PCI: qcom: Add basic interconnect support
On Qualcomm platforms like SC8280XP and SA8540P, interconnect bandwidth must be requested before enabling interconnect clocks. Add basic support for managing an optional "pcie-mem" interconnect path by setting a low constraint before enabling clocks and updating it after the link is up. Note that it is not possible for a controller driver to set anything but a maximum peak bandwidth as expected average bandwidth will vary with use case and actual use (and power policy?). This very much remains an unresolved problem with the interconnect framework. Also note that no constraint is set for the SC8280XP/SA8540P "cpu-pcie" path for now as it is not clear what an appropriate constraint would be (and the system does not crash when left unspecified). Link: https://lore.kernel.org/r/20221102090705.23634-3-johan+linaro@kernel.org Fixes: 70574511 ("PCI: qcom: Add support for SC8280XP") Signed-off-by:Johan Hovold <johan+linaro@kernel.org> Signed-off-by:
Lorenzo Pieralisi <lpieralisi@kernel.org> Reviewed-by:
Brian Masney <bmasney@redhat.com> Reviewed-by:
Manivannan Sadhasivam <mani@kernel.org> Acked-by:
Georgi Djakov <djakov@kernel.org>
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