Add support to provide Silicon Debug interface to userspace.
This set of debug registers are part of the RAS DES feature present in
DesignWare PCIe controllers.
Co-developed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Shradha Todi <shradha.t@samsung.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Tested-by: Hrishikesh Deleep <hrishikesh.d@samsung.com>
Link: https://lore.kernel.org/r/20250221131548.59616-4-shradha.t@samsung.com
[kwilczynski: commit log, tidy up Kconfig and drop "default y", tidy up
code comments, squashed patch that fixes a NULL pointer dereference when
debugfs is already unavailable during clean-up from
https://lore.kernel.org/linux-pci/20250225171239.19574-2-manivannan.sadhasivam@linaro.org,
refactor dwc_pcie_debugfs_init() to not return errors, squashed patch that
changes how lack of the RAS DES capability is handled from
https://lore.kernel.org/linux-pci/20250304151814.6xu7cbpwpqrvcad5@thinkpad]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
4fbfa17f9a