Add a PMIC-based RTC driver for Gigabeat S.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17236 a1c6a512-1295-4272-9138-f99709370657

4 files changed, 242 insertions, 1 deletions

diff --git a/firmware/SOURCES b/firmware/SOURCES
index bf4fb86af4..0acfdd5bf9 100644
--- a/firmware/SOURCES
+++ b/firmware/SOURCES
@@ -149,6 +149,8 @@ drivers/rtc/rtc_as3514.c
 drivers/rtc/rtc_rx5x348ab.c
 #elif (CONFIG_RTC == RTC_MR100)
 drivers/rtc/rtc_mr100.c
+#elif (CONFIG_RTC == RTC_MC13783)
+drivers/rtc/rtc_mc13783.c
 #endif /* (CONFIG_RTC == RTC_) */
 #endif /* SIMULATOR */
 
diff --git a/firmware/drivers/rtc/rtc_mc13783.c b/firmware/drivers/rtc/rtc_mc13783.c
new file mode 100644
index 0000000000..2494e5ece5
--- /dev/null
+++ b/firmware/drivers/rtc/rtc_mc13783.c
@@ -0,0 +1,238 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2008 by Michael Sevakis
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "config.h"
+#include "system.h"
+#include "rtc.h"
+#include "mc13783.h"
+
+/* NOTE: Defined the base to be original firmware compatible if needed -
+ * ie. the day and year as it would interpret a DAY register value of zero. */
+
+/* Days passed since midnight 01 Jan, 1601 to midnight on the base date. */
+#ifdef TOSHIBA_GIGABEAT_S
+    /* Gigabeat S seems to be 1 day behind the ususual - this will
+     * make the RTC match file dates created by retailos. */
+    #define RTC_BASE_DAY_COUNT  138425
+    #define RTC_BASE_MONTH      12
+    #define RTC_BASE_DAY        31
+    #define RTC_BASE_YEAR       1979
+#elif 1
+    #define RTC_BASE_DAY_COUNT  138426
+    #define RTC_BASE_MONTH      1
+    #define RTC_BASE_DAY        1
+    #define RTC_BASE_YEAR       1980
+#else
+    #define RTC_BASE_DAY_COUNT  134774
+    #define RTC_BASE_MONTH      1
+    #define RTC_BASE_DAY        1
+    #define RTC_BASE_YEAR       1970
+#endif
+
+enum rtc_buffer_field_indexes
+{
+    RTC_I_SECONDS = 0,
+    RTC_I_MINUTES,
+    RTC_I_HOURS,
+    RTC_I_WEEKDAY,
+    RTC_I_DAY,
+    RTC_I_MONTH,
+    RTC_I_YEAR,
+    RTC_NUM_FIELDS,
+};
+
+enum rtc_registers_indexes
+{
+    RTC_REG_TIME = 0,
+    RTC_REG_DAY,
+    RTC_REG_TIME2,
+    RTC_NUM_REGS,
+};
+
+static const unsigned char rtc_registers[RTC_NUM_REGS] =
+{
+    [RTC_REG_TIME]  = MC13783_RTC_TIME,
+    [RTC_REG_DAY]   = MC13783_RTC_DAY,
+    [RTC_REG_TIME2] = MC13783_RTC_TIME,
+};
+
+static const unsigned char month_table[2][12] =
+{
+    { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+    { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+};
+
+static inline void to_bcd(unsigned char *bcd, const unsigned char *buf,
+                          int len)
+{
+    while (len-- > 0)
+    {
+        unsigned char d = *buf++;
+        *bcd++ = ((d / 10) << 4) | (d % 10);
+    }
+}
+
+static inline void from_bcd(unsigned char *buf, const unsigned char *bcd,
+                            int len)
+{
+    while (len-- > 0)
+    {
+        unsigned char d = *bcd++;
+        *buf++ = ((d >> 4) & 0x0f) * 10 + (d & 0xf);
+    }
+}
+
+/* Get number of leaps since the reference date of 1601/01/01 */
+static int get_leap_count(int d)
+{
+    int lm = (d + 1) / 146097;
+    int lc = (d + 1 - lm) / 36524;
+    int ly = (d + 1 - lm + lc) / 1461;
+    return ly - lc + lm;
+}
+
+static int is_leap_year(int y)
+{
+    return (y % 4) == 0 && ((y % 100) != 0 || (y % 400) == 0) ? 1 : 0;
+}
+
+/** Public APIs **/
+void rtc_init(void)
+{
+    /* Nothing to do */
+}
+
+int rtc_read_datetime(unsigned char* buf)
+{
+    uint32_t regs[RTC_NUM_REGS];
+    int year, leap, month, day;
+
+    /* Read time, day, time - 2nd read of time should be the same or
+     * greater */
+    do
+    {
+        if (mc13783_read_regset(rtc_registers, regs,
+                                RTC_NUM_REGS) < RTC_NUM_REGS)
+        {
+            /* Couldn't read registers */
+            return 0;
+        }
+    }
+    /* If TOD counter turned over - reread */
+    while (regs[RTC_REG_TIME2] < regs[RTC_REG_TIME]);
+
+    /* TOD: = 0 to 86399 */
+    buf[RTC_I_HOURS] = regs[RTC_REG_TIME] / 3600;
+    regs[RTC_REG_TIME] -= buf[RTC_I_HOURS]*3600;
+
+    buf[RTC_I_MINUTES] = regs[RTC_REG_TIME] / 60;
+    regs[RTC_REG_TIME] -= buf[RTC_I_MINUTES]*60;
+
+    buf[RTC_I_SECONDS] = regs[RTC_REG_TIME];
+
+    /* DAY: 0 to 32767 */
+    day = regs[RTC_REG_DAY] + RTC_BASE_DAY_COUNT;
+
+    /* Weekday */
+    buf[RTC_I_WEEKDAY] = (day + 1) % 7; /* 1601/01/01 = Monday */
+
+    /* Get number of leaps for today */
+    leap = get_leap_count(day);
+    year = (day - leap) / 365;
+
+    /* Get number of leaps for yesterday */
+    leap = get_leap_count(day - 1);
+
+    /* Get day number for year 0-364|365 */
+    day = day - leap - year * 365;
+
+    year += 1601;
+
+    /* Get the current month */
+    leap = is_leap_year(year);
+
+    for (month = 0; month < 12; month++)
+    {
+        int days = month_table[leap][month];
+
+        if (day < days)
+            break;
+
+        day -= days;
+    }
+
+    buf[RTC_I_DAY] = day + 1; /* 1 to 31 */
+    buf[RTC_I_MONTH] = month + 1; /* 1 to 12 */
+    buf[RTC_I_YEAR] = year % 100;
+
+    to_bcd(buf, buf, RTC_NUM_FIELDS);
+
+    return 7;
+}
+
+int rtc_write_datetime(unsigned char* buf)
+{
+    uint32_t regs[2];
+    unsigned char fld[RTC_NUM_FIELDS];
+    int year, leap, month, day, i, base_yearday;
+
+    from_bcd(fld, buf, RTC_NUM_FIELDS);
+
+    regs[RTC_REG_TIME] = fld[RTC_I_SECONDS] +
+                         fld[RTC_I_MINUTES]*60 +
+                         fld[RTC_I_HOURS]*3600;
+
+    year = fld[RTC_I_YEAR];
+
+    if (year < RTC_BASE_YEAR - 1900)
+        year += 2000;
+    else
+        year += 1900;
+
+    /* Get number of leaps for day before base */
+    leap = get_leap_count(RTC_BASE_DAY_COUNT - 1);
+
+    /* Get day number for base year 0-364|365 */
+    base_yearday = RTC_BASE_DAY_COUNT - leap -
+                    (RTC_BASE_YEAR - 1601) * 365;
+
+    /* Get the number of days elapsed from reference */
+    for (i = RTC_BASE_YEAR, day = 0; i < year; i++)
+    {
+        day += is_leap_year(i) ? 366 : 365;
+    }
+
+    /* Find the number of days passed this year up to the 1st of the
+     * month. */
+    leap = is_leap_year(year);
+    month = fld[RTC_I_MONTH] - 1;
+
+    for (i = 0; i < month; i++)
+    {
+        day += month_table[leap][i];
+    }
+
+    regs[RTC_REG_DAY] = day + fld[RTC_I_DAY] - 1 - base_yearday;
+
+    if (mc13783_write_regset(rtc_registers, regs, 2) == 2)
+    {
+        return RTC_NUM_FIELDS;
+    }
+
+    return 0;
+}
diff --git a/firmware/export/config-gigabeat-s.h b/firmware/export/config-gigabeat-s.h
index bc70956ced..6eb57b219c 100644
--- a/firmware/export/config-gigabeat-s.h
+++ b/firmware/export/config-gigabeat-s.h
@@ -43,7 +43,7 @@
 #define CONFIG_CODEC SWCODEC
 
 /* define this if you have a real-time clock */
-//#define CONFIG_RTC RTC_IMX31L
+#define CONFIG_RTC RTC_MC13783
 
 /* Define this for LCD backlight available */
 #define HAVE_BACKLIGHT
diff --git a/firmware/export/config.h b/firmware/export/config.h
index c108171d37..e502043844 100644
--- a/firmware/export/config.h
+++ b/firmware/export/config.h
@@ -165,6 +165,7 @@
 #define RTC_TCC77X   10
 #define RTC_TCC780X  11
 #define RTC_MR100  12
+#define RTC_MC13783  13 /* Freescale MC13783 PMIC */
 
 /* USB On-the-go */
 #define USBOTG_ISP1362 1362 /* iriver H300 */