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Commit 399afa4f authored by Maxim Levitsky's avatar Maxim Levitsky Committed by Linus Torvalds
Browse files

[PATCH] Add suspend/resume for HPET 



This adds support of suspend/resume on i386 for HPET, which fixes a
number of timer-related failures around STR.

Signed-off-by: default avatarMaxim Levitsky <maximlevitsky@gmail.com>
Acked-by: default avatarMichael S. Tsirkin <mst@dev.mellanox.co.il>
Acked-by: default avatarJeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 22c8c65d

arch/i386/kernel/hpet.c

+68 −0
Original line number Diff line number Diff line
@@ -3,6 +3,8 @@ 
#include <linux/errno.h>

#include <linux/hpet.h>

#include <linux/init.h>

#include <linux/sysdev.h>

#include <linux/pm.h>



#include <asm/hpet.h>

#include <asm/io.h>
@@ -307,6 +309,7 @@ int __init hpet_enable(void) 
out_nohpet:

	iounmap(hpet_virt_address);

	hpet_virt_address = NULL;

	boot_hpet_disable = 1;

	return 0;

}
@@ -521,3 +524,68 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) 
	return IRQ_HANDLED;

}

#endif





/*

 * Suspend/resume part

 */



#ifdef CONFIG_PM



static int hpet_suspend(struct sys_device *sys_device, pm_message_t state)

{

	unsigned long cfg = hpet_readl(HPET_CFG);



	cfg &= ~(HPET_CFG_ENABLE|HPET_CFG_LEGACY);

	hpet_writel(cfg, HPET_CFG);



	return 0;

}



static int hpet_resume(struct sys_device *sys_device)

{

	unsigned int id;



	hpet_start_counter();



	id = hpet_readl(HPET_ID);



	if (id & HPET_ID_LEGSUP)

		hpet_enable_int();



	return 0;

}



static struct sysdev_class hpet_class = {

	set_kset_name("hpet"),

	.suspend	= hpet_suspend,

	.resume		= hpet_resume,

};



static struct sys_device hpet_device = {

	.id		= 0,

	.cls		= &hpet_class,

};





static __init int hpet_register_sysfs(void)

{

	int err;



	if (!is_hpet_capable())

		return 0;



	err = sysdev_class_register(&hpet_class);



	if (!err) {

		err = sysdev_register(&hpet_device);

		if (err)

			sysdev_class_unregister(&hpet_class);

	}



	return err;

}



device_initcall(hpet_register_sysfs);



#endif