Inet K970

The tablet was available together with a bluetooth keyboard as an option.

= Identification =

On the back of the device, the following is printed: Tristan Auron Planet 1

The PCB has the following silkscreened on it: INET-K970-REV02 Zeng-gc 2013-08-27

= Sunxi support =

Current status
Supported by the legacy u-boot-sunxi and sunxi-3.4 kernel.

Only partially working are:
 * Bluetooth
 * USB OTG

No drivers are readily at hand for the following devices:
 * G-Sensor
 * Cameras

All devices not mentioned above are fully operational. For additional information, see below

Manual build

 * For building u-boot, use the A20-OLinuXino_Lime2 target.
 * The .fex file can be found in sunxi-boards as tristan-auron-planet-1.fex

Everything else is the same as the manual build howto.

Mainline U-Boot
For building mainline u-boot, use the A20-OLinuXino-Lime2_defconfig target.

= Tips, Tricks, Caveats =

FEL mode
The Vol+ button triggers FEL mode.

Reset button
The tablet has a reset button on its rear side.

Keys
The keys are working. Use the sun4i_keyboard module. Test using evtest. The power-key is available using the input/event0 device provided by axp.

Install acpid for controlled shutdown. Note the FEX power_start setting, which has the effect on reboot/halt, when connected to AC power.

Touchscreen
The touchscreen works well with the ft5x_ts driver available in linux-sunxi.

Following modifications were applied wrt. the original fex file:

[ctp_para] ctp_used = 1 +ctp_name = "ft5x_ts" ctp_twi_id = 2 -ctp_twi_addr = 0x40 +ctp_twi_addr = 0x38 ctp_screen_max_x = 1024 ctp_screen_max_y = 768 -ctp_revert_x_flag = 0 +ctp_revert_x_flag = 1 ctp_revert_y_flag = 0 -ctp_exchange_x_y_flag = 1 -ctp_ft5402_num = 9702 -mSSD253xDriverType = 9701 -ctp_cob_gslX680 = 8 +ctp_exchange_x_y_flag = 0 ctp_int_port = port:PH21<6> ctp_wakeup = port:PB13<1> <1> -ctp_power_en = port:PH22<1> <0> +ctp_power_port = port:PH22<1> <0>

The driver itself does not load on A20 without the following patch: diff --git a/drivers/input/touchscreen/ft5x_ts.c b/drivers/input/touchscreen/ft5x_ts.c index 5d8dc97..3d88694 100644 --- a/drivers/input/touchscreen/ft5x_ts.c +++ b/drivers/input/touchscreen/ft5x_ts.c @@ -1762,7 +1762,7 @@ ft5x_ts_probe(struct i2c_client *client, const struct i2c_device_id *id) pr_info("%s:ctp_ops.set_irq_mode err.\n", __func__); goto exit_set_irq_mode; } -      err = request_irq(SW_INT_IRQNO_PIO, ft5x_ts_interrupt, IRQF_TRIGGER_FALLING | IRQF_SHARED, "ft5x_ts", ft5x_ts); +      err = request_irq(SW_INT_IRQNO_PIO, ft5x_ts_interrupt, IRQF_SHARED, "ft5x_ts", ft5x_ts);

if (err < 0) { dev_err(&client->dev, "ft5x_ts_probe: request irq failed\n");

See the following conversation for more information.

Wifi
Wifi is provided by a RTL8723AU.

This is an USB device, attached to the third USB-bus. Make sure it is activated in the FEX file.

[usbc2] usb_used = 1 usb_port_type = 1 usb_detect_type = 0 usb_drv_vbus_gpio = port:PH03<1><0> <0> usb_restrict_gpio = usb_host_init_state = 1 usb_restric_flag = 0

Bluetooth
Bluetooth works using the rtk_btusb module, though I had mixed success working towards full operation of a Bluetooth keyboard.

Most particular, the Weezy userspace is not operational, see e.g. here for some fun ahead. I had more success with bluez-5.23 and could reliably connect and use the keyboard.

Automatic connection failed though, which may or may not related to recognizable driver issues, when running Wifi and Bluebooth together.

USB OTG
Activating the Dual Role Controller in the kernel is necessary to get the OTG powered. Its bus then shows up in lsusb -t, but inserting usb-gadget modules fails.

= Adding a serial port (voids warranty) =

To open the tablet, first remove the two screws on the connector's side. As the picture below shows, the back cover can most safely be lifted from the side opposite to the connectors. Try using a Plastic tool. A spool-like tool, shown with the opened device, worked better for me. Before trying to open the tablet, notice the eyelets on the back cover clearly visible both at the cover itself and its shadows. I found it best to open it first at one of the loops in the middle.

For now, I'll not try to identify the RX/TX pads, as the circuit is really small. Clearly, identifying the pads would only help one with quite some special equipment, e.g. a hand-free magnifier lamp and a lot of practice. Instead, the FEL/USBBoot approach might work better for most and might have the advantage of being even applicable for all sunxi devices. Additionally, mainstream U-Boot made quite some advances towards early diagnostics.

= Pictures =

= See also =


 * Olimex A20-OLinuXino-Lime2