[PATCH v4 0/4] PCI: mediatek-gen3: Add 2-lanes mode support + clock

[Christian Marangi <ansuelsmth@gmail.com>]

This small series introduce support for 2-lanes mode for Airoha AN7581
SoC. This is needed for correctly functionality of Eagle WiFi Card
normally attached to this SoC that require a 2-line PCIe card to
correctly work (and give the proper performance)

The first 2 patch address a limitation of the PCIe implementation
where the PERSTOUT reset were indirectly asserted and deasserted
all at the same time (for all the 3 PCIe card) with PCIe
enable and disable.
The 2 patch address this and introduce correct reset to control
reset line for the relevant PCIe line.

The last 2 patch add additional logic and support to assert
and deassert the PERSTOUT and also apply the required configuration
for 2-lanes mode.

2-lanes mode is implemented in DT by adding the required property
and by defining the "num-lanes" to 2.

Changes v4:
- Improve DT split patch (drop unneeded property)
- Handle power_down PERSTOUT
Changes v3:
- Add Ack from Krzysztof
- Improve commit description of PCIe patch
- Use pcie->num_lanes instead of possible uninit variable num_lanes
Changes v2:
- Address typo regs -> reg in Documentation
- Address typo lan -> lane in Documentation
- Apply a suggested fix from Airoha for PCIe MUX configuration
  before PHY init
- Parse secondary reg in probe
- Add missing reset_status handling for inverted bits
- Move SCU to local handling in power_up
- Add check for max num-lanes for EN7581

Christian Marangi (4):
  dt-bindings: clock: airoha: Add additional reset for PCIe PERSTOUT
  clk: en7523: add support for dedicated PCIe PERSTOUT reset
  dt-bindings: PCI: mediatek-gen3: Split Airoha schema and document
    2-lanes
  PCI: mediatek-gen3: Add 2-lanes mode support for Airoha AN7581

 .../bindings/pci/airoha,en7581-pcie.yaml      | 244 ++++++++++++++++++
 .../bindings/pci/mediatek-pcie-gen3.yaml      |  77 +-----
 drivers/clk/clk-en7523.c                      |  39 ++-
 drivers/pci/controller/pcie-mediatek-gen3.c   | 106 ++++++--
 .../dt-bindings/reset/airoha,en7581-reset.h   |   4 +
 5 files changed, 370 insertions(+), 100 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pci/airoha,en7581-pcie.yaml

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2.53.0