413 lines
11 KiB
C
413 lines
11 KiB
C
/*
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* rtc-palmas.c -- Palmas Real Time Clock driver.
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* RTC driver for TI Palma series devices like TPS65913,
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* TPS65914 power management IC.
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*
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* Copyright (c) 2012, NVIDIA Corporation.
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*
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* Author: Laxman Dewangan <ldewangan@nvidia.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
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* whether express or implied; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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* 02111-1307, USA
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*/
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#include <linux/bcd.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/mfd/palmas.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/rtc.h>
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#include <linux/types.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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struct palmas_rtc {
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struct rtc_device *rtc;
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struct device *dev;
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unsigned int irq;
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};
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/* Total number of RTC registers needed to set time*/
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#define PALMAS_NUM_TIME_REGS (PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)
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/*
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* Special bin2bcd mapping to deal with bcd storage of year.
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*
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* 0-69 -> 0xD0
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* 70-99 (1970 - 1999) -> 0xD0 - 0xF9 (correctly rolls to 0x00)
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* 100-199 (2000 - 2099) -> 0x00 - 0x99 (does not roll to 0xA0 :-( )
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* 200-229 (2100 - 2129) -> 0xA0 - 0xC9 (really for completeness)
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* 230- -> 0xC9
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*
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* Confirmed: the only transition that does not work correctly for this rtc
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* clock is the transition from 2099 to 2100, it proceeds to 2000. We will
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* accept this issue since the clock retains and transitions the year correctly
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* in all other conditions.
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*/
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static unsigned char year_bin2bcd(int val)
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{
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if (val < 70)
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return 0xD0;
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if (val < 100)
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return bin2bcd(val - 20) | 0x80; /* KISS leverage of bin2bcd */
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if (val >= 230)
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return 0xC9;
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if (val >= 200)
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return bin2bcd(val - 180) | 0x80;
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return bin2bcd(val - 100);
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}
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static int year_bcd2bin(unsigned char val)
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{
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if (val >= 0xD0)
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return bcd2bin(val & 0x7F) + 20;
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if (val >= 0xA0)
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return bcd2bin(val & 0x7F) + 180;
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return bcd2bin(val) + 100;
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}
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static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
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struct palmas *palmas = 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 = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
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PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
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if (ret < 0) {
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dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
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return ret;
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}
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ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
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rtc_data, PALMAS_NUM_TIME_REGS);
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if (ret < 0) {
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dev_err(dev, "RTC_SECONDS reg read failed, 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 = year_bcd2bin(rtc_data[5]);
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return ret;
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}
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static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
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struct palmas *palmas = 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] = year_bin2bcd(tm->tm_year);
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/* Stop RTC while updating the RTC time registers */
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ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
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PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
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if (ret < 0) {
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dev_err(dev, "RTC stop failed, err = %d\n", ret);
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return ret;
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}
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ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
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rtc_data, PALMAS_NUM_TIME_REGS);
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if (ret < 0) {
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dev_err(dev, "RTC_SECONDS reg write failed, err = %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 = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
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PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
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if (ret < 0)
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dev_err(dev, "RTC start failed, err = %d\n", ret);
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return ret;
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}
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static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
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{
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struct palmas *palmas = dev_get_drvdata(dev->parent);
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u8 val;
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val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
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return palmas_write(palmas, PALMAS_RTC_BASE,
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PALMAS_RTC_INTERRUPTS_REG, val);
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}
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static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
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{
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unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
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u32 int_val;
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struct palmas *palmas = dev_get_drvdata(dev->parent);
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int ret;
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ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE,
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PALMAS_ALARM_SECONDS_REG,
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alarm_data, PALMAS_NUM_TIME_REGS);
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if (ret < 0) {
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dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %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 = year_bcd2bin(alarm_data[5]);
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ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG,
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&int_val);
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if (ret < 0) {
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dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret);
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return ret;
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}
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if (int_val & PALMAS_RTC_INTERRUPTS_REG_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 palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
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{
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unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
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struct palmas *palmas = dev_get_drvdata(dev->parent);
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int ret;
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ret = palmas_rtc_alarm_irq_enable(dev, 0);
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if (ret < 0) {
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dev_err(dev, "Disable RTC alarm failed\n");
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return ret;
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}
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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] = year_bin2bcd(alm->time.tm_year);
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ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE,
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PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS);
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if (ret < 0) {
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dev_err(dev, "ALARM_SECONDS_REG write failed, err = %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 = palmas_rtc_alarm_irq_enable(dev, 1);
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return ret;
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}
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static int palmas_clear_interrupts(struct device *dev)
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{
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struct palmas *palmas = dev_get_drvdata(dev->parent);
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unsigned int rtc_reg;
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int ret;
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ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
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&rtc_reg);
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if (ret < 0) {
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dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret);
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return ret;
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}
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ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
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rtc_reg);
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if (ret < 0) {
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dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret);
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return ret;
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}
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return 0;
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}
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static irqreturn_t palmas_rtc_interrupt(int irq, void *context)
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{
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struct palmas_rtc *palmas_rtc = context;
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struct device *dev = palmas_rtc->dev;
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int ret;
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ret = palmas_clear_interrupts(dev);
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if (ret < 0) {
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dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret);
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return IRQ_NONE;
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}
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rtc_update_irq(palmas_rtc->rtc, 1, RTC_IRQF | RTC_AF);
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return IRQ_HANDLED;
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}
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static const struct rtc_class_ops palmas_rtc_ops = {
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.read_time = palmas_rtc_read_time,
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.set_time = palmas_rtc_set_time,
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.read_alarm = palmas_rtc_read_alarm,
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.set_alarm = palmas_rtc_set_alarm,
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.alarm_irq_enable = palmas_rtc_alarm_irq_enable,
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};
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static int palmas_rtc_probe(struct platform_device *pdev)
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{
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struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
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struct palmas_rtc *palmas_rtc = NULL;
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int ret;
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bool enable_bb_charging = false;
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bool high_bb_charging = false;
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if (pdev->dev.of_node) {
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enable_bb_charging = of_property_read_bool(pdev->dev.of_node,
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"ti,backup-battery-chargeable");
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high_bb_charging = of_property_read_bool(pdev->dev.of_node,
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"ti,backup-battery-charge-high-current");
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}
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palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc),
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GFP_KERNEL);
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if (!palmas_rtc)
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return -ENOMEM;
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/* Clear pending interrupts */
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ret = palmas_clear_interrupts(&pdev->dev);
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if (ret < 0) {
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dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret);
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return ret;
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}
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palmas_rtc->dev = &pdev->dev;
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platform_set_drvdata(pdev, palmas_rtc);
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if (enable_bb_charging) {
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unsigned reg = PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG;
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if (high_bb_charging)
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reg = 0;
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ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
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PALMAS_BACKUP_BATTERY_CTRL,
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PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG, reg);
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if (ret < 0) {
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dev_err(&pdev->dev,
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"BACKUP_BATTERY_CTRL update failed, %d\n", ret);
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return ret;
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}
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ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
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PALMAS_BACKUP_BATTERY_CTRL,
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PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN,
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PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN);
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if (ret < 0) {
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dev_err(&pdev->dev,
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"BACKUP_BATTERY_CTRL update failed, %d\n", ret);
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return ret;
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}
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}
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/* Start RTC */
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ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
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PALMAS_RTC_CTRL_REG_STOP_RTC,
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PALMAS_RTC_CTRL_REG_STOP_RTC);
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if (ret < 0) {
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dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret);
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return ret;
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}
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palmas_rtc->irq = platform_get_irq(pdev, 0);
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device_init_wakeup(&pdev->dev, 1);
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palmas_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
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&palmas_rtc_ops, THIS_MODULE);
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if (IS_ERR(palmas_rtc->rtc)) {
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ret = PTR_ERR(palmas_rtc->rtc);
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dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret);
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return ret;
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}
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ret = devm_request_threaded_irq(&pdev->dev, palmas_rtc->irq, NULL,
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palmas_rtc_interrupt,
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IRQF_TRIGGER_LOW | IRQF_ONESHOT,
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dev_name(&pdev->dev), palmas_rtc);
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if (ret < 0) {
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dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
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return ret;
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}
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return 0;
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}
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static int palmas_rtc_remove(struct platform_device *pdev)
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{
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palmas_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 palmas_rtc_suspend(struct device *dev)
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{
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struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
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if (device_may_wakeup(dev))
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enable_irq_wake(palmas_rtc->irq);
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return 0;
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}
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static int palmas_rtc_resume(struct device *dev)
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{
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struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
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if (device_may_wakeup(dev))
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disable_irq_wake(palmas_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(palmas_rtc_pm_ops, palmas_rtc_suspend,
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palmas_rtc_resume);
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#ifdef CONFIG_OF
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static const struct of_device_id of_palmas_rtc_match[] = {
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{ .compatible = "ti,palmas-rtc"},
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{ },
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};
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MODULE_DEVICE_TABLE(of, of_palmas_rtc_match);
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#endif
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static struct platform_driver palmas_rtc_driver = {
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.probe = palmas_rtc_probe,
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.remove = palmas_rtc_remove,
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.driver = {
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.name = "palmas-rtc",
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.pm = &palmas_rtc_pm_ops,
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.of_match_table = of_match_ptr(of_palmas_rtc_match),
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},
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};
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module_platform_driver(palmas_rtc_driver);
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MODULE_ALIAS("platform:palmas_rtc");
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MODULE_DESCRIPTION("TI PALMAS series RTC driver");
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MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
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MODULE_LICENSE("GPL v2");
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