[v3,06/10] PCI: apple: Add INTx and per-port interrupt support

diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
index dabbfc2e1fb0..d174a215a47d 100644
--- a/drivers/pci/controller/pcie-apple.c
+++ b/drivers/pci/controller/pcie-apple.c
@@ -21,6 +21,7 @@ 
 #include <linux/gpio/consumer.h>
 #include <linux/kernel.h>
 #include <linux/iopoll.h>
+#include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/module.h>
 #include <linux/msi.h>
@@ -118,12 +119,14 @@ 
 struct apple_pcie {
 	struct device		*dev;
 	void __iomem            *base;
+	struct completion	event;
 };
 
 struct apple_pcie_port {
 	struct apple_pcie	*pcie;
 	struct device_node	*np;
 	void __iomem		*base;
+	struct irq_domain	*domain;
 	int			idx;
 };
 
@@ -132,6 +135,200 @@  static inline void rmwl(u32 clr, u32 set, void __iomem *addr)
 	writel_relaxed((readl_relaxed(addr) & ~clr) | set, addr);
 }
 
+static void apple_port_irq_mask(struct irq_data *data)
+{
+	struct apple_pcie_port *port = irq_data_get_irq_chip_data(data);
+
+	writel_relaxed(BIT(data->hwirq), port->base + PORT_INTMSKSET);
+}
+
+static void apple_port_irq_unmask(struct irq_data *data)
+{
+	struct apple_pcie_port *port = irq_data_get_irq_chip_data(data);
+
+	writel_relaxed(BIT(data->hwirq), port->base + PORT_INTMSKCLR);
+}
+
+static bool hwirq_is_intx(unsigned int hwirq)
+{
+	return BIT(hwirq) & PORT_INT_INTx_MASK;
+}
+
+static void apple_port_irq_ack(struct irq_data *data)
+{
+	struct apple_pcie_port *port = irq_data_get_irq_chip_data(data);
+
+	if (!hwirq_is_intx(data->hwirq))
+		writel_relaxed(BIT(data->hwirq), port->base + PORT_INTSTAT);
+}
+
+static int apple_port_irq_set_type(struct irq_data *data, unsigned int type)
+{
+	/*
+	 * It doesn't seem that there is any way to configure the
+	 * trigger, so assume INTx have to be level (as per the spec),
+	 * and the rest is edge (which looks likely).
+	 */
+	if (hwirq_is_intx(data->hwirq) ^ !!(type & IRQ_TYPE_LEVEL_MASK))
+		return -EINVAL;
+
+	irqd_set_trigger_type(data, type);
+	return 0;
+}
+
+static struct irq_chip apple_port_irqchip = {
+	.name		= "PCIe",
+	.irq_ack	= apple_port_irq_ack,
+	.irq_mask	= apple_port_irq_mask,
+	.irq_unmask	= apple_port_irq_unmask,
+	.irq_set_type	= apple_port_irq_set_type,
+};
+
+static int apple_port_irq_domain_alloc(struct irq_domain *domain,
+				       unsigned int virq, unsigned int nr_irqs,
+				       void *args)
+{
+	struct apple_pcie_port *port = domain->host_data;
+	struct irq_fwspec *fwspec = args;
+	int i;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_flow_handler_t flow = handle_edge_irq;
+		unsigned int type = IRQ_TYPE_EDGE_RISING;
+
+		if (hwirq_is_intx(fwspec->param[0] + i)) {
+			flow = handle_level_irq;
+			type = IRQ_TYPE_LEVEL_HIGH;
+		}
+
+		irq_domain_set_info(domain, virq + i, fwspec->param[0] + i,
+				    &apple_port_irqchip, port, flow,
+				    NULL, NULL);
+
+		irq_set_irq_type(virq + i, type);
+	}
+
+	return 0;
+}
+
+static void apple_port_irq_domain_free(struct irq_domain *domain,
+				       unsigned int virq, unsigned int nr_irqs)
+{
+	int i;
+
+	for (i = 0; i < nr_irqs; i++) {
+		struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
+		irq_set_handler(virq + i, NULL);
+		irq_domain_reset_irq_data(d);
+	}
+}
+
+static const struct irq_domain_ops apple_port_irq_domain_ops = {
+	.translate	= irq_domain_translate_onecell,
+	.alloc		= apple_port_irq_domain_alloc,
+	.free		= apple_port_irq_domain_free,
+};
+
+static void apple_port_irq_handler(struct irq_desc *desc)
+{
+	struct apple_pcie_port *port = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned long stat;
+	int i;
+
+	chained_irq_enter(chip, desc);
+
+	stat = readl_relaxed(port->base + PORT_INTSTAT);
+
+	for_each_set_bit(i, &stat, 32)
+		generic_handle_domain_irq(port->domain, i);
+
+	chained_irq_exit(chip, desc);
+}
+
+static int apple_pcie_port_setup_irq(struct apple_pcie_port *port)
+{
+	struct fwnode_handle *fwnode = &port->np->fwnode;
+	unsigned int irq;
+
+	/* FIXME: consider moving each interrupt under each port */
+	irq = irq_of_parse_and_map(to_of_node(dev_fwnode(port->pcie->dev)),
+				   port->idx);
+	if (!irq)
+		return -ENXIO;
+
+	port->domain = irq_domain_create_linear(fwnode, 32,
+						&apple_port_irq_domain_ops,
+						port);
+	if (!port->domain)
+		return -ENOMEM;
+
+	/* Disable all interrupts */
+	writel_relaxed(~0, port->base + PORT_INTMSKSET);
+	writel_relaxed(~0, port->base + PORT_INTSTAT);
+
+	irq_set_chained_handler_and_data(irq, apple_port_irq_handler, port);
+
+	return 0;
+}
+
+static irqreturn_t apple_pcie_port_irq(int irq, void *data)
+{
+	struct apple_pcie_port *port = data;
+	unsigned int hwirq = irq_domain_get_irq_data(port->domain, irq)->hwirq;
+
+	switch (hwirq) {
+	case PORT_INT_LINK_UP:
+		dev_info_ratelimited(port->pcie->dev, "Link up on %pOF\n",
+				     port->np);
+		complete_all(&port->pcie->event);
+		break;
+	case PORT_INT_LINK_DOWN:
+		dev_info_ratelimited(port->pcie->dev, "Link down on %pOF\n",
+				     port->np);
+		break;
+	default:
+		return IRQ_NONE;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int apple_pcie_port_register_irqs(struct apple_pcie_port *port)
+{
+	static struct {
+		unsigned int	hwirq;
+		const char	*name;
+	} port_irqs[] = {
+		{ PORT_INT_LINK_UP,	"Link up",	},
+		{ PORT_INT_LINK_DOWN,	"Link down",	},
+	};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(port_irqs); i++) {
+		struct irq_fwspec fwspec = {
+			.fwnode		= &port->np->fwnode,
+			.param_count	= 1,
+			.param		= {
+				[0]	= port_irqs[i].hwirq,
+			},
+		};
+		unsigned int irq;
+		int ret;
+
+		irq = irq_domain_alloc_irqs(port->domain, 1, NUMA_NO_NODE,
+					    &fwspec);
+		if (WARN_ON(!irq))
+			continue;
+
+		ret = request_irq(irq, apple_pcie_port_irq, 0,
+				  port_irqs[i].name, port);
+		WARN_ON(ret);
+	}
+
+	return 0;
+}
+
 static int apple_pcie_setup_refclk(struct apple_pcie *pcie,
 				   struct apple_pcie_port *port)
 {
@@ -222,8 +419,20 @@  static int apple_pcie_setup_port(struct apple_pcie *pcie,
 	/* Flush writes and enable the link */
 	dma_wmb();
 
+	ret = apple_pcie_port_setup_irq(port);
+	if (ret)
+		return ret;
+
+	init_completion(&pcie->event);
+
+	ret = apple_pcie_port_register_irqs(port);
+	WARN_ON(ret);
+
 	writel_relaxed(PORT_LTSSMCTL_START, port->base + PORT_LTSSMCTL);
 
+	if (!wait_for_completion_timeout(&pcie->event, HZ / 10))
+		dev_warn(pcie->dev, "%pOF link didn't come up\n", np);
+
 	return 0;
 }