diff options
Diffstat (limited to 'drivers/rtc/rs5c372.c')
| -rw-r--r-- | drivers/rtc/rs5c372.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/rtc/rs5c372.c b/drivers/rtc/rs5c372.c new file mode 100644 index 0000000000..3d1346eaa7 --- /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 |