| Message ID | 20240930121601.172216-1-herve.codina@bootlin.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add support for the LAN966x PCI device using a DT overlay | expand |
Hi Herve, On Mon, 2024-09-30 at 14:15 +0200, Herve Codina wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you > know the content is safe > > In the LAN966x PCI device use case, syscon cannot be used as syscon > devices do not support removal [1]. A syscon device is a core > "system" > device and not a device available in some addon boards and so, it is > not > supposed to be removed. > > In order to remove the syscon usage, use a local mapping of a reg > address range when cpu-syscon is not present. > > Link: > https://lore.kernel.org/all/20240923100741.11277439@bootlin.com/ [1] > Signed-off-by: Herve Codina <herve.codina@bootlin.com> > --- > drivers/reset/reset-microchip-sparx5.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/reset/reset-microchip-sparx5.c > b/drivers/reset/reset-microchip-sparx5.c > index 636e85c388b0..1c095fa41d69 100644 > --- a/drivers/reset/reset-microchip-sparx5.c > +++ b/drivers/reset/reset-microchip-sparx5.c > @@ -114,8 +114,22 @@ static int mchp_sparx5_reset_probe(struct > platform_device *pdev) > return -ENOMEM; > > err = mchp_sparx5_map_syscon(pdev, "cpu-syscon", &ctx- > >cpu_ctrl); > - if (err) > + switch (err) { > + case 0: > + break; > + case -ENODEV: > + /* > + * The cpu-syscon device is not available. > + * Fall back with IO mapping (i.e. mapping from reg > property). > + */ > + err = mchp_sparx5_map_io(pdev, 1, &ctx->cpu_ctrl); > + if (err) > + return err; > + break; > + default: > return err; > + } > + > err = mchp_sparx5_map_io(pdev, 0, &ctx->gcb_ctrl); > if (err) > return err; > -- > 2.46.1 > LGTM Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com> BR Steen
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 reuse 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 and 2 (new in this version) allow to remove the syscon device usage from the reset driver (only the reset driver use the syscon device) - Patches 3 and 4 introduce the LAN996x PCI driver itself, together with its DT overlay and the related MAINTAINER entry. - Patches 5 to 7 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/20240808154658.247873-1-herve.codina@bootlin.com/ this v6 series mainly: - Remove patches adding support for refcounting and device removal in syscon. - Remove the syscon usage from the reset controller (the only syscon user). - Remove a patch already applied. - Add a 'Acked-by' - Rebase on top of v6.12-rc1 Best regards, Hervé Changes v5 -> v6 - Patch 1 New patch in v6 relatead to removing syscon usage. - Patch 2 New patch in v6 related to removing syscon usage. - Patch 3 (patch 1 in v5) Add 'Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>' Remove syscon node from the overlay. - Patch 4, 5, 6 and 7 (patches 2, 4, 5 and 8 in v5) No changes Patches removed in v6 - Patch 3 in v5 Rejected - Patch 6 in v5 No more applicable - Patch 7 in v5 Already applied Changes v4 -> v5 - Patch 1 Add missing include files and keep pci_ids.h. Remove IRQ_RETVAL() usage. Use __free(). Remove the pdev->irq check. Avoid local variables in devm_pci_dev_remove_intr_ctrl() and lan966x_pci_load_overlay(). Use dev_err_probe(). Sort header includes in alphabetical order in dtbs file. - Patch 3 Fix a typo in commit log. Simplify modification done in device_node_get_syscon(). Use devm_add_action_or_reset(). - Patches 4, 5, 6 and 8 Add 'Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>' 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@bootlin.com/ - Patches 9 Already applied - Patches 8, 10 to 12 Extracted, reworked and sent separately https://lore.kernel.org/lkml/20240614173232.1184015-1-herve.codina@bootlin.com/ - 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@bootlin.com/ - Patch 8 (v1 patch 9) Add 'Reviewed-by: Rob Herring (Arm) <robh@kernel.org>' - 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 (2): reset: mchp: sparx5: Allow building as a module reset: mchp: sparx5: set the dev member of the reset controller Herve Codina (5): dt-bindings: reset: microchip,rst: Allow to replace cpu-syscon by an additional reg item reset: mchp: sparx5: Use the second reg item when cpu-syscon is not present misc: Add support for LAN966x PCI device MAINTAINERS: Add the Microchip LAN966x PCI driver entry reset: mchp: sparx5: Add MCHP_LAN966X_PCI dependency .../bindings/reset/microchip,rst.yaml | 35 ++- MAINTAINERS | 6 + drivers/misc/Kconfig | 24 ++ drivers/misc/Makefile | 3 + drivers/misc/lan966x_pci.c | 215 ++++++++++++++++++ drivers/misc/lan966x_pci.dtso | 161 +++++++++++++ drivers/pci/quirks.c | 1 + drivers/reset/Kconfig | 4 +- drivers/reset/reset-microchip-sparx5.c | 19 +- 9 files changed, 464 insertions(+), 4 deletions(-) create mode 100644 drivers/misc/lan966x_pci.c create mode 100644 drivers/misc/lan966x_pci.dtso