On Fri, Dec 22, 2017 at 12:24 PM, Tony Lindgren [off-list ref] wrote:
* Kishon Vijay Abraham I [off-list ref] [171222 06:06]:
quoted
Hi Rob,
On Thursday 21 December 2017 12:27 AM, Rob Herring wrote:
quoted
On Tue, Dec 19, 2017 at 02:28:22PM +0530, Kishon Vijay Abraham I wrote:
quoted
Add syscon properties required for configuring PCIe in x2 lane mode.
Signed-off-by: Kishon Vijay Abraham I <redacted>
Signed-off-by: Sekhar Nori <redacted>
---
Documentation/devicetree/bindings/pci/ti-pci.txt | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/pci/ti-pci.txt b/Documentation/devicetree/bindings/pci/ti-pci.txt
index 82cb875e4cec..bfbc77ac7355 100644
--- a/Documentation/devicetree/bindings/pci/ti-pci.txt
+++ b/Documentation/devicetree/bindings/pci/ti-pci.txt
@@ -13,6 +13,12 @@ PCIe DesignWare Controller
- ti,hwmods : Name of the hwmod associated to the pcie, "pcie<X>",
where <X> is the instance number of the pcie from the HW spec.
- num-lanes as specified in ../designware-pcie.txt
+ - ti,syscon-lane-conf : phandle/offset pair. Phandle to the system control
+ module and the register offset to specify 1 lane or
+ 2 lane.
+ - ti,syscon-lane-sel : phandle/offset pair. Phandle to the system control
+ module and the register offset to specify lane
+ selection.
Adding a property for every syscon register doesn't really scale and
doesn't work if the register layout changes.
The register layout doesn't really change between silicon revisions and for new
SoCs, the phandle and the register offset for that SoC will have to be
populated again.
And what about SoCs that don't exist yet?
quoted
Having said that, I'm not aware of any other alternative here.
What would you do if you had 20 different syscon registers to
configure? Add 20 properties? No, you would have per SoC functions in
the driver to handle the different cases.
Sorry I did not realize this is still open. Sounds like I need to
revert commit 4ece93c020e3 ("ARM: dts: dra7: Add properties to
enable PCIe x2 lane mode"), let me know if that is not the case.
It's fine, I guess. Keep adding more syscon phandles and then I'll NAK
it (if I remember :)).
Rob