[PATCH v2 07/10] PCIe: qcom: fix init problem with missing PARF programming

Ansuel Smith
2020-04-02T12:12:17Z

PARF programming was missing and this cause initilizzation problem on
some ipq806x based device (Netgear R7800 for example). This cause a
total lock of the system on kernel load.

Fixes: 82a82383 PCI: qcom: Add Qualcomm PCIe controller driver
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
drivers/pci/controller/dwc/pcie-qcom.c | 48 +++++++++++++++++++++-----
1 file changed, 39 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 211a1aa7d0f1..77b1ab7e23a3 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 REF_SSP_EN BIT(16)
+#define REF_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
@@ -184,6 +199,16 @@ struct qcom_pcie {

#define to_qcom_pcie(x) dev_get_drvdata((x)->dev)

+static inline void qcom_clear_and_set_dword(void __iomem *addr,
+ u32 clear_mask, u32 set_mask)
+{
+ u32 val = readl(addr);
+
+ val &= ~clear_mask;
+ val |= set_mask;
+ writel(val, addr);
+}
+
static void qcom_ep_reset_assert(struct qcom_pcie *pcie)
{
gpiod_set_value_cansleep(pcie->reset, 1);
@@ -304,7 +329,6 @@ 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;
- u32 val;
int ret;

ret = regulator_bulk_enable(ARRAY_SIZE(res->supplies), res->supplies);
@@ -355,15 +379,21 @@ static int qcom_pcie_init_2_1_0(struct qcom_pcie *pcie)
goto err_deassert_ahb;
}

- /* enable PCIe clocks and resets */
- val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
- val &= ~BIT(0);
- writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
+ qcom_clear_and_set_dword(pcie->parf + PCIE20_PARF_PHY_CTRL, BIT(0), 0);
+
+ /* PARF programming */
+ writel(PCS_DEEMPH_TX_DEEMPH_GEN1(0x18) |
+ PCS_DEEMPH_TX_DEEMPH_GEN2_3_5DB(0x18) |
+ PCS_DEEMPH_TX_DEEMPH_GEN2_6DB(0x22),
+ pcie->parf + PCIE20_PARF_PCS_DEEMPH);
+ writel(PCS_SWING_TX_SWING_FULL(0x78) |
+ PCS_SWING_TX_SWING_LOW(0x78),
+ pcie->parf + PCIE20_PARF_PCS_SWING);
+ writel(PHY_RX0_EQ(0x4), pcie->parf + PCIE20_PARF_CONFIG_BITS);

- /* enable external reference clock */
- val = readl(pcie->parf + PCIE20_PARF_PHY_REFCLK);
- val |= BIT(16);
- writel(val, pcie->parf + PCIE20_PARF_PHY_REFCLK);
+ /* enable reference clock */
+ qcom_clear_and_set_dword(pcie->parf + PCIE20_PARF_PHY_REFCLK,
+ REF_USE_PAD, REF_SSP_EN);

ret = reset_control_deassert(res->phy_reset);
if (ret) {
--
2.25.1