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Diffstat (limited to 'arch/powerpc/platforms/powermac/time.c')
-rw-r--r--arch/powerpc/platforms/powermac/time.c29
1 files changed, 20 insertions, 9 deletions
diff --git a/arch/powerpc/platforms/powermac/time.c b/arch/powerpc/platforms/powermac/time.c
index 7c968e46736f..12e6e4d30602 100644
--- a/arch/powerpc/platforms/powermac/time.c
+++ b/arch/powerpc/platforms/powermac/time.c
@@ -42,7 +42,11 @@
#define DBG(x...)
#endif
-/* Apparently the RTC stores seconds since 1 Jan 1904 */
+/*
+ * Offset between Unix time (1970-based) and Mac time (1904-based). Cuda and PMU
+ * times wrap in 2040. If we need to handle later times, the read_time functions
+ * need to be changed to interpret wrapped times as post-2040.
+ */
#define RTC_OFFSET 2082844800
/*
@@ -97,8 +101,11 @@ static time64_t cuda_get_time(void)
if (req.reply_len != 7)
printk(KERN_ERR "cuda_get_time: got %d byte reply\n",
req.reply_len);
- now = (req.reply[3] << 24) + (req.reply[4] << 16)
- + (req.reply[5] << 8) + req.reply[6];
+ now = (u32)((req.reply[3] << 24) + (req.reply[4] << 16) +
+ (req.reply[5] << 8) + req.reply[6]);
+ /* it's either after year 2040, or the RTC has gone backwards */
+ WARN_ON(now < RTC_OFFSET);
+
return now - RTC_OFFSET;
}
@@ -106,10 +113,10 @@ static time64_t cuda_get_time(void)
static int cuda_set_rtc_time(struct rtc_time *tm)
{
- time64_t nowtime;
+ u32 nowtime;
struct adb_request req;
- nowtime = rtc_tm_to_time64(tm) + RTC_OFFSET;
+ nowtime = lower_32_bits(rtc_tm_to_time64(tm) + RTC_OFFSET);
if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
nowtime >> 24, nowtime >> 16, nowtime >> 8,
nowtime) < 0)
@@ -140,8 +147,12 @@ static time64_t pmu_get_time(void)
if (req.reply_len != 4)
printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n",
req.reply_len);
- now = (req.reply[0] << 24) + (req.reply[1] << 16)
- + (req.reply[2] << 8) + req.reply[3];
+ now = (u32)((req.reply[0] << 24) + (req.reply[1] << 16) +
+ (req.reply[2] << 8) + req.reply[3]);
+
+ /* it's either after year 2040, or the RTC has gone backwards */
+ WARN_ON(now < RTC_OFFSET);
+
return now - RTC_OFFSET;
}
@@ -149,10 +160,10 @@ static time64_t pmu_get_time(void)
static int pmu_set_rtc_time(struct rtc_time *tm)
{
- time64_t nowtime;
+ u32 nowtime;
struct adb_request req;
- nowtime = rtc_tm_to_time64(tm) + RTC_OFFSET;
+ nowtime = lower_32_bits(rtc_tm_to_time64(tm) + RTC_OFFSET);
if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24,
nowtime >> 16, nowtime >> 8, nowtime) < 0)
return -ENXIO;