
gt510wifi:~$ qrtr-lookup 16
 Service Version Instance Node  Port
      16       2        0    0    14 Location service (~ PDS v2)
gt510wifi:~$ ls -l /dev/modem
ls: cannot access '/dev/modem': No such file or directory

Guess at a device (basically, a character string, not a true URI),

gt510wifi:~$ qmicli -d qrtr://0 --loc-get-nmea-types
Successfully retrieved NMEA types: gga, rmc, gsv, gsa, vtg, pqxfi
gt510wifi:~$ qmicli -d qrtr://0 --loc-get-operation-mode
Successfully retrieved operation mode: standalone
gt510wifi:~$ qmicli -d qrtr://0 --loc-get-engine-lock
Successfully retrieved engine lock: none

If nmea-types are none, the value should be reset as soon as some satellites are seen. The command (if any) to start location service is unknown. Upstream gpsd does not contain PDS driver; use an unpackaged version,

gt510wifi:~$ which gpsd
/usr/local/sbin/gpsd
gt510wifi:~$ gpsd -V
gpsd: 3.22 (revision 3.22)
gt510wifi:~$ gpsd -l
  NMEA0183
  Qualcomm PDS
  PPS

Manually start the daemon, as root,

# /usr/local/sbin/gpsd -bn pds://any

Run an ncurses-based client,

gt510wifi:~$ gpsmon
...
GLGSV GPGSV GPGGA GNGNS GPVTG GPGSA GNGSA BDGSA GPRMC

Manually stop the daemon.

# pkill -u nobody gpsd

Location services are not exposed in the case rproc-all is replaced with soc-qcom-msm8916-rproc-no-modem.

Pictures

Samsung Galaxy Tab A running phosh