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authorMaxim Levitsky <maximlevitsky@gmail.com>2007-03-29 15:46:48 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-03-29 10:25:32 -0700
commit399afa4fc9238fbae42116cf25a54671c0e8f56e (patch)
tree875b69d487a1ee858cf1c871649627e213bc1019 /arch
parent22c8c65d24b37cef1d28583c7a7ffbf84f840e7a (diff)
downloadlwn-399afa4fc9238fbae42116cf25a54671c0e8f56e.tar.gz
lwn-399afa4fc9238fbae42116cf25a54671c0e8f56e.zip
[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: Maxim Levitsky <maximlevitsky@gmail.com> Acked-by: Michael S. Tsirkin <mst@dev.mellanox.co.il> Acked-by: Jeff Chua <jeff.chua.linux@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/kernel/hpet.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/i386/kernel/hpet.c b/arch/i386/kernel/hpet.c
index 76afea67f691..17d73459fc5f 100644
--- a/arch/i386/kernel/hpet.c
+++ b/arch/i386/kernel/hpet.c
@@ -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