Add support for Tx De-Emphasis, Tx Swing and Rx equalization definition
needed on some ipq8064 based device (Netgear R7800 for example). This
cause a total lock of the system on kernel load.
Fixes: 82a823833f4e PCI: qcom: Add Qualcomm PCIe controller driver
Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.5+
---
drivers/pci/controller/dwc/pcie-qcom.c | 47 ++++++++++++++++++++++++--
1 file changed, 45 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index a4fd5baada34..da8058fd1925 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
@@ -97,6 +112,12 @@ struct qcom_pcie_resources_2_1_0 {
struct reset_control *phy_reset;
struct reset_control *ext_reset;
struct regulator_bulk_data supplies[QCOM_PCIE_2_1_0_MAX_SUPPLY];
+ u32 tx_deemph_gen1;
+ u32 tx_deemph_gen2_3p5db;
+ u32 tx_deemph_gen2_6db;
+ u32 tx_swing_full;
+ u32 tx_swing_low;
+ u32 rx0_eq;
};
struct qcom_pcie_resources_1_0_0 {
@@ -234,8 +255,21 @@ static int qcom_pcie_get_resources_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;
int ret;
+ of_property_read_u32(node, "qcom,tx-deemph-gen1",
+ &res->tx_deemph_gen1);
+ of_property_read_u32(node, "qcom,tx-deemph-gen2-3p5db",
+ &res->tx_deemph_gen2_3p5db);
+ of_property_read_u32(node, "qcom,tx-deemph-gen2-6db",
+ &res->tx_deemph_gen2_6db);
+ of_property_read_u32(node, "qcom,tx-swing-full",
+ &res->tx_swing_full);
+ of_property_read_u32(node, "qcom,tx-swing-low",
+ &res->tx_swing_low);
+ of_property_read_u32(node, "qcom,rx0-eq", &res->rx0_eq);
+
res->supplies[0].supply = "vdda";
res->supplies[1].supply = "vdda_phy";
res->supplies[2].supply = "vdda_refclk";
@@ -368,9 +402,18 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
/* enable PCIe clocks and resets */
qcom_clear_and_set_dword(pcie->parf + PCIE20_PARF_PHY_CTRL, BIT(0), 0);
+ writel(PCS_DEEMPH_TX_DEEMPH_GEN1(res->tx_deemph_gen1) |
+ PCS_DEEMPH_TX_DEEMPH_GEN2_3_5DB(res->tx_deemph_gen2_3p5db) |
+ PCS_DEEMPH_TX_DEEMPH_GEN2_6DB(res->tx_deemph_gen2_6db),
+ pcie->parf + PCIE20_PARF_PCS_DEEMPH);
+ writel(PCS_SWING_TX_SWING_FULL(res->tx_swing_full) |
+ PCS_SWING_TX_SWING_LOW(res->tx_swing_low),
+ pcie->parf + PCIE20_PARF_PCS_SWING);
+ writel(PHY_RX0_EQ(res->rx0_eq), pcie->parf + PCIE20_PARF_CONFIG_BITS);
+
/* enable external reference clock */
- qcom_clear_and_set_dword(pcie->parf + PCIE20_PARF_PHY_REFCLK, 0,
- BIT(16));
+ qcom_clear_and_set_dword(pcie->parf + PCIE20_PARF_PHY_REFCLK,
+ PHY_REFCLK_USE_PAD, PHY_REFCLK_SSP_EN;
ret = reset_control_deassert(res->phy_reset);
if (ret) {
--
2.25.1
