[PATCH v4 0/2] Add support for SA8255P in the phy-qcom-snps-femto-v2 phy driver

[Mattijs Korpershoek]

The Qualcomm automotive  SA8255p SoC abstracts resources such as resets,
clocks and regulators in firmware. The SCMI firmware exposes multiple
protocols to control such resources which are identified by protocol_id.

For this USB phy, 2 SCMI protocols are exposed by the firmware:
* power domain management protocol (protocol_id=0x11)
* performance domain management protocol (protocol_id=0x13)

The power domain has 2 indices: 'core' and 'transfer'.
* core controls the regulators, the clocks and the reset
* transfer only controls the clocks

For example, to power on/off the PHY, we should use the 'core' domain.
To disable data transfer and keeping power enabled, we should use the
'transfer' domain.

Note: the performance domain (0x13) exposes opaques values (0xa to 0x11)
for which we don't have any information. Since it is not mandatory
for the PHY to be functional, we have omitted it from the bindings and
the driver.

Patch 1 adds the binding for sa8255p. Similarly to what has been done
for I2C [1], this is a separate binding.

Patch 2 adds the driver change, which is based on a public vendor
patch from qualcomm [2].
I did the following changes on top of that:
* Use devm_add_action_or_reset() for dev_pm_domain_detach_list() instead
  of implementing a driver .remove()
* Changed power domain names to drop 'usb_' prefix
* Fixed various error handling paths
* Added suspend/resume support

This has been tested on next-20261026 with a Ride4 SA8775P board that
has SCMI firmware (which is compatible).

[1] https://lore.kernel.org/all/20260617-enable-i2c-on-sa8255p-v7-1-ad736dbeab57@xxxxxxxxxxxxxxxx/
[2] https://git.codelinaro.org/clo/le/meta-qti-auto-kernel/-/blob/LY.AU.0.1.0.r1-16800-gen4meta.0/recipes-kernel/linux/files/usb/0014-PENDING-phy-qcom-snps-femto-v2-Add-support-for-SA825.patch

Signed-off-by: Mattijs Korpershoek <mkorpershoek@xxxxxxxxxx>
---
Changes in v4:
- Don't control regulator, clk and reset in SCMI path (Mani)
- Rename helper functions to qcom_snps_pds_{enable,disable}_all and
  qcom_snps_pd_{enable,disable}_transfer (Mani)
- Add some more helper functions to keep probe() cleaner.
- Dropped Neil's R-b due to the above driver changes
- Link to v3: https://lore.kernel.org/r/20261002-phy-qcom-snps-femto-v2-8255-v3-0-342542bd9bc6@xxxxxxxxxx

Changes in v3:
- Applied R-b from Krzysztof and Neil
- Link to v2: https://patch.msgid.link/20260831-phy-qcom-snps-femto-v2-8255-v2-0-dc6197ffde1b@xxxxxxxxxx

Changes in v2:
- Move 'core' as first domain, before 'transfer' (Krzysztof)
- Reworded binding commit message to be more precise about the various
  domains ('core', 'transfer' and 'perf') (Krzysztof)
- Link to v1: https://patch.msgid.link/20260730-phy-qcom-snps-femto-v2-8255-v1-0-8b8bf5105a68@xxxxxxxxxx

To: Vinod Koul <vkoul@xxxxxxxxxx>
To: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
To: Manivannan Sadhasivam <mani@xxxxxxxxxx>
To: Rob Herring <robh@xxxxxxxxxx>
To: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>
To: Conor Dooley <conor+dt@xxxxxxxxxx>
To: Mattijs Korpershoek <mkorpershoek@xxxxxxxxxx>
To: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Cc: linux-arm-msm@xxxxxxxxxxxxxxx
Cc: linux-phy@xxxxxxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

---
Mattijs Korpershoek (1):
      dt-bindings: phy: Add sa8255p high-speed USB PHY

Sriram Dash (1):
      phy: qcom-snps-femto-v2: Add support for SA8255P

 .../bindings/phy/qcom,sa8255p-usb-hs-phy.yaml      |  52 +++++
 drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c      | 253 +++++++++++++++++----
 2 files changed, 256 insertions(+), 49 deletions(-)
---
base-commit: f1ac44c32cba88ad65dcecd4a279661d14e93651
change-id: 20260729-phy-qcom-snps-femto-v2-8255-90ffe7674001

Best regards,
--  
Mattijs Korpershoek <mkorpershoek@xxxxxxxxxx>