[PATCH v2 2/2] pci, pcie-thunder-pem: Add PCIe host driver for ThunderX processors.
David Daney
ddaney at caviumnetworks.com
Mon Jan 4 10:18:48 PST 2016
On 12/29/2015 12:37 PM, Rob Herring wrote:
> On Tue, Dec 22, 2015 at 03:43:52PM -0800, David Daney wrote:
>> From: David Daney <david.daney at cavium.com>
>>
>> Some Cavium ThunderX processors require quirky access methods for the
>> config space of the PCIe bridge. Add a driver to provide these config
>> space accessor functions. The pci-host-common code is used to
>> configure the PCI machinery.
>
> Same comments again...
Yes, I think your initial reply and my v2 must have crossed in
mid-flight. Then I was on holiday, but now I can respond...
>
>> Signed-off-by: David Daney <david.daney at cavium.com>
>> ---
>> .../devicetree/bindings/pci/pcie-thunder-pem.txt | 43 ++++
>> drivers/pci/host/Kconfig | 7 +
>> drivers/pci/host/Makefile | 1 +
>> drivers/pci/host/pcie-thunder-pem.c | 283 +++++++++++++++++++++
>> 4 files changed, 334 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/pci/pcie-thunder-pem.txt
>> create mode 100644 drivers/pci/host/pcie-thunder-pem.c
>>
>> diff --git a/Documentation/devicetree/bindings/pci/pcie-thunder-pem.txt b/Documentation/devicetree/bindings/pci/pcie-thunder-pem.txt
>> new file mode 100644
>> index 0000000..52f56b3
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pci/pcie-thunder-pem.txt
>> @@ -0,0 +1,43 @@
>> +* ThunderX PEM PCIe host controller
>> +
>> +Firmware-initialized PCIe host controller found on some Cavium
>> +ThunderX processors.
>> +
>> +The properties and their meanings are identical to those described in
>> +host-generic-pci.txt except as listed below.
>> +
>> +Properties of the host controller node that differ from
>> +host-generic-pci.txt:
>> +
>> +- compatible : Must be "cavium,pci-host-thunder-pem"
>
> pcie rather than pci?
Technically it is a PCI host controller at the root, and doesn't become
PCIe until we traverse a PCIe RC bridge, Because of this, and also
because there is deployed firmware supplying this compatible string, I
would like to keep the name as is.
If you really want consistency, we could rename the driver (and this
binding description file) to be pci-thunder-pem.
>
>> +
>> +- reg : Two entries: First the configuration space for down
>> + stream devices base address and size, as accessed
>> + from the parent bus. Second, the register bank of
>> + the PEM device PCIe bridge.
>> +
>> +Example:
>> +
>> + pem2 {
>
> pcie-controller at ... instead of pem2.
That is purely cosmetic, as the names are not used for anything. I can
change it as you suggest.
[...]
Thanks,
David Daney
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