From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:43246) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ezoxd-0000Bv-Bd for qemu-devel@nongnu.org; Sat, 24 Mar 2018 15:37:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ezomu-0005lC-KO for qemu-devel@nongnu.org; Sat, 24 Mar 2018 15:28:50 -0400 Received: from mail-pf0-x243.google.com ([2607:f8b0:400e:c00::243]:33136) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1ezomu-0005ku-E2 for qemu-devel@nongnu.org; Sat, 24 Mar 2018 15:25:12 -0400 Received: by mail-pf0-x243.google.com with SMTP id f15so243982pfn.0 for ; Sat, 24 Mar 2018 12:25:12 -0700 (PDT) From: Michael Davidsaver Date: Sat, 24 Mar 2018 12:24:45 -0700 Message-Id: <20180324192455.12254-5-mdavidsaver@gmail.com> In-Reply-To: <20180324192455.12254-1-mdavidsaver@gmail.com> References: <20180324192455.12254-1-mdavidsaver@gmail.com> Subject: [Qemu-devel] [PATCH 04/14] timer: ds1338 clarify HOUR handling List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , Thomas Huth Cc: Antoine Mathys , David Gibson , qemu-devel@nongnu.org, Michael Davidsaver Simplify and comment the translation between registers and struct tm. Signed-off-by: Michael Davidsaver --- hw/timer/ds1338.c | 35 +++++++++++++++++------------------ 1 file changed, 17 insertions(+), 18 deletions(-) diff --git a/hw/timer/ds1338.c b/hw/timer/ds1338.c index 72a4692d60..9bcda26e51 100644 --- a/hw/timer/ds1338.c +++ b/hw/timer/ds1338.c @@ -88,23 +88,23 @@ static void capture_current_time(DS1338State *s) * which will be actually read by the data transfer operation. */ struct tm now; + bool mode12 = ARRAY_FIELD_EX32(s->nvram, HOUR, SET12); qemu_get_timedate(&now, s->offset); + s->nvram[R_SEC] = to_bcd(now.tm_sec); s->nvram[R_MIN] = to_bcd(now.tm_min); - if (ARRAY_FIELD_EX32(s->nvram, HOUR, SET12)) { - int tmp = now.tm_hour; - if (tmp % 12 == 0) { - tmp += 12; - } - s->nvram[R_HOUR] = 0; + s->nvram[R_HOUR] = 0; + if (mode12) { + /* map 0-23 to 1-12 am/pm */ ARRAY_FIELD_DP32(s->nvram, HOUR, SET12, 1); - if (tmp <= 12) { - ARRAY_FIELD_DP32(s->nvram, HOUR, AMPM, 0); - ARRAY_FIELD_DP32(s->nvram, HOUR, HOUR12, to_bcd(tmp)); - } else { - ARRAY_FIELD_DP32(s->nvram, HOUR, AMPM, 1); - ARRAY_FIELD_DP32(s->nvram, HOUR, HOUR12, to_bcd(tmp - 12)); + ARRAY_FIELD_DP32(s->nvram, HOUR, AMPM, now.tm_hour >= 12u); + now.tm_hour %= 12u; /* wrap 0-23 to 0-11 */ + if (now.tm_hour == 0u) { + /* midnight/noon stored as 12 */ + now.tm_hour = 12u; } + ARRAY_FIELD_DP32(s->nvram, HOUR, HOUR12, to_bcd(now.tm_hour)); + } else { ARRAY_FIELD_DP32(s->nvram, HOUR, HOUR24, to_bcd(now.tm_hour)); } @@ -182,14 +182,13 @@ static int ds1338_send(I2CSlave *i2c, uint8_t data) break; case R_HOUR: if (FIELD_EX32(data, HOUR, SET12)) { - int tmp = from_bcd(FIELD_EX32(data, HOUR, HOUR12)); + /* 12 hour (1-12) */ + /* read and wrap 1-12 -> 0-11 */ + now.tm_hour = from_bcd(FIELD_EX32(data, HOUR, HOUR12)) % 12u; if (FIELD_EX32(data, HOUR, AMPM)) { - tmp += 12; + now.tm_hour += 12; } - if (tmp % 12 == 0) { - tmp -= 12; - } - now.tm_hour = tmp; + } else { now.tm_hour = from_bcd(FIELD_EX32(data, HOUR, HOUR24)); } -- 2.11.0