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363 lines
8.0 KiB
363 lines
8.0 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Driver for NEC VR4100 series Real Time Clock unit. |
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* |
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* Copyright (C) 2003-2008 Yoichi Yuasa <[email protected]> |
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*/ |
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#include <linux/compat.h> |
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#include <linux/err.h> |
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#include <linux/fs.h> |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <linux/ioport.h> |
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#include <linux/interrupt.h> |
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#include <linux/module.h> |
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#include <linux/platform_device.h> |
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#include <linux/rtc.h> |
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#include <linux/spinlock.h> |
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#include <linux/types.h> |
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#include <linux/uaccess.h> |
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#include <linux/log2.h> |
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#include <asm/div64.h> |
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MODULE_AUTHOR("Yoichi Yuasa <[email protected]>"); |
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MODULE_DESCRIPTION("NEC VR4100 series RTC driver"); |
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MODULE_LICENSE("GPL v2"); |
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/* RTC 1 registers */ |
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#define ETIMELREG 0x00 |
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#define ETIMEMREG 0x02 |
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#define ETIMEHREG 0x04 |
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/* RFU */ |
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#define ECMPLREG 0x08 |
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#define ECMPMREG 0x0a |
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#define ECMPHREG 0x0c |
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/* RFU */ |
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#define RTCL1LREG 0x10 |
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#define RTCL1HREG 0x12 |
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#define RTCL1CNTLREG 0x14 |
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#define RTCL1CNTHREG 0x16 |
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#define RTCL2LREG 0x18 |
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#define RTCL2HREG 0x1a |
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#define RTCL2CNTLREG 0x1c |
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#define RTCL2CNTHREG 0x1e |
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/* RTC 2 registers */ |
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#define TCLKLREG 0x00 |
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#define TCLKHREG 0x02 |
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#define TCLKCNTLREG 0x04 |
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#define TCLKCNTHREG 0x06 |
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/* RFU */ |
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#define RTCINTREG 0x1e |
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#define TCLOCK_INT 0x08 |
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#define RTCLONG2_INT 0x04 |
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#define RTCLONG1_INT 0x02 |
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#define ELAPSEDTIME_INT 0x01 |
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#define RTC_FREQUENCY 32768 |
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#define MAX_PERIODIC_RATE 6553 |
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static void __iomem *rtc1_base; |
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static void __iomem *rtc2_base; |
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#define rtc1_read(offset) readw(rtc1_base + (offset)) |
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#define rtc1_write(offset, value) writew((value), rtc1_base + (offset)) |
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#define rtc2_read(offset) readw(rtc2_base + (offset)) |
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#define rtc2_write(offset, value) writew((value), rtc2_base + (offset)) |
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/* 32-bit compat for ioctls that nobody else uses */ |
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#define RTC_EPOCH_READ32 _IOR('p', 0x0d, __u32) |
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static unsigned long epoch = 1970; /* Jan 1 1970 00:00:00 */ |
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static DEFINE_SPINLOCK(rtc_lock); |
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static char rtc_name[] = "RTC"; |
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static unsigned long periodic_count; |
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static unsigned int alarm_enabled; |
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static int aie_irq; |
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static int pie_irq; |
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static inline time64_t read_elapsed_second(void) |
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{ |
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unsigned long first_low, first_mid, first_high; |
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unsigned long second_low, second_mid, second_high; |
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do { |
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first_low = rtc1_read(ETIMELREG); |
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first_mid = rtc1_read(ETIMEMREG); |
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first_high = rtc1_read(ETIMEHREG); |
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second_low = rtc1_read(ETIMELREG); |
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second_mid = rtc1_read(ETIMEMREG); |
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second_high = rtc1_read(ETIMEHREG); |
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} while (first_low != second_low || first_mid != second_mid || |
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first_high != second_high); |
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return ((u64)first_high << 17) | (first_mid << 1) | (first_low >> 15); |
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} |
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static inline void write_elapsed_second(time64_t sec) |
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{ |
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spin_lock_irq(&rtc_lock); |
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rtc1_write(ETIMELREG, (uint16_t)(sec << 15)); |
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rtc1_write(ETIMEMREG, (uint16_t)(sec >> 1)); |
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rtc1_write(ETIMEHREG, (uint16_t)(sec >> 17)); |
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spin_unlock_irq(&rtc_lock); |
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} |
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static int vr41xx_rtc_read_time(struct device *dev, struct rtc_time *time) |
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{ |
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time64_t epoch_sec, elapsed_sec; |
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epoch_sec = mktime64(epoch, 1, 1, 0, 0, 0); |
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elapsed_sec = read_elapsed_second(); |
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rtc_time64_to_tm(epoch_sec + elapsed_sec, time); |
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return 0; |
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} |
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static int vr41xx_rtc_set_time(struct device *dev, struct rtc_time *time) |
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{ |
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time64_t epoch_sec, current_sec; |
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epoch_sec = mktime64(epoch, 1, 1, 0, 0, 0); |
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current_sec = rtc_tm_to_time64(time); |
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write_elapsed_second(current_sec - epoch_sec); |
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return 0; |
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} |
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static int vr41xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) |
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{ |
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unsigned long low, mid, high; |
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struct rtc_time *time = &wkalrm->time; |
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spin_lock_irq(&rtc_lock); |
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low = rtc1_read(ECMPLREG); |
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mid = rtc1_read(ECMPMREG); |
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high = rtc1_read(ECMPHREG); |
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wkalrm->enabled = alarm_enabled; |
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spin_unlock_irq(&rtc_lock); |
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rtc_time64_to_tm((high << 17) | (mid << 1) | (low >> 15), time); |
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return 0; |
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} |
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static int vr41xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) |
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{ |
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time64_t alarm_sec; |
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alarm_sec = rtc_tm_to_time64(&wkalrm->time); |
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spin_lock_irq(&rtc_lock); |
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if (alarm_enabled) |
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disable_irq(aie_irq); |
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rtc1_write(ECMPLREG, (uint16_t)(alarm_sec << 15)); |
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rtc1_write(ECMPMREG, (uint16_t)(alarm_sec >> 1)); |
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rtc1_write(ECMPHREG, (uint16_t)(alarm_sec >> 17)); |
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if (wkalrm->enabled) |
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enable_irq(aie_irq); |
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alarm_enabled = wkalrm->enabled; |
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spin_unlock_irq(&rtc_lock); |
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return 0; |
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} |
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static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) |
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{ |
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switch (cmd) { |
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case RTC_EPOCH_READ: |
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return put_user(epoch, (unsigned long __user *)arg); |
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#ifdef CONFIG_64BIT |
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case RTC_EPOCH_READ32: |
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return put_user(epoch, (unsigned int __user *)arg); |
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#endif |
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case RTC_EPOCH_SET: |
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/* Doesn't support before 1900 */ |
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if (arg < 1900) |
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return -EINVAL; |
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epoch = arg; |
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break; |
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default: |
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return -ENOIOCTLCMD; |
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} |
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return 0; |
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} |
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static int vr41xx_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) |
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{ |
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spin_lock_irq(&rtc_lock); |
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if (enabled) { |
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if (!alarm_enabled) { |
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enable_irq(aie_irq); |
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alarm_enabled = 1; |
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} |
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} else { |
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if (alarm_enabled) { |
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disable_irq(aie_irq); |
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alarm_enabled = 0; |
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} |
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} |
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spin_unlock_irq(&rtc_lock); |
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return 0; |
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} |
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static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id) |
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{ |
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struct platform_device *pdev = (struct platform_device *)dev_id; |
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struct rtc_device *rtc = platform_get_drvdata(pdev); |
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rtc2_write(RTCINTREG, ELAPSEDTIME_INT); |
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rtc_update_irq(rtc, 1, RTC_AF); |
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return IRQ_HANDLED; |
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} |
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static irqreturn_t rtclong1_interrupt(int irq, void *dev_id) |
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{ |
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struct platform_device *pdev = (struct platform_device *)dev_id; |
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struct rtc_device *rtc = platform_get_drvdata(pdev); |
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unsigned long count = periodic_count; |
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rtc2_write(RTCINTREG, RTCLONG1_INT); |
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rtc1_write(RTCL1LREG, count); |
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rtc1_write(RTCL1HREG, count >> 16); |
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rtc_update_irq(rtc, 1, RTC_PF); |
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return IRQ_HANDLED; |
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} |
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static const struct rtc_class_ops vr41xx_rtc_ops = { |
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.ioctl = vr41xx_rtc_ioctl, |
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.read_time = vr41xx_rtc_read_time, |
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.set_time = vr41xx_rtc_set_time, |
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.read_alarm = vr41xx_rtc_read_alarm, |
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.set_alarm = vr41xx_rtc_set_alarm, |
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.alarm_irq_enable = vr41xx_rtc_alarm_irq_enable, |
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}; |
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static int rtc_probe(struct platform_device *pdev) |
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{ |
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struct resource *res; |
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struct rtc_device *rtc; |
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int retval; |
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if (pdev->num_resources != 4) |
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return -EBUSY; |
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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if (!res) |
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return -EBUSY; |
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rtc1_base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); |
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if (!rtc1_base) |
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return -EBUSY; |
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res = platform_get_resource(pdev, IORESOURCE_MEM, 1); |
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if (!res) { |
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retval = -EBUSY; |
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goto err_rtc1_iounmap; |
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} |
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rtc2_base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); |
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if (!rtc2_base) { |
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retval = -EBUSY; |
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goto err_rtc1_iounmap; |
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} |
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rtc = devm_rtc_allocate_device(&pdev->dev); |
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if (IS_ERR(rtc)) { |
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retval = PTR_ERR(rtc); |
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goto err_iounmap_all; |
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} |
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rtc->ops = &vr41xx_rtc_ops; |
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/* 48-bit counter at 32.768 kHz */ |
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rtc->range_max = (1ULL << 33) - 1; |
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rtc->max_user_freq = MAX_PERIODIC_RATE; |
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spin_lock_irq(&rtc_lock); |
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rtc1_write(ECMPLREG, 0); |
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rtc1_write(ECMPMREG, 0); |
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rtc1_write(ECMPHREG, 0); |
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rtc1_write(RTCL1LREG, 0); |
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rtc1_write(RTCL1HREG, 0); |
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spin_unlock_irq(&rtc_lock); |
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aie_irq = platform_get_irq(pdev, 0); |
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if (aie_irq <= 0) { |
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retval = -EBUSY; |
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goto err_iounmap_all; |
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} |
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retval = devm_request_irq(&pdev->dev, aie_irq, elapsedtime_interrupt, 0, |
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"elapsed_time", pdev); |
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if (retval < 0) |
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goto err_iounmap_all; |
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pie_irq = platform_get_irq(pdev, 1); |
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if (pie_irq <= 0) { |
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retval = -EBUSY; |
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goto err_iounmap_all; |
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} |
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retval = devm_request_irq(&pdev->dev, pie_irq, rtclong1_interrupt, 0, |
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"rtclong1", pdev); |
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if (retval < 0) |
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goto err_iounmap_all; |
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platform_set_drvdata(pdev, rtc); |
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disable_irq(aie_irq); |
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disable_irq(pie_irq); |
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dev_info(&pdev->dev, "Real Time Clock of NEC VR4100 series\n"); |
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retval = devm_rtc_register_device(rtc); |
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if (retval) |
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goto err_iounmap_all; |
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return 0; |
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err_iounmap_all: |
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rtc2_base = NULL; |
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err_rtc1_iounmap: |
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rtc1_base = NULL; |
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return retval; |
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} |
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/* work with hotplug and coldplug */ |
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MODULE_ALIAS("platform:RTC"); |
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static struct platform_driver rtc_platform_driver = { |
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.probe = rtc_probe, |
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.driver = { |
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.name = rtc_name, |
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}, |
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}; |
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module_platform_driver(rtc_platform_driver);
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