Dual mode DesignWare PCIe IP has PTM capability enabled (if supported) even
in the EP mode. The PCIe compliance for the EP mode expects PTM
capabilities (ROOT_CAPABLE, RES_CAPABLE, CLK_GRAN) be disabled.
Hence disable PTM for the EP mode.
Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
Reviewed-by: Jingoo Han <jingoohan1@xxxxxxxxx>
---
V2:
* Addressed review comment from Jingoo Han
* Added "Reviewed-by: Jingoo Han <jingoohan1@xxxxxxxxx>"
.../pci/controller/dwc/pcie-designware-ep.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 095fb0291ec9..b88b6597194a 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -638,6 +638,7 @@ static int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
struct dw_pcie_ep_func *ep_func;
struct device *dev = pci->dev;
struct pci_epc *epc = ep->epc;
+ unsigned int ptm_cap_base;
unsigned int offset;
unsigned int nbars;
u8 hdr_type;
@@ -690,6 +691,7 @@ static int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
}
offset = dw_pcie_ep_find_ext_capability(pci, PCI_EXT_CAP_ID_REBAR);
+ ptm_cap_base = dw_pcie_ep_find_ext_capability(pci, PCI_EXT_CAP_ID_PTM);
dw_pcie_dbi_ro_wr_en(pci);
@@ -702,6 +704,22 @@ static int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
dw_pcie_writel_dbi(pci, offset + PCI_REBAR_CAP, 0x0);
}
+ /*
+ * PTM responder capability can be disabled only after disabling
+ * PTM root capability.
+ */
+ if (ptm_cap_base) {
+ dw_pcie_dbi_ro_wr_en(pci);
+ reg = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
+ reg &= ~PCI_PTM_CAP_ROOT;
+ dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, reg);
+
+ reg = dw_pcie_readl_dbi(pci, ptm_cap_base + PCI_PTM_CAP);
+ reg &= ~(PCI_PTM_CAP_RES | PCI_PTM_GRANULARITY_MASK);
+ dw_pcie_writel_dbi(pci, ptm_cap_base + PCI_PTM_CAP, reg);
+ dw_pcie_dbi_ro_wr_dis(pci);
+ }
+
dw_pcie_setup(pci);
dw_pcie_dbi_ro_wr_dis(pci);
--
2.17.1
