From: Ansuel Smith <ansuelsmth@xxxxxxxxx> commit 5149901e9e6deca487c01cc434a3ac4125c7b00b upstream. 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. Link: https://lore.kernel.org/r/20200615210608.21469-8-ansuelsmth@xxxxxxxxx Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver") Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Reviewed-by: Rob Herring <robh@xxxxxxxxxx> Acked-by: Stanimir Varbanov <svarbanov@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx # v4.5+ Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/controller/dwc/pcie-qcom.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) --- a/drivers/pci/controller/dwc/pcie-qcom.c +++ b/drivers/pci/controller/dwc/pcie-qcom.c @@ -77,6 +77,18 @@ #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 @@ -286,6 +298,7 @@ static int qcom_pcie_init_2_1_0(struct q 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; @@ -330,6 +343,17 @@ static int qcom_pcie_init_2_1_0(struct q 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);
