diff options
Diffstat (limited to 'drivers/rtc/rx8025.c')
| -rw-r--r-- | drivers/rtc/rx8025.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/drivers/rtc/rx8025.c b/drivers/rtc/rx8025.c new file mode 100644 index 0000000..6c94ae1 --- /dev/null +++ b/drivers/rtc/rx8025.c @@ -0,0 +1,227 @@ +/* + * (C) Copyright 2007 + * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com. + * + * 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 as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * 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 + */ + +/* + * Epson RX8025 RTC driver. + */ + +#include <common.h> +#include <command.h> +#include <rtc.h> +#include <i2c.h> + +#if defined(CONFIG_RTC_RX8025) && defined(CONFIG_CMD_DATE) + +/*---------------------------------------------------------------------*/ +#undef DEBUG_RTC + +#ifdef DEBUG_RTC +#define DEBUGR(fmt,args...) printf(fmt ,##args) +#else +#define DEBUGR(fmt,args...) +#endif +/*---------------------------------------------------------------------*/ + +#ifndef CFG_I2C_RTC_ADDR +# define CFG_I2C_RTC_ADDR 0x32 +#endif + +/* + * RTC register addresses + */ +#define RTC_SEC_REG_ADDR 0x00 +#define RTC_MIN_REG_ADDR 0x01 +#define RTC_HR_REG_ADDR 0x02 +#define RTC_DAY_REG_ADDR 0x03 +#define RTC_DATE_REG_ADDR 0x04 +#define RTC_MON_REG_ADDR 0x05 +#define RTC_YR_REG_ADDR 0x06 + +#define RTC_CTL1_REG_ADDR 0x0e +#define RTC_CTL2_REG_ADDR 0x0f + +/* + * Control register 1 bits + */ +#define RTC_CTL1_BIT_2412 0x20 + +/* + * Control register 2 bits + */ +#define RTC_CTL2_BIT_PON 0x10 +#define RTC_CTL2_BIT_VDET 0x40 +#define RTC_CTL2_BIT_XST 0x20 +#define RTC_CTL2_BIT_VDSL 0x80 + +/* + * Note: the RX8025 I2C RTC requires register + * reads and write to consist of a single bus + * cycle. It is not allowed to write the register + * address in a first cycle that is terminated by + * a STOP condition. The chips needs a 'restart' + * sequence (start sequence without a prior stop). + * This driver has been written for a 4xx board. + * U-Boot's 4xx i2c driver is currently not capable + * to generate such cycles to some work arounds + * are used. + */ + +/* static uchar rtc_read (uchar reg); */ +#define rtc_read(reg) buf[((reg) + 1) & 0xf] + +static void rtc_write (uchar reg, uchar val); +static uchar bin2bcd (unsigned int n); +static unsigned bcd2bin (uchar c); + +/* + * Get the current time from the RTC + */ +void rtc_get (struct rtc_time *tmp) +{ + uchar sec, min, hour, mday, wday, mon, year, ctl2; + uchar buf[16]; + + if (i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, 16)) + printf("Error reading from RTC\n"); + + sec = rtc_read(RTC_SEC_REG_ADDR); + min = rtc_read(RTC_MIN_REG_ADDR); + hour = rtc_read(RTC_HR_REG_ADDR); + wday = rtc_read(RTC_DAY_REG_ADDR); + mday = rtc_read(RTC_DATE_REG_ADDR); + mon = rtc_read(RTC_MON_REG_ADDR); + year = rtc_read(RTC_YR_REG_ADDR); + + DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " + "hr: %02x min: %02x sec: %02x\n", + year, mon, mday, wday, hour, min, sec); + + /* dump status */ + ctl2 = rtc_read(RTC_CTL2_REG_ADDR); + if (ctl2 & RTC_CTL2_BIT_PON) + printf("RTC: power-on detected\n"); + + if (ctl2 & RTC_CTL2_BIT_VDET) + printf("RTC: voltage drop detected\n"); + + if (!(ctl2 & RTC_CTL2_BIT_XST)) + printf("RTC: oscillator stop detected\n"); + + tmp->tm_sec = bcd2bin (sec & 0x7F); + tmp->tm_min = bcd2bin (min & 0x7F); + tmp->tm_hour = bcd2bin (hour & 0x3F); + tmp->tm_mday = bcd2bin (mday & 0x3F); + tmp->tm_mon = bcd2bin (mon & 0x1F); + tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000); + tmp->tm_wday = bcd2bin (wday & 0x07); + tmp->tm_yday = 0; + tmp->tm_isdst= 0; + + DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", + tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, + tmp->tm_hour, tmp->tm_min, tmp->tm_sec); +} + + +/* + * Set the RTC + */ +void rtc_set (struct rtc_time *tmp) +{ + DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", + tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, + tmp->tm_hour, tmp->tm_min, tmp->tm_sec); + + if (tmp->tm_year < 1970 || tmp->tm_year > 2069) + printf("WARNING: year should be between 1970 and 2069!\n"); + + rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); + rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); + rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday)); + rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); + rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour)); + rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); + rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); + + rtc_write (RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412); +} + + +/* + * Reset the RTC. We setting the date back to 1970-01-01. + */ +void rtc_reset (void) +{ + struct rtc_time tmp; + uchar buf[16]; + uchar ctl2; + + if (i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, 16)) + printf("Error reading from RTC\n"); + + ctl2 = rtc_read(RTC_CTL2_REG_ADDR); + ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET); + ctl2 |= RTC_CTL2_BIT_XST | RTC_CTL2_BIT_VDSL; + rtc_write (RTC_CTL2_REG_ADDR, ctl2); + + tmp.tm_year = 1970; + tmp.tm_mon = 1; + 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; +} + + +/* + * Helper functions + */ +static void rtc_write (uchar reg, uchar val) +{ + uchar buf[2]; + buf[0] = reg << 4; + buf[1] = val; + if (i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, 2) != 0) + printf("Error writing to RTC\n"); + +} + +static unsigned bcd2bin (uchar n) +{ + return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F)); +} + +static unsigned char bin2bcd (unsigned int n) +{ + return (((n / 10) << 4) | (n % 10)); +} + +#endif /* CONFIG_RTC_RX8025 && (CFG_COMMANDS & CFG_CMD_DATE) */ |