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path: root/drivers/char/hpet.c
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Diffstat (limited to 'drivers/char/hpet.c')
-rw-r--r--drivers/char/hpet.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index e7fb0bca3667..c9bf5d44402d 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -184,6 +184,67 @@ static irqreturn_t hpet_interrupt(int irq, void *data)
return IRQ_HANDLED;
}
+static void hpet_timer_set_irq(struct hpet_dev *devp)
+{
+ unsigned long v;
+ int irq, gsi;
+ struct hpet_timer __iomem *timer;
+
+ spin_lock_irq(&hpet_lock);
+ if (devp->hd_hdwirq) {
+ spin_unlock_irq(&hpet_lock);
+ return;
+ }
+
+ timer = devp->hd_timer;
+
+ /* we prefer level triggered mode */
+ v = readl(&timer->hpet_config);
+ if (!(v & Tn_INT_TYPE_CNF_MASK)) {
+ v |= Tn_INT_TYPE_CNF_MASK;
+ writel(v, &timer->hpet_config);
+ }
+ spin_unlock_irq(&hpet_lock);
+
+ v = (readq(&timer->hpet_config) & Tn_INT_ROUTE_CAP_MASK) >>
+ Tn_INT_ROUTE_CAP_SHIFT;
+
+ /*
+ * In PIC mode, skip IRQ0-4, IRQ6-9, IRQ12-15 which is always used by
+ * legacy device. In IO APIC mode, we skip all the legacy IRQS.
+ */
+ if (acpi_irq_model == ACPI_IRQ_MODEL_PIC)
+ v &= ~0xf3df;
+ else
+ v &= ~0xffff;
+
+ for (irq = find_first_bit(&v, HPET_MAX_IRQ); irq < HPET_MAX_IRQ;
+ irq = find_next_bit(&v, HPET_MAX_IRQ, 1 + irq)) {
+
+ if (irq >= NR_IRQS) {
+ irq = HPET_MAX_IRQ;
+ break;
+ }
+
+ gsi = acpi_register_gsi(irq, ACPI_LEVEL_SENSITIVE,
+ ACPI_ACTIVE_LOW);
+ if (gsi > 0)
+ break;
+
+ /* FIXME: Setup interrupt source table */
+ }
+
+ if (irq < HPET_MAX_IRQ) {
+ spin_lock_irq(&hpet_lock);
+ v = readl(&timer->hpet_config);
+ v |= irq << Tn_INT_ROUTE_CNF_SHIFT;
+ writel(v, &timer->hpet_config);
+ devp->hd_hdwirq = gsi;
+ spin_unlock_irq(&hpet_lock);
+ }
+ return;
+}
+
static int hpet_open(struct inode *inode, struct file *file)
{
struct hpet_dev *devp;
@@ -215,6 +276,8 @@ static int hpet_open(struct inode *inode, struct file *file)
devp->hd_flags |= HPET_OPEN;
spin_unlock_irq(&hpet_lock);
+ hpet_timer_set_irq(devp);
+
return 0;
}