[POWERPC] Generic time suspend/resume code

This removes the time suspend/restore code that was done through
a PMU notifier in arch/platforms/powermac/time.c.

Instead, introduce arch/powerpc/sysdev/timer.c which creates a sys
device and handles time of day suspend/resume through that.

This should probably be replaced by using the generic RTC framework
but for now it gets rid of the arcane powermac specific hack.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 70 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/timer.c b/arch/powerpc/sysdev/timer.c
new file mode 100644
index 000000000000..bdbf8fe520e4
--- /dev/null
+++ b/arch/powerpc/sysdev/timer.c
@@ -0,0 +1,70 @@
+/*
+ * Common code to keep time when machine suspends.
+ *
+ * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
+ *
+ * GPLv2
+ */
+
+#include <linux/time.h>
+#include <asm/rtc.h>
+
+static unsigned long suspend_rtc_time;
+
+/*
+ * Reset the time after a sleep.
+ */
+static int timer_resume(struct sys_device *dev)
+{
+        struct timeval tv;
+        struct timespec ts;
+        struct rtc_time cur_rtc_tm;
+        unsigned long cur_rtc_time, diff;
+
+        /* get current RTC time and convert to seconds */
+        get_rtc_time(&cur_rtc_tm);
+        rtc_tm_to_time(&cur_rtc_tm, &cur_rtc_time);
+
+        diff = cur_rtc_time - suspend_rtc_time;
+
+        /* adjust time of day by seconds that elapsed while
+         * we were suspended */
+        do_gettimeofday(&tv);
+        ts.tv_sec = tv.tv_sec + diff;
+        ts.tv_nsec = tv.tv_usec * NSEC_PER_USEC;
+        do_settimeofday(&ts);
+
+        return 0;
+}
+
+static int timer_suspend(struct sys_device *dev, pm_message_t state)
+{
+        struct rtc_time suspend_rtc_tm;
+        WARN_ON(!ppc_md.get_rtc_time);
+
+        get_rtc_time(&suspend_rtc_tm);
+        rtc_tm_to_time(&suspend_rtc_tm, &suspend_rtc_time);
+
+        return 0;
+}
+
+static struct sysdev_class timer_sysclass = {
+        .resume = timer_resume,
+        .suspend = timer_suspend,
+        set_kset_name("timer"),
+};
+
+static struct sys_device device_timer = {
+        .id = 0,
+        .cls = &timer_sysclass,
+};
+
+static int time_init_device(void)
+{
+        int error = sysdev_class_register(&timer_sysclass);
+        if (!error)
+                error = sysdev_register(&device_timer);
+        return error;
+}
+
+device_initcall(time_init_device);