On Wed, Nov 28, 2018 at 01:04:26PM +0900, Kunihiko Hayashi wrote:

[...]

+static void uniphier_pcie_irq_ack(struct irq_data *d)
+{
+	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	u32 val;
+
+	val = readl(priv->base + PCL_RCV_INTX);
+	val &= ~PCL_RCV_INTX_ALL_STATUS;
+	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_STATUS_SHIFT);
+	writel(val, priv->base + PCL_RCV_INTX);
+}
+
+static void uniphier_pcie_irq_mask(struct irq_data *d)
+{
+	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	u32 val;
+
+	val = readl(priv->base + PCL_RCV_INTX);
+	val &= ~PCL_RCV_INTX_ALL_STATUS;
+	val |= BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
+	writel(val, priv->base + PCL_RCV_INTX);
+}
+
+static void uniphier_pcie_irq_unmask(struct irq_data *d)
+{
+	struct pcie_port *pp = irq_data_get_irq_chip_data(d);
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	u32 val;
+
+	val = readl(priv->base + PCL_RCV_INTX);
+	val &= ~PCL_RCV_INTX_ALL_STATUS;

I have noticed this operation is carried out on ACK/MASK/UNMASK,
what's its purpose ?

Lorenzo

+	val &= ~BIT(irqd_to_hwirq(d) + PCL_RCV_INTX_MASK_SHIFT);
+	writel(val, priv->base + PCL_RCV_INTX);
+}
+
+static struct irq_chip uniphier_pcie_irq_chip = {
+	.name = "PCI",
+	.irq_ack = uniphier_pcie_irq_ack,
+	.irq_mask = uniphier_pcie_irq_mask,
+	.irq_unmask = uniphier_pcie_irq_unmask,
+};
+
+static int uniphier_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
+				  irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &uniphier_pcie_irq_chip,
+				 handle_level_irq);
+	irq_set_chip_data(irq, domain->host_data);
+
+	return 0;
+}
+
+static const struct irq_domain_ops uniphier_intx_domain_ops = {
+	.map = uniphier_pcie_intx_map,
+};
+
+static void uniphier_pcie_irq_handler(struct irq_desc *desc)
+{
+	struct pcie_port *pp = irq_desc_get_handler_data(desc);
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned long reg;
+	u32 val, bit, virq;
+
+	/* INT for debug */
+	val = readl(priv->base + PCL_RCV_INT);
+
+	if (val & PCL_CFG_BW_MGT_STATUS)
+		dev_dbg(pci->dev, "Link Bandwidth Management Event\n");
+	if (val & PCL_CFG_LINK_AUTO_BW_STATUS)
+		dev_dbg(pci->dev, "Link Autonomous Bandwidth Event\n");
+	if (val & PCL_CFG_AER_RC_ERR_MSI_STATUS)
+		dev_dbg(pci->dev, "Root Error\n");
+	if (val & PCL_CFG_PME_MSI_STATUS)
+		dev_dbg(pci->dev, "PME Interrupt\n");
+
+	writel(val, priv->base + PCL_RCV_INT);
+
+	/* INTx */
+	chained_irq_enter(chip, desc);
+
+	val = readl(priv->base + PCL_RCV_INTX);
+	reg = FIELD_GET(PCL_RCV_INTX_ALL_STATUS, val);
+
+	for_each_set_bit(bit, &reg, PCI_NUM_INTX) {
+		virq = irq_linear_revmap(priv->legacy_irq_domain, bit);
+		generic_handle_irq(virq);
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static int uniphier_pcie_config_legacy_irq(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	struct device_node *np = pci->dev->of_node;
+	struct device_node *np_intc;
+
+	np_intc = of_get_child_by_name(np, "legacy-interrupt-controller");
+	if (!np_intc) {
+		dev_err(pci->dev, "Failed to get legacy-interrupt-controller node\n");
+		return -EINVAL;
+	}
+
+	pp->irq = irq_of_parse_and_map(np_intc, 0);
+	if (!pp->irq) {
+		dev_err(pci->dev, "Failed to get an IRQ entry in legacy-interrupt-controller\n");
+		return -EINVAL;
+	}
+
+	priv->legacy_irq_domain = irq_domain_add_linear(np_intc, PCI_NUM_INTX,
+						&uniphier_intx_domain_ops, pp);
+	if (!priv->legacy_irq_domain) {
+		dev_err(pci->dev, "Failed to get INTx domain\n");
+		return -ENODEV;
+	}
+
+	irq_set_chained_handler_and_data(pp->irq, uniphier_pcie_irq_handler,
+					 pp);
+
+	return 0;
+}
+
+static int uniphier_pcie_host_init(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct uniphier_pcie_priv *priv = to_uniphier_pcie(pci);
+	int ret;
+
+	ret = uniphier_pcie_config_legacy_irq(pp);
+	if (ret)
+		return ret;
+
+	uniphier_pcie_irq_enable(priv);
+
+	dw_pcie_setup_rc(pp);
+	ret = uniphier_pcie_establish_link(pci);
+	if (ret)
+		return ret;
+
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		dw_pcie_msi_init(pp);
+
+	return 0;
+}
+
+static const struct dw_pcie_host_ops uniphier_pcie_host_ops = {
+	.host_init = uniphier_pcie_host_init,
+};
+
+static int uniphier_add_pcie_port(struct uniphier_pcie_priv *priv,
+				  struct platform_device *pdev)
+{
+	struct dw_pcie *pci = &priv->pci;
+	struct pcie_port *pp = &pci->pp;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	pp->ops = &uniphier_pcie_host_ops;
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		pp->msi_irq = platform_get_irq_byname(pdev, "msi");
+		if (pp->msi_irq < 0)
+			return pp->msi_irq;
+	}
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(dev, "Failed to initialize host (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int uniphier_pcie_host_enable(struct uniphier_pcie_priv *priv)
+{
+	int ret;
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	ret = reset_control_deassert(priv->rst);
+	if (ret)
+		goto out_clk_disable;
+
+	uniphier_pcie_init_rc(priv);
+
+	ret = phy_init(priv->phy);
+	if (ret)
+		goto out_rst_assert;
+
+	ret = uniphier_pcie_wait_rc(priv);
+	if (ret)
+		goto out_phy_exit;
+
+	return 0;
+
+out_phy_exit:
+	phy_exit(priv->phy);
+out_rst_assert:
+	reset_control_assert(priv->rst);
+out_clk_disable:
+	clk_disable_unprepare(priv->clk);
+
+	return ret;
+}
+
+static void uniphier_pcie_host_disable(struct uniphier_pcie_priv *priv)
+{
+	uniphier_pcie_irq_disable(priv);
+	phy_exit(priv->phy);
+	reset_control_assert(priv->rst);
+	clk_disable_unprepare(priv->clk);
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.start_link = uniphier_pcie_establish_link,
+	.stop_link = uniphier_pcie_stop_link,
+	.link_up = uniphier_pcie_link_up,
+};
+
+static int uniphier_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct uniphier_pcie_priv *priv;
+	struct resource *res;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->pci.dev = dev;
+	priv->pci.ops = &dw_pcie_ops;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
+	priv->pci.dbi_base = devm_pci_remap_cfg_resource(dev, res);
+	if (IS_ERR(priv->pci.dbi_base))
+		return PTR_ERR(priv->pci.dbi_base);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "link");
+	priv->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk))
+		return PTR_ERR(priv->clk);
+
+	priv->rst = devm_reset_control_get_shared(dev, NULL);
+	if (IS_ERR(priv->rst))
+		return PTR_ERR(priv->rst);
+
+	priv->phy = devm_phy_optional_get(dev, "pcie-phy");
+	if (IS_ERR(priv->phy))
+		return PTR_ERR(priv->phy);
+
+	platform_set_drvdata(pdev, priv);
+
+	ret = uniphier_pcie_host_enable(priv);
+	if (ret)
+		return ret;
+
+	return uniphier_add_pcie_port(priv, pdev);
+}
+
+static int uniphier_pcie_remove(struct platform_device *pdev)
+{
+	struct uniphier_pcie_priv *priv = platform_get_drvdata(pdev);
+
+	uniphier_pcie_host_disable(priv);
+
+	return 0;
+}
+
+static const struct of_device_id uniphier_pcie_match[] = {
+	{ .compatible = "socionext,uniphier-pcie", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, uniphier_pcie_match);
+
+static struct platform_driver uniphier_pcie_driver = {
+	.probe  = uniphier_pcie_probe,
+	.remove = uniphier_pcie_remove,
+	.driver = {
+		.name = "uniphier-pcie",
+		.of_match_table = uniphier_pcie_match,
+	},
+};
+builtin_platform_driver(uniphier_pcie_driver);
+
+MODULE_AUTHOR("Kunihiko Hayashi [off-list ref]");
+MODULE_DESCRIPTION("UniPhier PCIe host controller driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4