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Commit 70ef6d59 authored by Kevin Hao's avatar Kevin Hao Committed by Ingo Molnar
Browse files

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: default avatarKevin Hao <kexin.hao@windriver.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e490517a

drivers/char/hpet.c

+63 −0
Original line number Diff line number Diff line
@@ -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;

}

include/linux/hpet.h

+2 −1
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ struct hpet { 
#define	hpet_compare	_u1._hpet_compare



#define	HPET_MAX_TIMERS	(32)

#define	HPET_MAX_IRQ	(32)



/*

 * HPET general capabilities register
@@ -64,7 +65,7 @@ struct hpet { 
 */



#define	Tn_INT_ROUTE_CAP_MASK		(0xffffffff00000000ULL)

#define	Tn_INI_ROUTE_CAP_SHIFT		(32UL)

#define	Tn_INT_ROUTE_CAP_SHIFT		(32UL)

#define	Tn_FSB_INT_DELCAP_MASK		(0x8000UL)

#define	Tn_FSB_INT_DELCAP_SHIFT		(15)

#define	Tn_FSB_EN_CNF_MASK		(0x4000UL)