[PATCH v6 00/10] PCI: dw-rockchip: add system suspend support

[Sebastian Reichel]

I've been working on fixing up at least basic system suspend support on
the Rockchip RK3576 platform. The last open issue is missing support in
the PCIe driver. This series is a follow-up for Shawn Lin's series with
feedback from Niklas Cassel and Manivannan Sadhasivam being handled as
well as some of my own changes fixing up things I noticed.

I've tested this on multiple RK3576 and RK3588 boards and things look
good to me on the PCIe side.

On RK3588, I also needed [0] to fix PCIe IOMMU issues after resume. I
consider this an independent issue. Also on the Rockchip EVBs the
brcmfmac driver fails to suspend. The WIFI card is connected via PCIe,
but the problem is with the driver/firmware and unrelated to PCIe
itself. I will send a separate workaround patch for that. Additionally
on RK3588 the system will run into SError on resume due to a USB2
problem. This problem is also independent and will be handled
separately.

[0] https://lore.kernel.org/all/20260728210928.1050849-1-praan@google.com/

Changes since PATCHv5:
 * https://lore.kernel.org/r/20260316-rockchip-pcie-system-suspend-v5-0-5bb5ad37d643@collabora.com
 * Rebase to pci/next
 * Minor changes to make checkpatch happy
 * Update patch description of the last patch and drop RFC tag
   according to feedback from Shawn Lin
 * Prepend new patch, which fixes Nicolas Frattaroli's conversion
   to FIELD_PREP_WM16 accidently dropping a flag.
 * Add another new patch, which sets .broken_l1ss_resume to tell the
   PCI core that the controller is powered off during suspend following
   the Qcom example

Changes since PATCHv4:
 * https://lore.kernel.org/r/20251029-rockchip-pcie-system-suspend-v4-0-ce2e1b0692d2@collabora.com
 * rebase to v7.0-rc1
 * Add an RFC patch at the end with some bits I found in the Rockchip vendor kernel;
 * Made some tests on Rock 5B+ (RK3588); with this patch series suspending works
   when setting pm_test to devices. A full system suspend fails in a later step,
   but that is independent of PCIe.

Changes since PATCHv3:
 * https://lore.kernel.org/linux-pci/1744940759-23823-1-git-send-email-shawn.lin@rock-chips.com/
 * rename rockchip_pcie_get_ltssm to rockchip_pcie_get_ltssm_status_reg
   in a separate patch (Niklas Cassel)
 * rename rockchip_pcie_get_pure_ltssm to rockchip_pcie_get_ltssm_state
   in a separate patch (Niklas Cassel)
 * Move devm_phy_get out of phy_init to probe in a separate patch
   (Manivannan Sadhasivam)
 * Add helper function for enhanced LTSSM control mode in a separate patch
   (Niklas Cassel)
 * Add helper function for controller mode in a separate patch
   (Niklas Cassel)
 * Add helper function for DDL indicator in a separate patch
   (Niklas Cassel)
 * Move rockchip_pcie_pme_turn_off implementation in a separate patch
 * Rebase to v6.18-rc3 using new FIELD_PREP_WM16()
 * Improve readability of PME_TURN_OFF/PME_TO_ACK defines (Manivannan Sadhasivam)
 * Fix usage of reverse Xmas (Manivannan Sadhasivam)
 * Assert PERST# before turning off other resources (Manivannan Sadhasivam)
 * Improve some error messages (Manivannan Sadhasivam)
 * Rename goto labels as per their purpose (Manivannan Sadhasivam)
 * Add extra patch for dw_pcie_resume_noirq, since I've seen errors
   during resume on boards not having anything plugged into their PCIe
   port

Signed-off-by: Sebastian Reichel <sebastian.reichel at collabora.com>
---
Sebastian Reichel (10):
      PCI: dw-rockchip: Fix LTSSM set functions
      PCI: dw-rockchip: Restore vpcie3v3 regulator handle
      PCI: dw-rockchip: Move devm_phy_get out of phy_init
      PCI: dw-rockchip: Add helper function for enhanced LTSSM control mode
      PCI: dw-rockchip: Add helper function for controller mode
      PCI: dw-rockchip: Add helper function for DDL indicator
      PCI: dw-rockchip: Add pme_turn_off support
      PCI: dw-rockchip: Set broken L1SS resume flag
      PCI: dw-rockchip: Add system PM support
      PCI: dw-rockchip: Clear debug buffer before entering L2

 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 274 ++++++++++++++++++++++----
 1 file changed, 235 insertions(+), 39 deletions(-)
---
base-commit: 39ee38a9fa2eaeff030a6c865abb244597c091eb
change-id: 20251028-rockchip-pcie-system-suspend-86cf08a7b229

Best regards,
--  
Sebastian Reichel <sebastian.reichel at collabora.com>