Re: [RFC 0/9] power: sequencing: implement the subsystem and add first users

[Bjorn Andersson]

On Thu, Feb 01, 2024 at 04:55:23PM +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> 

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...

> 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.

Regards,
Bjorn

> [1] https://lore.kernel.org/all/CAMRc=MckG32DQv7b1AQL-mbnYdx4fsdYWtLwCyXc5Ma7EeSAKw@xxxxxxxxxxxxxx/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
>