Programming of QMP PCIe PHYs slightly differs between RC and EP modes.
Currently both qcom and qcom-ep PCIe controllers setup the PHY in the
default mode, making it impossible to select at runtime whether the PHY
should be running in RC or in EP modes. Usually this is not an issue,
since for most devices only the RC mode is used. Some devices (SDX55)
currently support only the EP mode without supporting the RC mode (at
this moment).
Nevertheless some of the Qualcomm platforms (e.g. the aforementioned
SDX55) would still benefit from being able to switch between RC and EP
depending on the driver being used. While it is possible to use
different compat strings for the PHY depending on the mode, it seems
like an incorrect approach, since the PHY doesn't differ between
usecases. It's the PCIe controller, who should decide how to configure
the PHY.
This patch series implements the ability to select between RC and EP
modes, by allowing the PCIe QMP PHY driver to switch between
programming tables.
Unlike previous iterations, this series brings in the dependecy from
PCI parts onto the first patch. Merging of PHY and PCI parts should be
coordinated by the maintainers (e.g. by putting the first patch into the
immutable branch).
Changes since v2:
- Added PHY_SUBMODE_PCIE_RC/EP defines (Vinod),
- Changed `primary' table name to `main', added extra comments
describing that `secondary' are the additional tables, not required in
most of the cases (following the suggestion by Johan to rename
`primary' table),
- Changed secondary tables into the pointers to stop wasting extra
memory (Vinod),
- Split several functions for programming the PHY using these tables.
Changes since v1:
- Split the if(table) removal to the separate patch
- Expanded commit messages and comments to provide additional details
- Fixed build error on pcie-qcom.c
- Added support for EP mode on sm8450 to demonstrate the usage of this
patchset
Changes since RFC:
- Fixed the compilation of PCIe EP driver,
- Changed pri/sec names to primary and secondary,
- Added comments regarding usage of secondary_rc/_ep fields.
Dmitry Baryshkov (9):
phy: define submodes for PCIe PHYs
phy: qcom-qmp-pcie: drop if (table) conditions
phy: qcom-qmp-pcie: split register tables into main and secondary
parts
phy: qcom-qmp-pcie: split PHY programming to separate functions
phy: qcom-qmp-pcie: turn secondary programming table into a pointer
phy: qcom-qmp-pcie: support separate tables for EP mode
phy: qcom-qmp-pcie: Support SM8450 PCIe1 PHY in EP mode
PCI: qcom: Setup PHY to work in RC mode
PCI: qcom-ep: Setup PHY to work in EP mode
drivers/pci/controller/dwc/pcie-qcom-ep.c | 4 +
drivers/pci/controller/dwc/pcie-qcom.c | 4 +
drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 312 ++++++++++++------
.../qualcomm/phy-qcom-qmp-pcs-pcie-v5_20.h | 1 +
include/linux/phy/phy.h | 9 +
5 files changed, 229 insertions(+), 101 deletions(-)
--
2.35.1
