1 files changed, 294 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/xilinx_intc.c b/arch/powerpc/sysdev/xilinx_intc.c
new file mode 100644
index 00000000..61837997
--- /dev/null
+++ b/arch/powerpc/sysdev/xilinx_intc.c
@@ -0,0 +1,294 @@
+/*
+ * Interrupt controller driver for Xilinx Virtex FPGAs
+ *
+ * Copyright (C) 2007 Secret Lab Technologies Ltd.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ *
+ */
+
+/*
+ * This is a driver for the interrupt controller typically found in
+ * Xilinx Virtex FPGA designs.
+ *
+ * The interrupt sense levels are hard coded into the FPGA design with
+ * typically a 1:1 relationship between irq lines and devices (no shared
+ * irq lines).  Therefore, this driver does not attempt to handle edge
+ * and level interrupts differently.
+ */
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/i8259.h>
+#include <asm/irq.h>
+
+/*
+ * INTC Registers
+ */
+#define XINTC_ISR	0	/* Interrupt Status */
+#define XINTC_IPR	4	/* Interrupt Pending */
+#define XINTC_IER	8	/* Interrupt Enable */
+#define XINTC_IAR	12	/* Interrupt Acknowledge */
+#define XINTC_SIE	16	/* Set Interrupt Enable bits */
+#define XINTC_CIE	20	/* Clear Interrupt Enable bits */
+#define XINTC_IVR	24	/* Interrupt Vector */
+#define XINTC_MER	28	/* Master Enable */
+
+static struct irq_host *master_irqhost;
+
+#define XILINX_INTC_MAXIRQS	(32)
+
+/* The following table allows the interrupt type, edge or level,
+ * to be cached after being read from the device tree until the interrupt
+ * is mapped
+ */
+static int xilinx_intc_typetable[XILINX_INTC_MAXIRQS];
+
+/* Map the interrupt type from the device tree to the interrupt types
+ * used by the interrupt subsystem
+ */
+static unsigned char xilinx_intc_map_senses[] = {
+	IRQ_TYPE_EDGE_RISING,
+	IRQ_TYPE_EDGE_FALLING,
+	IRQ_TYPE_LEVEL_HIGH,
+	IRQ_TYPE_LEVEL_LOW,
+};
+
+/*
+ * The interrupt controller is setup such that it doesn't work well with
+ * the level interrupt handler in the kernel because the handler acks the
+ * interrupt before calling the application interrupt handler. To deal with
+ * that, we use 2 different irq chips so that different functions can be
+ * used for level and edge type interrupts.
+ *
+ * IRQ Chip common (across level and edge) operations
+ */
+static void xilinx_intc_mask(struct irq_data *d)
+{
+	int irq = irqd_to_hwirq(d);
+	void * regs = irq_data_get_irq_chip_data(d);
+	pr_debug("mask: %d\n", irq);
+	out_be32(regs + XINTC_CIE, 1 << irq);
+}
+
+static int xilinx_intc_set_type(struct irq_data *d, unsigned int flow_type)
+{
+	return 0;
+}
+
+/*
+ * IRQ Chip level operations
+ */
+static void xilinx_intc_level_unmask(struct irq_data *d)
+{
+	int irq = irqd_to_hwirq(d);
+	void * regs = irq_data_get_irq_chip_data(d);
+	pr_debug("unmask: %d\n", irq);
+	out_be32(regs + XINTC_SIE, 1 << irq);
+
+	/* ack level irqs because they can't be acked during
+	 * ack function since the handle_level_irq function
+	 * acks the irq before calling the inerrupt handler
+	 */
+	out_be32(regs + XINTC_IAR, 1 << irq);
+}
+
+static struct irq_chip xilinx_intc_level_irqchip = {
+	.name = "Xilinx Level INTC",
+	.irq_mask = xilinx_intc_mask,
+	.irq_mask_ack = xilinx_intc_mask,
+	.irq_unmask = xilinx_intc_level_unmask,
+	.irq_set_type = xilinx_intc_set_type,
+};
+
+/*
+ * IRQ Chip edge operations
+ */
+static void xilinx_intc_edge_unmask(struct irq_data *d)
+{
+	int irq = irqd_to_hwirq(d);
+	void *regs = irq_data_get_irq_chip_data(d);
+	pr_debug("unmask: %d\n", irq);
+	out_be32(regs + XINTC_SIE, 1 << irq);
+}
+
+static void xilinx_intc_edge_ack(struct irq_data *d)
+{
+	int irq = irqd_to_hwirq(d);
+	void * regs = irq_data_get_irq_chip_data(d);
+	pr_debug("ack: %d\n", irq);
+	out_be32(regs + XINTC_IAR, 1 << irq);
+}
+
+static struct irq_chip xilinx_intc_edge_irqchip = {
+	.name = "Xilinx Edge  INTC",
+	.irq_mask = xilinx_intc_mask,
+	.irq_unmask = xilinx_intc_edge_unmask,
+	.irq_ack = xilinx_intc_edge_ack,
+	.irq_set_type = xilinx_intc_set_type,
+};
+
+/*
+ * IRQ Host operations
+ */
+
+/**
+ * xilinx_intc_xlate - translate virq# from device tree interrupts property
+ */
+static int xilinx_intc_xlate(struct irq_host *h, struct device_node *ct,
+				const u32 *intspec, unsigned int intsize,
+				irq_hw_number_t *out_hwirq,
+				unsigned int *out_flags)
+{
+	if ((intsize < 2) || (intspec[0] >= XILINX_INTC_MAXIRQS))
+		return -EINVAL;
+
+	/* keep a copy of the interrupt type til the interrupt is mapped
+	 */
+	xilinx_intc_typetable[intspec[0]] = xilinx_intc_map_senses[intspec[1]];
+
+	/* Xilinx uses 2 interrupt entries, the 1st being the h/w
+	 * interrupt number, the 2nd being the interrupt type, edge or level
+	 */
+	*out_hwirq = intspec[0];
+	*out_flags = xilinx_intc_map_senses[intspec[1]];
+
+	return 0;
+}
+static int xilinx_intc_map(struct irq_host *h, unsigned int virq,
+				  irq_hw_number_t irq)
+{
+	irq_set_chip_data(virq, h->host_data);
+
+	if (xilinx_intc_typetable[irq] == IRQ_TYPE_LEVEL_HIGH ||
+	    xilinx_intc_typetable[irq] == IRQ_TYPE_LEVEL_LOW) {
+		irq_set_chip_and_handler(virq, &xilinx_intc_level_irqchip,
+					 handle_level_irq);
+	} else {
+		irq_set_chip_and_handler(virq, &xilinx_intc_edge_irqchip,
+					 handle_edge_irq);
+	}
+	return 0;
+}
+
+static struct irq_host_ops xilinx_intc_ops = {
+	.map = xilinx_intc_map,
+	.xlate = xilinx_intc_xlate,
+};
+
+struct irq_host * __init
+xilinx_intc_init(struct device_node *np)
+{
+	struct irq_host * irq;
+	void * regs;
+
+	/* Find and map the intc registers */
+	regs = of_iomap(np, 0);
+	if (!regs) {
+		pr_err("xilinx_intc: could not map registers\n");
+		return NULL;
+	}
+
+	/* Setup interrupt controller */
+	out_be32(regs + XINTC_IER, 0); /* disable all irqs */
+	out_be32(regs + XINTC_IAR, ~(u32) 0); /* Acknowledge pending irqs */
+	out_be32(regs + XINTC_MER, 0x3UL); /* Turn on the Master Enable. */
+
+	/* Allocate and initialize an irq_host structure. */
+	irq = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, XILINX_INTC_MAXIRQS,
+			     &xilinx_intc_ops, -1);
+	if (!irq)
+		panic(__FILE__ ": Cannot allocate IRQ host\n");
+	irq->host_data = regs;
+
+	return irq;
+}
+
+int xilinx_intc_get_irq(void)
+{
+	void * regs = master_irqhost->host_data;
+	pr_debug("get_irq:\n");
+	return irq_linear_revmap(master_irqhost, in_be32(regs + XINTC_IVR));
+}
+
+#if defined(CONFIG_PPC_I8259)
+/*
+ * Support code for cascading to 8259 interrupt controllers
+ */
+static void xilinx_i8259_cascade(unsigned int irq, struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned int cascade_irq = i8259_irq();
+
+	if (cascade_irq)
+		generic_handle_irq(cascade_irq);
+
+	/* Let xilinx_intc end the interrupt */
+	chip->irq_unmask(&desc->irq_data);
+}
+
+static void __init xilinx_i8259_setup_cascade(void)
+{
+	struct device_node *cascade_node;
+	int cascade_irq;
+
+	/* Initialize i8259 controller */
+	cascade_node = of_find_compatible_node(NULL, NULL, "chrp,iic");
+	if (!cascade_node)
+		return;
+
+	cascade_irq = irq_of_parse_and_map(cascade_node, 0);
+	if (!cascade_irq) {
+		pr_err("virtex_ml510: Failed to map cascade interrupt\n");
+		goto out;
+	}
+
+	i8259_init(cascade_node, 0);
+	irq_set_chained_handler(cascade_irq, xilinx_i8259_cascade);
+
+	/* Program irq 7 (usb/audio), 14/15 (ide) to level sensitive */
+	/* This looks like a dirty hack to me --gcl */
+	outb(0xc0, 0x4d0);
+	outb(0xc0, 0x4d1);
+
+ out:
+	of_node_put(cascade_node);
+}
+#else
+static inline void xilinx_i8259_setup_cascade(void) { return; }
+#endif /* defined(CONFIG_PPC_I8259) */
+
+static struct of_device_id xilinx_intc_match[] __initconst = {
+	{ .compatible = "xlnx,opb-intc-1.00.c", },
+	{ .compatible = "xlnx,xps-intc-1.00.a", },
+	{}
+};
+
+/*
+ * Initialize master Xilinx interrupt controller
+ */
+void __init xilinx_intc_init_tree(void)
+{
+	struct device_node *np;
+
+	/* find top level interrupt controller */
+	for_each_matching_node(np, xilinx_intc_match) {
+		if (!of_get_property(np, "interrupts", NULL))
+			break;
+	}
+	BUG_ON(!np);
+
+	master_irqhost = xilinx_intc_init(np);
+	BUG_ON(!master_irqhost);
+
+	irq_set_default_host(master_irqhost);
+	of_node_put(np);
+
+	xilinx_i8259_setup_cascade();
+}