[PATCH v1 2/3] PCI: qcom-ep: Enable cache coherency for SA8775P EP

From: Mrinmay Sarkar
Date: Tue Oct 31 2023 - 11:46:51 EST


This change will enable cache snooping logic to support
cache coherency for SA8755P EP platform.

Signed-off-by: Mrinmay Sarkar <quic_msarkar@xxxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-qcom-ep.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 3a53d97..bc958a0 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -47,6 +47,7 @@
#define PARF_DBI_BASE_ADDR_HI 0x354
#define PARF_SLV_ADDR_SPACE_SIZE 0x358
#define PARF_SLV_ADDR_SPACE_SIZE_HI 0x35c
+#define PCIE_PARF_NO_SNOOP_OVERIDE 0x3d4
#define PARF_ATU_BASE_ADDR 0x634
#define PARF_ATU_BASE_ADDR_HI 0x638
#define PARF_SRIS_MODE 0x644
@@ -86,6 +87,9 @@
#define PARF_DEBUG_INT_CFG_BUS_MASTER_EN BIT(2)
#define PARF_DEBUG_INT_RADM_PM_TURNOFF BIT(3)

+/* PARF_NO_SNOOP_OVERIDE register value */
+#define NO_SNOOP_OVERIDE_EN 0xa
+
/* PARF_DEVICE_TYPE register fields */
#define PARF_DEVICE_TYPE_EP 0x0

@@ -489,6 +493,10 @@ static int qcom_pcie_perst_deassert(struct dw_pcie *pci)
val |= BIT(8);
writel_relaxed(val, pcie_ep->parf + PARF_LTSSM);

+ /* Enable cache snooping for SA8775P */
+ if (of_device_is_compatible(dev->of_node, "qcom,sa8775p-pcie-ep"))
+ writel_relaxed(NO_SNOOP_OVERIDE_EN, pcie_ep->parf + PCIE_PARF_NO_SNOOP_OVERIDE);
+
return 0;

err_disable_resources:
--
2.7.4