384 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			384 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| /*
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|  * Real Time Clock driver for Marvell 88PM860x PMIC
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|  *
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|  * Copyright (c) 2010 Marvell International Ltd.
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|  * Author:	Haojian Zhuang <haojian.zhuang@marvell.com>
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|  */
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| 
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| #include <linux/kernel.h>
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| #include <linux/module.h>
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| #include <linux/of.h>
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| #include <linux/platform_device.h>
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| #include <linux/slab.h>
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| #include <linux/mutex.h>
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| #include <linux/rtc.h>
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| #include <linux/delay.h>
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| #include <linux/mfd/core.h>
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| #include <linux/mfd/88pm860x.h>
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| 
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| #define VRTC_CALIBRATION
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| 
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| struct pm860x_rtc_info {
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| 	struct pm860x_chip	*chip;
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| 	struct i2c_client	*i2c;
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| 	struct rtc_device	*rtc_dev;
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| 	struct device		*dev;
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| 	struct delayed_work	calib_work;
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| 
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| 	int			irq;
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| 	int			vrtc;
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| };
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| 
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| #define REG_VRTC_MEAS1		0x7D
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| 
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| #define REG0_ADDR		0xB0
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| #define REG1_ADDR		0xB2
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| #define REG2_ADDR		0xB4
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| #define REG3_ADDR		0xB6
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| 
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| #define REG0_DATA		0xB1
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| #define REG1_DATA		0xB3
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| #define REG2_DATA		0xB5
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| #define REG3_DATA		0xB7
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| 
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| /* bit definitions of Measurement Enable Register 2 (0x51) */
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| #define MEAS2_VRTC		(1 << 0)
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| 
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| /* bit definitions of RTC Register 1 (0xA0) */
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| #define ALARM_EN		(1 << 3)
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| #define ALARM_WAKEUP		(1 << 4)
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| #define ALARM			(1 << 5)
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| #define RTC1_USE_XO		(1 << 7)
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| 
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| #define VRTC_CALIB_INTERVAL	(HZ * 60 * 10)		/* 10 minutes */
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| 
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| static irqreturn_t rtc_update_handler(int irq, void *data)
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| {
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| 	struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
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| 	int mask;
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| 
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| 	mask = ALARM | ALARM_WAKEUP;
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| 	pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
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| 	rtc_update_irq(info->rtc_dev, 1, RTC_AF);
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| 	return IRQ_HANDLED;
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| }
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| 
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| static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
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| {
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| 	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
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| 
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| 	if (enabled)
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| 		pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN);
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| 	else
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| 		pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
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| 	return 0;
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| }
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| 
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| static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
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| {
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| 	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
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| 	unsigned char buf[8];
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| 	unsigned long ticks, base, data;
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| 
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| 	pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
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| 	dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
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| 		buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
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| 	base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
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| 		(buf[5] << 8) | buf[7];
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| 
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| 	/* load 32-bit read-only counter */
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| 	pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
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| 	data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
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| 		(buf[1] << 8) | buf[0];
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| 	ticks = base + data;
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| 	dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
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| 		base, data, ticks);
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| 
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| 	rtc_time64_to_tm(ticks, tm);
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| 
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| 	return 0;
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| }
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| 
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| static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
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| {
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| 	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
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| 	unsigned char buf[4];
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| 	unsigned long ticks, base, data;
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| 
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| 	ticks = rtc_tm_to_time64(tm);
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| 
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| 	/* load 32-bit read-only counter */
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| 	pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
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| 	data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
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| 		(buf[1] << 8) | buf[0];
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| 	base = ticks - data;
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| 	dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
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| 		base, data, ticks);
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| 
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| 	pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
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| 	pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
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| 	pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
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| 	pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
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| 
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| 	return 0;
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| }
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| 
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| static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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| {
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| 	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
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| 	unsigned char buf[8];
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| 	unsigned long ticks, base, data;
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| 	int ret;
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| 
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| 	pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
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| 	dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
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| 		buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
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| 	base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
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| 		(buf[5] << 8) | buf[7];
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| 
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| 	pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
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| 	data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
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| 		(buf[1] << 8) | buf[0];
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| 	ticks = base + data;
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| 	dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
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| 		base, data, ticks);
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| 
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| 	rtc_time64_to_tm(ticks, &alrm->time);
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| 	ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
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| 	alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
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| 	alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
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| 	return 0;
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| }
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| 
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| static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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| {
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| 	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
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| 	unsigned long ticks, base, data;
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| 	unsigned char buf[8];
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| 	int mask;
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| 
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| 	pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
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| 
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| 	pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
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| 	dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
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| 		buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
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| 	base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
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| 		(buf[5] << 8) | buf[7];
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| 
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| 	ticks = rtc_tm_to_time64(&alrm->time);
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| 	data = ticks - base;
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| 
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| 	buf[0] = data & 0xff;
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| 	buf[1] = (data >> 8) & 0xff;
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| 	buf[2] = (data >> 16) & 0xff;
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| 	buf[3] = (data >> 24) & 0xff;
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| 	pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
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| 	if (alrm->enabled) {
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| 		mask = ALARM | ALARM_WAKEUP | ALARM_EN;
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| 		pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
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| 	} else {
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| 		mask = ALARM | ALARM_WAKEUP | ALARM_EN;
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| 		pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
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| 				ALARM | ALARM_WAKEUP);
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| 	}
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| 	return 0;
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| }
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| 
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| static const struct rtc_class_ops pm860x_rtc_ops = {
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| 	.read_time	= pm860x_rtc_read_time,
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| 	.set_time	= pm860x_rtc_set_time,
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| 	.read_alarm	= pm860x_rtc_read_alarm,
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| 	.set_alarm	= pm860x_rtc_set_alarm,
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| 	.alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
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| };
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| 
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| #ifdef VRTC_CALIBRATION
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| static void calibrate_vrtc_work(struct work_struct *work)
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| {
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| 	struct pm860x_rtc_info *info = container_of(work,
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| 		struct pm860x_rtc_info, calib_work.work);
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| 	unsigned char buf[2];
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| 	unsigned int sum, data, mean, vrtc_set;
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| 	int i;
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| 
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| 	for (i = 0, sum = 0; i < 16; i++) {
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| 		msleep(100);
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| 		pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
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| 		data = (buf[0] << 4) | buf[1];
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| 		data = (data * 5400) >> 12;	/* convert to mv */
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| 		sum += data;
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| 	}
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| 	mean = sum >> 4;
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| 	vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
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| 	dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);
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| 
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| 	sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
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| 	data = sum & 0x3;
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| 	if ((mean + 200) < vrtc_set) {
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| 		/* try higher voltage */
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| 		if (++data == 4)
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| 			goto out;
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| 		data = (sum & 0xf8) | (data & 0x3);
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| 		pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
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| 	} else if ((mean - 200) > vrtc_set) {
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| 		/* try lower voltage */
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| 		if (data-- == 0)
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| 			goto out;
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| 		data = (sum & 0xf8) | (data & 0x3);
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| 		pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
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| 	} else
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| 		goto out;
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| 	dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
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| 	/* trigger next calibration since VRTC is updated */
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| 	schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
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| 	return;
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| out:
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| 	/* disable measurement */
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| 	pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
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| 	dev_dbg(info->dev, "finish VRTC calibration\n");
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| 	return;
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| }
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| #endif
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| 
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| #ifdef CONFIG_OF
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| static int pm860x_rtc_dt_init(struct platform_device *pdev,
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| 			      struct pm860x_rtc_info *info)
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| {
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| 	struct device_node *np = pdev->dev.parent->of_node;
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| 	int ret;
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| 	if (!np)
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| 		return -ENODEV;
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| 	np = of_get_child_by_name(np, "rtc");
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| 	if (!np) {
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| 		dev_err(&pdev->dev, "failed to find rtc node\n");
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| 		return -ENODEV;
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| 	}
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| 	ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc);
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| 	if (ret)
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| 		info->vrtc = 0;
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| 	of_node_put(np);
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| 	return 0;
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| }
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| #else
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| #define pm860x_rtc_dt_init(x, y)	do { } while (0)
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| #endif
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| 
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| static int pm860x_rtc_probe(struct platform_device *pdev)
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| {
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| 	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
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| 	struct pm860x_rtc_info *info;
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| 	int ret;
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| 
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| 	info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info),
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| 			    GFP_KERNEL);
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| 	if (!info)
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| 		return -ENOMEM;
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| 	info->irq = platform_get_irq(pdev, 0);
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| 	if (info->irq < 0)
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| 		return info->irq;
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| 
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| 	info->chip = chip;
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| 	info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
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| 	info->dev = &pdev->dev;
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| 	dev_set_drvdata(&pdev->dev, info);
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| 
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| 	info->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
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| 	if (IS_ERR(info->rtc_dev))
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| 		return PTR_ERR(info->rtc_dev);
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| 
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| 	ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
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| 					rtc_update_handler, IRQF_ONESHOT, "rtc",
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| 					info);
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| 	if (ret < 0) {
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| 		dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
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| 			info->irq, ret);
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| 		return ret;
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| 	}
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| 
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| 	/* set addresses of 32-bit base value for RTC time */
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| 	pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
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| 	pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
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| 	pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
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| 	pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
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| 
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| 	pm860x_rtc_dt_init(pdev, info);
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| 
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| 	info->rtc_dev->ops = &pm860x_rtc_ops;
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| 	info->rtc_dev->range_max = U32_MAX;
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| 
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| 	ret = devm_rtc_register_device(info->rtc_dev);
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| 	if (ret)
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| 		return ret;
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| 
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| 	/*
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| 	 * enable internal XO instead of internal 3.25MHz clock since it can
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| 	 * free running in PMIC power-down state.
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| 	 */
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| 	pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);
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| 
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| #ifdef VRTC_CALIBRATION
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| 	/* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
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| 	pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);
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| 
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| 	/* calibrate VRTC */
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| 	INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
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| 	schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
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| #endif	/* VRTC_CALIBRATION */
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| 
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| 	device_init_wakeup(&pdev->dev, 1);
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| 
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| 	return 0;
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| }
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| 
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| static int pm860x_rtc_remove(struct platform_device *pdev)
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| {
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| 	struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
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| 
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| #ifdef VRTC_CALIBRATION
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| 	cancel_delayed_work_sync(&info->calib_work);
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| 	/* disable measurement */
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| 	pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
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| #endif	/* VRTC_CALIBRATION */
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| 
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| 	return 0;
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| }
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| 
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| #ifdef CONFIG_PM_SLEEP
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| static int pm860x_rtc_suspend(struct device *dev)
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| {
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| 	struct platform_device *pdev = to_platform_device(dev);
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| 	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
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| 
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| 	if (device_may_wakeup(dev))
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| 		chip->wakeup_flag |= 1 << PM8607_IRQ_RTC;
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| 	return 0;
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| }
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| static int pm860x_rtc_resume(struct device *dev)
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| {
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| 	struct platform_device *pdev = to_platform_device(dev);
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| 	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
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| 
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| 	if (device_may_wakeup(dev))
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| 		chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC);
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| 	return 0;
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| }
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| #endif
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| 
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| static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume);
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| 
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| static struct platform_driver pm860x_rtc_driver = {
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| 	.driver		= {
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| 		.name	= "88pm860x-rtc",
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| 		.pm	= &pm860x_rtc_pm_ops,
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| 	},
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| 	.probe		= pm860x_rtc_probe,
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| 	.remove		= pm860x_rtc_remove,
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| };
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| 
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| module_platform_driver(pm860x_rtc_driver);
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| 
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| MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
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| MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
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| MODULE_LICENSE("GPL");
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