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237 lines
6.4 KiB
237 lines
6.4 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* (C) Copyright 2007 |
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* Larry Johnson, [email protected] |
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* |
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* based on rtc/m41t11.c which is ... |
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* |
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* (C) Copyright 2002 |
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* Andrew May, Viasat Inc, [email protected] |
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*/ |
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/* |
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* STMicroelectronics M41T60 serial access real-time clock |
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*/ |
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/* #define DEBUG 1 */ |
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#include <common.h> |
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#include <command.h> |
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#include <rtc.h> |
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#include <i2c.h> |
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/* |
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* Convert between century and "century bits" (CB1 and CB0). These routines |
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* assume years are in the range 1900 - 2299. |
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*/ |
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static unsigned char year2cb(unsigned const year) |
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{ |
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if (year < 1900 || year >= 2300) |
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printf("M41T60 RTC: year %d out of range\n", year); |
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return (year / 100) & 0x3; |
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} |
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static unsigned cb2year(unsigned const cb) |
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{ |
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return 1900 + 100 * ((cb + 1) & 0x3); |
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} |
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/* |
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* These are simple defines for the chip local to here so they aren't too |
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* verbose. DAY/DATE aren't nice but that is how they are on the data sheet. |
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*/ |
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#define RTC_SEC 0x0 |
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#define RTC_MIN 0x1 |
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#define RTC_HOUR 0x2 |
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#define RTC_DAY 0x3 |
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#define RTC_DATE 0x4 |
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#define RTC_MONTH 0x5 |
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#define RTC_YEAR 0x6 |
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#define RTC_REG_CNT 7 |
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#define RTC_CTRL 0x7 |
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#if defined(DEBUG) |
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static void rtc_dump(char const *const label) |
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{ |
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uchar data[8]; |
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if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) { |
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printf("I2C read failed in rtc_dump()\n"); |
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return; |
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} |
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printf("RTC dump %s: %02X-%02X-%02X-%02X-%02X-%02X-%02X-%02X\n", |
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label, data[0], data[1], data[2], data[3], |
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data[4], data[5], data[6], data[7]); |
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} |
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#else |
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#define rtc_dump(label) |
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#endif |
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static uchar *rtc_validate(void) |
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{ |
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/* |
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* This routine uses the OUT bit and the validity of the time values to |
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* determine whether there has been an initial power-up since the last |
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* time the routine was run. It assumes that the OUT bit is not being |
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* used for any other purpose. |
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*/ |
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static const uchar daysInMonth[0x13] = { |
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0x00, 0x31, 0x29, 0x31, 0x30, 0x31, 0x30, 0x31, |
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0x31, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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0x31, 0x30, 0x31 |
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}; |
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static uchar data[8]; |
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uchar min, date, month, years; |
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rtc_dump("begin validate"); |
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if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) { |
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printf("I2C read failed in rtc_validate()\n"); |
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return 0; |
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} |
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/* |
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* If the OUT bit is "1", there has been a loss of power, so stop the |
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* oscillator so it can be "kick-started" as per data sheet. |
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*/ |
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if (0x00 != (data[RTC_CTRL] & 0x80)) { |
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printf("M41T60 RTC clock lost power.\n"); |
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data[RTC_SEC] = 0x80; |
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if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC, 1, data, 1)) { |
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printf("I2C write failed in rtc_validate()\n"); |
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return 0; |
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} |
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} |
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/* |
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* If the oscillator is stopped or the date is invalid, then reset the |
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* OUT bit to "0", reset the date registers, and start the oscillator. |
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*/ |
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min = data[RTC_MIN] & 0x7F; |
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date = data[RTC_DATE]; |
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month = data[RTC_MONTH] & 0x3F; |
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years = data[RTC_YEAR]; |
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if (0x59 < data[RTC_SEC] || 0x09 < (data[RTC_SEC] & 0x0F) || |
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0x59 < min || 0x09 < (min & 0x0F) || |
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0x23 < data[RTC_HOUR] || 0x09 < (data[RTC_HOUR] & 0x0F) || |
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0x07 < data[RTC_DAY] || 0x00 == data[RTC_DAY] || |
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0x12 < month || |
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0x99 < years || 0x09 < (years & 0x0F) || |
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daysInMonth[month] < date || 0x09 < (date & 0x0F) || 0x00 == date || |
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(0x29 == date && 0x02 == month && |
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((0x00 != (years & 0x03)) || |
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(0x00 == years && 0x00 != (data[RTC_MONTH] & 0xC0))))) { |
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printf("Resetting M41T60 RTC clock.\n"); |
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/* |
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* Set to 00:00:00 1900-01-01 (Monday) |
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*/ |
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data[RTC_SEC] = 0x00; |
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data[RTC_MIN] &= 0x80; /* preserve OFIE bit */ |
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data[RTC_HOUR] = 0x00; |
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data[RTC_DAY] = 0x02; |
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data[RTC_DATE] = 0x01; |
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data[RTC_MONTH] = 0xC1; |
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data[RTC_YEAR] = 0x00; |
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data[RTC_CTRL] &= 0x7F; /* reset OUT bit */ |
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if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) { |
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printf("I2C write failed in rtc_validate()\n"); |
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return 0; |
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} |
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} |
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return data; |
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} |
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int rtc_get(struct rtc_time *tmp) |
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{ |
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uchar const *const data = rtc_validate(); |
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if (!data) |
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return -1; |
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tmp->tm_sec = bcd2bin(data[RTC_SEC] & 0x7F); |
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tmp->tm_min = bcd2bin(data[RTC_MIN] & 0x7F); |
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tmp->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3F); |
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tmp->tm_mday = bcd2bin(data[RTC_DATE] & 0x3F); |
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tmp->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1F); |
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tmp->tm_year = cb2year(data[RTC_MONTH] >> 6) + bcd2bin(data[RTC_YEAR]); |
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tmp->tm_wday = bcd2bin(data[RTC_DAY] & 0x07) - 1; |
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tmp->tm_yday = 0; |
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tmp->tm_isdst = 0; |
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debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", |
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tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, |
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tmp->tm_hour, tmp->tm_min, tmp->tm_sec); |
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return 0; |
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} |
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int rtc_set(struct rtc_time *tmp) |
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{ |
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uchar *const data = rtc_validate(); |
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if (!data) |
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return -1; |
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debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", |
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tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, |
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tmp->tm_hour, tmp->tm_min, tmp->tm_sec); |
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data[RTC_SEC] = (data[RTC_SEC] & 0x80) | (bin2bcd(tmp->tm_sec) & 0x7F); |
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data[RTC_MIN] = (data[RTC_MIN] & 0X80) | (bin2bcd(tmp->tm_min) & 0X7F); |
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data[RTC_HOUR] = bin2bcd(tmp->tm_hour) & 0x3F; |
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data[RTC_DATE] = bin2bcd(tmp->tm_mday) & 0x3F; |
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data[RTC_MONTH] = bin2bcd(tmp->tm_mon) & 0x1F; |
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data[RTC_YEAR] = bin2bcd(tmp->tm_year % 100); |
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data[RTC_MONTH] |= year2cb(tmp->tm_year) << 6; |
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data[RTC_DAY] = bin2bcd(tmp->tm_wday + 1) & 0x07; |
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if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, RTC_REG_CNT)) { |
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printf("I2C write failed in rtc_set()\n"); |
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return -1; |
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} |
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return 0; |
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} |
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void rtc_reset(void) |
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{ |
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uchar *const data = rtc_validate(); |
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char const *const s = env_get("rtccal"); |
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if (!data) |
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return; |
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rtc_dump("begin reset"); |
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/* |
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* If environmental variable "rtccal" is present, it must be a hex value |
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* between 0x00 and 0x3F, inclusive. The five least-significan bits |
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* represent the calibration magnitude, and the sixth bit the sign bit. |
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* If these do not match the contents of the hardware register, that |
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* register is updated. The value 0x00 imples no correction. Consult |
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* the M41T60 documentation for further details. |
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*/ |
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if (s) { |
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unsigned long const l = simple_strtoul(s, 0, 16); |
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if (l <= 0x3F) { |
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if ((data[RTC_CTRL] & 0x3F) != l) { |
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printf("Setting RTC calibration to 0x%02lX\n", |
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l); |
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data[RTC_CTRL] &= 0xC0; |
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data[RTC_CTRL] |= (uchar) l; |
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} |
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} else |
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printf("environment parameter \"rtccal\" not valid: " |
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"ignoring\n"); |
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} |
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/* |
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* Turn off frequency test. |
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*/ |
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data[RTC_CTRL] &= 0xBF; |
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if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CTRL, 1, data + RTC_CTRL, 1)) { |
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printf("I2C write failed in rtc_reset()\n"); |
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return; |
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} |
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rtc_dump("end reset"); |
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}
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