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authorKevin Hao <kexin.hao@windriver.com>2008-05-29 18:41:04 +0800
committerIngo Molnar <mingo@elte.hu>2008-06-02 11:35:12 +0200
commit70ef6d595b6e51618a0cbe44b848d8c9db11a010 (patch)
tree78129b50ab2f76752d1012502d724a78ad7bc648 /drivers/char/hpet.c
parente490517a039a99d692cb3a5561941b0a5f576172 (diff)
downloadlinux-70ef6d595b6e51618a0cbe44b848d8c9db11a010.tar.bz2
x86: get irq for hpet timer
HPET timer's IRQ is 0 by default. So we have to select which irq will be used by these timers. We wait to set the timer's irq until we really open it in order to reduce the chance of conflicting with other device. Signed-off-by: Kevin Hao <kexin.hao@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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;
}