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

From: Vidya Sagar
Date: Tue Aug 13 2019 - 07:36:21 EST

On 8/13/2019 4:27 PM, Lorenzo Pieralisi wrote:
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.

Thanks for the review.
I'll address all these comments in the next series.

Thanks,
Vidya Sagar

+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