[PATCH v7 08/12] PCI: qcom: Add support for tx term offset for rev 2.1.0

[Ansuel Smith]

Add tx term offset support to pcie qcom driver need in some revision of
the ipq806x SoC. Ipq8064 needs tx term offset set to 7.

Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver")
Signed-off-by: Sham Muthayyan <smuthayy@xxxxxxxxxxxxxx>
Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.5+
---
 drivers/pci/controller/dwc/pcie-qcom.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 85313493d51b..2cd6d1456210 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -45,7 +45,13 @@
 #define PCIE_CAP_CPL_TIMEOUT_DISABLE		0x10
 
 #define PCIE20_PARF_PHY_CTRL			0x40
+#define PHY_CTRL_PHY_TX0_TERM_OFFSET_MASK	GENMASK(20, 16)
+#define PHY_CTRL_PHY_TX0_TERM_OFFSET(x)		((x) << 16)
+
 #define PCIE20_PARF_PHY_REFCLK			0x4C
+#define PHY_REFCLK_SSP_EN			BIT(16)
+#define PHY_REFCLK_USE_PAD			BIT(12)
+
 #define PCIE20_PARF_DBI_BASE_ADDR		0x168
 #define PCIE20_PARF_SLV_ADDR_SPACE_SIZE		0x16C
 #define PCIE20_PARF_MHI_CLOCK_RESET_CTRL	0x174
@@ -371,9 +377,18 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
 		writel(PHY_RX0_EQ(4), pcie->parf + PCIE20_PARF_CONFIG_BITS);
 	}
 
+	if (of_device_is_compatible(node, "qcom,pcie-ipq8064")) {
+		/* set TX termination offset */
+		val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
+		val &= ~PHY_CTRL_PHY_TX0_TERM_OFFSET_MASK;
+		val |= PHY_CTRL_PHY_TX0_TERM_OFFSET(7);
+		writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
+	}
+
 	/* enable external reference clock */
 	val = readl(pcie->parf + PCIE20_PARF_PHY_REFCLK);
-	val |= BIT(16);
+	val &= ~PHY_REFCLK_USE_PAD;
+	val |= PHY_REFCLK_SSP_EN;
 	writel(val, pcie->parf + PCIE20_PARF_PHY_REFCLK);
 
 	/* wait for clock acquisition */
-- 
2.27.0.rc0