461 lines
13 KiB
C
461 lines
13 KiB
C
/*
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* RTC driver for Rockchip RK808
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*
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* Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
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*
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* Author: Chris Zhong <zyw@rock-chips.com>
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* Author: Zhang Qing <zhangqing@rock-chips.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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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/rtc.h>
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#include <linux/bcd.h>
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#include <linux/mfd/rk808.h>
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#include <linux/platform_device.h>
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#include <linux/i2c.h>
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/* RTC_CTRL_REG bitfields */
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#define BIT_RTC_CTRL_REG_STOP_RTC_M BIT(0)
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/* RK808 has a shadowed register for saving a "frozen" RTC time.
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* When user setting "GET_TIME" to 1, the time will save in this shadowed
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* register. If set "READSEL" to 1, user read rtc time register, actually
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* get the time of that moment. If we need the real time, clr this bit.
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*/
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#define BIT_RTC_CTRL_REG_RTC_GET_TIME BIT(6)
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#define BIT_RTC_CTRL_REG_RTC_READSEL_M BIT(7)
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#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M BIT(3)
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#define RTC_STATUS_MASK 0xFE
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#define SECONDS_REG_MSK 0x7F
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#define MINUTES_REG_MAK 0x7F
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#define HOURS_REG_MSK 0x3F
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#define DAYS_REG_MSK 0x3F
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#define MONTHS_REG_MSK 0x1F
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#define YEARS_REG_MSK 0xFF
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#define WEEKS_REG_MSK 0x7
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/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
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#define NUM_TIME_REGS (RK808_WEEKS_REG - RK808_SECONDS_REG + 1)
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#define NUM_ALARM_REGS (RK808_ALARM_YEARS_REG - RK808_ALARM_SECONDS_REG + 1)
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struct rk808_rtc {
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struct rk808 *rk808;
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struct rtc_device *rtc;
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int irq;
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};
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/*
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* The Rockchip calendar used by the RK808 counts November with 31 days. We use
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* these translation functions to convert its dates to/from the Gregorian
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* calendar used by the rest of the world. We arbitrarily define Jan 1st, 2016
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* as the day when both calendars were in sync, and treat all other dates
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* relative to that.
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* NOTE: Other system software (e.g. firmware) that reads the same hardware must
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* implement this exact same conversion algorithm, with the same anchor date.
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*/
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static time64_t nov2dec_transitions(struct rtc_time *tm)
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{
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return (tm->tm_year + 1900) - 2016 + (tm->tm_mon + 1 > 11 ? 1 : 0);
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}
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static void rockchip_to_gregorian(struct rtc_time *tm)
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{
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/* If it's Nov 31st, rtc_tm_to_time64() will count that like Dec 1st */
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time64_t time = rtc_tm_to_time64(tm);
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rtc_time64_to_tm(time + nov2dec_transitions(tm) * 86400, tm);
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}
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static void gregorian_to_rockchip(struct rtc_time *tm)
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{
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time64_t extra_days = nov2dec_transitions(tm);
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time64_t time = rtc_tm_to_time64(tm);
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rtc_time64_to_tm(time - extra_days * 86400, tm);
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/* Compensate if we went back over Nov 31st (will work up to 2381) */
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if (nov2dec_transitions(tm) < extra_days) {
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if (tm->tm_mon + 1 == 11)
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tm->tm_mday++; /* This may result in 31! */
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else
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rtc_time64_to_tm(time - (extra_days - 1) * 86400, tm);
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}
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}
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/* Read current time and date in RTC */
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static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm)
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{
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struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
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struct rk808 *rk808 = rk808_rtc->rk808;
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u8 rtc_data[NUM_TIME_REGS];
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int ret;
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/* Force an update of the shadowed registers right now */
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ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
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BIT_RTC_CTRL_REG_RTC_GET_TIME,
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BIT_RTC_CTRL_REG_RTC_GET_TIME);
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if (ret) {
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dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
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return ret;
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}
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/*
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* After we set the GET_TIME bit, the rtc time can't be read
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* immediately. So we should wait up to 31.25 us, about one cycle of
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* 32khz. If we clear the GET_TIME bit here, the time of i2c transfer
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* certainly more than 31.25us: 16 * 2.5us at 400kHz bus frequency.
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*/
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ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
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BIT_RTC_CTRL_REG_RTC_GET_TIME,
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0);
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if (ret) {
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dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
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return ret;
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}
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ret = regmap_bulk_read(rk808->regmap, RK808_SECONDS_REG,
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rtc_data, NUM_TIME_REGS);
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if (ret) {
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dev_err(dev, "Failed to bulk read rtc_data: %d\n", ret);
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return ret;
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}
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tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK);
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tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK);
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tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK);
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tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK);
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tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK)) - 1;
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tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100;
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tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);
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rockchip_to_gregorian(tm);
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dev_dbg(dev, "RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
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1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
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tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
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return ret;
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}
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/* Set current time and date in RTC */
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static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
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struct rk808 *rk808 = rk808_rtc->rk808;
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u8 rtc_data[NUM_TIME_REGS];
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int ret;
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dev_dbg(dev, "set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
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1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
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tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
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gregorian_to_rockchip(tm);
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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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rtc_data[6] = bin2bcd(tm->tm_wday);
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/* Stop RTC while updating the RTC registers */
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ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
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BIT_RTC_CTRL_REG_STOP_RTC_M,
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BIT_RTC_CTRL_REG_STOP_RTC_M);
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if (ret) {
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dev_err(dev, "Failed to update RTC control: %d\n", ret);
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return ret;
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}
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ret = regmap_bulk_write(rk808->regmap, RK808_SECONDS_REG,
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rtc_data, NUM_TIME_REGS);
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if (ret) {
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dev_err(dev, "Failed to bull write rtc_data: %d\n", ret);
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return ret;
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}
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/* Start RTC again */
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ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
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BIT_RTC_CTRL_REG_STOP_RTC_M, 0);
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if (ret) {
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dev_err(dev, "Failed to update RTC control: %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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/* Read alarm time and date in RTC */
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static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
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struct rk808 *rk808 = rk808_rtc->rk808;
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u8 alrm_data[NUM_ALARM_REGS];
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uint32_t int_reg;
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int ret;
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ret = regmap_bulk_read(rk808->regmap, RK808_ALARM_SECONDS_REG,
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alrm_data, NUM_ALARM_REGS);
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alrm->time.tm_sec = bcd2bin(alrm_data[0] & SECONDS_REG_MSK);
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alrm->time.tm_min = bcd2bin(alrm_data[1] & MINUTES_REG_MAK);
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alrm->time.tm_hour = bcd2bin(alrm_data[2] & HOURS_REG_MSK);
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alrm->time.tm_mday = bcd2bin(alrm_data[3] & DAYS_REG_MSK);
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alrm->time.tm_mon = (bcd2bin(alrm_data[4] & MONTHS_REG_MSK)) - 1;
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alrm->time.tm_year = (bcd2bin(alrm_data[5] & YEARS_REG_MSK)) + 100;
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rockchip_to_gregorian(&alrm->time);
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ret = regmap_read(rk808->regmap, RK808_RTC_INT_REG, &int_reg);
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if (ret) {
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dev_err(dev, "Failed to read RTC INT REG: %d\n", ret);
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return ret;
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}
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dev_dbg(dev, "alrm read RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
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1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
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alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
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alrm->time.tm_min, alrm->time.tm_sec);
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alrm->enabled = (int_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) ? 1 : 0;
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return 0;
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}
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static int rk808_rtc_stop_alarm(struct rk808_rtc *rk808_rtc)
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{
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struct rk808 *rk808 = rk808_rtc->rk808;
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int ret;
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ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
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BIT_RTC_INTERRUPTS_REG_IT_ALARM_M, 0);
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return ret;
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}
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static int rk808_rtc_start_alarm(struct rk808_rtc *rk808_rtc)
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{
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struct rk808 *rk808 = rk808_rtc->rk808;
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int ret;
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ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
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BIT_RTC_INTERRUPTS_REG_IT_ALARM_M,
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BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
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return ret;
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}
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static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
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{
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struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
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struct rk808 *rk808 = rk808_rtc->rk808;
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u8 alrm_data[NUM_ALARM_REGS];
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int ret;
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ret = rk808_rtc_stop_alarm(rk808_rtc);
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if (ret) {
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dev_err(dev, "Failed to stop alarm: %d\n", ret);
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return ret;
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}
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dev_dbg(dev, "alrm set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
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1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
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alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
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alrm->time.tm_min, alrm->time.tm_sec);
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gregorian_to_rockchip(&alrm->time);
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alrm_data[0] = bin2bcd(alrm->time.tm_sec);
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alrm_data[1] = bin2bcd(alrm->time.tm_min);
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alrm_data[2] = bin2bcd(alrm->time.tm_hour);
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alrm_data[3] = bin2bcd(alrm->time.tm_mday);
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alrm_data[4] = bin2bcd(alrm->time.tm_mon + 1);
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alrm_data[5] = bin2bcd(alrm->time.tm_year - 100);
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ret = regmap_bulk_write(rk808->regmap, RK808_ALARM_SECONDS_REG,
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alrm_data, NUM_ALARM_REGS);
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if (ret) {
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dev_err(dev, "Failed to bulk write: %d\n", ret);
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return ret;
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}
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if (alrm->enabled) {
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ret = rk808_rtc_start_alarm(rk808_rtc);
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if (ret) {
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dev_err(dev, "Failed to start alarm: %d\n", ret);
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return ret;
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}
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}
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return 0;
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}
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static int rk808_rtc_alarm_irq_enable(struct device *dev,
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unsigned int enabled)
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{
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struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
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if (enabled)
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return rk808_rtc_start_alarm(rk808_rtc);
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return rk808_rtc_stop_alarm(rk808_rtc);
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}
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/*
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* We will just handle setting the frequency and make use the framework for
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* reading the periodic interupts.
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*
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* @freq: Current periodic IRQ freq:
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* bit 0: every second
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* bit 1: every minute
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* bit 2: every hour
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* bit 3: every day
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*/
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static irqreturn_t rk808_alarm_irq(int irq, void *data)
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{
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struct rk808_rtc *rk808_rtc = data;
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struct rk808 *rk808 = rk808_rtc->rk808;
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struct i2c_client *client = rk808->i2c;
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int ret;
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ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
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RTC_STATUS_MASK);
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if (ret) {
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dev_err(&client->dev,
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"%s:Failed to update RTC status: %d\n", __func__, ret);
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return ret;
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}
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rtc_update_irq(rk808_rtc->rtc, 1, RTC_IRQF | RTC_AF);
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dev_dbg(&client->dev,
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"%s:irq=%d\n", __func__, irq);
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return IRQ_HANDLED;
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}
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static const struct rtc_class_ops rk808_rtc_ops = {
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.read_time = rk808_rtc_readtime,
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.set_time = rk808_rtc_set_time,
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.read_alarm = rk808_rtc_readalarm,
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.set_alarm = rk808_rtc_setalarm,
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.alarm_irq_enable = rk808_rtc_alarm_irq_enable,
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};
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#ifdef CONFIG_PM_SLEEP
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/* Turn off the alarm if it should not be a wake source. */
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static int rk808_rtc_suspend(struct device *dev)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
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if (device_may_wakeup(dev))
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enable_irq_wake(rk808_rtc->irq);
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return 0;
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}
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/* Enable the alarm if it should be enabled (in case it was disabled to
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* prevent use as a wake source).
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*/
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static int rk808_rtc_resume(struct device *dev)
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{
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struct platform_device *pdev = to_platform_device(dev);
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struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
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if (device_may_wakeup(dev))
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disable_irq_wake(rk808_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(rk808_rtc_pm_ops,
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rk808_rtc_suspend, rk808_rtc_resume);
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static int rk808_rtc_probe(struct platform_device *pdev)
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{
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struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
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struct rk808_rtc *rk808_rtc;
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struct rtc_time tm;
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int ret;
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rk808_rtc = devm_kzalloc(&pdev->dev, sizeof(*rk808_rtc), GFP_KERNEL);
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if (rk808_rtc == NULL)
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return -ENOMEM;
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platform_set_drvdata(pdev, rk808_rtc);
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rk808_rtc->rk808 = rk808;
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/* start rtc running by default, and use shadowed timer. */
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ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
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BIT_RTC_CTRL_REG_STOP_RTC_M |
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BIT_RTC_CTRL_REG_RTC_READSEL_M,
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BIT_RTC_CTRL_REG_RTC_READSEL_M);
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if (ret) {
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dev_err(&pdev->dev,
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"Failed to update RTC control: %d\n", ret);
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return ret;
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}
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ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
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RTC_STATUS_MASK);
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if (ret) {
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dev_err(&pdev->dev,
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"Failed to write RTC status: %d\n", ret);
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return ret;
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}
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/* set init time */
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ret = rk808_rtc_readtime(&pdev->dev, &tm);
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if (ret) {
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dev_err(&pdev->dev, "Failed to read RTC time\n");
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return ret;
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}
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ret = rtc_valid_tm(&tm);
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if (ret)
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dev_warn(&pdev->dev, "invalid date/time\n");
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device_init_wakeup(&pdev->dev, 1);
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rk808_rtc->rtc = devm_rtc_device_register(&pdev->dev, "rk808-rtc",
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&rk808_rtc_ops, THIS_MODULE);
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if (IS_ERR(rk808_rtc->rtc)) {
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ret = PTR_ERR(rk808_rtc->rtc);
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return ret;
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}
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rk808_rtc->irq = platform_get_irq(pdev, 0);
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if (rk808_rtc->irq < 0) {
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if (rk808_rtc->irq != -EPROBE_DEFER)
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dev_err(&pdev->dev, "Wake up is not possible as irq = %d\n",
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rk808_rtc->irq);
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return rk808_rtc->irq;
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}
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|
/* request alarm irq of rk808 */
|
|
ret = devm_request_threaded_irq(&pdev->dev, rk808_rtc->irq, NULL,
|
|
rk808_alarm_irq, 0,
|
|
"RTC alarm", rk808_rtc);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
|
|
rk808_rtc->irq, ret);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct platform_driver rk808_rtc_driver = {
|
|
.probe = rk808_rtc_probe,
|
|
.driver = {
|
|
.name = "rk808-rtc",
|
|
.pm = &rk808_rtc_pm_ops,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(rk808_rtc_driver);
|
|
|
|
MODULE_DESCRIPTION("RTC driver for the rk808 series PMICs");
|
|
MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
|
|
MODULE_AUTHOR("Zhang Qing <zhangqing@rock-chips.com>");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:rk808-rtc");
|