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![Thierry Reding](/assets/img/avatar_default.png)
The interrupt handler gets the driver data associated with the RTC device and doesn't check it for validity. This can cause a NULL pointer being dereferenced when and interrupt fires before the driver data was properly set up. Fix this by setting the driver data earlier (before the interrupt is requested). Signed-off-by: Thierry Reding <treding@nvidia.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
338 lines
8.6 KiB
C
338 lines
8.6 KiB
C
/*
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* rtc-tps65910.c -- TPS65910 Real Time Clock interface
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*
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* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
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* Author: Venu Byravarasu <vbyravarasu@nvidia.com>
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*
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* Based on original TI driver rtc-twl.c
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* Copyright (C) 2007 MontaVista Software, Inc
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* Author: Alexandre Rusev <source@mvista.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
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/rtc.h>
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#include <linux/bcd.h>
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#include <linux/platform_device.h>
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#include <linux/interrupt.h>
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#include <linux/mfd/tps65910.h>
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struct tps65910_rtc {
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struct rtc_device *rtc;
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int irq;
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};
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/* Total number of RTC registers needed to set time*/
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#define NUM_TIME_REGS (TPS65910_YEARS - TPS65910_SECONDS + 1)
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static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
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{
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struct tps65910 *tps = dev_get_drvdata(dev->parent);
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u8 val = 0;
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if (enabled)
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val = TPS65910_RTC_INTERRUPTS_IT_ALARM;
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return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val);
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}
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/*
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* Gets current tps65910 RTC time and date parameters.
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*
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* The RTC's time/alarm representation is not what gmtime(3) requires
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* Linux to use:
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*
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* - Months are 1..12 vs Linux 0-11
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* - Years are 0..99 vs Linux 1900..N (we assume 21st century)
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*/
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static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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unsigned char rtc_data[NUM_TIME_REGS];
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struct tps65910 *tps = dev_get_drvdata(dev->parent);
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int ret;
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/* Copy RTC counting registers to static registers or latches */
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ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
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TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME);
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if (ret < 0) {
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dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret);
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return ret;
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}
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ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data,
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NUM_TIME_REGS);
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if (ret < 0) {
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dev_err(dev, "reading from RTC failed with err:%d\n", ret);
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return ret;
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}
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tm->tm_sec = bcd2bin(rtc_data[0]);
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tm->tm_min = bcd2bin(rtc_data[1]);
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tm->tm_hour = bcd2bin(rtc_data[2]);
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tm->tm_mday = bcd2bin(rtc_data[3]);
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tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
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tm->tm_year = bcd2bin(rtc_data[5]) + 100;
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return ret;
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}
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static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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unsigned char rtc_data[NUM_TIME_REGS];
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struct tps65910 *tps = dev_get_drvdata(dev->parent);
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int ret;
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rtc_data[0] = bin2bcd(tm->tm_sec);
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rtc_data[1] = bin2bcd(tm->tm_min);
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rtc_data[2] = bin2bcd(tm->tm_hour);
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rtc_data[3] = bin2bcd(tm->tm_mday);
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rtc_data[4] = bin2bcd(tm->tm_mon + 1);
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rtc_data[5] = bin2bcd(tm->tm_year - 100);
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/* Stop RTC while updating the RTC time registers */
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ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
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TPS65910_RTC_CTRL_STOP_RTC, 0);
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if (ret < 0) {
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dev_err(dev, "RTC stop failed with err:%d\n", ret);
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return ret;
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}
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/* update all the time registers in one shot */
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ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data,
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NUM_TIME_REGS);
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if (ret < 0) {
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dev_err(dev, "rtc_set_time error %d\n", ret);
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return ret;
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}
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/* Start back RTC */
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ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
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TPS65910_RTC_CTRL_STOP_RTC, 1);
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if (ret < 0)
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dev_err(dev, "RTC start failed with err:%d\n", ret);
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return ret;
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}
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/*
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* Gets current tps65910 RTC alarm time.
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*/
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static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
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{
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unsigned char alarm_data[NUM_TIME_REGS];
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u32 int_val;
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struct tps65910 *tps = dev_get_drvdata(dev->parent);
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int ret;
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ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, alarm_data,
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NUM_TIME_REGS);
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if (ret < 0) {
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dev_err(dev, "rtc_read_alarm error %d\n", ret);
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return ret;
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}
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alm->time.tm_sec = bcd2bin(alarm_data[0]);
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alm->time.tm_min = bcd2bin(alarm_data[1]);
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alm->time.tm_hour = bcd2bin(alarm_data[2]);
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alm->time.tm_mday = bcd2bin(alarm_data[3]);
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alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
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alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
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ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val);
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if (ret < 0)
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return ret;
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if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM)
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alm->enabled = 1;
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return ret;
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}
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static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
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{
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unsigned char alarm_data[NUM_TIME_REGS];
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struct tps65910 *tps = dev_get_drvdata(dev->parent);
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int ret;
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ret = tps65910_rtc_alarm_irq_enable(dev, 0);
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if (ret)
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return ret;
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alarm_data[0] = bin2bcd(alm->time.tm_sec);
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alarm_data[1] = bin2bcd(alm->time.tm_min);
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alarm_data[2] = bin2bcd(alm->time.tm_hour);
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alarm_data[3] = bin2bcd(alm->time.tm_mday);
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alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
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alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
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/* update all the alarm registers in one shot */
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ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS,
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alarm_data, NUM_TIME_REGS);
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if (ret) {
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dev_err(dev, "rtc_set_alarm error %d\n", ret);
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return ret;
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}
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if (alm->enabled)
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ret = tps65910_rtc_alarm_irq_enable(dev, 1);
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return ret;
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}
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static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc)
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{
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struct device *dev = rtc;
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unsigned long events = 0;
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struct tps65910 *tps = dev_get_drvdata(dev->parent);
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struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
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int ret;
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u32 rtc_reg;
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ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg);
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if (ret)
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return IRQ_NONE;
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if (rtc_reg & TPS65910_RTC_STATUS_ALARM)
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events = RTC_IRQF | RTC_AF;
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ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg);
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if (ret)
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return IRQ_NONE;
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/* Notify RTC core on event */
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rtc_update_irq(tps_rtc->rtc, 1, events);
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return IRQ_HANDLED;
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}
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static const struct rtc_class_ops tps65910_rtc_ops = {
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.read_time = tps65910_rtc_read_time,
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.set_time = tps65910_rtc_set_time,
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.read_alarm = tps65910_rtc_read_alarm,
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.set_alarm = tps65910_rtc_set_alarm,
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.alarm_irq_enable = tps65910_rtc_alarm_irq_enable,
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};
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static int tps65910_rtc_probe(struct platform_device *pdev)
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{
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struct tps65910 *tps65910 = NULL;
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struct tps65910_rtc *tps_rtc = NULL;
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int ret;
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int irq;
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u32 rtc_reg;
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tps65910 = dev_get_drvdata(pdev->dev.parent);
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tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc),
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GFP_KERNEL);
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if (!tps_rtc)
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return -ENOMEM;
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/* Clear pending interrupts */
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ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg);
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if (ret < 0)
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return ret;
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ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg);
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if (ret < 0)
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return ret;
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dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n");
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/* Enable RTC digital power domain */
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ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL,
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DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT);
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if (ret < 0)
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return ret;
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rtc_reg = TPS65910_RTC_CTRL_STOP_RTC;
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ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg);
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if (ret < 0)
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return ret;
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platform_set_drvdata(pdev, tps_rtc);
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irq = platform_get_irq(pdev, 0);
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if (irq <= 0) {
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dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n",
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irq);
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return -ENXIO;
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}
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ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
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tps65910_rtc_interrupt, IRQF_TRIGGER_LOW | IRQF_EARLY_RESUME,
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dev_name(&pdev->dev), &pdev->dev);
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if (ret < 0) {
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dev_err(&pdev->dev, "IRQ is not free.\n");
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return ret;
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}
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tps_rtc->irq = irq;
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device_set_wakeup_capable(&pdev->dev, 1);
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tps_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
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&tps65910_rtc_ops, THIS_MODULE);
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if (IS_ERR(tps_rtc->rtc)) {
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ret = PTR_ERR(tps_rtc->rtc);
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dev_err(&pdev->dev, "RTC device register: 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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/*
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* Disable tps65910 RTC interrupts.
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* Sets status flag to free.
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*/
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static int tps65910_rtc_remove(struct platform_device *pdev)
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{
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tps65910_rtc_alarm_irq_enable(&pdev->dev, 0);
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int tps65910_rtc_suspend(struct device *dev)
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{
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struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
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if (device_may_wakeup(dev))
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enable_irq_wake(tps_rtc->irq);
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return 0;
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}
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static int tps65910_rtc_resume(struct device *dev)
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{
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struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
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if (device_may_wakeup(dev))
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disable_irq_wake(tps_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(tps65910_rtc_pm_ops, tps65910_rtc_suspend,
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tps65910_rtc_resume);
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static struct platform_driver tps65910_rtc_driver = {
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.probe = tps65910_rtc_probe,
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.remove = tps65910_rtc_remove,
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.driver = {
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.owner = THIS_MODULE,
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.name = "tps65910-rtc",
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.pm = &tps65910_rtc_pm_ops,
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},
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};
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module_platform_driver(tps65910_rtc_driver);
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MODULE_ALIAS("platform:rtc-tps65910");
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MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
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MODULE_LICENSE("GPL");
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