[Feature Request] Steam Deck Support?

[ChrisRevocateur]

Any plans on adding a layout for the new Steam Deck inputs?

[kozec]

I'd like to, but it will take few months before I can even think about buying one from here.

[pattontim]

Most likely I will receive my deck in May-June. I'm not as experienced as the other devs here so I can test some stuff plus maybe write some code.

[ChrisRevocateur]

Just glad to hear it's on the radar.

[yoshimo]

Would you also look into pushing support for the kernel driver?
hid-steam was being worked on in 2018

[tjhorner]

Hello, Steam Deck owner here! Got mine last Friday.

The Steam Deck inputs are connected internally via USB, similar to how a wired Steam Controller works. Its vid:pid is 28de:1205, and even reports itself as "Valve Software Steam Controller".

@Jack-Sibley was doing some reverse engineering of the HID reports that it sends and at least got the gyro to work. It seems pretty similar to how the Steam Controller sends reports, so hopefully only the modifications that need to be made are minor.

I am not familiar with how this project actually obtains a handle for the USB HID, but according to Jack, Steam gets upset when other apps try to access it. As a sort of workaround we were using usbmon to get the raw HID events directly from the kernel (at /dev/usbmonX).

Anyway, my point is that it's basically a necessity for this to work while Steam is open and actively using the controller, otherwise games launched from the Deck's UI wouldn't be able to utilize this. (There are cases where you would want to use SC Controller instead of the native Steam Input bindings, for e.g. cemuhook. I detailed it more here)

@kozec If there is anything I can do to help out, by providing USB pcaps or otherwise, let me know! Would love to see this work with Steam Deck.

[offalynne]

@tjhorner does UINPUT do anything with it if Steam isn't running ? Does it show up as a DirectInput gamepad device when Windows is installed ?

[Jack-Sibley]

@offalynne I'm afraid not, without steam it's just a raw hid device.

[pattontim]

The official steam client now has support for Steam Deck trackpad typing. The keyboard works more similar to sc-controller where the input is stretched horizontally rather than completely square like with the SC via Steam
Here is my rendition of the input area and how it maps to the square trackpads on Steam with the Steam Deck.

This is the default keyboard in Steam with SC

[yoshimo]

Would a non-developer be able to supply any useful info from the deck to give the development for a driver a head start?

[pattontim]

An unofficial mod for adding plugins to the steam deck menu. If devs do make it work alongside steam, may consider a tool which can modify config.py integrated with steam

https://github.com/SteamDeckHomebrew/PluginLoader

example, calculator app:
https://github.com/SpyrexDE/SDH-Calculator

[cyrozap]

I got my Steam Deck yesterday, but it seemed that no one else had reverse engineered the HID data layout yet, so I decided to give it a try today. Here's what I have so far:

Digital inputs

A bit set in these locations indicates the following:

• 0x08, bit 0: Right trigger (virtual) button pressed
• 0x08, bit 1: Left trigger (virtual) button pressed
• 0x08, bit 2: Right bumper pressed
• 0x08, bit 3: Left bumper pressed
• 0x08, bit 4: "Y" button pressed
• 0x08, bit 5: "B" button pressed
• 0x08, bit 6: "X" button pressed
• 0x08, bit 7: "A" button pressed
• 0x09, bit 0: D-pad UP pressed
• 0x09, bit 1: D-pad RIGHT pressed
• 0x09, bit 2: D-pad LEFT pressed
• 0x09, bit 3: D-pad DOWN pressed
• 0x09, bit 4: "View" button (two rectangles, above left thumbstick) pressed
• 0x09, bit 5: "STEAM" button pressed
• 0x09, bit 6: "Options" ("≡", above right thumbstick) button pressed
• 0x09, bit 7: L5 pressed
• 0x0A, bit 0: R5 pressed
• 0x0A, bit 1: Left trackpad pressed (not possible for a "press" to be detected without the pad being touched--i.e., bit 3 also being set)
• 0x0A, bit 2: Right trackpad pressed (not possible for a "press" to be detected without the pad being touched--i.e., bit 4 also being set)
• 0x0A, bit 3: Left trackpad touched
• 0x0A, bit 4: Right trackpad touched
• 0x0A, bit 6: Left thumbstick pressed
• 0x0B, bit 2: Right thumbstick pressed
• 0x0D, bit 1: L4 pressed
• 0x0D, bit 2: R4 pressed
• 0x0D, bit 6: Left thumbstick capacitive pad touched
• 0x0D, bit 7: Right thumbstick capacitive pad touched
• 0x0E, bit 2: "Quick access" ("...") button pressed

Analog inputs

Notes

• All fields are 16-bit, signed, little-endian integers unless otherwise noted.
• Accelerometer axes are treated as follows:
  • With the screen as the "front" of the console, and the exhaust vent as the "top" of the console, and the screen facing the user:
    • Moving the console ventward will result in a positive acceleration in the X-direction.
    • Moving the console left will result in a positive acceleration in the Y-direction.
    • Moving the console toward the user will result in a positive acceleration in the Z-direction.
  • Basically, it's the right-hand rule. With the thumb pointing up and the index finger pointing forward:
    • Thumb is positive-Z.
    • Index finger is positive-X.
    • Middle finger is positive-Y.
• Gyroscope axes are treated as follows:
  • Pitch axis points out the right side of the console.
  • Yaw axis points out the exhaust vent side of the console.
  • Roll axis points out the screen side of the console.

Fields

• 0x10: Left trackpad X-axis, positive == East, negative == West
• 0x12: Left trackpad Y-axis, positive == North, negative == South
• 0x14: Right trackpad X-axis, positive == East, negative == West
• 0x16: Right trackpad Y-axis, positive == North, negative == South
• 0x18: Accelerometer X-axis
• 0x1A: Accelerometer Y-axis
• 0x1C: Accelerometer Z-axis
• 0x1E: Gyroscope pitch
• 0x20: Gyroscope yaw
• 0x22: Gyroscope roll
• 0x24: Q1?
• 0x26: Q2?
• 0x28: Q3?
• 0x2A: Q4?
• 0x2C: Left analog trigger pressure (never goes negative--bit 15 always zero), higher value == higher pressure
• 0x2E: Right analog trigger pressure (never goes negative--bit 15 always zero), higher value == higher pressure
• 0x30: Left thumbstick X-axis, positive == East, negative == West
• 0x32: Left thumbstick Y-axis, positive == North, negative == South
• 0x34: Right thumbstick X-axis, positive == East, negative == West
• 0x36: Right thumbstick Y-axis, positive == North, negative == South
• 0x38: Left trackpad pressure (never goes negative--bit 15 always zero), higher value == higher pressure
• 0x3A: Right trackpad pressure (never goes negative--bit 15 always zero), higher value == higher pressure
• 0x3C: ?
• 0x3E: ?

@kozec, does this help?

[tjhorner]

@cyrozap I believe 0x20 is yaw and 0x22 is roll

[cyrozap]

Here's the USB descriptor, in case anyone needs it:

Bus 003 Device 002: ID 28de:1205 Valve Software Steam Controller
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x28de Valve Software
  idProduct          0x1205 
  bcdDevice            1.00
  iManufacturer           1 Valve Software
  iProduct                2 Steam Controller
  iSerial                 3 123456789ABCDEF
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x005b
    bNumInterfaces          3
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              500mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      0 
      bInterfaceProtocol      2 Mouse
      iInterface              0 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.10
          bCountryCode           33 US
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      50
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval               1
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      1 Boot Interface Subclass
      bInterfaceProtocol      1 Keyboard
      iInterface              0 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.10
          bCountryCode           33 US
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      39
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval               1
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass         3 Human Interface Device
      bInterfaceSubClass      0 
      bInterfaceProtocol      0 
      iInterface              0 
        HID Device Descriptor:
          bLength                 9
          bDescriptorType        33
          bcdHID               1.10
          bCountryCode           33 US
          bNumDescriptors         1
          bDescriptorType        34 Report
          wDescriptorLength      53
         Report Descriptors: 
           ** UNAVAILABLE **
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x83  EP 3 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               1
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x03  EP 3 OUT
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               1
Device Status:     0x0000
  (Bus Powered)

[cyrozap]

@tjhorner I did some more testing today, and you're correct--I didn't follow the right-hand rule when labeling the accelerometer and gyroscope axes, so I had X/Y and roll/yaw swapped. I've updated my earlier comment to reflect these changes, as well as to describe the gyroscope axes (since they're different from the accelerometer axes).

All this has really started to confuse me, so I'm tempted to mock up a diagram illustrating how the six axes are positioned relative to the controller and how they relate to the values in the HID report.

[cyrozap]

Behold--my extremely professional diagrams:

Axis names and positive directions correspond to the ones in my earlier post.