482 lines
11 KiB
C
482 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Real Time Clock driver for Wolfson Microelectronics WM8350
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*
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* Copyright (C) 2007, 2008 Wolfson Microelectronics PLC.
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*
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* Author: Liam Girdwood
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* linux@wolfsonmicro.com
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/time.h>
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#include <linux/rtc.h>
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#include <linux/bcd.h>
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#include <linux/interrupt.h>
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#include <linux/ioctl.h>
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#include <linux/completion.h>
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#include <linux/mfd/wm8350/rtc.h>
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#include <linux/mfd/wm8350/core.h>
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#include <linux/delay.h>
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#include <linux/platform_device.h>
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#define WM8350_SET_ALM_RETRIES 5
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#define WM8350_SET_TIME_RETRIES 5
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#define WM8350_GET_TIME_RETRIES 5
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/*
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* Read current time and date in RTC
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*/
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static int wm8350_rtc_readtime(struct device *dev, struct rtc_time *tm)
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{
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struct wm8350 *wm8350 = dev_get_drvdata(dev);
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u16 time1[4], time2[4];
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int retries = WM8350_GET_TIME_RETRIES, ret;
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/*
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* Read the time twice and compare.
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* If time1 == time2, then time is valid else retry.
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*/
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do {
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ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,
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4, time1);
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if (ret < 0)
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return ret;
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ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,
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4, time2);
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if (ret < 0)
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return ret;
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if (memcmp(time1, time2, sizeof(time1)) == 0) {
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tm->tm_sec = time1[0] & WM8350_RTC_SECS_MASK;
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tm->tm_min = (time1[0] & WM8350_RTC_MINS_MASK)
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>> WM8350_RTC_MINS_SHIFT;
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tm->tm_hour = time1[1] & WM8350_RTC_HRS_MASK;
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tm->tm_wday = ((time1[1] >> WM8350_RTC_DAY_SHIFT)
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& 0x7) - 1;
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tm->tm_mon = ((time1[2] & WM8350_RTC_MTH_MASK)
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>> WM8350_RTC_MTH_SHIFT) - 1;
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tm->tm_mday = (time1[2] & WM8350_RTC_DATE_MASK);
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tm->tm_year = ((time1[3] & WM8350_RTC_YHUNDREDS_MASK)
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>> WM8350_RTC_YHUNDREDS_SHIFT) * 100;
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tm->tm_year += time1[3] & WM8350_RTC_YUNITS_MASK;
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tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon,
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tm->tm_year);
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tm->tm_year -= 1900;
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dev_dbg(dev, "Read (%d left): %04x %04x %04x %04x\n",
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retries,
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time1[0], time1[1], time1[2], time1[3]);
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return 0;
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}
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} while (retries--);
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dev_err(dev, "timed out reading RTC time\n");
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return -EIO;
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}
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/*
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* Set current time and date in RTC
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*/
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static int wm8350_rtc_settime(struct device *dev, struct rtc_time *tm)
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{
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struct wm8350 *wm8350 = dev_get_drvdata(dev);
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u16 time[4];
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u16 rtc_ctrl;
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int ret, retries = WM8350_SET_TIME_RETRIES;
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time[0] = tm->tm_sec;
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time[0] |= tm->tm_min << WM8350_RTC_MINS_SHIFT;
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time[1] = tm->tm_hour;
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time[1] |= (tm->tm_wday + 1) << WM8350_RTC_DAY_SHIFT;
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time[2] = tm->tm_mday;
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time[2] |= (tm->tm_mon + 1) << WM8350_RTC_MTH_SHIFT;
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time[3] = ((tm->tm_year + 1900) / 100) << WM8350_RTC_YHUNDREDS_SHIFT;
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time[3] |= (tm->tm_year + 1900) % 100;
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dev_dbg(dev, "Setting: %04x %04x %04x %04x\n",
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time[0], time[1], time[2], time[3]);
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/* Set RTC_SET to stop the clock */
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ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL, WM8350_RTC_SET);
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if (ret < 0)
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return ret;
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/* Wait until confirmation of stopping */
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do {
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rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
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schedule_timeout_uninterruptible(msecs_to_jiffies(1));
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} while (--retries && !(rtc_ctrl & WM8350_RTC_STS));
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if (!retries) {
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dev_err(dev, "timed out on set confirmation\n");
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return -EIO;
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}
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/* Write time to RTC */
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ret = wm8350_block_write(wm8350, WM8350_RTC_SECONDS_MINUTES, 4, time);
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if (ret < 0)
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return ret;
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/* Clear RTC_SET to start the clock */
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ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
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WM8350_RTC_SET);
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return ret;
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}
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/*
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* Read alarm time and date in RTC
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*/
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static int wm8350_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct wm8350 *wm8350 = dev_get_drvdata(dev);
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struct rtc_time *tm = &alrm->time;
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u16 time[4];
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int ret;
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ret = wm8350_block_read(wm8350, WM8350_ALARM_SECONDS_MINUTES, 4, time);
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if (ret < 0)
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return ret;
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tm->tm_sec = time[0] & WM8350_RTC_ALMSECS_MASK;
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if (tm->tm_sec == WM8350_RTC_ALMSECS_MASK)
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tm->tm_sec = -1;
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tm->tm_min = time[0] & WM8350_RTC_ALMMINS_MASK;
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if (tm->tm_min == WM8350_RTC_ALMMINS_MASK)
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tm->tm_min = -1;
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else
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tm->tm_min >>= WM8350_RTC_ALMMINS_SHIFT;
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tm->tm_hour = time[1] & WM8350_RTC_ALMHRS_MASK;
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if (tm->tm_hour == WM8350_RTC_ALMHRS_MASK)
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tm->tm_hour = -1;
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tm->tm_wday = ((time[1] >> WM8350_RTC_ALMDAY_SHIFT) & 0x7) - 1;
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if (tm->tm_wday > 7)
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tm->tm_wday = -1;
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tm->tm_mon = time[2] & WM8350_RTC_ALMMTH_MASK;
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if (tm->tm_mon == WM8350_RTC_ALMMTH_MASK)
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tm->tm_mon = -1;
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else
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tm->tm_mon = (tm->tm_mon >> WM8350_RTC_ALMMTH_SHIFT) - 1;
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tm->tm_mday = (time[2] & WM8350_RTC_ALMDATE_MASK);
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if (tm->tm_mday == WM8350_RTC_ALMDATE_MASK)
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tm->tm_mday = -1;
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tm->tm_year = -1;
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alrm->enabled = !(time[3] & WM8350_RTC_ALMSTS);
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return 0;
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}
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static int wm8350_rtc_stop_alarm(struct wm8350 *wm8350)
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{
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int retries = WM8350_SET_ALM_RETRIES;
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u16 rtc_ctrl;
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int ret;
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/* Set RTC_SET to stop the clock */
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ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,
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WM8350_RTC_ALMSET);
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if (ret < 0)
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return ret;
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/* Wait until confirmation of stopping */
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do {
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rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
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schedule_timeout_uninterruptible(msecs_to_jiffies(1));
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} while (retries-- && !(rtc_ctrl & WM8350_RTC_ALMSTS));
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if (!(rtc_ctrl & WM8350_RTC_ALMSTS))
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return -ETIMEDOUT;
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return 0;
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}
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static int wm8350_rtc_start_alarm(struct wm8350 *wm8350)
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{
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int ret;
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int retries = WM8350_SET_ALM_RETRIES;
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u16 rtc_ctrl;
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ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
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WM8350_RTC_ALMSET);
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if (ret < 0)
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return ret;
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/* Wait until confirmation */
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do {
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rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
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schedule_timeout_uninterruptible(msecs_to_jiffies(1));
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} while (retries-- && rtc_ctrl & WM8350_RTC_ALMSTS);
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if (rtc_ctrl & WM8350_RTC_ALMSTS)
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return -ETIMEDOUT;
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return 0;
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}
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static int wm8350_rtc_alarm_irq_enable(struct device *dev,
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unsigned int enabled)
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{
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struct wm8350 *wm8350 = dev_get_drvdata(dev);
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if (enabled)
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return wm8350_rtc_start_alarm(wm8350);
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else
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return wm8350_rtc_stop_alarm(wm8350);
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}
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static int wm8350_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct wm8350 *wm8350 = dev_get_drvdata(dev);
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struct rtc_time *tm = &alrm->time;
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u16 time[3];
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int ret;
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memset(time, 0, sizeof(time));
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if (tm->tm_sec != -1)
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time[0] |= tm->tm_sec;
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else
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time[0] |= WM8350_RTC_ALMSECS_MASK;
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if (tm->tm_min != -1)
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time[0] |= tm->tm_min << WM8350_RTC_ALMMINS_SHIFT;
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else
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time[0] |= WM8350_RTC_ALMMINS_MASK;
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if (tm->tm_hour != -1)
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time[1] |= tm->tm_hour;
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else
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time[1] |= WM8350_RTC_ALMHRS_MASK;
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if (tm->tm_wday != -1)
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time[1] |= (tm->tm_wday + 1) << WM8350_RTC_ALMDAY_SHIFT;
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else
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time[1] |= WM8350_RTC_ALMDAY_MASK;
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if (tm->tm_mday != -1)
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time[2] |= tm->tm_mday;
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else
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time[2] |= WM8350_RTC_ALMDATE_MASK;
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if (tm->tm_mon != -1)
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time[2] |= (tm->tm_mon + 1) << WM8350_RTC_ALMMTH_SHIFT;
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else
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time[2] |= WM8350_RTC_ALMMTH_MASK;
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ret = wm8350_rtc_stop_alarm(wm8350);
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if (ret < 0)
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return ret;
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/* Write time to RTC */
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ret = wm8350_block_write(wm8350, WM8350_ALARM_SECONDS_MINUTES,
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3, time);
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if (ret < 0)
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return ret;
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if (alrm->enabled)
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ret = wm8350_rtc_start_alarm(wm8350);
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return ret;
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}
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static irqreturn_t wm8350_rtc_alarm_handler(int irq, void *data)
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{
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struct wm8350 *wm8350 = data;
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struct rtc_device *rtc = wm8350->rtc.rtc;
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int ret;
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rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
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/* Make it one shot */
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ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,
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WM8350_RTC_ALMSET);
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if (ret != 0) {
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dev_err(&(wm8350->rtc.pdev->dev),
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"Failed to disable alarm: %d\n", ret);
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}
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return IRQ_HANDLED;
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}
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static irqreturn_t wm8350_rtc_update_handler(int irq, void *data)
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{
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struct wm8350 *wm8350 = data;
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struct rtc_device *rtc = wm8350->rtc.rtc;
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rtc_update_irq(rtc, 1, RTC_IRQF | RTC_UF);
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return IRQ_HANDLED;
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}
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static const struct rtc_class_ops wm8350_rtc_ops = {
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.read_time = wm8350_rtc_readtime,
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.set_time = wm8350_rtc_settime,
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.read_alarm = wm8350_rtc_readalarm,
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.set_alarm = wm8350_rtc_setalarm,
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.alarm_irq_enable = wm8350_rtc_alarm_irq_enable,
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};
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#ifdef CONFIG_PM_SLEEP
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static int wm8350_rtc_suspend(struct device *dev)
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{
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struct wm8350 *wm8350 = dev_get_drvdata(dev);
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int ret = 0;
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u16 reg;
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reg = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
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if (device_may_wakeup(&wm8350->rtc.pdev->dev) &&
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reg & WM8350_RTC_ALMSTS) {
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ret = wm8350_rtc_stop_alarm(wm8350);
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if (ret != 0)
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dev_err(dev, "Failed to stop RTC alarm: %d\n", ret);
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}
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return ret;
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}
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static int wm8350_rtc_resume(struct device *dev)
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{
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struct wm8350 *wm8350 = dev_get_drvdata(dev);
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int ret;
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if (wm8350->rtc.alarm_enabled) {
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ret = wm8350_rtc_start_alarm(wm8350);
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if (ret != 0)
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dev_err(dev, "Failed to restart RTC alarm: %d\n", ret);
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}
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return 0;
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}
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#endif
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static int wm8350_rtc_probe(struct platform_device *pdev)
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{
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struct wm8350 *wm8350 = platform_get_drvdata(pdev);
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struct wm8350_rtc *wm_rtc = &wm8350->rtc;
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int ret = 0;
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u16 timectl, power5;
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timectl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
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if (timectl & WM8350_RTC_BCD) {
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dev_err(&pdev->dev, "RTC BCD mode not supported\n");
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return -EINVAL;
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}
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if (timectl & WM8350_RTC_12HR) {
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dev_err(&pdev->dev, "RTC 12 hour mode not supported\n");
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return -EINVAL;
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}
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/* enable the RTC if it's not already enabled */
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power5 = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5);
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if (!(power5 & WM8350_RTC_TICK_ENA)) {
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dev_info(wm8350->dev, "Starting RTC\n");
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wm8350_reg_unlock(wm8350);
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ret = wm8350_set_bits(wm8350, WM8350_POWER_MGMT_5,
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WM8350_RTC_TICK_ENA);
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if (ret < 0) {
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dev_err(&pdev->dev, "failed to enable RTC: %d\n", ret);
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return ret;
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}
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wm8350_reg_lock(wm8350);
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}
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if (timectl & WM8350_RTC_STS) {
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int retries;
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ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
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WM8350_RTC_SET);
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if (ret < 0) {
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dev_err(&pdev->dev, "failed to start: %d\n", ret);
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return ret;
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}
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retries = WM8350_SET_TIME_RETRIES;
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do {
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timectl = wm8350_reg_read(wm8350,
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WM8350_RTC_TIME_CONTROL);
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} while (timectl & WM8350_RTC_STS && --retries);
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if (retries == 0) {
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dev_err(&pdev->dev, "failed to start: timeout\n");
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return -ENODEV;
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}
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}
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device_init_wakeup(&pdev->dev, 1);
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wm_rtc->rtc = devm_rtc_device_register(&pdev->dev, "wm8350",
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&wm8350_rtc_ops, THIS_MODULE);
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if (IS_ERR(wm_rtc->rtc)) {
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ret = PTR_ERR(wm_rtc->rtc);
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dev_err(&pdev->dev, "failed to register RTC: %d\n", ret);
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return ret;
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}
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ret = wm8350_register_irq(wm8350, WM8350_IRQ_RTC_SEC,
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wm8350_rtc_update_handler, 0,
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"RTC Seconds", wm8350);
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if (ret)
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return ret;
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wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC);
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ret = wm8350_register_irq(wm8350, WM8350_IRQ_RTC_ALM,
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wm8350_rtc_alarm_handler, 0,
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"RTC Alarm", wm8350);
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if (ret) {
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wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350);
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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 wm8350_rtc_remove(struct platform_device *pdev)
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{
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struct wm8350 *wm8350 = platform_get_drvdata(pdev);
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wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350);
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wm8350_free_irq(wm8350, WM8350_IRQ_RTC_ALM, wm8350);
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(wm8350_rtc_pm_ops, wm8350_rtc_suspend,
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wm8350_rtc_resume);
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static struct platform_driver wm8350_rtc_driver = {
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.probe = wm8350_rtc_probe,
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.remove = wm8350_rtc_remove,
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.driver = {
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.name = "wm8350-rtc",
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.pm = &wm8350_rtc_pm_ops,
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},
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};
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module_platform_driver(wm8350_rtc_driver);
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MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
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MODULE_DESCRIPTION("RTC driver for the WM8350");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:wm8350-rtc");
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