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![Anthony Olech](/assets/img/avatar_default.png)
Setting the alarm to a time not on a minute boundary results in repeated interrupts being generated by the DA9052/3 PMIC device until the kernel RTC core sees that the alarm has rung. Sometimes the number and frequency of interrupts can cause the kernel to disable the IRQ line used by the DA9052/3 PMIC with disasterous consequences. This patch fixes the problem. Even though the DA9052/3 PMIC is capable generating periodic interrupts, ie TICKS, the method used to distinguish RTC_AF from RTC_PF events was flawed and can not work in conjunction with the regmap_irq kernel core. Thus that flawed detection has also been removed by the DA9052/3 PMIC RTC driver's irq handler, so that it no longer reports the wrong type of event to the kernel RTC core. The internal static functions within the DA9052/3 PMIC RTC driver have been changed to pass the 'da9052_rtc' structure instead of the 'da9052' because there is no backwards pointer from the 'da9052' structure. This patch fixes the three issues described above. The first is serious because usiing the RTC alarm set to a non minute boundary will eventually cause all component drivers that depend on the interrupt line to fail. The solution adopted is to round up to alarm time to the next highest minute. The second bug, reporting a RTC_PF event instead of an RTC_AF event turns out to not matter with the current implementation of the kernel RTC core as it seems to ignore the event type. However, should that change in the future it is better to fix the issue now and not have 'problems waiting to happen' The third set of changes are to make the da9052_rtc structure available to all the local internal functions in the driver. This was done during testing so that diagnostic data could be stored there. Should the solution to the first issue be found not acceptable, then the alternative of using the TICKS interrupt at the fixed one second interval in order to step to the exact second of the requested alarm requires an extra (alarm time) piece of data to be stored. In devices that use the alarm function to wake up from sleep, accuracy to the second will result in the device being awake for up to nearly a minute longer than expected. Signed-off-by: Anthony Olech <anthony.olech.opensource@diasemi.com> Cc: David Dajun Chen <dchen@diasemi.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>
277 lines
6.6 KiB
C
277 lines
6.6 KiB
C
/*
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* Real time clock driver for DA9052
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*
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* Copyright(c) 2012 Dialog Semiconductor Ltd.
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*
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* Author: Dajun Dajun Chen <dajun.chen@diasemi.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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*/
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/rtc.h>
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#include <linux/err.h>
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#include <linux/mfd/da9052/da9052.h>
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#include <linux/mfd/da9052/reg.h>
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#define rtc_err(rtc, fmt, ...) \
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dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)
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struct da9052_rtc {
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struct rtc_device *rtc;
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struct da9052 *da9052;
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};
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static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable)
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{
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int ret;
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if (enable) {
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ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
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DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON,
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DA9052_ALARM_Y_ALARM_ON);
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if (ret != 0)
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rtc_err(rtc, "Failed to enable ALM: %d\n", ret);
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} else {
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ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
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DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0);
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if (ret != 0)
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rtc_err(rtc, "Write error: %d\n", ret);
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}
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return ret;
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}
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static irqreturn_t da9052_rtc_irq(int irq, void *data)
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{
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struct da9052_rtc *rtc = data;
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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 int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
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{
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int ret;
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uint8_t v[5];
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ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, v);
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if (ret != 0) {
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rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
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return ret;
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}
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rtc_tm->tm_year = (v[4] & DA9052_RTC_YEAR) + 100;
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rtc_tm->tm_mon = (v[3] & DA9052_RTC_MONTH) - 1;
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rtc_tm->tm_mday = v[2] & DA9052_RTC_DAY;
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rtc_tm->tm_hour = v[1] & DA9052_RTC_HOUR;
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rtc_tm->tm_min = v[0] & DA9052_RTC_MIN;
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ret = rtc_valid_tm(rtc_tm);
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return ret;
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}
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static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
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{
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struct da9052 *da9052 = rtc->da9052;
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unsigned long alm_time;
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int ret;
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uint8_t v[3];
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ret = rtc_tm_to_time(rtc_tm, &alm_time);
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if (ret != 0)
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return ret;
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if (rtc_tm->tm_sec > 0) {
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alm_time += 60 - rtc_tm->tm_sec;
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rtc_time_to_tm(alm_time, rtc_tm);
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}
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BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
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rtc_tm->tm_year -= 100;
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rtc_tm->tm_mon += 1;
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ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
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DA9052_RTC_MIN, rtc_tm->tm_min);
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if (ret != 0) {
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rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret);
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return ret;
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}
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v[0] = rtc_tm->tm_hour;
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v[1] = rtc_tm->tm_mday;
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v[2] = rtc_tm->tm_mon;
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ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
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if (ret < 0)
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return ret;
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ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
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DA9052_RTC_YEAR, rtc_tm->tm_year);
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if (ret != 0)
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rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret);
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return ret;
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}
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static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
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{
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int ret;
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ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
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if (ret < 0) {
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rtc_err(rtc, "Failed to read ALM: %d\n", ret);
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return ret;
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}
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return !!(ret&DA9052_ALARM_Y_ALARM_ON);
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}
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static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
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{
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struct da9052_rtc *rtc = dev_get_drvdata(dev);
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uint8_t v[6];
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int ret;
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ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
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if (ret < 0) {
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rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
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return ret;
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}
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rtc_tm->tm_year = (v[5] & DA9052_RTC_YEAR) + 100;
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rtc_tm->tm_mon = (v[4] & DA9052_RTC_MONTH) - 1;
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rtc_tm->tm_mday = v[3] & DA9052_RTC_DAY;
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rtc_tm->tm_hour = v[2] & DA9052_RTC_HOUR;
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rtc_tm->tm_min = v[1] & DA9052_RTC_MIN;
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rtc_tm->tm_sec = v[0] & DA9052_RTC_SEC;
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ret = rtc_valid_tm(rtc_tm);
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return ret;
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}
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static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct da9052_rtc *rtc;
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uint8_t v[6];
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int ret;
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rtc = dev_get_drvdata(dev);
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v[0] = tm->tm_sec;
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v[1] = tm->tm_min;
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v[2] = tm->tm_hour;
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v[3] = tm->tm_mday;
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v[4] = tm->tm_mon + 1;
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v[5] = tm->tm_year - 100;
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ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
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if (ret < 0)
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rtc_err(rtc, "failed to set RTC time: %d\n", ret);
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return ret;
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}
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static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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int ret;
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struct rtc_time *tm = &alrm->time;
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struct da9052_rtc *rtc = dev_get_drvdata(dev);
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ret = da9052_read_alarm(rtc, tm);
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if (ret < 0) {
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rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
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return ret;
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}
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alrm->enabled = da9052_rtc_get_alarm_status(rtc);
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return 0;
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}
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static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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int ret;
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struct rtc_time *tm = &alrm->time;
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struct da9052_rtc *rtc = dev_get_drvdata(dev);
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ret = da9052_rtc_enable_alarm(rtc, 0);
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if (ret < 0)
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return ret;
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ret = da9052_set_alarm(rtc, tm);
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if (ret < 0)
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return ret;
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ret = da9052_rtc_enable_alarm(rtc, 1);
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return ret;
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}
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static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
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{
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struct da9052_rtc *rtc = dev_get_drvdata(dev);
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return da9052_rtc_enable_alarm(rtc, enabled);
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}
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static const struct rtc_class_ops da9052_rtc_ops = {
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.read_time = da9052_rtc_read_time,
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.set_time = da9052_rtc_set_time,
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.read_alarm = da9052_rtc_read_alarm,
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.set_alarm = da9052_rtc_set_alarm,
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.alarm_irq_enable = da9052_rtc_alarm_irq_enable,
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};
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static int da9052_rtc_probe(struct platform_device *pdev)
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{
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struct da9052_rtc *rtc;
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int ret;
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rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
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if (!rtc)
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return -ENOMEM;
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rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
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platform_set_drvdata(pdev, rtc);
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ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
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if (ret < 0) {
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rtc_err(rtc,
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"Failed to setup RTC battery charging: %d\n", ret);
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return ret;
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}
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ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
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DA9052_ALARM_Y_TICK_ON, 0);
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if (ret != 0)
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rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
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ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
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da9052_rtc_irq, rtc);
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if (ret != 0) {
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rtc_err(rtc, "irq registration failed: %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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&da9052_rtc_ops, THIS_MODULE);
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return PTR_ERR_OR_ZERO(rtc->rtc);
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}
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static struct platform_driver da9052_rtc_driver = {
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.probe = da9052_rtc_probe,
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.driver = {
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.name = "da9052-rtc",
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.owner = THIS_MODULE,
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},
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};
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module_platform_driver(da9052_rtc_driver);
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MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
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MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:da9052-rtc");
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