pasemi: hardware rng driver

[linux-2.6] / drivers / rtc / rtc-dev.c

diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 671b14ec28bb32473b2c9a8f34b69b0b11a83d7f..f4e5f0040ff7a43263a2af50b9eb694624f3fa91 100644 (file)
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -277,12 +277,48 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
 
                alarm.enabled = 0;
                alarm.pending = 0;
-               alarm.time.tm_mday = -1;
-               alarm.time.tm_mon = -1;
-               alarm.time.tm_year = -1;
                alarm.time.tm_wday = -1;
                alarm.time.tm_yday = -1;
                alarm.time.tm_isdst = -1;
+
+               /* RTC_ALM_SET alarms may be up to 24 hours in the future.
+                * Rather than expecting every RTC to implement "don't care"
+                * for day/month/year fields, just force the alarm to have
+                * the right values for those fields.
+                *
+                * RTC_WKALM_SET should be used instead.  Not only does it
+                * eliminate the need for a separate RTC_AIE_ON call, it
+                * doesn't have the "alarm 23:59:59 in the future" race.
+                *
+                * NOTE:  some legacy code may have used invalid fields as
+                * wildcards, exposing hardware "periodic alarm" capabilities.
+                * Not supported here.
+                */
+               {
+                       unsigned long now, then;
+
+                       err = rtc_read_time(rtc, &tm);
+                       if (err < 0)
+                               return err;
+                       rtc_tm_to_time(&tm, &now);
+
+                       alarm.time.tm_mday = tm.tm_mday;
+                       alarm.time.tm_mon = tm.tm_mon;
+                       alarm.time.tm_year = tm.tm_year;
+                       err  = rtc_valid_tm(&alarm.time);
+                       if (err < 0)
+                               return err;
+                       rtc_tm_to_time(&alarm.time, &then);
+
+                       /* alarm may need to wrap into tomorrow */
+                       if (then < now) {
+                               rtc_time_to_tm(now + 24 * 60 * 60, &tm);
+                               alarm.time.tm_mday = tm.tm_mday;
+                               alarm.time.tm_mon = tm.tm_mon;
+                               alarm.time.tm_year = tm.tm_year;
+                       }
+               }
+
                err = rtc_set_alarm(rtc, &alarm);
                break;