On Sat, May 15, 2021 at 02:40:51PM +0200, Sergio Paracuellos wrote:
> MediaTek MT7621 PCIe subsys supports single Root complex (RC)
> with 3 Root Ports. Each Root Ports supports a Gen1 1-lane Link.
> Topology is as follows:
>
> MT7621 PCIe HOST Topology
>
> .-------.
> | |
> | CPU |
> | |
> '-------'
> |
> |
> |
> v
> .------------------.
> .-----------| HOST/PCI Bridge |------------.
> | '------------------' | Type1
> BUS0 | | | Access
> v v v On Bus0
> .-------------. .-------------. .-------------.
> | VIRTUAL P2P | | VIRTUAL P2P | | VIRTUAL P2P |
> | BUS0 | | BUS0 | | BUS0 |
> | DEV0 | | DEV1 | | DEV2 |
> '-------------' '-------------' '-------------'
> Type0 | Type0 | Type0 |
> Access BUS1 | Access BUS2| Access BUS3|
> On Bus1 v On Bus2 v On Bus3 v
> .----------. .----------. .----------.
> | Device 0 | | Device 0 | | Device 0 |
> | Func 0 | | Func 0 | | Func 0 |
> '----------' '----------' '----------'
>
> This driver has been very long time in staging and I have been cleaning
> it from its first versions where there was code kaos and PCI_LEGACY support.
> Original code came probably from openWRT based on mediatek's SDK code. There
> is no documentation at all about the mt7621 PCI subsystem.
> I have been cleaning it targeting mt7621 SoC which is the one I use in
> my GNUBee PC1 board and HiLink HLK-MT7621A evaluation board.
>
> Now I think is clean enough to be moved into 'arch/mips/pci'.
>
> This driver also uses already mainlined pci phy driver located in
> 'drivers/phy/ralink/phy-mt7621-pci.c'. There are two instances of
> the phy being the first one dual ported for pci0 and pci1, and the
> second one not dual ported dedicated to pci2. Because of writing twice
> some phy registers of the dual-ported one sometimes become in not
> confident boot cycles we have to take care of this when device link
> is checked here in controller driver. We power on the dual ported-phy
> if there is something connected in pcie0 or pcie1. In the same manner
> we have to properly disable it only if nothing is connected in of both
> pcie0 and pci1 slots.
>
> Another thing that must be mentioned is that this driver uses IO
> in physical address 0x001e160000. IO_SPACE_LIMIT for MIPS is 0xffff
> so some generic PCI functions (like of_pci_range_to_resource) won't
> work and the resource ranges part for IO is set manually.
>
> I had already sent binding documentation to be reviewed but I am
> include also here with the driver itself and this cover letter
> to make easy review process.
>
> Best regards,
> Sergio Paracuellos
>
> Sergio Paracuellos (4):
> dt-bindings: mt7621-pci: PCIe binding documentation for MT7621 SoCs
> MIPS: pci: Add driver for MT7621 PCIe controller
> staging: mt7621-pci: remove driver from staging
Generally it's better if the move can be done in one commit instead of
an add followed by a remove.
I see there are a bunch of MIPS PCI controller drivers in
arch/mips/pci/, so I see the argument for putting this one there as
well.
But most of the similar drivers are in drivers/pci/controller/, where
I think it's easier to keep them up to date with changes in the PCI
core. Have you considered putting this one there?
> MAINTAINERS: add myself as maintainer of the MT7621 PCI controller
> driver
>
> .../bindings/pci/mediatek,mt7621-pci.yaml | 149 ++++++++++++++++++
> MAINTAINERS | 6 +
> arch/mips/pci/Makefile | 1 +
> .../mt7621-pci => arch/mips/pci}/pci-mt7621.c | 0
> arch/mips/ralink/Kconfig | 9 +-
> drivers/staging/Kconfig | 2 -
> drivers/staging/Makefile | 1 -
> drivers/staging/mt7621-pci/Kconfig | 8 -
> drivers/staging/mt7621-pci/Makefile | 2 -
> drivers/staging/mt7621-pci/TODO | 4 -
> .../mt7621-pci/mediatek,mt7621-pci.txt | 104 ------------
> 11 files changed, 164 insertions(+), 122 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.yaml
> rename {drivers/staging/mt7621-pci => arch/mips/pci}/pci-mt7621.c (100%)
> delete mode 100644 drivers/staging/mt7621-pci/Kconfig
> delete mode 100644 drivers/staging/mt7621-pci/Makefile
> delete mode 100644 drivers/staging/mt7621-pci/TODO
> delete mode 100644 drivers/staging/mt7621-pci/mediatek,mt7621-pci.txt
>
> --
> 2.25.1
