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From:   Mrinmay Sarkar <quic_msarkar@quicinc.com>
To:     agross@kernel.org, andersson@kernel.org,
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Subject: [PATCH v3 2/3] PCI: qcom-ep: Enable cache coherency for SA8775P EP
Date:   Wed, 15 Nov 2023 18:07:00 +0530
Message-Id: <1700051821-1087-3-git-send-email-quic_msarkar@quicinc.com>
In-Reply-To: <1700051821-1087-1-git-send-email-quic_msarkar@quicinc.com>
References: <1700051821-1087-1-git-send-email-quic_msarkar@quicinc.com>
Precedence: bulk

This change will enable cache snooping logic to support
cache coherency for 8775 EP platform.

Signed-off-by: Mrinmay Sarkar <quic_msarkar@quicinc.com>
---
 drivers/pci/controller/dwc/pcie-qcom-ep.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 3a53d97..ee99fb1 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 +87,10 @@
 #define PARF_DEBUG_INT_CFG_BUS_MASTER_EN	BIT(2)
 #define PARF_DEBUG_INT_RADM_PM_TURNOFF		BIT(3)
 
+/* PARF_NO_SNOOP_OVERIDE register fields */
+#define WR_NO_SNOOP_OVERIDE_EN                 BIT(1)
+#define RD_NO_SNOOP_OVERIDE_EN                 BIT(3)
+
 /* PARF_DEVICE_TYPE register fields */
 #define PARF_DEVICE_TYPE_EP			0x0
 
@@ -489,6 +494,11 @@ 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(WR_NO_SNOOP_OVERIDE_EN | RD_NO_SNOOP_OVERIDE_EN,
+				pcie_ep->parf + PCIE_PARF_NO_SNOOP_OVERIDE);
+
 	return 0;
 
 err_disable_resources:
-- 
2.7.4