PCI: qcom: Add support for tx term offset for rev 2.1.0

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+

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 69c7b11..34d961e 100644 (file)
--- 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 */