265 lines
		
	
	
		
			6.3 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			265 lines
		
	
	
		
			6.3 KiB
		
	
	
	
		
			C
		
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * (C) Copyright 2007
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|  * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com.
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|  */
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| 
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| /*
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|  * Epson RX8025 RTC driver.
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|  */
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| 
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| #include <common.h>
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| #include <command.h>
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| #include <dm.h>
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| #include <i2c.h>
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| #include <rtc.h>
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| 
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| /*---------------------------------------------------------------------*/
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| #undef DEBUG_RTC
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| 
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| #ifdef DEBUG_RTC
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| #define DEBUGR(fmt,args...) printf(fmt ,##args)
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| #else
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| #define DEBUGR(fmt,args...)
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| #endif
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| /*---------------------------------------------------------------------*/
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| 
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| enum rx_model {
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| 	model_rx_8025,
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| 	model_rx_8035,
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| };
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| 
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| /*
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|  * RTC register addresses
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|  */
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| #define RTC_SEC_REG_ADDR	0x00
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| #define RTC_MIN_REG_ADDR	0x01
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| #define RTC_HR_REG_ADDR		0x02
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| #define RTC_DAY_REG_ADDR	0x03
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| #define RTC_DATE_REG_ADDR	0x04
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| #define RTC_MON_REG_ADDR	0x05
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| #define RTC_YR_REG_ADDR		0x06
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| #define RTC_OFFSET_REG_ADDR	0x07
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| 
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| #define RTC_CTL1_REG_ADDR	0x0e
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| #define RTC_CTL2_REG_ADDR	0x0f
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| 
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| /*
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|  * Control register 1 bits
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|  */
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| #define RTC_CTL1_BIT_2412	0x20
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| 
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| /*
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|  * Control register 2 bits
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|  */
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| #define RTC_CTL2_BIT_PON	0x10
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| #define RTC_CTL2_BIT_VDET	0x40
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| #define RTC_CTL2_BIT_XST	0x20
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| #define RTC_CTL2_BIT_VDSL	0x80
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| 
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| /*
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|  * Note: the RX8025 I2C RTC requires register
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|  * reads and write to consist of a single bus
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|  * cycle. It is not allowed to write the register
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|  * address in a first cycle that is terminated by
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|  * a STOP condition. The chips needs a 'restart'
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|  * sequence (start sequence without a prior stop).
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|  */
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| 
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| #define rtc_read(reg) buf[(reg) & 0xf]
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| 
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| static int rtc_write(struct udevice *dev, uchar reg, uchar val);
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| 
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| static int rx8025_is_osc_stopped(enum rx_model model, int ctrl2)
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| {
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| 	int xstp = ctrl2 & RTC_CTL2_BIT_XST;
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| 	/* XSTP bit has different polarity on RX-8025 vs RX-8035.
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| 	 * RX-8025: 0 == oscillator stopped
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| 	 * RX-8035: 1 == oscillator stopped
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| 	 */
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| 
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| 	if (model == model_rx_8025)
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| 		xstp = !xstp;
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| 
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| 	return xstp;
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| }
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| 
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| /*
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|  * Get the current time from the RTC
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|  */
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| static int rx8025_rtc_get(struct udevice *dev, struct rtc_time *tmp)
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| {
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| 	int rel = 0;
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| 	uchar sec, min, hour, mday, wday, mon, year, ctl2;
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| 	uchar buf[16];
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| 
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| 	if (dm_i2c_read(dev, 0, buf, sizeof(buf))) {
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| 		printf("Error reading from RTC\n");
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| 		return -EIO;
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| 	}
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| 
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| 	sec = rtc_read(RTC_SEC_REG_ADDR);
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| 	min = rtc_read(RTC_MIN_REG_ADDR);
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| 	hour = rtc_read(RTC_HR_REG_ADDR);
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| 	wday = rtc_read(RTC_DAY_REG_ADDR);
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| 	mday = rtc_read(RTC_DATE_REG_ADDR);
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| 	mon = rtc_read(RTC_MON_REG_ADDR);
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| 	year = rtc_read(RTC_YR_REG_ADDR);
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| 
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| 	DEBUGR("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
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| 	       "hr: %02x min: %02x sec: %02x\n",
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| 	       year, mon, mday, wday, hour, min, sec);
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| 
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| 	/* dump status */
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| 	ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
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| 	if (ctl2 & RTC_CTL2_BIT_PON) {
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| 		printf("RTC: power-on detected\n");
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| 		rel = -1;
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| 	}
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| 
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| 	if (ctl2 & RTC_CTL2_BIT_VDET) {
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| 		printf("RTC: voltage drop detected\n");
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| 		rel = -1;
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| 	}
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| 	if (rx8025_is_osc_stopped(dev->driver_data, ctl2)) {
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| 		printf("RTC: oscillator stop detected\n");
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| 		rel = -1;
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| 	}
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| 
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| 	tmp->tm_sec  = bcd2bin(sec & 0x7F);
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| 	tmp->tm_min  = bcd2bin(min & 0x7F);
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| 	if (rtc_read(RTC_CTL1_REG_ADDR) & RTC_CTL1_BIT_2412)
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| 		tmp->tm_hour = bcd2bin(hour & 0x3F);
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| 	else
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| 		tmp->tm_hour = bcd2bin(hour & 0x1F) % 12 +
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| 			       ((hour & 0x20) ? 12 : 0);
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| 
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| 	tmp->tm_mday = bcd2bin (mday & 0x3F);
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| 	tmp->tm_mon  = bcd2bin (mon & 0x1F);
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| 	tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
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| 	tmp->tm_wday = bcd2bin (wday & 0x07);
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| 	tmp->tm_yday = 0;
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| 	tmp->tm_isdst= 0;
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| 
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| 	DEBUGR("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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| 
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| 	return rel;
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| }
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| 
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| /*
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|  * Set the RTC
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|  */
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| static int rx8025_rtc_set(struct udevice *dev, const struct rtc_time *tmp)
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| {
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| 	/* To work around the read/write cycle issue mentioned
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| 	 * at the top of this file, write all the time registers
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| 	 * in one I2C transaction
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| 	 */
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| 	u8 write_op[8];
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| 
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| 	/* 2412 flag must be set before doing a RTC write,
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| 	 * otherwise the seconds and minute register
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| 	 * will be cleared when the flag is set
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| 	 */
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| 	if (rtc_write(dev, RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412))
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| 		return -EIO;
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| 
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| 	DEBUGR("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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| 
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| 	if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
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| 		printf("WARNING: year should be between 1970 and 2069!\n");
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| 
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| 	write_op[RTC_SEC_REG_ADDR]  = bin2bcd(tmp->tm_sec);
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| 	write_op[RTC_MIN_REG_ADDR]  = bin2bcd(tmp->tm_min);
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| 	write_op[RTC_HR_REG_ADDR]   = bin2bcd(tmp->tm_hour);
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| 	write_op[RTC_DAY_REG_ADDR]	= bin2bcd(tmp->tm_wday);
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| 	write_op[RTC_DATE_REG_ADDR]	= bin2bcd(tmp->tm_mday);
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| 	write_op[RTC_MON_REG_ADDR]  = bin2bcd(tmp->tm_mon);
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| 	write_op[RTC_YR_REG_ADDR]	= bin2bcd(tmp->tm_year % 100);
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| 	write_op[RTC_OFFSET_REG_ADDR] = 0;
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| 
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| 	return dm_i2c_write(dev, 0, &write_op[0], 8);
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| }
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| 
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| /*
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|  * Reset the RTC
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|  */
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| static int rx8025_rtc_reset(struct udevice *dev)
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| {
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| 	uchar buf[16];
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| 	uchar ctl2;
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| 
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| 	if (dm_i2c_read(dev, 0, buf, sizeof(buf))) {
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| 		printf("Error reading from RTC\n");
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| 		return -EIO;
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| 	}
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| 
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| 	ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
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| 	ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET);
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| 
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| 	if (dev->driver_data == model_rx_8035)
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| 		ctl2 &= ~(RTC_CTL2_BIT_XST);
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| 	else
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| 		ctl2 |= RTC_CTL2_BIT_XST;
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| 
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| 	return rtc_write(dev, RTC_CTL2_REG_ADDR, ctl2);
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| }
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| 
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| /*
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|  * Helper functions
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|  */
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| static int rtc_write(struct udevice *dev, uchar reg, uchar val)
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| {
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| 	/* The RX8025/RX8035 uses the top 4 bits of the
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| 	 * 'offset' byte as the start register address,
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| 	 * and the bottom 4 bits as a 'transfer' mode setting
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| 	 * (only applicable for reads)
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| 	 */
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| 	u8 offset = (reg << 4);
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| 
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| 	if (dm_i2c_reg_write(dev, offset, val)) {
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| 		printf("Error writing to RTC\n");
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| 		return -EIO;
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| static int rx8025_probe(struct udevice *dev)
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| {
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| 	uchar buf[16];
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| 	int ret = 0;
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| 
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| 	if (i2c_get_chip_offset_len(dev) != 1)
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| 		ret = i2c_set_chip_offset_len(dev, 1);
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| 
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| 	if (ret)
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| 		return ret;
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| 
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| 	return dm_i2c_read(dev, 0, buf, sizeof(buf));
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| }
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| 
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| static const struct rtc_ops rx8025_rtc_ops = {
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| 	.get = rx8025_rtc_get,
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| 	.set = rx8025_rtc_set,
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| 	.reset = rx8025_rtc_reset,
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| };
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| 
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| static const struct udevice_id rx8025_rtc_ids[] = {
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| 	{ .compatible = "epson,rx8025", .data = model_rx_8025 },
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| 	{ .compatible = "epson,rx8035", .data = model_rx_8035 },
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| 	{ }
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| };
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| 
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| U_BOOT_DRIVER(rx8025_rtc) = {
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| 	.name	  = "rx8025_rtc",
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| 	.id	      = UCLASS_RTC,
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| 	.probe    = rx8025_probe,
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| 	.of_match = rx8025_rtc_ids,
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| 	.ops	  = &rx8025_rtc_ops,
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| };
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