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491 lines
12 KiB
491 lines
12 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* drivers/rtc/rtc-spear.c |
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* |
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* Copyright (C) 2010 ST Microelectronics |
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* Rajeev Kumar<[email protected]> |
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*/ |
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#include <linux/bcd.h> |
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#include <linux/clk.h> |
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#include <linux/delay.h> |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <linux/irq.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/platform_device.h> |
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#include <linux/rtc.h> |
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#include <linux/slab.h> |
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#include <linux/spinlock.h> |
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/* RTC registers */ |
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#define TIME_REG 0x00 |
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#define DATE_REG 0x04 |
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#define ALARM_TIME_REG 0x08 |
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#define ALARM_DATE_REG 0x0C |
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#define CTRL_REG 0x10 |
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#define STATUS_REG 0x14 |
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/* TIME_REG & ALARM_TIME_REG */ |
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#define SECONDS_UNITS (0xf<<0) /* seconds units position */ |
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#define SECONDS_TENS (0x7<<4) /* seconds tens position */ |
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#define MINUTES_UNITS (0xf<<8) /* minutes units position */ |
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#define MINUTES_TENS (0x7<<12) /* minutes tens position */ |
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#define HOURS_UNITS (0xf<<16) /* hours units position */ |
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#define HOURS_TENS (0x3<<20) /* hours tens position */ |
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/* DATE_REG & ALARM_DATE_REG */ |
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#define DAYS_UNITS (0xf<<0) /* days units position */ |
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#define DAYS_TENS (0x3<<4) /* days tens position */ |
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#define MONTHS_UNITS (0xf<<8) /* months units position */ |
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#define MONTHS_TENS (0x1<<12) /* months tens position */ |
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#define YEARS_UNITS (0xf<<16) /* years units position */ |
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#define YEARS_TENS (0xf<<20) /* years tens position */ |
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#define YEARS_HUNDREDS (0xf<<24) /* years hundereds position */ |
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#define YEARS_MILLENIUMS (0xf<<28) /* years millenium position */ |
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/* MASK SHIFT TIME_REG & ALARM_TIME_REG*/ |
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#define SECOND_SHIFT 0x00 /* seconds units */ |
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#define MINUTE_SHIFT 0x08 /* minutes units position */ |
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#define HOUR_SHIFT 0x10 /* hours units position */ |
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#define MDAY_SHIFT 0x00 /* Month day shift */ |
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#define MONTH_SHIFT 0x08 /* Month shift */ |
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#define YEAR_SHIFT 0x10 /* Year shift */ |
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#define SECOND_MASK 0x7F |
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#define MIN_MASK 0x7F |
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#define HOUR_MASK 0x3F |
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#define DAY_MASK 0x3F |
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#define MONTH_MASK 0x7F |
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#define YEAR_MASK 0xFFFF |
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/* date reg equal to time reg, for debug only */ |
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#define TIME_BYP (1<<9) |
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#define INT_ENABLE (1<<31) /* interrupt enable */ |
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/* STATUS_REG */ |
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#define CLK_UNCONNECTED (1<<0) |
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#define PEND_WR_TIME (1<<2) |
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#define PEND_WR_DATE (1<<3) |
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#define LOST_WR_TIME (1<<4) |
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#define LOST_WR_DATE (1<<5) |
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#define RTC_INT_MASK (1<<31) |
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#define STATUS_BUSY (PEND_WR_TIME | PEND_WR_DATE) |
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#define STATUS_FAIL (LOST_WR_TIME | LOST_WR_DATE) |
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struct spear_rtc_config { |
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struct rtc_device *rtc; |
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struct clk *clk; |
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spinlock_t lock; |
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void __iomem *ioaddr; |
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unsigned int irq_wake; |
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}; |
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static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config) |
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{ |
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unsigned int val; |
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unsigned long flags; |
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spin_lock_irqsave(&config->lock, flags); |
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val = readl(config->ioaddr + STATUS_REG); |
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val |= RTC_INT_MASK; |
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writel(val, config->ioaddr + STATUS_REG); |
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spin_unlock_irqrestore(&config->lock, flags); |
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} |
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static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config) |
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{ |
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unsigned int val; |
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val = readl(config->ioaddr + CTRL_REG); |
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if (!(val & INT_ENABLE)) { |
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spear_rtc_clear_interrupt(config); |
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val |= INT_ENABLE; |
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writel(val, config->ioaddr + CTRL_REG); |
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} |
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} |
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static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config) |
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{ |
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unsigned int val; |
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val = readl(config->ioaddr + CTRL_REG); |
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if (val & INT_ENABLE) { |
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val &= ~INT_ENABLE; |
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writel(val, config->ioaddr + CTRL_REG); |
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} |
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} |
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static inline int is_write_complete(struct spear_rtc_config *config) |
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{ |
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int ret = 0; |
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unsigned long flags; |
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spin_lock_irqsave(&config->lock, flags); |
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if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL) |
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ret = -EIO; |
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spin_unlock_irqrestore(&config->lock, flags); |
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return ret; |
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} |
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static void rtc_wait_not_busy(struct spear_rtc_config *config) |
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{ |
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int status, count = 0; |
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unsigned long flags; |
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/* Assuming BUSY may stay active for 80 msec) */ |
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for (count = 0; count < 80; count++) { |
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spin_lock_irqsave(&config->lock, flags); |
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status = readl(config->ioaddr + STATUS_REG); |
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spin_unlock_irqrestore(&config->lock, flags); |
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if ((status & STATUS_BUSY) == 0) |
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break; |
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/* check status busy, after each msec */ |
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msleep(1); |
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} |
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} |
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static irqreturn_t spear_rtc_irq(int irq, void *dev_id) |
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{ |
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struct spear_rtc_config *config = dev_id; |
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unsigned long events = 0; |
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unsigned int irq_data; |
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spin_lock(&config->lock); |
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irq_data = readl(config->ioaddr + STATUS_REG); |
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spin_unlock(&config->lock); |
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if ((irq_data & RTC_INT_MASK)) { |
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spear_rtc_clear_interrupt(config); |
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events = RTC_IRQF | RTC_AF; |
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rtc_update_irq(config->rtc, 1, events); |
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return IRQ_HANDLED; |
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} else |
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return IRQ_NONE; |
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} |
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static void tm2bcd(struct rtc_time *tm) |
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{ |
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tm->tm_sec = bin2bcd(tm->tm_sec); |
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tm->tm_min = bin2bcd(tm->tm_min); |
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tm->tm_hour = bin2bcd(tm->tm_hour); |
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tm->tm_mday = bin2bcd(tm->tm_mday); |
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tm->tm_mon = bin2bcd(tm->tm_mon + 1); |
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tm->tm_year = bin2bcd(tm->tm_year); |
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} |
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static void bcd2tm(struct rtc_time *tm) |
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{ |
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tm->tm_sec = bcd2bin(tm->tm_sec); |
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tm->tm_min = bcd2bin(tm->tm_min); |
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tm->tm_hour = bcd2bin(tm->tm_hour); |
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tm->tm_mday = bcd2bin(tm->tm_mday); |
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tm->tm_mon = bcd2bin(tm->tm_mon) - 1; |
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/* epoch == 1900 */ |
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tm->tm_year = bcd2bin(tm->tm_year); |
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} |
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/* |
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* spear_rtc_read_time - set the time |
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* @dev: rtc device in use |
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* @tm: holds date and time |
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* |
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* This function read time and date. On success it will return 0 |
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* otherwise -ve error is returned. |
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*/ |
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static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm) |
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{ |
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struct spear_rtc_config *config = dev_get_drvdata(dev); |
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unsigned int time, date; |
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/* we don't report wday/yday/isdst ... */ |
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rtc_wait_not_busy(config); |
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time = readl(config->ioaddr + TIME_REG); |
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date = readl(config->ioaddr + DATE_REG); |
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tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; |
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tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; |
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tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; |
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tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; |
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tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; |
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tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; |
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bcd2tm(tm); |
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return 0; |
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} |
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/* |
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* spear_rtc_set_time - set the time |
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* @dev: rtc device in use |
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* @tm: holds date and time |
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* |
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* This function set time and date. On success it will return 0 |
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* otherwise -ve error is returned. |
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*/ |
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static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm) |
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{ |
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struct spear_rtc_config *config = dev_get_drvdata(dev); |
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unsigned int time, date; |
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tm2bcd(tm); |
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rtc_wait_not_busy(config); |
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time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) | |
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(tm->tm_hour << HOUR_SHIFT); |
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date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) | |
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(tm->tm_year << YEAR_SHIFT); |
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writel(time, config->ioaddr + TIME_REG); |
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writel(date, config->ioaddr + DATE_REG); |
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return is_write_complete(config); |
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} |
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/* |
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* spear_rtc_read_alarm - read the alarm time |
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* @dev: rtc device in use |
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* @alm: holds alarm date and time |
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* |
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* This function read alarm time and date. On success it will return 0 |
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* otherwise -ve error is returned. |
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*/ |
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static int spear_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) |
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{ |
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struct spear_rtc_config *config = dev_get_drvdata(dev); |
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unsigned int time, date; |
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rtc_wait_not_busy(config); |
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time = readl(config->ioaddr + ALARM_TIME_REG); |
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date = readl(config->ioaddr + ALARM_DATE_REG); |
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alm->time.tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK; |
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alm->time.tm_min = (time >> MINUTE_SHIFT) & MIN_MASK; |
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alm->time.tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK; |
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alm->time.tm_mday = (date >> MDAY_SHIFT) & DAY_MASK; |
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alm->time.tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK; |
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alm->time.tm_year = (date >> YEAR_SHIFT) & YEAR_MASK; |
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bcd2tm(&alm->time); |
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alm->enabled = readl(config->ioaddr + CTRL_REG) & INT_ENABLE; |
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return 0; |
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} |
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/* |
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* spear_rtc_set_alarm - set the alarm time |
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* @dev: rtc device in use |
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* @alm: holds alarm date and time |
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* |
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* This function set alarm time and date. On success it will return 0 |
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* otherwise -ve error is returned. |
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*/ |
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static int spear_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) |
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{ |
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struct spear_rtc_config *config = dev_get_drvdata(dev); |
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unsigned int time, date; |
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int err; |
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tm2bcd(&alm->time); |
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rtc_wait_not_busy(config); |
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time = (alm->time.tm_sec << SECOND_SHIFT) | (alm->time.tm_min << |
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MINUTE_SHIFT) | (alm->time.tm_hour << HOUR_SHIFT); |
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date = (alm->time.tm_mday << MDAY_SHIFT) | (alm->time.tm_mon << |
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MONTH_SHIFT) | (alm->time.tm_year << YEAR_SHIFT); |
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writel(time, config->ioaddr + ALARM_TIME_REG); |
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writel(date, config->ioaddr + ALARM_DATE_REG); |
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err = is_write_complete(config); |
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if (err < 0) |
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return err; |
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if (alm->enabled) |
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spear_rtc_enable_interrupt(config); |
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else |
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spear_rtc_disable_interrupt(config); |
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return 0; |
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} |
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static int spear_alarm_irq_enable(struct device *dev, unsigned int enabled) |
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{ |
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struct spear_rtc_config *config = dev_get_drvdata(dev); |
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int ret = 0; |
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spear_rtc_clear_interrupt(config); |
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switch (enabled) { |
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case 0: |
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/* alarm off */ |
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spear_rtc_disable_interrupt(config); |
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break; |
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case 1: |
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/* alarm on */ |
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spear_rtc_enable_interrupt(config); |
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break; |
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default: |
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ret = -EINVAL; |
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break; |
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} |
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return ret; |
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} |
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static const struct rtc_class_ops spear_rtc_ops = { |
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.read_time = spear_rtc_read_time, |
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.set_time = spear_rtc_set_time, |
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.read_alarm = spear_rtc_read_alarm, |
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.set_alarm = spear_rtc_set_alarm, |
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.alarm_irq_enable = spear_alarm_irq_enable, |
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}; |
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static int spear_rtc_probe(struct platform_device *pdev) |
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{ |
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struct spear_rtc_config *config; |
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int status = 0; |
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int irq; |
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config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL); |
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if (!config) |
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return -ENOMEM; |
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/* alarm irqs */ |
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irq = platform_get_irq(pdev, 0); |
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if (irq < 0) |
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return irq; |
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status = devm_request_irq(&pdev->dev, irq, spear_rtc_irq, 0, pdev->name, |
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config); |
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if (status) { |
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dev_err(&pdev->dev, "Alarm interrupt IRQ%d already claimed\n", |
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irq); |
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return status; |
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} |
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config->ioaddr = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(config->ioaddr)) |
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return PTR_ERR(config->ioaddr); |
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config->clk = devm_clk_get(&pdev->dev, NULL); |
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if (IS_ERR(config->clk)) |
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return PTR_ERR(config->clk); |
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status = clk_prepare_enable(config->clk); |
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if (status < 0) |
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return status; |
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spin_lock_init(&config->lock); |
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platform_set_drvdata(pdev, config); |
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config->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, |
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&spear_rtc_ops, THIS_MODULE); |
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if (IS_ERR(config->rtc)) { |
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dev_err(&pdev->dev, "can't register RTC device, err %ld\n", |
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PTR_ERR(config->rtc)); |
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status = PTR_ERR(config->rtc); |
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goto err_disable_clock; |
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} |
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config->rtc->uie_unsupported = 1; |
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if (!device_can_wakeup(&pdev->dev)) |
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device_init_wakeup(&pdev->dev, 1); |
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return 0; |
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err_disable_clock: |
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clk_disable_unprepare(config->clk); |
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return status; |
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} |
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static int spear_rtc_remove(struct platform_device *pdev) |
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{ |
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struct spear_rtc_config *config = platform_get_drvdata(pdev); |
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spear_rtc_disable_interrupt(config); |
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clk_disable_unprepare(config->clk); |
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device_init_wakeup(&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 spear_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 spear_rtc_config *config = platform_get_drvdata(pdev); |
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int irq; |
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irq = platform_get_irq(pdev, 0); |
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if (device_may_wakeup(&pdev->dev)) { |
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if (!enable_irq_wake(irq)) |
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config->irq_wake = 1; |
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} else { |
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spear_rtc_disable_interrupt(config); |
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clk_disable(config->clk); |
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} |
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return 0; |
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} |
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static int spear_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 spear_rtc_config *config = platform_get_drvdata(pdev); |
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int irq; |
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irq = platform_get_irq(pdev, 0); |
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if (device_may_wakeup(&pdev->dev)) { |
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if (config->irq_wake) { |
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disable_irq_wake(irq); |
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config->irq_wake = 0; |
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} |
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} else { |
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clk_enable(config->clk); |
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spear_rtc_enable_interrupt(config); |
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} |
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return 0; |
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} |
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#endif |
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static SIMPLE_DEV_PM_OPS(spear_rtc_pm_ops, spear_rtc_suspend, spear_rtc_resume); |
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static void spear_rtc_shutdown(struct platform_device *pdev) |
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{ |
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struct spear_rtc_config *config = platform_get_drvdata(pdev); |
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spear_rtc_disable_interrupt(config); |
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clk_disable(config->clk); |
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} |
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#ifdef CONFIG_OF |
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static const struct of_device_id spear_rtc_id_table[] = { |
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{ .compatible = "st,spear600-rtc" }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(of, spear_rtc_id_table); |
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#endif |
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static struct platform_driver spear_rtc_driver = { |
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.probe = spear_rtc_probe, |
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.remove = spear_rtc_remove, |
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.shutdown = spear_rtc_shutdown, |
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.driver = { |
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.name = "rtc-spear", |
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.pm = &spear_rtc_pm_ops, |
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.of_match_table = of_match_ptr(spear_rtc_id_table), |
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}, |
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}; |
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module_platform_driver(spear_rtc_driver); |
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MODULE_ALIAS("platform:rtc-spear"); |
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MODULE_AUTHOR("Rajeev Kumar <[email protected]>"); |
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MODULE_DESCRIPTION("ST SPEAr Realtime Clock Driver (RTC)"); |
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MODULE_LICENSE("GPL");
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