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Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
521 lines
12 KiB
C
521 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* rtc-mrst.c: Driver for Moorestown virtual RTC
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*
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* (C) Copyright 2009 Intel Corporation
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* Author: Jacob Pan (jacob.jun.pan@intel.com)
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* Feng Tang (feng.tang@intel.com)
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*
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* Note:
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* VRTC is emulated by system controller firmware, the real HW
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* RTC is located in the PMIC device. SCU FW shadows PMIC RTC
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* in a memory mapped IO space that is visible to the host IA
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* processor.
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*
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* This driver is based upon drivers/rtc/rtc-cmos.c
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*/
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/*
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* Note:
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* * vRTC only supports binary mode and 24H mode
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* * vRTC only support PIE and AIE, no UIE, and its PIE only happens
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* at 23:59:59pm everyday, no support for adjustable frequency
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* * Alarm function is also limited to hr/min/sec.
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*/
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#include <linux/mod_devicetable.h>
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#include <linux/platform_device.h>
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#include <linux/interrupt.h>
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#include <linux/spinlock.h>
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#include <linux/kernel.h>
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#include <linux/mc146818rtc.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/sfi.h>
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#include <asm/intel_scu_ipc.h>
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#include <asm/intel-mid.h>
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#include <asm/intel_mid_vrtc.h>
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struct mrst_rtc {
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struct rtc_device *rtc;
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struct device *dev;
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int irq;
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u8 enabled_wake;
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u8 suspend_ctrl;
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};
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static const char driver_name[] = "rtc_mrst";
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#define RTC_IRQMASK (RTC_PF | RTC_AF)
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static inline int is_intr(u8 rtc_intr)
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{
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if (!(rtc_intr & RTC_IRQF))
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return 0;
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return rtc_intr & RTC_IRQMASK;
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}
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static inline unsigned char vrtc_is_updating(void)
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{
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unsigned char uip;
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unsigned long flags;
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spin_lock_irqsave(&rtc_lock, flags);
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uip = (vrtc_cmos_read(RTC_FREQ_SELECT) & RTC_UIP);
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spin_unlock_irqrestore(&rtc_lock, flags);
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return uip;
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}
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/*
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* rtc_time's year contains the increment over 1900, but vRTC's YEAR
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* register can't be programmed to value larger than 0x64, so vRTC
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* driver chose to use 1972 (1970 is UNIX time start point) as the base,
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* and does the translation at read/write time.
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*
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* Why not just use 1970 as the offset? it's because using 1972 will
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* make it consistent in leap year setting for both vrtc and low-level
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* physical rtc devices. Then why not use 1960 as the offset? If we use
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* 1960, for a device's first use, its YEAR register is 0 and the system
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* year will be parsed as 1960 which is not a valid UNIX time and will
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* cause many applications to fail mysteriously.
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*/
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static int mrst_read_time(struct device *dev, struct rtc_time *time)
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{
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unsigned long flags;
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if (vrtc_is_updating())
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msleep(20);
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spin_lock_irqsave(&rtc_lock, flags);
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time->tm_sec = vrtc_cmos_read(RTC_SECONDS);
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time->tm_min = vrtc_cmos_read(RTC_MINUTES);
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time->tm_hour = vrtc_cmos_read(RTC_HOURS);
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time->tm_mday = vrtc_cmos_read(RTC_DAY_OF_MONTH);
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time->tm_mon = vrtc_cmos_read(RTC_MONTH);
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time->tm_year = vrtc_cmos_read(RTC_YEAR);
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spin_unlock_irqrestore(&rtc_lock, flags);
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/* Adjust for the 1972/1900 */
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time->tm_year += 72;
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time->tm_mon--;
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return 0;
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}
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static int mrst_set_time(struct device *dev, struct rtc_time *time)
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{
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int ret;
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unsigned long flags;
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unsigned char mon, day, hrs, min, sec;
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unsigned int yrs;
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yrs = time->tm_year;
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mon = time->tm_mon + 1; /* tm_mon starts at zero */
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day = time->tm_mday;
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hrs = time->tm_hour;
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min = time->tm_min;
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sec = time->tm_sec;
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if (yrs < 72 || yrs > 172)
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return -EINVAL;
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yrs -= 72;
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spin_lock_irqsave(&rtc_lock, flags);
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vrtc_cmos_write(yrs, RTC_YEAR);
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vrtc_cmos_write(mon, RTC_MONTH);
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vrtc_cmos_write(day, RTC_DAY_OF_MONTH);
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vrtc_cmos_write(hrs, RTC_HOURS);
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vrtc_cmos_write(min, RTC_MINUTES);
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vrtc_cmos_write(sec, RTC_SECONDS);
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spin_unlock_irqrestore(&rtc_lock, flags);
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ret = intel_scu_ipc_simple_command(IPCMSG_VRTC, IPC_CMD_VRTC_SETTIME);
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return ret;
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}
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static int mrst_read_alarm(struct device *dev, struct rtc_wkalrm *t)
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{
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struct mrst_rtc *mrst = dev_get_drvdata(dev);
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unsigned char rtc_control;
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if (mrst->irq <= 0)
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return -EIO;
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/* vRTC only supports binary mode */
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spin_lock_irq(&rtc_lock);
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t->time.tm_sec = vrtc_cmos_read(RTC_SECONDS_ALARM);
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t->time.tm_min = vrtc_cmos_read(RTC_MINUTES_ALARM);
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t->time.tm_hour = vrtc_cmos_read(RTC_HOURS_ALARM);
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rtc_control = vrtc_cmos_read(RTC_CONTROL);
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spin_unlock_irq(&rtc_lock);
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t->enabled = !!(rtc_control & RTC_AIE);
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t->pending = 0;
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return 0;
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}
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static void mrst_checkintr(struct mrst_rtc *mrst, unsigned char rtc_control)
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{
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unsigned char rtc_intr;
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/*
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* NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
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* allegedly some older rtcs need that to handle irqs properly
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*/
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rtc_intr = vrtc_cmos_read(RTC_INTR_FLAGS);
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rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
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if (is_intr(rtc_intr))
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rtc_update_irq(mrst->rtc, 1, rtc_intr);
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}
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static void mrst_irq_enable(struct mrst_rtc *mrst, unsigned char mask)
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{
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unsigned char rtc_control;
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/*
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* Flush any pending IRQ status, notably for update irqs,
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* before we enable new IRQs
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*/
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rtc_control = vrtc_cmos_read(RTC_CONTROL);
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mrst_checkintr(mrst, rtc_control);
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rtc_control |= mask;
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vrtc_cmos_write(rtc_control, RTC_CONTROL);
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mrst_checkintr(mrst, rtc_control);
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}
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static void mrst_irq_disable(struct mrst_rtc *mrst, unsigned char mask)
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{
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unsigned char rtc_control;
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rtc_control = vrtc_cmos_read(RTC_CONTROL);
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rtc_control &= ~mask;
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vrtc_cmos_write(rtc_control, RTC_CONTROL);
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mrst_checkintr(mrst, rtc_control);
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}
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static int mrst_set_alarm(struct device *dev, struct rtc_wkalrm *t)
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{
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struct mrst_rtc *mrst = dev_get_drvdata(dev);
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unsigned char hrs, min, sec;
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int ret = 0;
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if (!mrst->irq)
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return -EIO;
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hrs = t->time.tm_hour;
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min = t->time.tm_min;
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sec = t->time.tm_sec;
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spin_lock_irq(&rtc_lock);
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/* Next rtc irq must not be from previous alarm setting */
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mrst_irq_disable(mrst, RTC_AIE);
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/* Update alarm */
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vrtc_cmos_write(hrs, RTC_HOURS_ALARM);
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vrtc_cmos_write(min, RTC_MINUTES_ALARM);
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vrtc_cmos_write(sec, RTC_SECONDS_ALARM);
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spin_unlock_irq(&rtc_lock);
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ret = intel_scu_ipc_simple_command(IPCMSG_VRTC, IPC_CMD_VRTC_SETALARM);
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if (ret)
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return ret;
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spin_lock_irq(&rtc_lock);
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if (t->enabled)
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mrst_irq_enable(mrst, RTC_AIE);
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spin_unlock_irq(&rtc_lock);
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return 0;
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}
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/* Currently, the vRTC doesn't support UIE ON/OFF */
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static int mrst_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
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{
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struct mrst_rtc *mrst = dev_get_drvdata(dev);
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unsigned long flags;
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spin_lock_irqsave(&rtc_lock, flags);
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if (enabled)
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mrst_irq_enable(mrst, RTC_AIE);
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else
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mrst_irq_disable(mrst, RTC_AIE);
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spin_unlock_irqrestore(&rtc_lock, flags);
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return 0;
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}
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#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
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static int mrst_procfs(struct device *dev, struct seq_file *seq)
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{
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unsigned char rtc_control;
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spin_lock_irq(&rtc_lock);
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rtc_control = vrtc_cmos_read(RTC_CONTROL);
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spin_unlock_irq(&rtc_lock);
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seq_printf(seq,
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"periodic_IRQ\t: %s\n"
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"alarm\t\t: %s\n"
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"BCD\t\t: no\n"
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"periodic_freq\t: daily (not adjustable)\n",
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(rtc_control & RTC_PIE) ? "on" : "off",
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(rtc_control & RTC_AIE) ? "on" : "off");
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return 0;
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}
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#else
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#define mrst_procfs NULL
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#endif
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static const struct rtc_class_ops mrst_rtc_ops = {
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.read_time = mrst_read_time,
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.set_time = mrst_set_time,
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.read_alarm = mrst_read_alarm,
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.set_alarm = mrst_set_alarm,
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.proc = mrst_procfs,
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.alarm_irq_enable = mrst_rtc_alarm_irq_enable,
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};
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static struct mrst_rtc mrst_rtc;
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/*
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* When vRTC IRQ is captured by SCU FW, FW will clear the AIE bit in
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* Reg B, so no need for this driver to clear it
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*/
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static irqreturn_t mrst_rtc_irq(int irq, void *p)
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{
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u8 irqstat;
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spin_lock(&rtc_lock);
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/* This read will clear all IRQ flags inside Reg C */
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irqstat = vrtc_cmos_read(RTC_INTR_FLAGS);
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spin_unlock(&rtc_lock);
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irqstat &= RTC_IRQMASK | RTC_IRQF;
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if (is_intr(irqstat)) {
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rtc_update_irq(p, 1, irqstat);
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return IRQ_HANDLED;
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}
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return IRQ_NONE;
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}
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static int vrtc_mrst_do_probe(struct device *dev, struct resource *iomem,
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int rtc_irq)
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{
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int retval = 0;
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unsigned char rtc_control;
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/* There can be only one ... */
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if (mrst_rtc.dev)
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return -EBUSY;
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if (!iomem)
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return -ENODEV;
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iomem = devm_request_mem_region(dev, iomem->start, resource_size(iomem),
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driver_name);
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if (!iomem) {
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dev_dbg(dev, "i/o mem already in use.\n");
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return -EBUSY;
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}
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mrst_rtc.irq = rtc_irq;
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mrst_rtc.dev = dev;
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dev_set_drvdata(dev, &mrst_rtc);
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mrst_rtc.rtc = devm_rtc_allocate_device(dev);
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if (IS_ERR(mrst_rtc.rtc))
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return PTR_ERR(mrst_rtc.rtc);
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mrst_rtc.rtc->ops = &mrst_rtc_ops;
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rename_region(iomem, dev_name(&mrst_rtc.rtc->dev));
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spin_lock_irq(&rtc_lock);
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mrst_irq_disable(&mrst_rtc, RTC_PIE | RTC_AIE);
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rtc_control = vrtc_cmos_read(RTC_CONTROL);
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spin_unlock_irq(&rtc_lock);
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if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY)))
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dev_dbg(dev, "TODO: support more than 24-hr BCD mode\n");
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if (rtc_irq) {
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retval = devm_request_irq(dev, rtc_irq, mrst_rtc_irq,
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0, dev_name(&mrst_rtc.rtc->dev),
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mrst_rtc.rtc);
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if (retval < 0) {
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dev_dbg(dev, "IRQ %d is already in use, err %d\n",
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rtc_irq, retval);
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goto cleanup0;
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}
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}
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retval = rtc_register_device(mrst_rtc.rtc);
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if (retval)
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goto cleanup0;
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dev_dbg(dev, "initialised\n");
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return 0;
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cleanup0:
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mrst_rtc.dev = NULL;
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dev_err(dev, "rtc-mrst: unable to initialise\n");
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return retval;
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}
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static void rtc_mrst_do_shutdown(void)
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{
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spin_lock_irq(&rtc_lock);
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mrst_irq_disable(&mrst_rtc, RTC_IRQMASK);
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spin_unlock_irq(&rtc_lock);
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}
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static void rtc_mrst_do_remove(struct device *dev)
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{
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struct mrst_rtc *mrst = dev_get_drvdata(dev);
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rtc_mrst_do_shutdown();
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mrst->rtc = NULL;
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mrst->dev = NULL;
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}
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#ifdef CONFIG_PM_SLEEP
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static int mrst_suspend(struct device *dev)
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{
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struct mrst_rtc *mrst = dev_get_drvdata(dev);
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unsigned char tmp;
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/* Only the alarm might be a wakeup event source */
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spin_lock_irq(&rtc_lock);
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mrst->suspend_ctrl = tmp = vrtc_cmos_read(RTC_CONTROL);
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if (tmp & (RTC_PIE | RTC_AIE)) {
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unsigned char mask;
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if (device_may_wakeup(dev))
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mask = RTC_IRQMASK & ~RTC_AIE;
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else
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mask = RTC_IRQMASK;
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tmp &= ~mask;
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vrtc_cmos_write(tmp, RTC_CONTROL);
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mrst_checkintr(mrst, tmp);
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}
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spin_unlock_irq(&rtc_lock);
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if (tmp & RTC_AIE) {
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mrst->enabled_wake = 1;
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enable_irq_wake(mrst->irq);
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}
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dev_dbg(&mrst_rtc.rtc->dev, "suspend%s, ctrl %02x\n",
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(tmp & RTC_AIE) ? ", alarm may wake" : "",
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tmp);
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return 0;
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}
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/*
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* We want RTC alarms to wake us from the deep power saving state
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*/
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static inline int mrst_poweroff(struct device *dev)
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{
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return mrst_suspend(dev);
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}
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static int mrst_resume(struct device *dev)
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{
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struct mrst_rtc *mrst = dev_get_drvdata(dev);
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unsigned char tmp = mrst->suspend_ctrl;
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/* Re-enable any irqs previously active */
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if (tmp & RTC_IRQMASK) {
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unsigned char mask;
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if (mrst->enabled_wake) {
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disable_irq_wake(mrst->irq);
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mrst->enabled_wake = 0;
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}
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spin_lock_irq(&rtc_lock);
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do {
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vrtc_cmos_write(tmp, RTC_CONTROL);
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mask = vrtc_cmos_read(RTC_INTR_FLAGS);
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mask &= (tmp & RTC_IRQMASK) | RTC_IRQF;
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if (!is_intr(mask))
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break;
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rtc_update_irq(mrst->rtc, 1, mask);
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tmp &= ~RTC_AIE;
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} while (mask & RTC_AIE);
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spin_unlock_irq(&rtc_lock);
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}
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dev_dbg(&mrst_rtc.rtc->dev, "resume, ctrl %02x\n", tmp);
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(mrst_pm_ops, mrst_suspend, mrst_resume);
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#define MRST_PM_OPS (&mrst_pm_ops)
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#else
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#define MRST_PM_OPS NULL
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static inline int mrst_poweroff(struct device *dev)
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{
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return -ENOSYS;
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}
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#endif
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static int vrtc_mrst_platform_probe(struct platform_device *pdev)
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{
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return vrtc_mrst_do_probe(&pdev->dev,
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platform_get_resource(pdev, IORESOURCE_MEM, 0),
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platform_get_irq(pdev, 0));
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}
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static int vrtc_mrst_platform_remove(struct platform_device *pdev)
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{
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rtc_mrst_do_remove(&pdev->dev);
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return 0;
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}
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static void vrtc_mrst_platform_shutdown(struct platform_device *pdev)
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{
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if (system_state == SYSTEM_POWER_OFF && !mrst_poweroff(&pdev->dev))
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return;
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rtc_mrst_do_shutdown();
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}
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MODULE_ALIAS("platform:vrtc_mrst");
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|
|
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static struct platform_driver vrtc_mrst_platform_driver = {
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|
.probe = vrtc_mrst_platform_probe,
|
|
.remove = vrtc_mrst_platform_remove,
|
|
.shutdown = vrtc_mrst_platform_shutdown,
|
|
.driver = {
|
|
.name = driver_name,
|
|
.pm = MRST_PM_OPS,
|
|
}
|
|
};
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|
|
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module_platform_driver(vrtc_mrst_platform_driver);
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|
|
|
MODULE_AUTHOR("Jacob Pan; Feng Tang");
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MODULE_DESCRIPTION("Driver for Moorestown virtual RTC");
|
|
MODULE_LICENSE("GPL");
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