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Subject[PATCH 4.19 06/92] PCI: qcom: Define some PARF params needed for ipq8064 SoC
Date
From: Ansuel Smith <ansuelsmth@gmail.com>

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@gmail.com
Fixes: 82a823833f4e ("PCI: qcom: Add Qualcomm PCIe controller driver")
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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
@@ -76,6 +76,18 @@
#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
@@ -275,6 +287,7 @@ 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;

@@ -319,6 +332,17 @@ 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);

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