Re: What is TYPE_TPM_TIS_ISA? (Not an ISA Device)

[Stefan Berger]

On 7/21/20 12:02 PM, Philippe Mathieu-Daudé wrote:
> Hi Stefan,
>
> I'm trying to understand what is modelling the
> TYPE_TPM_TIS_ISA device.
>
> It inherits from TYPE_ISA_DEVICE, so I expected
> to see an ISA device, but then I noticed:
>
> 1/ it doesn't use the ISA I/O space, it directly
> maps the device in the system memory at a fixed
> address that is not addressable by the ISA bus:
>
> #define TPM_TIS_ADDR_BASE           0xFED40000
>
> 2/ it is not plugged to an ISA BUS (ISABus*)
>
> 3/ no machine plug it using isa_register_ioport()
>     (it is not registered to the ISA memory space)
>
> 4/ the only thing slightly related to ISA is it
> checks the IRQ number is < ISA_NUM_IRQS
>
>
> So it seems this is a plain SysBusDevice. But then
> there is TYPE_TPM_TIS_SYSBUS... What is the difference?

The TIS is modeled as an ISA device as an alternative to being connected 
to the LPC bus, to which it would typically be connected to. I believe 
we also have the ISA.TPM because of Windows only accepting it. Maybe 
this was not quite correct, but does it cause issues?

                } else {
                    dev = aml_device("ISA.TPM");
                    aml_append(dev, aml_name_decl("_HID",
aml_eisaid("PNP0C31")));
                }




> Thanks,
>
> Phil.