Re: [PATCH V15 13/13] PCI: tegra: Add Tegra194 PCIe support

From: Lorenzo Pieralisi
Date: Tue Aug 13 2019 - 06:57:48 EST


Some style comments - we have time to fix them.

On Fri, Aug 09, 2019 at 10:16:09AM +0530, Vidya Sagar wrote:

[...]

I do not know why up to here the line spacing is OK and here
you started cramming code all together :)

Just a matter of consistency, thanks for fixing them up.

> +static void tegra_pcie_downstream_dev_to_D0(struct tegra_pcie_dw *pcie)
> +{
> + struct pcie_port *pp = &pcie->pci.pp;
> + struct pci_bus *child;
> + struct pci_dev *pdev;
> +
> + /*
> + * link doesn't go into L2 state with some of the endpoints with Tegra
> + * if they are not in D0 state. So, need to make sure that immediate
> + * downstream devices are in D0 state before sending PME_TurnOff to put
> + * link into L2 state.
> + * This is as per PCI Express Base r4.0 v1.0 September 27-2017,
> + * 5.2 Link State Power Management (Page #428).
> + */
> +
> + list_for_each_entry(child, &pp->root_bus->children, node) {
> + /* Bring downstream devices to D0 if they are not already in */
> + if (child->parent == pp->root_bus)
> + break;
> + }

Add empty line.

> + list_for_each_entry(pdev, &child->devices, bus_list) {
> + if (PCI_SLOT(pdev->devfn) == 0) {
> + if (pci_set_power_state(pdev, PCI_D0))
> + dev_err(pcie->dev,
> + "Failed to transition %s to D0 state\n",
> + dev_name(&pdev->dev));
> + }
> + }
> +}
> +
> +static int tegra_pcie_config_controller(struct tegra_pcie_dw *pcie,
> + bool en_hw_hot_rst)
> +{
> + int ret;
> + u32 val;
> +
> + ret = tegra_pcie_bpmp_set_ctrl_state(pcie, true);
> + if (ret) {
> + dev_err(pcie->dev,
> + "Failed to enable controller %u: %d\n", pcie->cid, ret);
> + return ret;
> + }
> +
> + ret = regulator_enable(pcie->pex_ctl_supply);
> + if (ret < 0) {
> + dev_err(pcie->dev, "Failed to enable regulator: %d\n", ret);
> + goto fail_reg_en;
> + }
> +
> + ret = clk_prepare_enable(pcie->core_clk);
> + if (ret) {
> + dev_err(pcie->dev, "Failed to enable core clock: %d\n", ret);
> + goto fail_core_clk;
> + }
> +
> + ret = reset_control_deassert(pcie->core_apb_rst);
> + if (ret) {
> + dev_err(pcie->dev, "Failed to deassert core APB reset: %d\n",
> + ret);
> + goto fail_core_apb_rst;
> + }
> +
> + if (en_hw_hot_rst) {
> + /* Enable HW_HOT_RST mode */
> + val = appl_readl(pcie, APPL_CTRL);
> + val &= ~(APPL_CTRL_HW_HOT_RST_MODE_MASK <<
> + APPL_CTRL_HW_HOT_RST_MODE_SHIFT);
> + val |= APPL_CTRL_HW_HOT_RST_EN;
> + appl_writel(pcie, val, APPL_CTRL);
> + }
> +
> + ret = tegra_pcie_enable_phy(pcie);
> + if (ret) {
> + dev_err(pcie->dev, "Failed to enable PHY: %d\n", ret);
> + goto fail_phy;
> + }
> +
> + /* Update CFG base address */
> + appl_writel(pcie, pcie->dbi_res->start & APPL_CFG_BASE_ADDR_MASK,
> + APPL_CFG_BASE_ADDR);
> +
> + /* Configure this core for RP mode operation */
> + appl_writel(pcie, APPL_DM_TYPE_RP, APPL_DM_TYPE);
> +
> + appl_writel(pcie, 0x0, APPL_CFG_SLCG_OVERRIDE);
> +
> + val = appl_readl(pcie, APPL_CTRL);
> + appl_writel(pcie, val | APPL_CTRL_SYS_PRE_DET_STATE, APPL_CTRL);
> +
> + val = appl_readl(pcie, APPL_CFG_MISC);
> + val |= (APPL_CFG_MISC_ARCACHE_VAL << APPL_CFG_MISC_ARCACHE_SHIFT);
> + appl_writel(pcie, val, APPL_CFG_MISC);
> +
> + if (!pcie->supports_clkreq) {
> + val = appl_readl(pcie, APPL_PINMUX);
> + val |= APPL_PINMUX_CLKREQ_OUT_OVRD_EN;
> + val |= APPL_PINMUX_CLKREQ_OUT_OVRD;
> + appl_writel(pcie, val, APPL_PINMUX);
> + }
> +
> + /* Update iATU_DMA base address */
> + appl_writel(pcie,
> + pcie->atu_dma_res->start & APPL_CFG_IATU_DMA_BASE_ADDR_MASK,
> + APPL_CFG_IATU_DMA_BASE_ADDR);
> +
> + reset_control_deassert(pcie->core_rst);
> +
> + pcie->pcie_cap_base = dw_pcie_find_capability(&pcie->pci,
> + PCI_CAP_ID_EXP);
> +
> + /* Disable ASPM-L1SS advertisement as there is no CLKREQ routing */
> + if (!pcie->supports_clkreq) {
> + disable_aspm_l11(pcie);
> + disable_aspm_l12(pcie);
> + }
> +
> + return ret;
> +
> +fail_phy:
> + reset_control_assert(pcie->core_apb_rst);
> +fail_core_apb_rst:
> + clk_disable_unprepare(pcie->core_clk);
> +fail_core_clk:
> + regulator_disable(pcie->pex_ctl_supply);
> +fail_reg_en:
> + tegra_pcie_bpmp_set_ctrl_state(pcie, false);
> +
> + return ret;
> +}
> +
> +static int __deinit_controller(struct tegra_pcie_dw *pcie)
> +{
> + int ret;
> +
> + ret = reset_control_assert(pcie->core_rst);
> + if (ret) {
> + dev_err(pcie->dev, "Failed to assert \"core\" reset: %d\n",
> + ret);
> + return ret;
> + }

Add empty line.

> + tegra_pcie_disable_phy(pcie);

Add empty line.

> + ret = reset_control_assert(pcie->core_apb_rst);
> + if (ret) {
> + dev_err(pcie->dev, "Failed to assert APB reset: %d\n", ret);
> + return ret;
> + }

Add empty line.

> + clk_disable_unprepare(pcie->core_clk);

Add empty line.

> + ret = regulator_disable(pcie->pex_ctl_supply);
> + if (ret) {
> + dev_err(pcie->dev, "Failed to disable regulator: %d\n", ret);
> + return ret;
> + }

Add empty line.

> + ret = tegra_pcie_bpmp_set_ctrl_state(pcie, false);
> + if (ret) {
> + dev_err(pcie->dev, "Failed to disable controller %d: %d\n",
> + pcie->cid, ret);
> + return ret;
> + }

Add empty line.

> + return ret;
> +}
> +
> +static int tegra_pcie_init_controller(struct tegra_pcie_dw *pcie)
> +{
> + struct dw_pcie *pci = &pcie->pci;
> + struct pcie_port *pp = &pci->pp;
> + int ret;
> +
> + ret = tegra_pcie_config_controller(pcie, false);
> + if (ret < 0)
> + return ret;
> +
> + pp->ops = &tegra_pcie_dw_host_ops;
> +
> + ret = dw_pcie_host_init(pp);
> + if (ret < 0) {
> + dev_err(pcie->dev, "Failed to add PCIe port: %d\n", ret);
> + goto fail_host_init;
> + }
> +
> + return 0;
> +
> +fail_host_init:
> + return __deinit_controller(pcie);
> +}
> +
> +static int tegra_pcie_try_link_l2(struct tegra_pcie_dw *pcie)
> +{
> + u32 val;
> +
> + if (!tegra_pcie_dw_link_up(&pcie->pci))
> + return 0;
> +
> + val = appl_readl(pcie, APPL_RADM_STATUS);
> + val |= APPL_PM_XMT_TURNOFF_STATE;
> + appl_writel(pcie, val, APPL_RADM_STATUS);
> +
> + return readl_poll_timeout_atomic(pcie->appl_base + APPL_DEBUG, val,
> + val & APPL_DEBUG_PM_LINKST_IN_L2_LAT,
> + 1, PME_ACK_TIMEOUT);
> +}
> +
> +static void tegra_pcie_dw_pme_turnoff(struct tegra_pcie_dw *pcie)
> +{
> + u32 data;
> + int err;
> +
> + if (!tegra_pcie_dw_link_up(&pcie->pci)) {
> + dev_dbg(pcie->dev, "PCIe link is not up...!\n");
> + return;
> + }
> +
> + if (tegra_pcie_try_link_l2(pcie)) {
> + dev_info(pcie->dev, "Link didn't transition to L2 state\n");
> + /*
> + * TX lane clock freq will reset to Gen1 only if link is in L2
> + * or detect state.
> + * So apply pex_rst to end point to force RP to go into detect
> + * state
> + */
> + data = appl_readl(pcie, APPL_PINMUX);
> + data &= ~APPL_PINMUX_PEX_RST;
> + appl_writel(pcie, data, APPL_PINMUX);
> +
> + err = readl_poll_timeout_atomic(pcie->appl_base + APPL_DEBUG,
> + data,
> + ((data &
> + APPL_DEBUG_LTSSM_STATE_MASK) >>
> + APPL_DEBUG_LTSSM_STATE_SHIFT) ==
> + LTSSM_STATE_PRE_DETECT,
> + 1, LTSSM_TIMEOUT);
> + if (err) {
> + dev_info(pcie->dev, "Link didn't go to detect state\n");
> + } else {
> + /* Disable LTSSM after link is in detect state */
> + data = appl_readl(pcie, APPL_CTRL);
> + data &= ~APPL_CTRL_LTSSM_EN;
> + appl_writel(pcie, data, APPL_CTRL);
> + }
> + }
> + /*
> + * DBI registers may not be accessible after this as PLL-E would be
> + * down depending on how CLKREQ is pulled by end point
> + */
> + data = appl_readl(pcie, APPL_PINMUX);
> + data |= (APPL_PINMUX_CLKREQ_OVERRIDE_EN | APPL_PINMUX_CLKREQ_OVERRIDE);
> + /* Cut REFCLK to slot */
> + data |= APPL_PINMUX_CLK_OUTPUT_IN_OVERRIDE_EN;
> + data &= ~APPL_PINMUX_CLK_OUTPUT_IN_OVERRIDE;
> + appl_writel(pcie, data, APPL_PINMUX);
> +}
> +
> +static int tegra_pcie_deinit_controller(struct tegra_pcie_dw *pcie)
> +{
> + tegra_pcie_downstream_dev_to_D0(pcie);
> + dw_pcie_host_deinit(&pcie->pci.pp);
> + tegra_pcie_dw_pme_turnoff(pcie);

Add empty line.

> + return __deinit_controller(pcie);
> +}
> +
> +static int tegra_pcie_config_rp(struct tegra_pcie_dw *pcie)
> +{
> + struct pcie_port *pp = &pcie->pci.pp;
> + struct device *dev = pcie->dev;
> + char *name;
> + int ret;
> +
> + if (IS_ENABLED(CONFIG_PCI_MSI)) {
> + pp->msi_irq = of_irq_get_byname(dev->of_node, "msi");
> + if (!pp->msi_irq) {
> + dev_err(dev, "Failed to get MSI interrupt\n");
> + return -ENODEV;
> + }
> + }
> +
> + pm_runtime_enable(dev);
> + ret = pm_runtime_get_sync(dev);
> + if (ret < 0) {
> + dev_err(dev, "Failed to get runtime sync for PCIe dev: %d\n",
> + ret);
> + pm_runtime_disable(dev);
> + return ret;
> + }
> +
> + tegra_pcie_init_controller(pcie);
> +
> + pcie->link_state = tegra_pcie_dw_link_up(&pcie->pci);
> +
> + if (!pcie->link_state) {
> + ret = -ENOMEDIUM;
> + goto fail_host_init;
> + }
> +
> + name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
> + if (!name) {
> + ret = -ENOMEM;
> + goto fail_host_init;
> + }
> +
> + pcie->debugfs = debugfs_create_dir(name, NULL);
> + if (!pcie->debugfs)
> + dev_err(dev, "Failed to create debugfs\n");
> + else
> + init_debugfs(pcie);
> +
> + return ret;
> +
> +fail_host_init:
> + tegra_pcie_deinit_controller(pcie);
> + pm_runtime_put_sync(dev);
> + pm_runtime_disable(dev);
> + return ret;
> +}
> +
> +static int tegra_pcie_dw_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct resource *atu_dma_res;
> + struct tegra_pcie_dw *pcie;
> + struct resource *dbi_res;
> + struct pcie_port *pp;
> + struct dw_pcie *pci;
> + struct phy **phys;
> + char *name;
> + int ret;
> + u32 i;
> +
> + pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
> + if (!pcie)
> + return -ENOMEM;
> +
> + pci = &pcie->pci;
> + pci->dev = &pdev->dev;
> + pci->ops = &tegra_dw_pcie_ops;
> + pp = &pci->pp;
> + pcie->dev = &pdev->dev;
> +
> + ret = tegra_pcie_dw_parse_dt(pcie);
> + if (ret < 0) {
> + dev_err(dev, "Failed to parse device tree: %d\n", ret);
> + return ret;
> + }
> +
> + pcie->pex_ctl_supply = devm_regulator_get(dev, "vddio-pex-ctl");
> + if (IS_ERR(pcie->pex_ctl_supply)) {
> + dev_err(dev, "Failed to get regulator: %ld\n",
> + PTR_ERR(pcie->pex_ctl_supply));
> + return PTR_ERR(pcie->pex_ctl_supply);
> + }
> +
> + pcie->core_clk = devm_clk_get(dev, "core");
> + if (IS_ERR(pcie->core_clk)) {
> + dev_err(dev, "Failed to get core clock: %ld\n",
> + PTR_ERR(pcie->core_clk));
> + return PTR_ERR(pcie->core_clk);
> + }
> +
> + pcie->appl_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> + "appl");
> + if (!pcie->appl_res) {
> + dev_err(dev, "Failed to find \"appl\" region\n");
> + return PTR_ERR(pcie->appl_res);
> + }
> +
> + pcie->appl_base = devm_ioremap_resource(dev, pcie->appl_res);
> + if (IS_ERR(pcie->appl_base))
> + return PTR_ERR(pcie->appl_base);
> +
> + pcie->core_apb_rst = devm_reset_control_get(dev, "apb");
> + if (IS_ERR(pcie->core_apb_rst)) {
> + dev_err(dev, "Failed to get APB reset: %ld\n",
> + PTR_ERR(pcie->core_apb_rst));
> + return PTR_ERR(pcie->core_apb_rst);
> + }
> +
> + phys = devm_kcalloc(dev, pcie->phy_count, sizeof(*phys), GFP_KERNEL);
> + if (!phys)
> + return PTR_ERR(phys);
> +
> + for (i = 0; i < pcie->phy_count; i++) {
> + name = kasprintf(GFP_KERNEL, "p2u-%u", i);
> + if (!name) {
> + dev_err(dev, "Failed to create P2U string\n");
> + return -ENOMEM;
> + }
> + phys[i] = devm_phy_get(dev, name);
> + kfree(name);
> + if (IS_ERR(phys[i])) {
> + ret = PTR_ERR(phys[i]);
> + dev_err(dev, "Failed to get PHY: %d\n", ret);
> + return ret;
> + }
> + }
> +
> + pcie->phys = phys;
> +
> + dbi_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
> + if (!dbi_res) {
> + dev_err(dev, "Failed to find \"dbi\" region\n");
> + return PTR_ERR(dbi_res);
> + }
> + pcie->dbi_res = dbi_res;
> +
> + pci->dbi_base = devm_ioremap_resource(dev, dbi_res);
> + if (IS_ERR(pci->dbi_base))
> + return PTR_ERR(pci->dbi_base);
> +
> + /* Tegra HW locates DBI2 at a fixed offset from DBI */
> + pci->dbi_base2 = pci->dbi_base + 0x1000;
> +
> + atu_dma_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> + "atu_dma");
> + if (!atu_dma_res) {
> + dev_err(dev, "Failed to find \"atu_dma\" region\n");
> + return PTR_ERR(atu_dma_res);
> + }
> + pcie->atu_dma_res = atu_dma_res;
> +
> + pci->atu_base = devm_ioremap_resource(dev, atu_dma_res);
> + if (IS_ERR(pci->atu_base))
> + return PTR_ERR(pci->atu_base);
> +
> + pcie->core_rst = devm_reset_control_get(dev, "core");
> + if (IS_ERR(pcie->core_rst)) {
> + dev_err(dev, "Failed to get core reset: %ld\n",
> + PTR_ERR(pcie->core_rst));
> + return PTR_ERR(pcie->core_rst);
> + }
> +
> + pp->irq = platform_get_irq_byname(pdev, "intr");
> + if (!pp->irq) {
> + dev_err(dev, "Failed to get \"intr\" interrupt\n");
> + return -ENODEV;
> + }
> +
> + ret = devm_request_irq(dev, pp->irq, tegra_pcie_irq_handler,
> + IRQF_SHARED, "tegra-pcie-intr", pcie);
> + if (ret) {
> + dev_err(dev, "Failed to request IRQ %d: %d\n", pp->irq, ret);
> + return ret;
> + }
> +
> + pcie->bpmp = tegra_bpmp_get(dev);
> + if (IS_ERR(pcie->bpmp))
> + return PTR_ERR(pcie->bpmp);
> +
> + platform_set_drvdata(pdev, pcie);
> +
> + ret = tegra_pcie_config_rp(pcie);
> + if (ret && ret != -ENOMEDIUM)
> + goto fail;
> + else
> + return 0;
> +
> +fail:
> + tegra_bpmp_put(pcie->bpmp);
> + return ret;
> +}
> +
> +static int tegra_pcie_dw_remove(struct platform_device *pdev)
> +{
> + struct tegra_pcie_dw *pcie = platform_get_drvdata(pdev);
> +
> + if (!pcie->link_state)
> + return 0;
> +
> + debugfs_remove_recursive(pcie->debugfs);
> + tegra_pcie_deinit_controller(pcie);
> + pm_runtime_put_sync(pcie->dev);
> + pm_runtime_disable(pcie->dev);
> + tegra_bpmp_put(pcie->bpmp);
> +
> + return 0;
> +}
> +
> +static int tegra_pcie_dw_suspend_late(struct device *dev)
> +{
> + struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
> + u32 val;
> +
> + if (!pcie->link_state)
> + return 0;
> +
> + /* Enable HW_HOT_RST mode */
> + val = appl_readl(pcie, APPL_CTRL);
> + val &= ~(APPL_CTRL_HW_HOT_RST_MODE_MASK <<
> + APPL_CTRL_HW_HOT_RST_MODE_SHIFT);
> + val |= APPL_CTRL_HW_HOT_RST_EN;
> + appl_writel(pcie, val, APPL_CTRL);
> +
> + return 0;
> +}
> +
> +static int tegra_pcie_dw_suspend_noirq(struct device *dev)
> +{
> + struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
> +
> + if (!pcie->link_state)
> + return 0;
> +
> + /* Save MSI interrupt vector */
> + pcie->msi_ctrl_int = dw_pcie_readl_dbi(&pcie->pci,
> + PORT_LOGIC_MSI_CTRL_INT_0_EN);
> + tegra_pcie_downstream_dev_to_D0(pcie);
> + tegra_pcie_dw_pme_turnoff(pcie);

Add empty line.

> + return __deinit_controller(pcie);
> +}
> +
> +static int tegra_pcie_dw_resume_noirq(struct device *dev)
> +{
> + struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
> + int ret;
> +
> + if (!pcie->link_state)
> + return 0;
> +
> + ret = tegra_pcie_config_controller(pcie, true);
> + if (ret < 0)
> + return ret;
> +
> + ret = tegra_pcie_dw_host_init(&pcie->pci.pp);
> + if (ret < 0) {
> + dev_err(dev, "Failed to init host: %d\n", ret);
> + goto fail_host_init;
> + }
> +
> + /* Restore MSI interrupt vector */
> + dw_pcie_writel_dbi(&pcie->pci, PORT_LOGIC_MSI_CTRL_INT_0_EN,
> + pcie->msi_ctrl_int);
> +
> + return 0;

Add empty line.

Thanks,
Lorenzo

> +fail_host_init:
> + return __deinit_controller(pcie);
> +}
> +
> +static int tegra_pcie_dw_resume_early(struct device *dev)
> +{
> + struct tegra_pcie_dw *pcie = dev_get_drvdata(dev);
> + u32 val;
> +
> + if (!pcie->link_state)
> + return 0;
> +
> + /* Disable HW_HOT_RST mode */
> + val = appl_readl(pcie, APPL_CTRL);
> + val &= ~(APPL_CTRL_HW_HOT_RST_MODE_MASK <<
> + APPL_CTRL_HW_HOT_RST_MODE_SHIFT);
> + val |= APPL_CTRL_HW_HOT_RST_MODE_IMDT_RST <<
> + APPL_CTRL_HW_HOT_RST_MODE_SHIFT;
> + val &= ~APPL_CTRL_HW_HOT_RST_EN;
> + appl_writel(pcie, val, APPL_CTRL);
> +
> + return 0;
> +}
> +
> +static void tegra_pcie_dw_shutdown(struct platform_device *pdev)
> +{
> + struct tegra_pcie_dw *pcie = platform_get_drvdata(pdev);
> +
> + if (!pcie->link_state)
> + return;
> +
> + debugfs_remove_recursive(pcie->debugfs);
> + tegra_pcie_downstream_dev_to_D0(pcie);
> +
> + disable_irq(pcie->pci.pp.irq);
> + if (IS_ENABLED(CONFIG_PCI_MSI))
> + disable_irq(pcie->pci.pp.msi_irq);
> +
> + tegra_pcie_dw_pme_turnoff(pcie);
> + __deinit_controller(pcie);
> +}
> +
> +static const struct of_device_id tegra_pcie_dw_of_match[] = {
> + {
> + .compatible = "nvidia,tegra194-pcie",
> + },
> + {},
> +};
> +
> +static const struct dev_pm_ops tegra_pcie_dw_pm_ops = {
> + .suspend_late = tegra_pcie_dw_suspend_late,
> + .suspend_noirq = tegra_pcie_dw_suspend_noirq,
> + .resume_noirq = tegra_pcie_dw_resume_noirq,
> + .resume_early = tegra_pcie_dw_resume_early,
> +};
> +
> +static struct platform_driver tegra_pcie_dw_driver = {
> + .probe = tegra_pcie_dw_probe,
> + .remove = tegra_pcie_dw_remove,
> + .shutdown = tegra_pcie_dw_shutdown,
> + .driver = {
> + .name = "tegra194-pcie",
> + .pm = &tegra_pcie_dw_pm_ops,
> + .of_match_table = tegra_pcie_dw_of_match,
> + },
> +};
> +module_platform_driver(tegra_pcie_dw_driver);
> +
> +MODULE_DEVICE_TABLE(of, tegra_pcie_dw_of_match);
> +
> +MODULE_AUTHOR("Vidya Sagar <vidyas@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("NVIDIA PCIe host controller driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.17.1
>