[PATCH v3 07/11] PCI: qcom: add support for defining some PARF params

[Ansuel Smith <ansuelsmth@gmail.com>]

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@gmail.com>
Cc: stable@vger.kernel.org # 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