339 lines
8.9 KiB
C
339 lines
8.9 KiB
C
/*
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* rtc-tps80031.c -- TI TPS80031/TPS80032 RTC driver
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*
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* RTC driver for TI TPS80031/TPS80032 Fully Integrated
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* Power Management with Power Path and Battery Charger
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*
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* Copyright (c) 2012, NVIDIA Corporation.
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*
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* Author: Laxman Dewangan <ldewangan@nvidia.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
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* whether express or implied; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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* 02111-1307, USA
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*/
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#include <linux/bcd.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mfd/tps80031.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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#include <linux/rtc.h>
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#include <linux/slab.h>
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#define ENABLE_ALARM_INT 0x08
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#define ALARM_INT_STATUS 0x40
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/**
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* Setting bit to 1 in STOP_RTC will run the RTC and
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* setting this bit to 0 will freeze RTC.
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*/
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#define STOP_RTC 0x1
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/* Power on reset Values of RTC registers */
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#define TPS80031_RTC_POR_YEAR 0
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#define TPS80031_RTC_POR_MONTH 1
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#define TPS80031_RTC_POR_DAY 1
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/* Numbers of registers for time and alarms */
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#define TPS80031_RTC_TIME_NUM_REGS 7
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#define TPS80031_RTC_ALARM_NUM_REGS 6
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/**
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* PMU RTC have only 2 nibbles to store year information, so using an
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* offset of 100 to set the base year as 2000 for our driver.
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*/
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#define RTC_YEAR_OFFSET 100
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struct tps80031_rtc {
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struct rtc_device *rtc;
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int irq;
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};
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static int tps80031_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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u8 buff[TPS80031_RTC_TIME_NUM_REGS];
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int ret;
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ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
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TPS80031_SECONDS_REG, TPS80031_RTC_TIME_NUM_REGS, buff);
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if (ret < 0) {
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dev_err(dev, "reading RTC_SECONDS_REG failed, err = %d\n", ret);
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return ret;
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}
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tm->tm_sec = bcd2bin(buff[0]);
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tm->tm_min = bcd2bin(buff[1]);
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tm->tm_hour = bcd2bin(buff[2]);
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tm->tm_mday = bcd2bin(buff[3]);
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tm->tm_mon = bcd2bin(buff[4]) - 1;
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tm->tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
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tm->tm_wday = bcd2bin(buff[6]);
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return 0;
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}
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static int tps80031_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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u8 buff[7];
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int ret;
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buff[0] = bin2bcd(tm->tm_sec);
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buff[1] = bin2bcd(tm->tm_min);
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buff[2] = bin2bcd(tm->tm_hour);
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buff[3] = bin2bcd(tm->tm_mday);
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buff[4] = bin2bcd(tm->tm_mon + 1);
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buff[5] = bin2bcd(tm->tm_year % RTC_YEAR_OFFSET);
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buff[6] = bin2bcd(tm->tm_wday);
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/* Stop RTC while updating the RTC time registers */
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ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
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TPS80031_RTC_CTRL_REG, STOP_RTC);
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if (ret < 0) {
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dev_err(dev->parent, "Stop RTC failed, err = %d\n", ret);
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return ret;
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}
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ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
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TPS80031_SECONDS_REG,
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TPS80031_RTC_TIME_NUM_REGS, buff);
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if (ret < 0) {
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dev_err(dev, "writing RTC_SECONDS_REG failed, err %d\n", ret);
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return ret;
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}
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ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
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TPS80031_RTC_CTRL_REG, STOP_RTC);
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if (ret < 0)
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dev_err(dev->parent, "Start RTC failed, err = %d\n", ret);
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return ret;
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}
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static int tps80031_rtc_alarm_irq_enable(struct device *dev,
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unsigned int enable)
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{
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int ret;
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if (enable)
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ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
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TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
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else
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ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
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TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
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if (ret < 0) {
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dev_err(dev, "Update on RTC_INT failed, err = %d\n", ret);
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return ret;
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}
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return 0;
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}
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static int tps80031_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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u8 buff[TPS80031_RTC_ALARM_NUM_REGS];
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int ret;
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buff[0] = bin2bcd(alrm->time.tm_sec);
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buff[1] = bin2bcd(alrm->time.tm_min);
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buff[2] = bin2bcd(alrm->time.tm_hour);
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buff[3] = bin2bcd(alrm->time.tm_mday);
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buff[4] = bin2bcd(alrm->time.tm_mon + 1);
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buff[5] = bin2bcd(alrm->time.tm_year % RTC_YEAR_OFFSET);
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ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
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TPS80031_ALARM_SECONDS_REG,
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TPS80031_RTC_ALARM_NUM_REGS, buff);
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if (ret < 0) {
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dev_err(dev, "Writing RTC_ALARM failed, err %d\n", ret);
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return ret;
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}
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return tps80031_rtc_alarm_irq_enable(dev, alrm->enabled);
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}
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static int tps80031_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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u8 buff[6];
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int ret;
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ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
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TPS80031_ALARM_SECONDS_REG,
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TPS80031_RTC_ALARM_NUM_REGS, buff);
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if (ret < 0) {
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dev_err(dev->parent,
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"reading RTC_ALARM failed, err = %d\n", ret);
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return ret;
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}
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alrm->time.tm_sec = bcd2bin(buff[0]);
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alrm->time.tm_min = bcd2bin(buff[1]);
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alrm->time.tm_hour = bcd2bin(buff[2]);
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alrm->time.tm_mday = bcd2bin(buff[3]);
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alrm->time.tm_mon = bcd2bin(buff[4]) - 1;
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alrm->time.tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
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return 0;
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}
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static int clear_alarm_int_status(struct device *dev, struct tps80031_rtc *rtc)
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{
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int ret;
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u8 buf;
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/**
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* As per datasheet, A dummy read of this RTC_STATUS_REG register
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* is necessary before each I2C read in order to update the status
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* register value.
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*/
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ret = tps80031_read(dev->parent, TPS80031_SLAVE_ID1,
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TPS80031_RTC_STATUS_REG, &buf);
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if (ret < 0) {
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dev_err(dev, "reading RTC_STATUS failed. err = %d\n", ret);
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return ret;
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}
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/* clear Alarm status bits.*/
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ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
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TPS80031_RTC_STATUS_REG, ALARM_INT_STATUS);
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if (ret < 0) {
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dev_err(dev, "clear Alarm INT failed, err = %d\n", ret);
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return ret;
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}
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return 0;
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}
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static irqreturn_t tps80031_rtc_irq(int irq, void *data)
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{
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struct device *dev = data;
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struct tps80031_rtc *rtc = dev_get_drvdata(dev);
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int ret;
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ret = clear_alarm_int_status(dev, rtc);
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if (ret < 0)
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return ret;
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rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
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return IRQ_HANDLED;
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}
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static const struct rtc_class_ops tps80031_rtc_ops = {
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.read_time = tps80031_rtc_read_time,
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.set_time = tps80031_rtc_set_time,
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.set_alarm = tps80031_rtc_set_alarm,
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.read_alarm = tps80031_rtc_read_alarm,
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.alarm_irq_enable = tps80031_rtc_alarm_irq_enable,
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};
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static int tps80031_rtc_probe(struct platform_device *pdev)
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{
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struct tps80031_rtc *rtc;
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struct rtc_time tm;
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int ret;
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rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
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if (!rtc)
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return -ENOMEM;
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rtc->irq = platform_get_irq(pdev, 0);
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platform_set_drvdata(pdev, rtc);
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/* Start RTC */
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ret = tps80031_set_bits(pdev->dev.parent, TPS80031_SLAVE_ID1,
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TPS80031_RTC_CTRL_REG, STOP_RTC);
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if (ret < 0) {
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dev_err(&pdev->dev, "failed to start RTC. err = %d\n", ret);
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return ret;
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}
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/* If RTC have POR values, set time 01:01:2000 */
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tps80031_rtc_read_time(&pdev->dev, &tm);
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if ((tm.tm_year == RTC_YEAR_OFFSET + TPS80031_RTC_POR_YEAR) &&
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(tm.tm_mon == (TPS80031_RTC_POR_MONTH - 1)) &&
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(tm.tm_mday == TPS80031_RTC_POR_DAY)) {
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tm.tm_year = 2000;
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tm.tm_mday = 1;
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tm.tm_mon = 1;
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ret = tps80031_rtc_set_time(&pdev->dev, &tm);
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if (ret < 0) {
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dev_err(&pdev->dev,
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"RTC set time failed, err = %d\n", ret);
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return ret;
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}
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}
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/* Clear alarm intretupt status if it is there */
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ret = clear_alarm_int_status(&pdev->dev, rtc);
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if (ret < 0) {
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dev_err(&pdev->dev, "Clear alarm int failed, err = %d\n", ret);
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return ret;
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}
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rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
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&tps80031_rtc_ops, THIS_MODULE);
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if (IS_ERR(rtc->rtc)) {
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ret = PTR_ERR(rtc->rtc);
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dev_err(&pdev->dev, "RTC registration failed, err %d\n", ret);
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return ret;
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}
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ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
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tps80031_rtc_irq,
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IRQF_ONESHOT | IRQF_EARLY_RESUME,
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dev_name(&pdev->dev), rtc);
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if (ret < 0) {
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dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n",
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rtc->irq, ret);
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return ret;
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}
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device_set_wakeup_capable(&pdev->dev, 1);
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int tps80031_rtc_suspend(struct device *dev)
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{
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struct tps80031_rtc *rtc = dev_get_drvdata(dev);
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if (device_may_wakeup(dev))
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enable_irq_wake(rtc->irq);
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return 0;
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}
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static int tps80031_rtc_resume(struct device *dev)
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{
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struct tps80031_rtc *rtc = dev_get_drvdata(dev);
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if (device_may_wakeup(dev))
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disable_irq_wake(rtc->irq);
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return 0;
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};
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#endif
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static SIMPLE_DEV_PM_OPS(tps80031_pm_ops, tps80031_rtc_suspend,
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tps80031_rtc_resume);
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static struct platform_driver tps80031_rtc_driver = {
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.driver = {
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.name = "tps80031-rtc",
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.owner = THIS_MODULE,
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.pm = &tps80031_pm_ops,
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},
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.probe = tps80031_rtc_probe,
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};
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module_platform_driver(tps80031_rtc_driver);
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MODULE_ALIAS("platform:tps80031-rtc");
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MODULE_DESCRIPTION("TI TPS80031/TPS80032 RTC driver");
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MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
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MODULE_LICENSE("GPL v2");
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