1 files changed, 101 insertions, 15 deletions

diff --git a/arch/arm/plat-versatile/fpga-irq.c b/arch/arm/plat-versatile/fpga-irq.c
index f0cc8e19b094..6e70d03824a1 100644
--- a/arch/arm/plat-versatile/fpga-irq.c
+++ b/arch/arm/plat-versatile/fpga-irq.c
@@ -3,7 +3,10 @@
  */
 #include <linux/irq.h>
 #include <linux/io.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
 
+#include <asm/exception.h>
 #include <asm/mach/irq.h>
 #include <plat/fpga-irq.h>
 
@@ -12,10 +15,32 @@
 #define IRQ_ENABLE_SET          0x08
 #define IRQ_ENABLE_CLEAR        0x0c
 
+/**
+ * struct fpga_irq_data - irq data container for the FPGA IRQ controller
+ * @base: memory offset in virtual memory
+ * @irq_start: first IRQ number handled by this instance
+ * @chip: chip container for this instance
+ * @domain: IRQ domain for this instance
+ * @valid: mask for valid IRQs on this controller
+ * @used_irqs: number of active IRQs on this controller
+ */
+struct fpga_irq_data {
+        void __iomem *base;
+        unsigned int irq_start;
+        struct irq_chip chip;
+        u32 valid;
+        struct irq_domain *domain;
+        u8 used_irqs;
+};
+
+/* we cannot allocate memory when the controllers are initially registered */
+static struct fpga_irq_data fpga_irq_devices[CONFIG_PLAT_VERSATILE_FPGA_IRQ_NR];
+static int fpga_irq_id;
+
 static void fpga_irq_mask(struct irq_data *d)
 {
         struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
-        u32 mask = 1 << (d->irq - f->irq_start);
+        u32 mask = 1 << d->hwirq;
 
         writel(mask, f->base + IRQ_ENABLE_CLEAR);
 }
@@ -23,7 +48,7 @@ static void fpga_irq_mask(struct irq_data *d)
 static void fpga_irq_unmask(struct irq_data *d)
 {
         struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
-        u32 mask = 1 << (d->irq - f->irq_start);
+        u32 mask = 1 << d->hwirq;
 
         writel(mask, f->base + IRQ_ENABLE_SET);
 }
@@ -41,32 +66,93 @@ static void fpga_irq_handle(unsigned int irq, struct irq_desc *desc)
         do {
                 irq = ffs(status) - 1;
                 status &= ~(1 << irq);
-
-                generic_handle_irq(irq + f->irq_start);
+                generic_handle_irq(irq_find_mapping(f->domain, irq));
         } while (status);
 }
 
-void __init fpga_irq_init(int parent_irq, u32 valid, struct fpga_irq_data *f)
+/*
+ * Handle each interrupt in a single FPGA IRQ controller.  Returns non-zero
+ * if we've handled at least one interrupt.  This does a single read of the
+ * status register and handles all interrupts in order from LSB first.
+ */
+static int handle_one_fpga(struct fpga_irq_data *f, struct pt_regs *regs)
+{
+        int handled = 0;
+        int irq;
+        u32 status;
+
+        while ((status  = readl(f->base + IRQ_STATUS))) {
+                irq = ffs(status) - 1;
+                handle_IRQ(irq_find_mapping(f->domain, irq), regs);
+                handled = 1;
+        }
+
+        return handled;
+}
+
+/*
+ * Keep iterating over all registered FPGA IRQ controllers until there are
+ * no pending interrupts.
+ */
+asmlinkage void __exception_irq_entry fpga_handle_irq(struct pt_regs *regs)
 {
-        unsigned int i;
+        int i, handled;
 
+        do {
+                for (i = 0, handled = 0; i < fpga_irq_id; ++i)
+                        handled |= handle_one_fpga(&fpga_irq_devices[i], regs);
+        } while (handled);
+}
+
+static int fpga_irqdomain_map(struct irq_domain *d, unsigned int irq,
+                irq_hw_number_t hwirq)
+{
+        struct fpga_irq_data *f = d->host_data;
+
+        /* Skip invalid IRQs, only register handlers for the real ones */
+        if (!(f->valid & (1 << hwirq)))
+                return -ENOTSUPP;
+        irq_set_chip_data(irq, f);
+        irq_set_chip_and_handler(irq, &f->chip,
+                                handle_level_irq);
+        set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+        f->used_irqs++;
+        return 0;
+}
+
+static struct irq_domain_ops fpga_irqdomain_ops = {
+        .map = fpga_irqdomain_map,
+        .xlate = irq_domain_xlate_onetwocell,
+};
+
+void __init fpga_irq_init(void __iomem *base, const char *name, int irq_start,
+                          int parent_irq, u32 valid, struct device_node *node)
+{
+        struct fpga_irq_data *f;
+
+        if (fpga_irq_id >= ARRAY_SIZE(fpga_irq_devices)) {
+                printk(KERN_ERR "%s: too few FPGA IRQ controllers, increase CONFIG_PLAT_VERSATILE_FPGA_IRQ_NR\n", __func__);
+                return;
+        }
+
+        f = &fpga_irq_devices[fpga_irq_id];
+        f->base = base;
+        f->irq_start = irq_start;
+        f->chip.name = name;
         f->chip.irq_ack = fpga_irq_mask;
         f->chip.irq_mask = fpga_irq_mask;
         f->chip.irq_unmask = fpga_irq_unmask;
+        f->valid = valid;
 
         if (parent_irq != -1) {
                 irq_set_handler_data(parent_irq, f);
                 irq_set_chained_handler(parent_irq, fpga_irq_handle);
         }
 
-        for (i = 0; i < 32; i++) {
-                if (valid & (1 << i)) {
-                        unsigned int irq = f->irq_start + i;
+        f->domain = irq_domain_add_legacy(node, fls(valid), f->irq_start, 0,
+                                          &fpga_irqdomain_ops, f);
+        pr_info("FPGA IRQ chip %d \"%s\" @ %p, %u irqs\n",
+                fpga_irq_id, name, base, f->used_irqs);
 
-                        irq_set_chip_data(irq, f);
-                        irq_set_chip_and_handler(irq, &f->chip,
-                                                 handle_level_irq);
-                        set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
-                }
-        }
+        fpga_irq_id++;
 }