[PATCH v2 3/3] PCI: ARM: add support for generic PCI host controller

[Rob Herring]

On Thu, Feb 13, 2014 at 10:22 AM, Kumar Gala <galak at codeaurora.org> wrote:
>
> On Feb 13, 2014, at 5:07 AM, Will Deacon <will.deacon at arm.com> wrote:
>
>> On Wed, Feb 12, 2014 at 09:51:48PM +0000, Kumar Gala wrote:
>>>
>>> On Feb 12, 2014, at 2:16 PM, Will Deacon <will.deacon at arm.com> wrote:
>>>
>>>> This patch adds support for a generic PCI host controller, such as a
>>>> firmware-initialised device with static windows or an emulation by
>>>> something such as kvmtool.
>>>>
>>>> The controller itself has no configuration registers and has its address
>>>> spaces described entirely by the device-tree (using the bindings from
>>>> ePAPR). Both CAM and ECAM are supported for Config Space accesses.
>>>>
>>>> Corresponding documentation is added for the DT binding.
>>>>
>>>> Signed-off-by: Will Deacon <will.deacon at arm.com>
>>>> ---
>>>> .../devicetree/bindings/pci/arm-generic-pci.txt    |  51 ++++
>>>> drivers/pci/host/Kconfig                           |   7 +
>>>> drivers/pci/host/Makefile                          |   1 +
>>>> drivers/pci/host/pci-arm-generic.c                 | 318 +++++++++++++++++++++
>>>> 4 files changed, 377 insertions(+)
>>>> create mode 100644 Documentation/devicetree/bindings/pci/arm-generic-pci.txt
>>>> create mode 100644 drivers/pci/host/pci-arm-generic.c
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/pci/arm-generic-pci.txt b/Documentation/devicetree/bindings/pci/arm-generic-pci.txt
>>>> new file mode 100644
>>>> index 000000000000..cc7a35ecfa2d
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/pci/arm-generic-pci.txt
>>>> @@ -0,0 +1,51 @@
>>>> +* ARM generic PCI host controller
>>>> +
>>>> +Firmware-initialised PCI host controllers and PCI emulations, such as the
>>>> +virtio-pci implementations found in kvmtool and other para-virtualised
>>>> +systems, do not require driver support for complexities such as regulator and
>>>> +clock management. In fact, the controller may not even require the
>>>> +configuration of a control interface by the operating system, instead
>>>> +presenting a set of fixed windows describing a subset of IO, Memory and
>>>> +Configuration Spaces.
>>>> +
>>>> +Such a controller can be described purely in terms of the standardized device
>>>> +tree bindings communicated in pci.txt:
>>>> +
>>>> +- compatible     : Must be "arm,pci-cam-generic" or "arm,pci-ecam-generic"
>>>> +                   depending on the layout of configuration space (CAM vs
>>>> +                   ECAM respectively)
>>>
>>> What's arm specific here?  I don't have a great suggestion, but seems odd
>>> for this to be vendor prefixed with "arm".
>>
>> Happy to change it, but I'm also struggling for names. Maybe "linux,..."?
>
> I was thinking that as well, I'd say go with "linux,".

Just drop the prefix altogether.

I'm wondering if this should have host or rc in the name.

Rob