Date: Fri, 2 Feb 2024 09:53:21 +0100
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Bjorn Andersson <andersson@...nel.org>
Cc: Konrad Dybcio <konrad.dybcio@...aro.org>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley <conor+dt@...nel.org>, 
	Marcel Holtmann <marcel@...tmann.org>, Luiz Augusto von Dentz <luiz.dentz@...il.com>, 
	Bjorn Helgaas <bhelgaas@...gle.com>, Neil Armstrong <neil.armstrong@...aro.org>, 
	Alex Elder <elder@...aro.org>, Srini Kandagatla <srinivas.kandagatla@...aro.org>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Arnd Bergmann <arnd@...db.de>, 
	Abel Vesa <abel.vesa@...aro.org>, Manivannan Sadhasivam <mani@...nel.org>, Lukas Wunner <lukas@...ner.de>, 
	linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-bluetooth@...r.kernel.org, 
	linux-pci@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [RFC 0/9] power: sequencing: implement the subsystem and add
 first users

On Fri, Feb 2, 2024 at 1:40 AM Bjorn Andersson <andersson@...nel.org> wrote:
>
> On Thu, Feb 01, 2024 at 04:55:23PM +0100, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> >
>
> We now have 3 RFC and 1 PATCH versions of these patches on the list in
> under a month. Please at least add a version to your subject...
>

So there was an RFC for the PCI power sequencing (now renamed to PCI
power control - pci_pwrctl), then a proper series for it (with changes
listed). Then an RFC with just proposed DT changes (sent mostly to DT
maintainers to clear it with them) and now an RFC with power
sequencing + PCI power control. Hard to figure out how to version it
if these are pretty much separate developments.

I'll provide links to everything next time.

> > I'd like to preface the cover letter by saying right away that this
> > series is not complete. It's an RFC that presents my approach and is sent
> > to the list for discussion. There are no DT bindings nor docs in
> > Documentation/ yet. Please review it as an RFC and not an upstreambound
> > series. If the approach is accepted as correct, I'll add missing bits.
> >
> > The RFC[1] presenting my proposed device-tree representation of the
> > QCA6391 package present on the RB5 board - while not really officially
> > accepted - was not outright rejected which is a good sign.
> >
> > This series incorporates it and builds a proposed power sequencing
> > subsystem together with the first dedicated driver around it. Then it
> > adds first two users: the Bluetooth and WLAN modules of the QCA6391.
> >
> > The Bluetooth part is pretty straightforward. The WLAN however is a PCIe
> > device and as such needs to be powered-up *before* it's detected on the
> > PCI bus. To that end, we modify the PCI core to instantiate platform
> > devices for existing DT child nodes of the PCIe ports. For those nodes
> > for which a power-sequencing driver exists, we bind it and let it probe.
> > The driver then triggers a rescan of the PCI bus with the aim of
> > detecting the now powered-on device. The device will consume the same DT
> > node as the platform, power-sequencing device. We use device links to
> > make the latter become the parent of the former.
> >
> > The main advantage of the above approach (both for PCI as well as
> > generic power sequencers) is that we don't introduce significant changes
> > in DT bindings and don't introduce new properties. We merely define new
> > resources.
> >
>
> How can we tell? There are still no Documentation/dt-bindings changes in
> your series.

Noted.

Bartosz

>
> Regards,
> Bjorn
>
> > [1] https://lore.kernel.org/all/CAMRc=MckG32DQv7b1AQL-mbnYdx4fsdYWtLwCyXc5Ma7EeSAKw@mail.gmail.com/T/#md5dc62007d12f6833d4e51658b14e0493954ba68
> >
> > Bartosz Golaszewski (9):
> >   of: provide a cleanup helper for OF nodes
> >   arm64: dts: qcom: qrb5165-rb5: model the PMU of the QCA6391
> >   power: sequencing: new subsystem
> >   power: pwrseq: add a driver for the QCA6390 PMU module
> >   Bluetooth: qca: use the power sequencer for QCA6390
> >   PCI: create platform devices for child OF nodes of the port node
> >   PCI: hold the rescan mutex when scanning for the first time
> >   PCI/pwrctl: add PCI power control core code
> >   PCI/pwrctl: add a PCI power control driver for power sequenced devices
> >
> >  arch/arm64/boot/dts/qcom/qrb5165-rb5.dts  | 128 +++++-
> >  arch/arm64/boot/dts/qcom/sm8250.dtsi      |  10 +
> >  drivers/bluetooth/hci_qca.c               |  30 ++
> >  drivers/pci/Kconfig                       |   1 +
> >  drivers/pci/Makefile                      |   1 +
> >  drivers/pci/bus.c                         |   9 +-
> >  drivers/pci/probe.c                       |   2 +
> >  drivers/pci/pwrctl/Kconfig                |  17 +
> >  drivers/pci/pwrctl/Makefile               |   4 +
> >  drivers/pci/pwrctl/core.c                 |  82 ++++
> >  drivers/pci/pwrctl/pci-pwrctl-pwrseq.c    |  83 ++++
> >  drivers/pci/remove.c                      |   2 +
> >  drivers/power/Kconfig                     |   1 +
> >  drivers/power/Makefile                    |   1 +
> >  drivers/power/sequencing/Kconfig          |  28 ++
> >  drivers/power/sequencing/Makefile         |   6 +
> >  drivers/power/sequencing/core.c           | 482 ++++++++++++++++++++++
> >  drivers/power/sequencing/pwrseq-qca6390.c | 232 +++++++++++
> >  include/linux/of.h                        |   4 +
> >  include/linux/pci-pwrctl.h                |  24 ++
> >  include/linux/pwrseq/consumer.h           |  53 +++
> >  include/linux/pwrseq/provider.h           |  41 ++
> >  22 files changed, 1229 insertions(+), 12 deletions(-)
> >  create mode 100644 drivers/pci/pwrctl/Kconfig
> >  create mode 100644 drivers/pci/pwrctl/Makefile
> >  create mode 100644 drivers/pci/pwrctl/core.c
> >  create mode 100644 drivers/pci/pwrctl/pci-pwrctl-pwrseq.c
> >  create mode 100644 drivers/power/sequencing/Kconfig
> >  create mode 100644 drivers/power/sequencing/Makefile
> >  create mode 100644 drivers/power/sequencing/core.c
> >  create mode 100644 drivers/power/sequencing/pwrseq-qca6390.c
> >  create mode 100644 include/linux/pci-pwrctl.h
> >  create mode 100644 include/linux/pwrseq/consumer.h
> >  create mode 100644 include/linux/pwrseq/provider.h
> >
> > --
> > 2.40.1
> >

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