Thread (17 messages) 17 messages, 3 authors, 2020-07-07
STALE2199d LANDED: 7 (7M)
Revisions (6)
  1. v2 [diff vs current]
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  3. v4 [diff vs current]
  4. v5 [diff vs current]
  5. v6 [diff vs current]
  6. v7 current

[PATCH v7 07/12] PCI: qcom: Define some PARF params needed for ipq8064 SoC

From: Ansuel Smith <ansuelsmth@gmail.com>
Date: 2020-06-15 21:06:40
Also in: linux-arm-msm, linux-pci, lkml, stable
Subsystem: arm/qualcomm mailing list, pci native host bridge and endpoint drivers, pci subsystem, pcie driver for qualcomm msm, the rest · Maintainers: Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds

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+
Reviewed-by: Rob Herring <robh@kernel.org>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index f2ea1ab6f584..85313493d51b 100644
--- 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
@@ -293,6 +305,7 @@ 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 +360,17 @@ 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);
-- 
2.27.0.rc0
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