rtc: sandbox-rtc: fix set method

The current set method is broken; a simple test case is to first set
the date to something in April, then change the date to 31st May:

=> date 040412122020.34
Date: 2020-04-04 (Saturday)    Time: 12:12:34
=> date 053112122020.34
Date: 2020-05-01 (Friday)    Time: 12:12:34

or via the amending of the existing rtc_set_get test case similarly:

$ ./u-boot -T -v
=> ut dm rtc_set_get
Test: dm_test_rtc_set_get: rtc.c
expected: 31/08/2004 18:18:00
actual: 01/08/2004 18:18:00

The problem is that after each register write,
sandbox_i2c_rtc_complete_write() gets called and sets the internal
time from the current set of registers. However, when we get to
writing 31 to mday, the registers are in an inconsistent state (mon is
still 4), so the mktime machinery ends up translating April 31st to
May 1st. Upon the next register write, the registers are populated by
sandbox_i2c_rtc_prepare_read(), so the 31 we just wrote to mday gets
overwritten by a 1.

Fix it by writing all registers at once, and for consistency, update
the get method to retrieve them all with one "i2c transfer".

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>

diff --git a/drivers/rtc/sandbox_rtc.c b/drivers/rtc/sandbox_rtc.c
index b08d758a74ef596222512ac32ecd7e459660a7f1..77065e49c76975a356fbbc322b43f1d00bcb7a62 100644 (file)
--- a/drivers/rtc/sandbox_rtc.c
+++ b/drivers/rtc/sandbox_rtc.c
@@ -14,55 +14,38 @@
 
 static int sandbox_rtc_get(struct udevice *dev, struct rtc_time *time)
 {
-       time->tm_sec = dm_i2c_reg_read(dev, REG_SEC);
-       if (time->tm_sec < 0)
-               return time->tm_sec;
-       time->tm_min = dm_i2c_reg_read(dev, REG_MIN);
-       if (time->tm_min < 0)
-               return time->tm_min;
-       time->tm_hour = dm_i2c_reg_read(dev, REG_HOUR);
-       if (time->tm_hour < 0)
-               return time->tm_hour;
-       time->tm_mday = dm_i2c_reg_read(dev, REG_MDAY);
-       if (time->tm_mday < 0)
-               return time->tm_mday;
-       time->tm_mon = dm_i2c_reg_read(dev, REG_MON);
-       if (time->tm_mon < 0)
-               return time->tm_mon;
-       time->tm_year = dm_i2c_reg_read(dev, REG_YEAR);
-       if (time->tm_year < 0)
-               return time->tm_year;
-       time->tm_year += 1900;
-       time->tm_wday = dm_i2c_reg_read(dev, REG_WDAY);
-       if (time->tm_wday < 0)
-               return time->tm_wday;
+       u8 buf[7];
+       int ret;
+
+       ret = dm_i2c_read(dev, REG_SEC, buf, sizeof(buf));
+       if (ret < 0)
+               return ret;
+
+       time->tm_sec  = buf[REG_SEC - REG_SEC];
+       time->tm_min  = buf[REG_MIN - REG_SEC];
+       time->tm_hour = buf[REG_HOUR - REG_SEC];
+       time->tm_mday = buf[REG_MDAY - REG_SEC];
+       time->tm_mon  = buf[REG_MON - REG_SEC];
+       time->tm_year = buf[REG_YEAR - REG_SEC] + 1900;
+       time->tm_wday = buf[REG_WDAY - REG_SEC];
 
        return 0;
 }
 
 static int sandbox_rtc_set(struct udevice *dev, const struct rtc_time *time)
 {
+       u8 buf[7];
        int ret;
 
-       ret = dm_i2c_reg_write(dev, REG_SEC, time->tm_sec);
-       if (ret < 0)
-               return ret;
-       ret = dm_i2c_reg_write(dev, REG_MIN, time->tm_min);
-       if (ret < 0)
-               return ret;
-       ret = dm_i2c_reg_write(dev, REG_HOUR, time->tm_hour);
-       if (ret < 0)
-               return ret;
-       ret = dm_i2c_reg_write(dev, REG_MDAY, time->tm_mday);
-       if (ret < 0)
-               return ret;
-       ret = dm_i2c_reg_write(dev, REG_MON, time->tm_mon);
-       if (ret < 0)
-               return ret;
-       ret = dm_i2c_reg_write(dev, REG_YEAR, time->tm_year - 1900);
-       if (ret < 0)
-               return ret;
-       ret = dm_i2c_reg_write(dev, REG_WDAY, time->tm_wday);
+       buf[REG_SEC - REG_SEC]  = time->tm_sec;
+       buf[REG_MIN - REG_SEC]  = time->tm_min;
+       buf[REG_HOUR - REG_SEC] = time->tm_hour;
+       buf[REG_MDAY - REG_SEC] = time->tm_mday;
+       buf[REG_MON  - REG_SEC] = time->tm_mon;
+       buf[REG_YEAR - REG_SEC] = time->tm_year - 1900;
+       buf[REG_WDAY - REG_SEC] = time->tm_wday;
+
+       ret = dm_i2c_write(dev, REG_SEC, buf, sizeof(buf));
        if (ret < 0)
                return ret;
 

diff --git a/test/dm/rtc.c b/test/dm/rtc.c
index 88f86581cce77c446e98bef1e7c49f79a54e6982..e072fd618b084ed5774bab81de1dcec9880a19b1 100644 (file)
--- a/test/dm/rtc.c
+++ b/test/dm/rtc.c
@@ -70,7 +70,20 @@ static int dm_test_rtc_set_get(struct unit_test_state *uts)
        old_base_time = sandbox_i2c_rtc_get_set_base_time(emul, -1);
 
        memset(&time, '\0', sizeof(time));
-       time.tm_mday = 25;
+       time.tm_mday = 3;
+       time.tm_mon = 6;
+       time.tm_year = 2004;
+       time.tm_sec = 0;
+       time.tm_min = 18;
+       time.tm_hour = 18;
+       ut_assertok(dm_rtc_set(dev, &time));
+
+       memset(&cmp, '\0', sizeof(cmp));
+       ut_assertok(dm_rtc_get(dev, &cmp));
+       ut_assertok(cmp_times(&time, &cmp, true));
+
+       memset(&time, '\0', sizeof(time));
+       time.tm_mday = 31;
        time.tm_mon = 8;
        time.tm_year = 2004;
        time.tm_sec = 0;