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-rw-r--r--arch/arm/plat-versatile/fpga-irq.c116
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 f0cc8e1..6e70d03 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++;
}