Re: [PATCH v7 3/3] PCI: qcom: Add IPQ60xx support

Johan Hovold
2022-06-20T15:57:14Z

On Sun, Jun 12, 2022 at 01:18:35PM +0300, Baruch Siach wrote:
> From: Selvam Sathappan Periakaruppan <quic_speriaka@quicinc.com>
>
> IPQ60xx series of SoCs have one port of PCIe gen 3. Add support for that
> platform.
>
> The code is based on downstream[1] Codeaurora kernel v5.4 (branch
> win.linuxopenwrt.2.0).
>
> Split out the DBI registers access part from .init into .post_init. DBI
> registers are only accessible after phy_power_on().
>
> [1] https://source.codeaurora.org/quic/qsdk/oss/kernel/linux-ipq-5.4/
>
> Signed-off-by: Selvam Sathappan Periakaruppan <speriaka@codeaurora.org>
> Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
> ---

> +static void qcom_pcie_deinit_2_9_0(struct qcom_pcie *pcie)
> +{
> + struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
> +
> + clk_bulk_disable_unprepare(ARRAY_SIZE(res->clks), res->clks);

Assert reset as you do in the init error path?

> +}
> +
> +static int qcom_pcie_init_2_9_0(struct qcom_pcie *pcie)
> +{
> + struct qcom_pcie_resources_2_9_0 *res = &pcie->res.v2_9_0;
> + struct device *dev = pcie->pci->dev;
> + int ret;
> +
> + ret = reset_control_assert(res->rst);
> + if (ret) {
> + dev_err(dev, "reset assert failed (%d)\n", ret);
> + return ret;
> + }
> +
> + /*
> + * Delay periods before and after reset deassert are working values
> + * from downstream Codeaurora kernel
> + */
> + usleep_range(2000, 2500);
> +
> + ret = reset_control_deassert(res->rst);
> + if (ret) {
> + dev_err(dev, "reset deassert failed (%d)\n", ret);
> + return ret;
> + }
> +
> + usleep_range(2000, 2500);
> +
> + ret = clk_bulk_prepare_enable(ARRAY_SIZE(res->clks), res->clks);
> + if (ret)
> + goto err_reset;
> +
> + return 0;
> +
> +err_reset:
> + reset_control_assert(res->rst);
> +
> + return ret;
> +}
> +
> +static int qcom_pcie_post_init_2_9_0(struct qcom_pcie *pcie)
> +{
> + struct dw_pcie *pci = pcie->pci;
> + u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
> + u32 val;
> + int i;
> +
> + writel(SLV_ADDR_SPACE_SZ,
> + pcie->parf + PCIE20_v3_PARF_SLV_ADDR_SPACE_SIZE);
> +
> + val = readl(pcie->parf + PCIE20_PARF_PHY_CTRL);
> + val &= ~BIT(0);
> + writel(val, pcie->parf + PCIE20_PARF_PHY_CTRL);
> +
> + writel(0, pcie->parf + PCIE20_PARF_DBI_BASE_ADDR);
> +
> + writel(DEVICE_TYPE_RC, pcie->parf + PCIE20_PARF_DEVICE_TYPE);
> + writel(BYPASS | MSTR_AXI_CLK_EN | AHB_CLK_EN,
> + pcie->parf + PCIE20_PARF_MHI_CLOCK_RESET_CTRL);
> + writel(GEN3_RELATED_OFF_RXEQ_RGRDLESS_RXTS
> + | GEN3_RELATED_OFF_GEN3_ZRXDC_NONCOMPL,

I noticed that some of this probably has been copied from from
qcom_pcie_init_2_3_3(), but please move the | operator to the previous
line.

> + pci->dbi_base + GEN3_RELATED_OFF);
> +
> + writel(MST_WAKEUP_EN | SLV_WAKEUP_EN | MSTR_ACLK_CGC_DIS
> + | SLV_ACLK_CGC_DIS | CORE_CLK_CGC_DIS |

Same here.

> + AUX_PWR_DET | L23_CLK_RMV_DIS | L1_CLK_RMV_DIS,
> + pcie->parf + PCIE20_PARF_SYS_CTRL);
> +
> + writel(0, pcie->parf + PCIE20_PARF_Q2A_FLUSH);
> +
> + dw_pcie_dbi_ro_wr_en(pci);
> + writel(PCIE_CAP_SLOT_VAL, pci->dbi_base + offset + PCI_EXP_SLTCAP);
> +
> + val = readl(pci->dbi_base + offset + PCI_EXP_LNKCAP);
> + val &= ~PCI_EXP_LNKCAP_ASPMS;
> + writel(val, pci->dbi_base + offset + PCI_EXP_LNKCAP);
> +
> + writel(PCI_EXP_DEVCTL2_COMP_TMOUT_DIS, pci->dbi_base + offset +
> + PCI_EXP_DEVCTL2);
> +
> + for (i = 0; i < 256; i++)
> + writel(0x0, pcie->parf + PCIE20_PARF_BDF_TO_SID_TABLE_N
> + + (4 * i));

And here for +, but you should probably just remove the line break (you
can go up to 100 chars if it makes the code more readable).

Please drop the 0x prefix too.

> +
> + return 0;
> +}

Johan