From: Ansuel Smith <ansuelsmth@gmail.com>
Date: Mon, 15 Jun 2020 23:06:04 +0200
Subject: PCI: qcom: Add support for tx term offset for rev 2.1.0
Git-commit: de3c4bf648975ea0b1d344d811e9b0748907b47c
Patch-mainline: 5.9-rc1
References: git-fixes

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.

Link: https://lore.kernel.org/r/20200615210608.21469-9-ansuelsmth@gmail.com
Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver")
Signed-off-by: Sham Muthayyan <smuthayy@codeaurora.org>
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/pci/dwc/pcie-qcom.c |   17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

--- a/drivers/pci/dwc/pcie-qcom.c
+++ b/drivers/pci/dwc/pcie-qcom.c
@@ -53,7 +53,13 @@
 #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
@@ -394,9 +400,18 @@ static int qcom_pcie_init_2_1_0(struct q
 		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);
 
 	ret = reset_control_deassert(res->phy_reset);