# Dell Latitude 7480 - Built in touchpad not working

## AshVince

Hi

I having issues getting the mouse and touchpad built into a new Dell Latitiude 7480 working under Gentoo Linux.

I have confirmed they are recognised under Fedora 27 (using the kernel 4.13) and they report the following in /proc/bus/input/devices

```
I: Bus=0018 Vendor=044e Product=120b Version=0100

N: Name="DualPoint Stick"

P: Phys=i2c-DLL07A0:01

S: Sysfs=/devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-1/i2c-DLL07A0:01/0018:044E:120B.0003/input/input12

U: Uniq=

H: Handlers=mouse1 event11

B: PROP=21

B: EV=7

B: KEY=70000 0 0 0 0

B: REL=3

I: Bus=0018 Vendor=044e Product=120b Version=0100

N: Name="DLL07A0:01 044E:120B"

P: Phys=i2c-DLL07A0:01

S: Sysfs=/devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-1/i2c-DLL07A0:01/0018:044E:120B.0003/input/input11

U: Uniq=

H: Handlers=mouse2 event12

B: PROP=1

B: EV=b

B: KEY=e520 30000 0 0 0 0

B: ABS=660800001000003

```

The first of these is the little stick thing in the middle of the keyboard, the second is the actual touchpad in front of the keyboard. I am guessing I need to add some additional modules into the kernel at compile time but am struggling to find what I need to enable.I have tried to move to kernel 4.14 just in case and have this compiled and working fine in every other regard, just still no touchpad support.

Thanks for any pointers in the right direction anyone can provide,

Ash

[Moderator edit: added [code] tags to preserve output layout. -Hu]

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## Ralphred

Make sure you have 

```
CONFIG_MOUSE_PS2_SYNAPTICS=y

CONFIG_MOUSE_SYNAPTICS_I2C=y

CONFIG_MOUSE_SYNAPTICS_USB=y
```

set as well as

```
CONFIG_MOUSE_PS2_ALPS=y

CONFIG_HID_ALPS=y
```

That said, I have experience will Dell touchpads, and you are better off with the nipplemouse.

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## AshVince

Unfortunately in my case neither the nipplemourse nor the touchpad were working.

In case anyone else out there has a similar issue though and fins this the answer was to turn on INTEL_LPSS.

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## ridelub

I landed here, having exactly the same issue, so I hope this will save some else's time.

After much search/test, I followed the https://wiki.gentoo.org/wiki/Dell_Latitude_5580 guide.

What did it for me was the (completely irrelevant imho) "Synopsys DesignWare Platform".

So for DLL07A8:01 044E:120B / Latitude 7480 touchpad/trackpoint to work, make sure those are also enabled in kernel:

```
CONFIG_I2C_DESIGNWARE_PLATFORM=y

CONFIG_MFD_INTEL_LPSS_PCI=y

CONFIG_HID_ALPS=y

CONFIG_I2C_HID=y
```

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## justin_brody

THANKS for posting these -- I've been banging my head against the wall for several hours, but this did it for me!

----------

