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From:   Mrinmay Sarkar <quic_msarkar@quicinc.com>
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Subject: [PATCH v1 1/3] PCI: qcom: Enable cache coherency for SA8775P RC
Date:   Tue, 31 Oct 2023 21:16:24 +0530
Message-Id: <1698767186-5046-2-git-send-email-quic_msarkar@quicinc.com>
In-Reply-To: <1698767186-5046-1-git-send-email-quic_msarkar@quicinc.com>
References: <1698767186-5046-1-git-send-email-quic_msarkar@quicinc.com>
Precedence: bulk

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

Signed-off-by: Mrinmay Sarkar <quic_msarkar@quicinc.com>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 6902e97..6f240fc 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -51,6 +51,7 @@
 #define PARF_SID_OFFSET				0x234
 #define PARF_BDF_TRANSLATE_CFG			0x24c
 #define PARF_SLV_ADDR_SPACE_SIZE		0x358
+#define PCIE_PARF_NO_SNOOP_OVERIDE		0x3d4
 #define PARF_DEVICE_TYPE			0x1000
 #define PARF_BDF_TO_SID_TABLE_N			0x2000
 
@@ -117,6 +118,9 @@
 /* PARF_LTSSM register fields */
 #define LTSSM_EN				BIT(8)
 
+/* PARF_NO_SNOOP_OVERIDE register value */
+#define NO_SNOOP_OVERIDE_EN			0xa
+
 /* PARF_DEVICE_TYPE register fields */
 #define DEVICE_TYPE_RC				0x4
 
@@ -961,6 +965,13 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
 
 static int qcom_pcie_post_init_2_7_0(struct qcom_pcie *pcie)
 {
+	struct dw_pcie *pci = pcie->pci;
+	struct device *dev = pci->dev;
+
+	/* Enable cache snooping for SA8775P */
+	if (of_device_is_compatible(dev->of_node, "qcom,pcie-sa8775p"))
+		writel(NO_SNOOP_OVERIDE_EN, pcie->parf + PCIE_PARF_NO_SNOOP_OVERIDE);
+
 	qcom_pcie_clear_hpc(pcie->pci);
 
 	return 0;
-- 
2.7.4