Calling all hotkey expertise...

Fri Feb 18 09:20:04 UTC 2011

On Thu, 2011-02-17 at 22:15 -0200, Herton Ronaldo Krzesinski wrote:
> Em Qui, 2011-02-17 às 12:31 +0000, Colin Ian King escreveu:
> > Thanks Herton,
> > 
> > On Thu, 2011-02-10 at 19:58 -0200, Herton Ronaldo Krzesinski wrote:
> > > Em Qui, 2011-02-10 às 21:00 +0000, Colin Ian King escreveu:
> > > From what I remember and from experience (correct me if I say something
> > > wrong), vendors usually implement hotkeys:
> > > - using a WMI interface, where a driver needs to be written. The driver
> > > receives a WMI notification and calls wmi_evaluate_method (WMXX) to get
> > > the response/data so if the event is a hotkey it gets a code and
> > > translates it to input layer. It's a lot easier if the vendor gives
> > > information on its WMI implementation, as by nature of ACPI-WMI every
> > > vendor can choose what parameters/format to accept on WMI methods etc.
> > 
> > Yep, good one and becoming more frequent. As documented here:
> > https://wiki.ubuntu.com/Kernel/Reference/WMI
> > 
> > Personally, I'd like to write a MOF disassembler to extract a high level
> > view of the WMI configuration from the WQxx objects rather than by
> > poking around and figuring out how these work by trial-and-error...
> > when I have time.. :-)
> 
> Nice, would be great to have such tool.
> 
> I remembered now, there is also the paramters of wmi module that were
> added "recently" to the kernel (2.6.35) and are very useful, specially
> in detecting if the machine has wmi objects and if we are receiving
> things through wmi.
> wmi.debug_dump_wdg=1 to list wmi interfaces
> wmi.debug_event=1 to show on dmesg events we received

Sweet.  The firmware test suite has a WMI dump test:

sudo fwts wmi -

..but no event dumping. That's one I can add by watching for SCIs and
GPEs..

> 
> Especially when hotkeys doesn't work, is useful to enable debug_event
> because if it's implemented by wmi, when we press the hotkey information
> will appear on dmesg. May be it isn't useful for vendor documentation,
> but is useful to us and users when hotkeys doesn't work and we want to
> check if it's done by wmi or testing when developing.
> 
> > > - sending codes directly via the keyboard controller (so implemented
> > > directly in embedded controller, also some people call it as keyboard
> > > bios, but anyway I think should be on ec firmware). So kernel directly
> > > receive keyboard codes on keyboard input device, no need to extra
> > > driver, but many times the codes have to be remaped on user space to the
> > > real key code meaning/value (udev keymaps)
> > 
> > I wonder if there are any standard configurations we can recommend for
> > this
> > method of hotkeys?  Any ideas anyone?
> 
> Well, I think at least use the common known 0xe0 scan codes for
> multimedia etc. If we look at some of the keymaps in udev, there are
> some multimedia keys which could have been reported using a common known
> scancode which atkbd recognizes (the so called "Windows Multimedia Scan
> Codes"). But instead the vendor chose a non-standard scan code, which
> have to be remmaped.
> 
> I did a test program (attached for reference) which prints current
> extended scan codes which atkbd translates to input layer. Here I paste
> only the relevant entries, first column is the key sent to user space
> (last column its respective numeric value):
> 
> E0 Scan Code Set 1 - scancodes
> 
> PreviousSong - key, press == 0xe0 0x10, release == 0xe0 0x90, ScanCode == 0x90, keycode == 165
>     NextSong - key, press == 0xe0 0x19, release == 0xe0 0x99, ScanCode == 0x99, keycode == 163
>         Mute - key, press == 0xe0 0x20, release == 0xe0 0xa0, ScanCode == 0xa0, keycode == 113
>         Calc - key, press == 0xe0 0x21, release == 0xe0 0xa1, ScanCode == 0xa1, keycode == 140
>    PlayPause - key, press == 0xe0 0x22, release == 0xe0 0xa2, ScanCode == 0xa2, keycode == 164
>       StopCD - key, press == 0xe0 0x24, release == 0xe0 0xa4, ScanCode == 0xa4, keycode == 166
>   VolumeDown - key, press == 0xe0 0x2e, release == 0xe0 0xae, ScanCode == 0xae, keycode == 114
>     VolumeUp - key, press == 0xe0 0x30, release == 0xe0 0xb0, ScanCode == 0xb0, keycode == 115
>     HomePage - key, press == 0xe0 0x32, release == 0xe0 0xb2, ScanCode == 0xb2, keycode == 172
>        Pause - key, press == 0xe0 0x45, release == 0xe0 0xc5, ScanCode == 0xc5, keycode == 119
>        Pause - key, press == 0xe0 0x46, release == 0xe0 0xc6, ScanCode == 0xc6, keycode == 119
>        Power - key, press == 0xe0 0x5e, release == 0xe0 0xde, ScanCode == 0xde, keycode == 116
>        Sleep - key, press == 0xe0 0x5f, release == 0xe0 0xdf, ScanCode == 0xdf, keycode == 142
>       WakeUp - key, press == 0xe0 0x63, release == 0xe0 0xe3, ScanCode == 0xe3, keycode == 143
>       Search - key, press == 0xe0 0x65, release == 0xe0 0xe5, ScanCode == 0xe5, keycode == 217
>    Bookmarks - key, press == 0xe0 0x66, release == 0xe0 0xe6, ScanCode == 0xe6, keycode == 156
>      Refresh - key, press == 0xe0 0x67, release == 0xe0 0xe7, ScanCode == 0xe7, keycode == 173
>         Stop - key, press == 0xe0 0x68, release == 0xe0 0xe8, ScanCode == 0xe8, keycode == 128
>      Forward - key, press == 0xe0 0x69, release == 0xe0 0xe9, ScanCode == 0xe9, keycode == 159
>         Back - key, press == 0xe0 0x6a, release == 0xe0 0xea, ScanCode == 0xea, keycode == 158
>     Computer - key, press == 0xe0 0x6b, release == 0xe0 0xeb, ScanCode == 0xeb, keycode == 157
>         Mail - key, press == 0xe0 0x6c, release == 0xe0 0xec, ScanCode == 0xec, keycode == 155
>        Media - key, press == 0xe0 0x6d, release == 0xe0 0xed, ScanCode == 0xed, keycode == 226
> 
> E0 Scan Code Set 2 - scancodes
> 
>       Search - key, press == 0xe0 0x10, release == 0xe0 0x90, ScanCode == 0x90, keycode == 217
> PreviousSong - key, press == 0xe0 0x15, release == 0xe0 0x95, ScanCode == 0x95, keycode == 165
>    Bookmarks - key, press == 0xe0 0x18, release == 0xe0 0x98, ScanCode == 0x98, keycode == 156
>      Refresh - key, press == 0xe0 0x20, release == 0xe0 0xa0, ScanCode == 0xa0, keycode == 173
>   VolumeDown - key, press == 0xe0 0x21, release == 0xe0 0xa1, ScanCode == 0xa1, keycode == 114
>         Mute - key, press == 0xe0 0x23, release == 0xe0 0xa3, ScanCode == 0xa3, keycode == 113
>         Stop - key, press == 0xe0 0x28, release == 0xe0 0xa8, ScanCode == 0xa8, keycode == 128
>         Calc - key, press == 0xe0 0x2b, release == 0xe0 0xab, ScanCode == 0xab, keycode == 140
>      Forward - key, press == 0xe0 0x30, release == 0xe0 0xb0, ScanCode == 0xb0, keycode == 159
>     VolumeUp - key, press == 0xe0 0x32, release == 0xe0 0xb2, ScanCode == 0xb2, keycode == 115
>    PlayPause - key, press == 0xe0 0x34, release == 0xe0 0xb4, ScanCode == 0xb4, keycode == 164
>        Power - key, press == 0xe0 0x37, release == 0xe0 0xb7, ScanCode == 0xb7, keycode == 116
>         Back - key, press == 0xe0 0x38, release == 0xe0 0xb8, ScanCode == 0xb8, keycode == 158
>     HomePage - key, press == 0xe0 0x3a, release == 0xe0 0xba, ScanCode == 0xba, keycode == 172
>       StopCD - key, press == 0xe0 0x3b, release == 0xe0 0xbb, ScanCode == 0xbb, keycode == 166
>        Sleep - key, press == 0xe0 0x3f, release == 0xe0 0xbf, ScanCode == 0xbf, keycode == 142
>     Computer - key, press == 0xe0 0x40, release == 0xe0 0xc0, ScanCode == 0xc0, keycode == 157
>         Mail - key, press == 0xe0 0x48, release == 0xe0 0xc8, ScanCode == 0xc8, keycode == 155
>     NextSong - key, press == 0xe0 0x4d, release == 0xe0 0xcd, ScanCode == 0xcd, keycode == 163
>        Media - key, press == 0xe0 0x50, release == 0xe0 0xd0, ScanCode == 0xd0, keycode == 226
>       WakeUp - key, press == 0xe0 0x5e, release == 0xe0 0xde, ScanCode == 0xde, keycode == 143
>        Pause - key, press == 0xe0 0x77, release == 0xe0 0xf7, ScanCode == 0xf7, keycode == 119
>        Pause - key, press == 0xe0 0x7e, release == 0xe0 0xfe, ScanCode == 0xfe, keycode == 119
> 
> So, for example, if vendor implements keyboard sending by default Scan
> Code Set 1 (Translated set 2 mode in atkbd), and he has a hotkey
> Play/Pause, then instead of using an arbitrary code he should send the
> raw scan code 0xe0 0x22 for press, 0xe0 0xa2 for release, as atkbd
> already has a default mapping.
> 
> If vendor implements keyboard sending by default Scan Code Set 2, for
> Play/Pause the codes should be 0xe0 0x34 / 0xe0 0xb4 (press/release).
> 
> I propose above based on documentation I found at
> http://www.computer-engineering.org/ps2keyboard/ (explains about scan
> codes etc.) and research I did today on atkbd code.
> 
> For keys which don't have scan code listed above, we can't do much, we
> will have to remap and vendor choose some code, unless someone comes
> with some standard for more scan code values, which then we can put into
> atkbd keymaps.
> 
> To be more clear also, I tested to confirm with my notebook (reports
> Scan Code Set 1) which send these standard multimedia scancodes, no
> remapping needed. To check raw scan codes sent by keyboard, I did:
> echo 0 > /sys/devices/platform/i8042/serio0/softraw
> To disable the softraw mode so you can get the raw codes and use evtest:
> evtest /dev/input/eventX
> 
> When I press the hotkey, I get the raw code, the emulated ScanCode
> (index which atkbd uses to get the real input code from keycode array)
> and the translated key code. This procedure of disabled softraw and
> evtest I found very useful for testing. 
> 
> If anyones sees something missing or other issue please feel free to add
> more information.
> 