Re: [PATCH v3 1/5] i8042: intel-8042 DT documentation

[Roman Volkov <rvolkov@v1ros.org>]

Sun, 31 May 2015 19:00:15 +0300
Roman Volkov <rvolkov@v1ros.org> wrote:

> В Sat, 14 Mar 2015 20:20:38 -0700
> Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> 
> > 
> > Hi Roman,
> > 
> > On Mon, Feb 16, 2015 at 12:11:43AM +0300, Roman Volkov wrote:  
> > > Documentation for 'intel,8042' DT compatible node.
> > > 
> > > Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
> > > Signed-off-by: Roman Volkov <v1ron@v1ros.org>
> > > ---
> > >  .../devicetree/bindings/input/intel-8042.txt       | 26
> > > ++++++++++++++++++++++ 1 file changed, 26 insertions(+)
> > >  create mode 100644
> > > Documentation/devicetree/bindings/input/intel-8042.txt
> > > 
> > > diff --git
> > > a/Documentation/devicetree/bindings/input/intel-8042.txt
> > > b/Documentation/devicetree/bindings/input/intel-8042.txt new file
> > > mode 100644 index 0000000..ab8a3e0 --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/input/intel-8042.txt
> > > @@ -0,0 +1,26 @@
> > > +Intel 8042 Keyboard Controller
> > > +
> > > +Required properties:
> > > +- compatible: should be "intel,8042"
> > > +- regs: memory for keyboard controller
> > > +- interrupts: usually, two interrupts should be specified
> > > (keyboard and aux).
> > > +	However, only one interrupt is also allowed in case of
> > > absence of the
> > > +	physical port in the controller. The i8042 driver must be
> > > loaded with
> > > +	nokbd/noaux option in this case.
> > > +- interrupt-names: interrupt names corresponding to numbers in
> > > the list.
> > > +	"kbd" is the keyboard interrupt and "aux" is the
> > > auxiliary (mouse)
> > > +	interrupt.
> > > +- command-reg: offset in memory for command register
> > > +- status-reg: offset in memory for status register
> > > +- data-reg: offset in memory for data register
> > > +
> > > +Example:
> > > +	i8042@d8008800 {
> > > +		compatible = "intel,8042";
> > > +		regs = <0xd8008800 0x100>;
> > > +		interrupts = <23>, <4>;
> > > +		interrupt-names = "kbd", "aux";
> > > +		command-reg = <0x04>;
> > > +		status-reg = <0x04>;
> > > +		data-reg = <0x00>;
> > > +	};  
> > 
> > No, we already have existing OF bindings for i8042 on sparc and
> > powerpc, I do not think we need to invent a brand new one.
> > 
> > Thanks.
> >   
> 
> Hi Dmitry,
> 
> I see some OF code in i8042-sparcio.h file. There are node definitions
> like "kb_ps2", "keyboard", "kdmouse", "mouse". Are these documented
> somewhere?
> 
> Great if vt8500 is not unique with OF bindings for i8042. The code
> from sparc even looks compatible, only register offsets are hardcoded
> for specific machine. Is it possible to read offsets from Device Tree
> using these existing bindings without dealing with the kernel
> configuration?
> 
> Regards,
> Roman

Sun, 31 May 2015 17:53:22 +0200
Hans de Goede <hdegoede@redhat.com> wrote:

> Have you looked at the existing bindings for ps/2 controllers
> under Documentation/devicetree/bindings/serio ?
>
> Regards,
>
> Hans

Hi Hans,

No, there is no bindings exactly for sparc ps/2 under that folder. There
is documentation for some custom drivers like altera and others, not
sure how much these are compatible with Intel's 8042. The sparcio
header looks like a special case when the Intel's 8042 driver is used
for non-x86 with OF. There is even no 'compatible' property in the
of_device_id in i8042-sparcio.h under drivers/input/serio, just the
name '8042'.

It is still open question what compatible strings should be used for
Intel's ps/2. Also I am not sure if it should be different in context
of different machines (as described in
http://devicetree.org/Device_Tree_Usage#Understanding_the_compatible_Property).
The difference between various machines may be in the register offsets.

Regards,
Roman