Hi, This series adds support for the LAN966x chip when used as a PCI device. For reference, the LAN996x chip is a System-on-chip that integrates an Ethernet switch and a number of other traditional hardware blocks such as a GPIO controller, I2C controllers, SPI controllers, etc. The LAN996x can be used in two different modes: - With Linux running on its Linux built-in ARM cores. This mode is already supported by the upstream Linux kernel, with the LAN996x described as a standard ARM Device Tree in arch/arm/boot/dts/microchip/lan966x.dtsi. Thanks to this support, all hardware blocks in the LAN996x already have drivers in the upstream Linux kernel. - As a PCI device, thanks to its built-in PCI endpoint controller. In this case, the LAN996x ARM cores are not used, but all peripherals of the LAN996x can be accessed by the PCI host using memory-mapped I/O through the PCI BARs. This series aims at supporting this second use-case. As all peripherals of the LAN996x already have drivers in the Linux kernel, our goal is to re-use them as-is to support this second use-case. Therefore, this patch series introduces a PCI driver that binds on the LAN996x PCI VID/PID, and when probed, instantiates all devices that are accessible through the PCI BAR. As the list and characteristics of such devices are non-discoverable, this PCI driver loads a Device Tree overlay that allows to teach the kernel about which devices are available, and allows to probe the relevant drivers in kernel, re-using all existing drivers with no change. This patch series for now adds a Device Tree overlay that describes an initial subset of the devices available over PCI in the LAN996x, and follow-up patch series will add support for more once this initial support has landed. In order to add this PCI driver, a number of preparation changes are needed: - Patches 1 to 5 allow the reset driver used for the LAN996x to be built as a module. Indeed, in the case where Linux runs on the ARM cores, it is common to have the reset driver built-in. However, when the LAN996x is used as a PCI device, it makes sense that all its drivers can be loaded as modules. - Patches 6 and 7 improve the MDIO controller driver to properly handle its reset signal. - Patch 8 fixes an issue in the LAN996x switch driver. - Patches 9 to 13 introduce the internal interrupt controller used in the LAN996x. It is one of the few peripherals in the LAN996x that are only relevant when the LAN996x is used as a PCI device, which is why this interrupt controller did not have a driver so far. - Patches 14 and 15 make some small additions to the OF core and PCI/OF core to consider the PCI device as an interrupt controller. This topic was previously mentioned in [1] to avoid the need of phandle interrupt parents which are not available at some points. - Patches 16 and 17 introduce the LAN996x PCI driver itself, together with its DT bindings. We believe all items from the above list can be merged separately, with no build dependencies. We expect: - Patches 1 to 5 to be taken by reset maintainers - Patches 6, 7 and 8 to be taken by network driver maintainers - Patches 9 to 13 to be taken by irqchip maintainers - Patch 14/15 to be taken by DT/PCI maintainers - Patch 16/17 by the MFD maintainers Additionally, we also believe all preparation items in this patch series can be taken even before there's a final agreement on the last part of the series (the MFD driver itself). [1] https://lore.kernel.org/all/CAL_Jsq+je7+9ATR=B6jXHjEJHjn24vQFs4Tvi9=vhDeK9n42Aw@xxxxxxxxxxxxxx/ Best regards, Hervé Clément Léger (5): mfd: syscon: Add reference counting and device managed support reset: mchp: sparx5: Remove dependencies and allow building as a module reset: mchp: sparx5: Release syscon when not use anymore reset: core: add get_device()/put_device on rcdev reset: mchp: sparx5: set the dev member of the reset controller Herve Codina (12): dt-bindings: net: mscc-miim: Add resets property net: mdio: mscc-miim: Handle the switch reset net: lan966x: remove debugfs directory in probe() error path dt-bindings: interrupt-controller: Add support for Microchip LAN966x OIC irqdomain: Add missing parameter descriptions in docs irqdomain: Introduce irq_domain_alloc() and irq_domain_publish() irqchip: Add support for LAN966x OIC MAINTAINERS: Add the Microchip LAN966x OIC driver entry of: dynamic: Introduce of_changeset_add_prop_bool() pci: of_property: Add the interrupt-controller property in PCI device nodes mfd: Add support for LAN966x PCI device MAINTAINERS: Add the Microchip LAN966x PCI driver entry .../microchip,lan966x-oic.yaml | 55 ++++ .../devicetree/bindings/net/mscc,miim.yaml | 8 + MAINTAINERS | 12 + drivers/irqchip/Kconfig | 12 + drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-lan966x-oic.c | 301 ++++++++++++++++++ drivers/mfd/Kconfig | 24 ++ drivers/mfd/Makefile | 4 + drivers/mfd/lan966x_pci.c | 229 +++++++++++++ drivers/mfd/lan966x_pci.dtso | 167 ++++++++++ drivers/mfd/syscon.c | 145 ++++++++- .../ethernet/microchip/lan966x/lan966x_main.c | 6 +- drivers/net/mdio/mdio-mscc-miim.c | 8 + drivers/of/dynamic.c | 25 ++ drivers/pci/of_property.c | 24 ++ drivers/pci/quirks.c | 1 + drivers/reset/Kconfig | 3 +- drivers/reset/core.c | 2 + drivers/reset/reset-microchip-sparx5.c | 11 +- include/linux/irqdomain.h | 16 + include/linux/mfd/syscon.h | 18 ++ include/linux/of.h | 3 + kernel/irq/irqdomain.c | 118 +++++-- 23 files changed, 1149 insertions(+), 44 deletions(-) create mode 100644 Documentation/devicetree/bindings/interrupt-controller/microchip,lan966x-oic.yaml create mode 100644 drivers/irqchip/irq-lan966x-oic.c create mode 100644 drivers/mfd/lan966x_pci.c create mode 100644 drivers/mfd/lan966x_pci.dtso -- 2.44.0
