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path: root/drivers/rtc/rs5c372.c
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Diffstat (limited to 'drivers/rtc/rs5c372.c')
-rw-r--r--drivers/rtc/rs5c372.c302
1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/rtc/rs5c372.c b/drivers/rtc/rs5c372.c
new file mode 100644
index 0000000..3d1346e
--- /dev/null
+++ b/drivers/rtc/rs5c372.c
@@ -0,0 +1,302 @@
+/*
+ * rs5c372.c
+ *
+ * Device driver for Ricoh's Real Time Controller RS5C372A.
+ *
+ * Copyright (C) 2004 Gary Jennejohn garyj@denx.de
+ *
+ * Based in part in ds1307.c -
+ * (C) Copyright 2001, 2002, 2003
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ * Keith Outwater, keith_outwater@mvis.com`
+ * Steven Scholz, steven.scholz@imc-berlin.de
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+#include <i2c.h>
+
+#if defined(CONFIG_RTC_RS5C372A) && defined(CONFIG_CMD_DATE)
+/*
+ * Reads are always done starting with register 15, which requires some
+ * jumping-through-hoops to access the data correctly.
+ *
+ * Writes are always done starting with register 0.
+ */
+
+#define DEBUG 0
+
+#if DEBUG
+static unsigned int rtc_debug = DEBUG;
+#else
+#define rtc_debug 0 /* gcc will remove all the debug code for us */
+#endif
+
+#ifndef CFG_I2C_RTC_ADDR
+#define CFG_I2C_RTC_ADDR 0x32
+#endif
+
+#define RS5C372_RAM_SIZE 0x10
+#define RATE_32000HZ 0x80 /* Rate Select 32.000KHz */
+#define RATE_32768HZ 0x00 /* Rate Select 32.768KHz */
+
+#define STATUS_XPT 0x10 /* data invalid because voltage was 0 */
+
+#define USE_24HOUR_MODE 0x20
+#define TWELVE_HOUR_MODE(n) ((((n) >> 5) & 1) == 0)
+#define HOURS_AP(n) (((n) >> 5) & 1)
+#define HOURS_12(n) bcd2bin((n) & 0x1F)
+#define HOURS_24(n) bcd2bin((n) & 0x3F)
+
+
+static uchar bin2bcd (unsigned int n);
+static unsigned bcd2bin (uchar c);
+
+static int setup_done = 0;
+
+static int
+rs5c372_readram(unsigned char *buf, int len)
+{
+ int ret;
+
+ ret = i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, len);
+ if (ret != 0) {
+ printf("%s: failed to read\n", __FUNCTION__);
+ return ret;
+ }
+
+ if (buf[0] & STATUS_XPT)
+ printf("### Warning: RTC lost power\n");
+
+ return ret;
+}
+
+static void
+rs5c372_enable(void)
+{
+ unsigned char buf[RS5C372_RAM_SIZE + 1];
+ int ret;
+
+ /* note that this returns reg. 15 in buf[1] */
+ ret = rs5c372_readram(&buf[1], RS5C372_RAM_SIZE);
+ if (ret != 0) {
+ printf("%s: failed\n", __FUNCTION__);
+ return;
+ }
+
+ buf[0] = 0;
+ /* we want to start writing at register 0 so we have to copy the */
+ /* register contents up one slot */
+ for (ret = 2; ret < 9; ret++)
+ buf[ret - 1] = buf[ret];
+ /* registers 0 to 6 (time values) are not touched */
+ buf[8] = RATE_32768HZ; /* reg. 7 */
+ buf[9] = 0; /* reg. 8 */
+ buf[10] = 0; /* reg. 9 */
+ buf[11] = 0; /* reg. 10 */
+ buf[12] = 0; /* reg. 11 */
+ buf[13] = 0; /* reg. 12 */
+ buf[14] = 0; /* reg. 13 */
+ buf[15] = 0; /* reg. 14 */
+ buf[16] = USE_24HOUR_MODE; /* reg. 15 */
+ ret = i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, RS5C372_RAM_SIZE+1);
+ if (ret != 0) {
+ printf("%s: failed\n", __FUNCTION__);
+ return;
+ }
+ setup_done = 1;
+
+ return;
+}
+
+static void
+rs5c372_convert_to_time(struct rtc_time *dt, unsigned char *buf)
+{
+ /* buf[0] is register 15 */
+ dt->tm_sec = bcd2bin(buf[1]);
+ dt->tm_min = bcd2bin(buf[2]);
+
+ if (TWELVE_HOUR_MODE(buf[0])) {
+ dt->tm_hour = HOURS_12(buf[3]);
+ if (HOURS_AP(buf[3])) /* PM */
+ dt->tm_hour += 12;
+ } else /* 24-hour-mode */
+ dt->tm_hour = HOURS_24(buf[3]);
+
+ dt->tm_mday = bcd2bin(buf[5]);
+ dt->tm_mon = bcd2bin(buf[6]);
+ dt->tm_year = bcd2bin(buf[7]);
+ if (dt->tm_year >= 70)
+ dt->tm_year += 1900;
+ else
+ dt->tm_year += 2000;
+ /* 0 is Sunday */
+ dt->tm_wday = bcd2bin(buf[4] & 0x07);
+ dt->tm_yday = 0;
+ dt->tm_isdst= 0;
+
+ if(rtc_debug > 2) {
+ printf("rs5c372_convert_to_time: year = %d\n", dt->tm_year);
+ printf("rs5c372_convert_to_time: mon = %d\n", dt->tm_mon);
+ printf("rs5c372_convert_to_time: mday = %d\n", dt->tm_mday);
+ printf("rs5c372_convert_to_time: hour = %d\n", dt->tm_hour);
+ printf("rs5c372_convert_to_time: min = %d\n", dt->tm_min);
+ printf("rs5c372_convert_to_time: sec = %d\n", dt->tm_sec);
+ }
+}
+
+/*
+ * Get the current time from the RTC
+ */
+void
+rtc_get (struct rtc_time *tmp)
+{
+ unsigned char buf[RS5C372_RAM_SIZE];
+ int ret;
+
+ if (!setup_done)
+ rs5c372_enable();
+
+ if (!setup_done)
+ return;
+
+ memset(buf, 0, sizeof(buf));
+
+ /* note that this returns reg. 15 in buf[0] */
+ ret = rs5c372_readram(buf, RS5C372_RAM_SIZE);
+ if (ret != 0) {
+ printf("%s: failed\n", __FUNCTION__);
+ return;
+ }
+
+ rs5c372_convert_to_time(tmp, buf);
+
+ return;
+}
+
+/*
+ * Set the RTC
+ */
+void
+rtc_set (struct rtc_time *tmp)
+{
+ unsigned char buf[8], reg15;
+ int ret;
+
+ if (!setup_done)
+ rs5c372_enable();
+
+ if (!setup_done)
+ return;
+
+ if(rtc_debug > 2) {
+ printf("rtc_set: tm_year = %d\n", tmp->tm_year);
+ printf("rtc_set: tm_mon = %d\n", tmp->tm_mon);
+ printf("rtc_set: tm_mday = %d\n", tmp->tm_mday);
+ printf("rtc_set: tm_hour = %d\n", tmp->tm_hour);
+ printf("rtc_set: tm_min = %d\n", tmp->tm_min);
+ printf("rtc_set: tm_sec = %d\n", tmp->tm_sec);
+ }
+
+ memset(buf, 0, sizeof(buf));
+
+ /* only read register 15 */
+ ret = i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, 1);
+
+ if (ret == 0) {
+ /* need to save register 15 */
+ reg15 = buf[0];
+ buf[0] = 0; /* register address on RS5C372 */
+ buf[1] = bin2bcd(tmp->tm_sec);
+ buf[2] = bin2bcd(tmp->tm_min);
+ /* need to handle 12 hour mode */
+ if (TWELVE_HOUR_MODE(reg15)) {
+ if (tmp->tm_hour >= 12) { /* PM */
+ /* 12 PM is a special case */
+ if (tmp->tm_hour == 12)
+ buf[3] = bin2bcd(tmp->tm_hour);
+ else
+ buf[3] = bin2bcd(tmp->tm_hour - 12);
+ buf[3] |= 0x20;
+ }
+ } else {
+ buf[3] = bin2bcd(tmp->tm_hour);
+ }
+
+ buf[4] = bin2bcd(tmp->tm_wday);
+ buf[5] = bin2bcd(tmp->tm_mday);
+ buf[6] = bin2bcd(tmp->tm_mon);
+ if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
+ printf("WARNING: year should be between 1970 and 2069!\n");
+ buf[7] = bin2bcd(tmp->tm_year % 100);
+
+ ret = i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, 8);
+ if (ret != 0)
+ printf("rs5c372_set_datetime(), i2c_master_send() returned %d\n",ret);
+ }
+
+ return;
+}
+
+/*
+ * Reset the RTC. We set the date back to 1970-01-01.
+ */
+void
+rtc_reset (void)
+{
+ struct rtc_time tmp;
+
+ if (!setup_done)
+ rs5c372_enable();
+
+ if (!setup_done)
+ return;
+
+ tmp.tm_year = 1970;
+ tmp.tm_mon = 1;
+ /* Jan. 1, 1970 was a Thursday */
+ tmp.tm_wday= 4;
+ tmp.tm_mday= 1;
+ tmp.tm_hour = 0;
+ tmp.tm_min = 0;
+ tmp.tm_sec = 0;
+
+ rtc_set(&tmp);
+
+ printf ("RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n",
+ tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
+ tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
+
+ return;
+}
+
+static unsigned int
+bcd2bin (unsigned char n)
+{
+ return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
+}
+
+static unsigned char
+bin2bcd (unsigned int n)
+{
+ return (((n / 10) << 4) | (n % 10));
+}
+#endif
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