[PATCH v6 0/9] Add support for Hikey 970 PCIe

[Mauro Carvalho Chehab <mchehab+huawei@kernel.org>]

This series depends on this one:
	https://lore.kernel.org/lkml/cover.1626515862.git.mchehab+huawei@kernel.org/

It is available, with its patch dependencies against v5.14-rc1 at:
	https://github.com/mchehab/linux/commits/pcie-alternate

This series add support at the pcie-kirin dirver for it to use a separate PHY driver.

Yet, in order to preserve the existing DT schema for Kirin 960, it keeps the
Kirin 960 PHY inside the pci driver. I tried to find a way to split it while keeping
the DT schema backward-compatible, but currently the PHY core doesn't allow
that, as it relies on a "phy" property at the pcie node in order to recognize the
PHY driver.

Once the pci-kiring is modified to support an external PHY driver, add a
Kirin 970 PHY and add the needed properties for the HiKey 970 board to
detect the PCIe.

It should be noticed that the HiKey 970 design uses 4 different GPIO pins, one 
for each PERST# signal for each PCIe bus device:

    - GPIO 56 has a pullup logic from 1V8 to 2V5
      connected to a PCIe bridge chip (PEX 8606);
    - GPIO 25 has a pullup logic from 1V8 to 3V3
      connected to the PERST# pin at the M.2 slot;
    - GPIO 220 has a pullup logic from 1V8 to 3V3
      connected to the PERST# pin at the PCIe mini slot;
    - GPIO 203 has a pullup logic from 1V8 to 3V3
      connected to the PERST# pin at the Ethernet chipset.

At the first versions, those were mapped as part of the pci-bus, but the
pci-bus.yaml schema only allows a single PERST# GPIO. So, on v5, those
were moved to the PHY DT schema. However, as Rob complained, on this
version, I opted to add a separate patch (the last one) that moves those
back to the PCIe of-node. 

If such patch 09/09 is accepted, then this patch for the DT schema should 
also be accepted:

   https://github.com/devicetree-org/dt-schema/pull/56

Tested on Hikey970:

  $ lspci
  00:00.0 PCI bridge: Huawei Technologies Co., Ltd. Device 3670 (rev 01)
  01:00.0 PCI bridge: PLX Technology, Inc. PEX 8606 6 Lane, 6 Port PCI Express Gen 2 (5.0 GT/s) Switch (rev ba)
  02:01.0 PCI bridge: PLX Technology, Inc. PEX 8606 6 Lane, 6 Port PCI Express Gen 2 (5.0 GT/s) Switch (rev ba)
  02:04.0 PCI bridge: PLX Technology, Inc. PEX 8606 6 Lane, 6 Port PCI Express Gen 2 (5.0 GT/s) Switch (rev ba)
  02:05.0 PCI bridge: PLX Technology, Inc. PEX 8606 6 Lane, 6 Port PCI Express Gen 2 (5.0 GT/s) Switch (rev ba)
  02:07.0 PCI bridge: PLX Technology, Inc. PEX 8606 6 Lane, 6 Port PCI Express Gen 2 (5.0 GT/s) Switch (rev ba)
  02:09.0 PCI bridge: PLX Technology, Inc. PEX 8606 6 Lane, 6 Port PCI Express Gen 2 (5.0 GT/s) Switch (rev ba)
  06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 07)

  $ ethtool enp6s0
  Settings for enp6s0:
	Supported ports: [ TP	 MII ]
	Supported link modes:   10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Half 1000baseT/Full
	Supported pause frame use: Symmetric Receive-only
	Supports auto-negotiation: Yes
	Supported FEC modes: Not reported
	Advertised link modes:  10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Half 1000baseT/Full
	Advertised pause frame use: Symmetric Receive-only
	Advertised auto-negotiation: Yes
	Advertised FEC modes: Not reported
	Link partner advertised link modes:  10baseT/Half 10baseT/Full
	                                     100baseT/Half 100baseT/Full
	Link partner advertised pause frame use: Symmetric Receive-only
	Link partner advertised auto-negotiation: Yes
	Link partner advertised FEC modes: Not reported
	Speed: 100Mb/s
	Duplex: Full
	Auto-negotiation: on
	master-slave cfg: preferred slave
	master-slave status: slave
	Port: Twisted Pair
	PHYAD: 0
	Transceiver: external
	MDI-X: Unknown
  netlink error: Operation not permitted
	Link detected: yes

Also tested  that Hikey 960 keeps being supported:

  $ lspci
  00:00.0 PCI bridge: Huawei Technologies Co., Ltd. Device 3660 (rev 01)

---

v6:
- Use an alternative approach, in order to keep the Kirin 960 PHY internal to 
  the driver, in order to not break the DT schema. The PHY-specific code
  were made self-contained at pcie-kirin, in order to make easier to split
  it in the future, if needed.

v5:
- added "static" to hi3670_pcie_get_eyeparam() declaration on patch 6/8

v4:

- dropped the DTS patch, as it depends on a PMIC-related patch series;
- minor changes at the patch description;
- HiKey and HiSilicon are now using the preferred CamelCase format.

Manivannan Sadhasivam (1):
  arm64: dts: HiSilicon: Add support for HiKey 970 PCIe controller
    hardware

Mauro Carvalho Chehab (8):
  PCI: kirin: Reorganize the PHY logic inside the driver
  PCI: kirin: add support for a PHY layer
  PCI: kirin: Use regmap for APB registers
  dt-bindings: PCI: kirin: Fix compatible string
  dt-bindings: phy: Add bindings for HiKey 970 PCIe PHY
  phy: HiSilicon: Add driver for Kirin 970 PCIe PHY
  dt-bindings: PCI: kirin-pcie.txt: Convert it to yaml
  phy-hi3670-pcie: move reset-gpios to the PCIe DT schema

 .../bindings/pci/hisilicon,kirin-pcie.yaml    |  87 ++
 .../devicetree/bindings/pci/kirin-pcie.txt    |  50 -
 .../devicetree/bindings/pci/snps,dw-pcie.yaml |   2 +-
 .../phy/hisilicon,phy-hi3670-pcie.yaml        |  94 ++
 MAINTAINERS                                   |   2 +-
 arch/arm64/boot/dts/hisilicon/hi3670.dtsi     |  70 ++
 .../boot/dts/hisilicon/hikey970-pmic.dtsi     |   1 -
 drivers/pci/controller/dwc/pcie-kirin.c       | 408 +++++---
 drivers/phy/hisilicon/Kconfig                 |  10 +
 drivers/phy/hisilicon/Makefile                |   1 +
 drivers/phy/hisilicon/phy-hi3670-pcie.c       | 896 ++++++++++++++++++
 11 files changed, 1424 insertions(+), 197 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pci/hisilicon,kirin-pcie.yaml
 delete mode 100644 Documentation/devicetree/bindings/pci/kirin-pcie.txt
 create mode 100644 Documentation/devicetree/bindings/phy/hisilicon,phy-hi3670-pcie.yaml
 create mode 100644 drivers/phy/hisilicon/phy-hi3670-pcie.c

-- 
2.31.1