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

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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





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