Subject: Re: [PATCH v8 0/6] Add support for the LAN966x PCI device using a DT overlay

From: Herve Codina <[email-masked]>
Date: Thu, 10 Oct 2024 08:26:53 +0200

Hi All,

Please ignore this series. It doesn't contain modifications done for this v8.
I will send a v9 to fix that.

Sorry for the noise.
Best regards,
Hervé

On Thu, 10 Oct 2024 08:16:08 +0200
Herve Codina <[email-masked]> wrote:

> 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 changes are needed:
>  - Patches 1 and 2 introduce the LAN996x PCI driver itself, together
>    with its DT overlay and the related MAINTAINER entry.
> 
>  - Patch 3 removes the syscon API usage from the reset driver used for
>    the LAN966x.
> 
>  - Patches 4 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/[email-masked]/
> this v8 series mainly:
>   - Add missing spaces
>   - Add "Reviewed-by" tags
> 
> Best regards,
> Hervé
> 
> Changes v7 -> v8
>   - Patch 1
>     Add missing spaces around '=' in dtso
> 
>   - Patches 2, 4, 5 and 6
>     Add 'Reviewed-by: Philipp Zabel <[email-masked]>'
> 
>   - Patch 3
>     Add 'Reviewed-by: Steen Hegelund <[email-masked]>'
>     Add	'Reviewed-by: Philipp Zabel <[email-masked]>'
> 
> Changes v6 -> v7
>   - Patch 1 (patch 3 in v6)
>     Re-introduce the syscon node in the overlay
> 
>   - Patch 2 (patch 4 in v6)
>     No changes
> 
>   - Patch 3 (patch 2 in v6)
>     Rework code to map the syscon device locally without using the
>     syscon API in the LAN966x case.
>     Update commit log
> 
>   - Patches 4, 5 and 6 (patches 5, 6, and 7 in v6)
>     No changes
> 
>   Patch removed in v7
>     - Patch 1 in v6 (reset controller DT binding modification)
>       Rejected
> 
> 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 <[email-masked]>'
>     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 <[email-masked]>'
> 
> 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/[email-masked]/
> 
>     - Patches 9
>       Already applied
> 
>     - Patches 8, 10 to 12
>       Extracted, reworked and sent separately
>       https://lore.kernel.org/lkml/[email-masked]/
> 
>     - 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/[email-masked]/
> 
>   - Patch 8 (v1 patch 9)
>     Add 'Reviewed-by: Rob Herring (Arm) <[email-masked]>'
> 
>   - 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 (4):
>   misc: Add support for LAN966x PCI device
>   MAINTAINERS: Add the Microchip LAN966x PCI driver entry
>   reset: mchp: sparx5: Map cpu-syscon locally in case of LAN966x
>   reset: mchp: sparx5: Add MCHP_LAN966X_PCI dependency
> 
>  MAINTAINERS                            |   6 +
>  drivers/misc/Kconfig                   |  24 +++
>  drivers/misc/Makefile                  |   3 +
>  drivers/misc/lan966x_pci.c             | 215 +++++++++++++++++++++++++
>  drivers/misc/lan966x_pci.dtso          | 167 +++++++++++++++++++
>  drivers/pci/quirks.c                   |   1 +
>  drivers/reset/Kconfig                  |   4 +-
>  drivers/reset/reset-microchip-sparx5.c |  38 ++++-
>  8 files changed, 455 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/misc/lan966x_pci.c
>  create mode 100644 drivers/misc/lan966x_pci.dtso
> 

-- 
Hervé Codina, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com