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

Ansuel Smith
2020-06-15T21:07:02Z

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@codeaurora.org>
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Cc: stable@vger.kernel.org # 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