--- /dev/null
+/*
+ * Interrupt handling for GE Fanuc's FPGA based PIC
+ *
+ * Author: Martyn Welch <martyn.welch@gefanuc.com>
+ *
+ * 2008 (c) GE Fanuc Intelligent Platforms Embedded Systems, Inc.
+ *
+ * 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.
+ */
+
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+
+#include <asm/byteorder.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/irq.h>
+
+#include "gef_pic.h"
+
+#define DEBUG
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(fmt...) do { printk(KERN_DEBUG "gef_pic: " fmt); } while (0)
+#else
+#define DBG(fmt...) do { } while (0)
+#endif
+
+#define GEF_PIC_NUM_IRQS 32
+
+/* Interrupt Controller Interface Registers */
+#define GEF_PIC_INTR_STATUS 0x0000
+
+#define GEF_PIC_INTR_MASK(cpu) (0x0010 + (0x4 * cpu))
+#define GEF_PIC_CPU0_INTR_MASK GEF_PIC_INTR_MASK(0)
+#define GEF_PIC_CPU1_INTR_MASK GEF_PIC_INTR_MASK(1)
+
+#define GEF_PIC_MCP_MASK(cpu) (0x0018 + (0x4 * cpu))
+#define GEF_PIC_CPU0_MCP_MASK GEF_PIC_MCP_MASK(0)
+#define GEF_PIC_CPU1_MCP_MASK GEF_PIC_MCP_MASK(1)
+
+#define gef_irq_to_hw(virq) ((unsigned int)irq_map[virq].hwirq)
+
+
+static DEFINE_SPINLOCK(gef_pic_lock);
+
+static void __iomem *gef_pic_irq_reg_base;
+static struct irq_host *gef_pic_irq_host;
+static int gef_pic_cascade_irq;
+
+/*
+ * Interrupt Controller Handling
+ *
+ * The interrupt controller handles interrupts for most on board interrupts,
+ * apart from PCI interrupts. For example on SBC610:
+ *
+ * 17:31 RO Reserved
+ * 16 RO PCI Express Doorbell 3 Status
+ * 15 RO PCI Express Doorbell 2 Status
+ * 14 RO PCI Express Doorbell 1 Status
+ * 13 RO PCI Express Doorbell 0 Status
+ * 12 RO Real Time Clock Interrupt Status
+ * 11 RO Temperature Interrupt Status
+ * 10 RO Temperature Critical Interrupt Status
+ * 9 RO Ethernet PHY1 Interrupt Status
+ * 8 RO Ethernet PHY3 Interrupt Status
+ * 7 RO PEX8548 Interrupt Status
+ * 6 RO Reserved
+ * 5 RO Watchdog 0 Interrupt Status
+ * 4 RO Watchdog 1 Interrupt Status
+ * 3 RO AXIS Message FIFO A Interrupt Status
+ * 2 RO AXIS Message FIFO B Interrupt Status
+ * 1 RO AXIS Message FIFO C Interrupt Status
+ * 0 RO AXIS Message FIFO D Interrupt Status
+ *
+ * Interrupts can be forwarded to one of two output lines. Nothing
+ * clever is done, so if the masks are incorrectly set, a single input
+ * interrupt could generate interrupts on both output lines!
+ *
+ * The dual lines are there to allow the chained interrupts to be easily
+ * passed into two different cores. We currently do not use this functionality
+ * in this driver.
+ *
+ * Controller can also be configured to generate Machine checks (MCP), again on
+ * two lines, to be attached to two different cores. It is suggested that these
+ * should be masked out.
+ */
+
+void gef_pic_cascade(unsigned int irq, struct irq_desc *desc)
+{
+ unsigned int cascade_irq;
+
+ /*
+ * See if we actually have an interrupt, call generic handling code if
+ * we do.
+ */
+ cascade_irq = gef_pic_get_irq();
+
+ if (cascade_irq != NO_IRQ)
+ generic_handle_irq(cascade_irq);
+
+ desc->chip->eoi(irq);
+
+}
+
+static void gef_pic_mask(unsigned int virq)
+{
+ unsigned long flags;
+ unsigned int hwirq;
+ u32 mask;
+
+ hwirq = gef_irq_to_hw(virq);
+
+ spin_lock_irqsave(&gef_pic_lock, flags);
+ mask = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0));
+ mask &= ~(1 << hwirq);
+ out_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0), mask);
+ spin_unlock_irqrestore(&gef_pic_lock, flags);
+}
+
+static void gef_pic_mask_ack(unsigned int virq)
+{
+ /* Don't think we actually have to do anything to ack an interrupt,
+ * we just need to clear down the devices interrupt and it will go away
+ */
+ gef_pic_mask(virq);
+}
+
+static void gef_pic_unmask(unsigned int virq)
+{
+ unsigned long flags;
+ unsigned int hwirq;
+ u32 mask;
+
+ hwirq = gef_irq_to_hw(virq);
+
+ spin_lock_irqsave(&gef_pic_lock, flags);
+ mask = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0));
+ mask |= (1 << hwirq);
+ out_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0), mask);
+ spin_unlock_irqrestore(&gef_pic_lock, flags);
+}
+
+static struct irq_chip gef_pic_chip = {
+ .typename = "gefp",
+ .mask = gef_pic_mask,
+ .mask_ack = gef_pic_mask_ack,
+ .unmask = gef_pic_unmask,
+};
+
+
+/* When an interrupt is being configured, this call allows some flexibilty
+ * in deciding which irq_chip structure is used
+ */
+static int gef_pic_host_map(struct irq_host *h, unsigned int virq,
+ irq_hw_number_t hwirq)
+{
+ /* All interrupts are LEVEL sensitive */
+ get_irq_desc(virq)->status |= IRQ_LEVEL;
+ set_irq_chip_and_handler(virq, &gef_pic_chip, handle_level_irq);
+
+ return 0;
+}
+
+static int gef_pic_host_xlate(struct irq_host *h, struct device_node *ct,
+ u32 *intspec, unsigned int intsize,
+ irq_hw_number_t *out_hwirq, unsigned int *out_flags)
+{
+
+ *out_hwirq = intspec[0];
+ if (intsize > 1)
+ *out_flags = intspec[1];
+ else
+ *out_flags = IRQ_TYPE_LEVEL_HIGH;
+
+ return 0;
+}
+
+static struct irq_host_ops gef_pic_host_ops = {
+ .map = gef_pic_host_map,
+ .xlate = gef_pic_host_xlate,
+};
+
+
+/*
+ * Initialisation of PIC, this should be called in BSP
+ */
+void __init gef_pic_init(struct device_node *np)
+{
+ unsigned long flags;
+
+ /* Map the devices registers into memory */
+ gef_pic_irq_reg_base = of_iomap(np, 0);
+
+ spin_lock_irqsave(&gef_pic_lock, flags);
+
+ /* Initialise everything as masked. */
+ out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU0_INTR_MASK, 0);
+ out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU1_INTR_MASK, 0);
+
+ out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU0_MCP_MASK, 0);
+ out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU1_MCP_MASK, 0);
+
+ spin_unlock_irqrestore(&gef_pic_lock, flags);
+
+ /* Map controller */
+ gef_pic_cascade_irq = irq_of_parse_and_map(np, 0);
+ if (gef_pic_cascade_irq == NO_IRQ) {
+ printk(KERN_ERR "SBC610: failed to map cascade interrupt");
+ return;
+ }
+
+ /* Setup an irq_host structure */
+ gef_pic_irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
+ GEF_PIC_NUM_IRQS,
+ &gef_pic_host_ops, NO_IRQ);
+ if (gef_pic_irq_host == NULL)
+ return;
+
+ /* Chain with parent controller */
+ set_irq_chained_handler(gef_pic_cascade_irq, gef_pic_cascade);
+}
+
+/*
+ * This is called when we receive an interrupt with apparently comes from this
+ * chip - check, returning the highest interrupt generated or return NO_IRQ
+ */
+unsigned int gef_pic_get_irq(void)
+{
+ u32 cause, mask, active;
+ unsigned int virq = NO_IRQ;
+ int hwirq;
+
+ cause = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_STATUS);
+
+ mask = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0));
+
+ active = cause & mask;
+
+ if (active) {
+ for (hwirq = GEF_PIC_NUM_IRQS - 1; hwirq > -1; hwirq--) {
+ if (active & (0x1 << hwirq))
+ break;
+ }
+ virq = irq_linear_revmap(gef_pic_irq_host,
+ (irq_hw_number_t)hwirq);
+ }
+
+ return virq;
+}
+
projects / linux-2.6-omap-h63xx.git / commitdiff