On Wed, Jul 18, 2018 at 12:44:22PM -0700, Trent Piepho wrote: > This is the workaround for the IMX7d Erratum e10728, failure of > initialize PCIe PLL VCO oscillation resulting in PLL lock failure and > failure of the PCI-e link to come up. > > The registers used in the workaround are based on the latest patch in > the NXP kernel, but many things around that have been changed. > > This uses a new node of type fsl,imx-pcie-phy to get the PHY's > registers. The node is found via a phandle added to the PCI-e > controller's node, rather than the incorrect way done in the NXP kernel. > > There is no error if the phandle is not preset (since it's needed except > for the imx7d workaround and no existing dtses have it), but if preset > it is an error if something relating to it does not work. > > ** Should the node be fsl,imx7d-pcie-phy? snps,dw-pcie-phy? > > There is little to no documenation from NXP and Synopsis about this, so I'm > unsure of the PHY's lineage. > > The imx6 PCI-e driver does not use the generic phy layer to interact > with the PHY. It appears PHY related hardware, like clocks, regulators, > and resets, are part of the fsl,imx6q-pcie node. But again, the > topology of this hardware is not documented very well. > > Another approach would be to add the PHY registers as another bank in > the PCI-e node. This would match how the PHY reset, clock, etc. are > done. However, the PHY is attached to a different AXI master than the > PCI-e controller, so the register range really does not belong there. > > Trent Piepho (2): > ARM: dts: imx7d: Add node for PCIe PHY > PCI: imx: Add workaround for e10728, IMX7d PCIe PLL failure Marked as "changes requested", following Lucas' review, please respin as appropriate. Lorenzo > .../devicetree/bindings/pci/fsl,imx6q-pcie.txt | 11 ++++ > arch/arm/boot/dts/imx7d.dtsi | 9 ++++ > drivers/pci/dwc/pci-imx6.c | 59 ++++++++++++++++++++++ > 3 files changed, 79 insertions(+) > > Cc: Shawn Guo <shawnguo@xxxxxxxxxx> > Cc: Sascha Hauer <kernel@xxxxxxxxxxxxxx> > Cc: Fabio Estevam <fabio.estevam@xxxxxxx> > Cc: Richard Zhu <hongxing.zhu@xxxxxxx> > Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx> > > -- > 2.14.4 > >
