linux-kernel - Re: [PATCH v9 -next 07/12] misc: rp1: RaspberryPi RP1 misc driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <2025042551-agency-boozy-dc3b@gregkh>
Date: Fri, 25 Apr 2025 15:20:00 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: Andrea della Porta <andrea.porta@...e.com>
Cc: Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...nel.org>, Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Florian Fainelli <florian.fainelli@...adcom.com>,
	Broadcom internal kernel review list <bcm-kernel-feedback-list@...adcom.com>,
	Lorenzo Pieralisi <lpieralisi@...nel.org>,
	Krzysztof Wilczynski <kw@...ux.com>,
	Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Linus Walleij <linus.walleij@...aro.org>,
	Catalin Marinas <catalin.marinas@....com>,
	Will Deacon <will@...nel.org>, Bartosz Golaszewski <brgl@...ev.pl>,
	Derek Kiernan <derek.kiernan@....com>,
	Dragan Cvetic <dragan.cvetic@....com>,
	Arnd Bergmann <arnd@...db.de>,
	Saravana Kannan <saravanak@...gle.com>, linux-clk@...r.kernel.org,
	devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
	linux-gpio@...r.kernel.org, Masahiro Yamada <masahiroy@...nel.org>,
	Stefan Wahren <wahrenst@....net>,
	Herve Codina <herve.codina@...tlin.com>,
	Luca Ceresoli <luca.ceresoli@...tlin.com>,
	Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
	Andrew Lunn <andrew@...n.ch>, Phil Elwell <phil@...pberrypi.com>,
	Dave Stevenson <dave.stevenson@...pberrypi.com>,
	kernel-list@...pberrypi.com, Matthias Brugger <mbrugger@...e.com>
Subject: Re: [PATCH v9 -next 07/12] misc: rp1: RaspberryPi RP1 misc driver

On Tue, Apr 22, 2025 at 08:53:16PM +0200, Andrea della Porta wrote:
> The RaspberryPi RP1 is a PCI multi function device containing
> peripherals ranging from Ethernet to USB controller, I2C, SPI
> and others.
> 
> Implement a bare minimum driver to operate the RP1, leveraging
> actual OF based driver implementations for the on-board peripherals
> by loading a devicetree overlay during driver probe if the RP1
> node is not already present in the DT.
> 
> The peripherals are accessed by mapping MMIO registers starting
> from PCI BAR1 region.
> 
> With the overlay approach we can achieve more generic and agnostic
> approach to managing this chipset, being that it is a PCI endpoint
> and could possibly be reused in other hw implementations. The
> presented approach is also used by Bootlin's Microchip LAN966x
> patchset (see link) as well, for a similar chipset.
> In this case, the inclusion tree for the DT overlay is as follow
> (the arrow points to the includer):
> 
>  rp1-pci.dtso <---- rp1-common.dtsi
> 
> On the other hand, to ensure compatibility with downstream, this
> driver can also work with a DT already comprising the RP1 node, so
> the dynamically loaded overlay will not be used if the DT is already
> fully defined.
> 
> The reason why this driver is contained in drivers/misc has
> been paved by Bootlin's LAN966X driver, which first used the
> overlay approach to implement non discoverable peripherals behind a
> PCI bus. For RP1, the same arguments apply: it's not used as an SoC
> since the driver code is not running on-chip and is not like an MFD
> since it does not really need all the MFD infrastructure (shared regs,
> etc.). So, for this particular use, misc has been proposed and deemed
> as a good choice. For further details about that please check the links.
> 
> This driver is heavily based on downstream code from RaspberryPi
> Foundation, and the original author is Phil Elwell.
> 
> Link: https://datasheets.raspberrypi.com/rp1/rp1-peripherals.pdf
> Link: https://lore.kernel.org/all/20240612140208.GC1504919@google.com/
> Link: https://lore.kernel.org/all/83f7fa09-d0e6-4f36-a27d-cee08979be2a@app.fastmail.com/
> Link: https://lore.kernel.org/all/2024081356-mutable-everyday-6f9d@gregkh/
> Link: https://lore.kernel.org/all/20240808154658.247873-1-herve.codina@bootlin.com/
> 
> Signed-off-by: Andrea della Porta <andrea.porta@...e.com>
> Acked-by: Bjorn Helgaas <bhelgaas@...gle.com>   # quirks.c, pci_ids.h
> ---
>  MAINTAINERS                   |   1 +
>  drivers/misc/Kconfig          |   1 +
>  drivers/misc/Makefile         |   1 +
>  drivers/misc/rp1/Kconfig      |  20 ++
>  drivers/misc/rp1/Makefile     |   3 +
>  drivers/misc/rp1/rp1-pci.dtso |  25 +++
>  drivers/misc/rp1/rp1_pci.c    | 333 ++++++++++++++++++++++++++++++++++
>  drivers/pci/quirks.c          |   1 +
>  include/linux/pci_ids.h       |   3 +
>  9 files changed, 388 insertions(+)
>  create mode 100644 drivers/misc/rp1/Kconfig
>  create mode 100644 drivers/misc/rp1/Makefile
>  create mode 100644 drivers/misc/rp1/rp1-pci.dtso
>  create mode 100644 drivers/misc/rp1/rp1_pci.c


Acked-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>