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, 2 introduce the LAN996x PCI driver itself, together with its DT overlay and the related MAINTAINTER entry. - Patches 3 to 8 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. Compare to the previous iteration: https://lore.kernel.org/lkml/20240627091137.370572-1-herve.codina@xxxxxxxxxxx/ this v4 series mainly: - Add a dependency between the reset controller and the LAN966x PCI driver. Reorder commits as the reset controller now depends on the LAN666x PCI device. - Move the LAN966x PCI driver from drivers/mfd to drivers/misc Best regards, Hervé Changes v3 -> v4 - Patch 1 and 2 (v3 patch 6 and 7) Move the driver from drivers/mfd to drivers/misc - Patch 4 and 5 (v3 patch 2) Rework reset driver dependencies and module building support. Split v3 patch into two distinct patches: - patch 4, as suggested by Geert, add a dependency on the LAN966x PCI device - patch 5, allows to build the reset controller driver as a module - Other patches Except reordering, no changes Changes v2 -> v3 - Patches 1 and 5 No changes - Patch 6 (v2 patch 18) Add a blank line in the commit log to split paragraphs Remove unneeded header file inclusion Use IRQ_RETVAL() Remove blank line Use dev_of_node() Use pci_{set,get}_drvdata() Remove unneeded pci_clear_master() call Move { 0, } to { } Remove the unneeded pci_dev member from the lan966x_pci structure Use PCI_VENDOR_ID_EFAR instead of the hardcoded 0x1055 PCI Vendor ID Add a comment related to the of_node check. - Patch 7 (v2 patch 19) No changes Patches removed in v3 - Patches 6 and 7 Extracted and sent separately https://lore.kernel.org/lkml/20240620120126.412323-1-herve.codina@xxxxxxxxxxx/ - Patches 9 Already applied - Patches 8, 10 to 12 Extracted, reworked and sent separately https://lore.kernel.org/lkml/20240614173232.1184015-1-herve.codina@xxxxxxxxxxx/ - Patches 13 to 14 Already applied Changes v1 -> v2 - Patch 1 Fix a typo in syscon.h (s/intline/inline/) - Patches 2..5 No changes - Patch 6 Improve the reset property description - Patch 7 Fix a wrong reverse x-mass tree declaration - Patch 8 removed (sent alone to net) https://lore.kernel.org/lkml/20240513111853.58668-1-herve.codina@xxxxxxxxxxx/ - Patch 8 (v1 patch 9) Add 'Reviewed-by: Rob Herring (Arm) <robh@xxxxxxxxxx>' - Patch 9 (v1 patch 10) Rephrase and ident parameters descriptions - Patch 10 (v1 patch 11) No changes - Patch 11 (v1 patch 12) Fix a missing ret value assignment before a goto in .probe() Limit lines to 80 columns Use indices in register offset definitions - Patch 13 and 14 (new patches in v2) Add new test cases for existing of_changeset_add_prop_*() - Patch 15 (v1 patch 14) No changes - Patch 16 (new patches in v2) Add tests for of_changeset_add_prop_bool() - Patch 17 (v1 patch 15) Update commit subject Rewrap a paragraph in commit log - Patch 18 (v1 patch 16) Use PCI_IRQ_INTX instead of PCI_IRQ_LEGACY - Patch 19 (v1 patch 17) No changes Clément Léger (5): mfd: syscon: Add reference counting and device managed support reset: mchp: sparx5: 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 (3): misc: Add support for LAN966x PCI device MAINTAINERS: Add the Microchip LAN966x PCI driver entry reset: mchp: sparx5: Add MCHP_LAN966X_PCI dependency MAINTAINERS | 6 + drivers/mfd/syscon.c | 145 +++++++++++++++- drivers/misc/Kconfig | 24 +++ drivers/misc/Makefile | 3 + drivers/misc/lan966x_pci.c | 229 +++++++++++++++++++++++++ drivers/misc/lan966x_pci.dtso | 167 ++++++++++++++++++ drivers/pci/quirks.c | 1 + drivers/reset/Kconfig | 4 +- drivers/reset/core.c | 2 + drivers/reset/reset-microchip-sparx5.c | 11 +- include/linux/mfd/syscon.h | 16 ++ 11 files changed, 591 insertions(+), 17 deletions(-) create mode 100644 drivers/misc/lan966x_pci.c create mode 100644 drivers/misc/lan966x_pci.dtso -- 2.45.0
