Set some specific value for Tx De-Emphasis, Tx Swing and Rx equalization needed on some ipq8064 based device (Netgear R7800 for example). Without this the system locks on kernel load.

Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver") Signed-off-by: Ansuel Smith ansuelsmth@gmail.com Cc: stable@vger.kernel.org # v4.5+ --- drivers/pci/controller/dwc/pcie-qcom.c | 27 ++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c index f2ea1ab6f584..f5398b0d270c 100644 --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -46,6 +46,9 @@

#define PCIE20_PARF_PHY_CTRL 0x40 #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 @@ -77,6 +80,18 @@ #define DBI_RO_WR_EN 1

#define PERST_DELAY_US 1000 +/* PARF registers */ +#define PCIE20_PARF_PCS_DEEMPH 0x34 +#define PCS_DEEMPH_TX_DEEMPH_GEN1(x) ((x) << 16) +#define PCS_DEEMPH_TX_DEEMPH_GEN2_3_5DB(x) ((x) << 8) +#define PCS_DEEMPH_TX_DEEMPH_GEN2_6DB(x) ((x) << 0) + +#define PCIE20_PARF_PCS_SWING 0x38 +#define PCS_SWING_TX_SWING_FULL(x) ((x) << 8) +#define PCS_SWING_TX_SWING_LOW(x) ((x) << 0) + +#define PCIE20_PARF_CONFIG_BITS 0x50 +#define PHY_RX0_EQ(x) ((x) << 24)

#define PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE 0x358 #define SLV_ADDR_SPACE_SZ 0x10000000 @@ -293,6 +308,7 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie) struct qcom_pcie_resources_2_1_0 *res = &pcie->res.v2_1_0; struct dw_pcie *pci = pcie->pci; struct device *dev = pci->dev; + struct device_node *node = dev->of_node; u32 val; int ret;

@@ -347,6 +363,17 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie) val &= ~BIT(0); writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);

+ if (of_device_is_compatible(node, "qcom,pcie-ipq8064")) { + writel(PCS_DEEMPH_TX_DEEMPH_GEN1(24) | + PCS_DEEMPH_TX_DEEMPH_GEN2_3_5DB(24) | + PCS_DEEMPH_TX_DEEMPH_GEN2_6DB(34), + pcie->parf + PCIE20_PARF_PCS_DEEMPH); + writel(PCS_SWING_TX_SWING_FULL(120) | + PCS_SWING_TX_SWING_LOW(120), + pcie->parf + PCIE20_PARF_PCS_SWING); + writel(PHY_RX0_EQ(4), pcie->parf + PCIE20_PARF_CONFIG_BITS); + } + /* enable external reference clock */ val = readl(pcie->parf + PCIE20_PARF_PHY_REFCLK); val |= BIT(16);