2024-02-02 00:41:08

by Bjorn Andersson

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

On Thu, Feb 01, 2024 at 04:55:23PM +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <[email protected]>
>

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@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
>