Re: [PATCH V5 3/3] ARM64 LPC: LPC driver implementation on Hip06

[zhichang.yuan]

Hi, Arnd,

On 2016/11/10 5:34, Arnd Bergmann wrote:
> On Wednesday, November 9, 2016 12:10:43 PM CET Gabriele Paoloni wrote:
>>> On Tuesday, November 8, 2016 11:47:09 AM CET zhichang.yuan wrote:
>>>> +       /*
>>>> +        * The first PCIBIOS_MIN_IO is reserved specifically for
>>> indirectIO.
>>>> +        * It will separate indirectIO range from pci host bridge to
>>>> +        * avoid the possible PIO conflict.
>>>> +        * Set the indirectIO range directly here.
>>>> +        */
>>>> +       lpcdev->io_ops.start = 0;
>>>> +       lpcdev->io_ops.end = PCIBIOS_MIN_IO - 1;
>>>> +       lpcdev->io_ops.devpara = lpcdev;
>>>> +       lpcdev->io_ops.pfin = hisilpc_comm_in;
>>>> +       lpcdev->io_ops.pfout = hisilpc_comm_out;
>>>> +       lpcdev->io_ops.pfins = hisilpc_comm_ins;
>>>> +       lpcdev->io_ops.pfouts = hisilpc_comm_outs;
>>>
>>> I have to look at patch 2 in more detail again, after missing a few
>>> review
>>> rounds. I'm still a bit skeptical about hardcoding a logical I/O port
>>> range here, and would hope that we can just go through the same
>>> assignment of logical port ranges that we have for PCI buses,
>>> decoupling
>>> the bus addresses from the linux-internal ones.
>>
>> The point here is that we want to avoid any conflict/overlap between
>> the LPC I/O space and the PCI I/O space. With the assignment above
>> we make sure that LPC never interfere with PCI I/O space.
> 
> But we already abstract the PCI I/O space using dynamic registration.
> There is no need to hardcode the logical address for ISA, though
> I think we can hardcode the bus address to start at zero here.

Do you means that we can pick up the maximal I/O address from all children's
device resources??

Thanks,
Zhichang

> 
> 	Arnd
> 
> .
>