diff options
Diffstat (limited to 'drivers/rtc/rtc-cmos.c')
-rw-r--r-- | drivers/rtc/rtc-cmos.c | 201 |
1 files changed, 130 insertions, 71 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 4eb53412b808..7c006c2b125f 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -222,6 +222,8 @@ static inline void cmos_write_bank2(unsigned char val, unsigned char addr) static int cmos_read_time(struct device *dev, struct rtc_time *t) { + int ret; + /* * If pm_trace abused the RTC for storage, set the timespec to 0, * which tells the caller that this RTC value is unusable. @@ -229,7 +231,12 @@ static int cmos_read_time(struct device *dev, struct rtc_time *t) if (!pm_trace_rtc_valid()) return -EIO; - mc146818_get_time(t); + ret = mc146818_get_time(t); + if (ret < 0) { + dev_err_ratelimited(dev, "unable to read current time\n"); + return ret; + } + return 0; } @@ -242,10 +249,46 @@ static int cmos_set_time(struct device *dev, struct rtc_time *t) return mc146818_set_time(t); } +struct cmos_read_alarm_callback_param { + struct cmos_rtc *cmos; + struct rtc_time *time; + unsigned char rtc_control; +}; + +static void cmos_read_alarm_callback(unsigned char __always_unused seconds, + void *param_in) +{ + struct cmos_read_alarm_callback_param *p = + (struct cmos_read_alarm_callback_param *)param_in; + struct rtc_time *time = p->time; + + time->tm_sec = CMOS_READ(RTC_SECONDS_ALARM); + time->tm_min = CMOS_READ(RTC_MINUTES_ALARM); + time->tm_hour = CMOS_READ(RTC_HOURS_ALARM); + + if (p->cmos->day_alrm) { + /* ignore upper bits on readback per ACPI spec */ + time->tm_mday = CMOS_READ(p->cmos->day_alrm) & 0x3f; + if (!time->tm_mday) + time->tm_mday = -1; + + if (p->cmos->mon_alrm) { + time->tm_mon = CMOS_READ(p->cmos->mon_alrm); + if (!time->tm_mon) + time->tm_mon = -1; + } + } + + p->rtc_control = CMOS_READ(RTC_CONTROL); +} + static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t) { struct cmos_rtc *cmos = dev_get_drvdata(dev); - unsigned char rtc_control; + struct cmos_read_alarm_callback_param p = { + .cmos = cmos, + .time = &t->time, + }; /* This not only a rtc_op, but also called directly */ if (!is_valid_irq(cmos->irq)) @@ -256,28 +299,18 @@ static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t) * the future. */ - spin_lock_irq(&rtc_lock); - t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM); - t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM); - t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM); - - if (cmos->day_alrm) { - /* ignore upper bits on readback per ACPI spec */ - t->time.tm_mday = CMOS_READ(cmos->day_alrm) & 0x3f; - if (!t->time.tm_mday) - t->time.tm_mday = -1; - - if (cmos->mon_alrm) { - t->time.tm_mon = CMOS_READ(cmos->mon_alrm); - if (!t->time.tm_mon) - t->time.tm_mon = -1; - } - } - - rtc_control = CMOS_READ(RTC_CONTROL); - spin_unlock_irq(&rtc_lock); + /* Some Intel chipsets disconnect the alarm registers when the clock + * update is in progress - during this time reads return bogus values + * and writes may fail silently. See for example "7th Generation IntelĀ® + * Processor Family I/O for U/Y Platforms [...] Datasheet", section + * 27.7.1 + * + * Use the mc146818_avoid_UIP() function to avoid this. + */ + if (!mc146818_avoid_UIP(cmos_read_alarm_callback, &p)) + return -EIO; - if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { + if (!(p.rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { if (((unsigned)t->time.tm_sec) < 0x60) t->time.tm_sec = bcd2bin(t->time.tm_sec); else @@ -306,7 +339,7 @@ static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t) } } - t->enabled = !!(rtc_control & RTC_AIE); + t->enabled = !!(p.rtc_control & RTC_AIE); t->pending = 0; return 0; @@ -437,10 +470,57 @@ static int cmos_validate_alarm(struct device *dev, struct rtc_wkalrm *t) return 0; } +struct cmos_set_alarm_callback_param { + struct cmos_rtc *cmos; + unsigned char mon, mday, hrs, min, sec; + struct rtc_wkalrm *t; +}; + +/* Note: this function may be executed by mc146818_avoid_UIP() more then + * once + */ +static void cmos_set_alarm_callback(unsigned char __always_unused seconds, + void *param_in) +{ + struct cmos_set_alarm_callback_param *p = + (struct cmos_set_alarm_callback_param *)param_in; + + /* next rtc irq must not be from previous alarm setting */ + cmos_irq_disable(p->cmos, RTC_AIE); + + /* update alarm */ + CMOS_WRITE(p->hrs, RTC_HOURS_ALARM); + CMOS_WRITE(p->min, RTC_MINUTES_ALARM); + CMOS_WRITE(p->sec, RTC_SECONDS_ALARM); + + /* the system may support an "enhanced" alarm */ + if (p->cmos->day_alrm) { + CMOS_WRITE(p->mday, p->cmos->day_alrm); + if (p->cmos->mon_alrm) + CMOS_WRITE(p->mon, p->cmos->mon_alrm); + } + + if (use_hpet_alarm()) { + /* + * FIXME the HPET alarm glue currently ignores day_alrm + * and mon_alrm ... + */ + hpet_set_alarm_time(p->t->time.tm_hour, p->t->time.tm_min, + p->t->time.tm_sec); + } + + if (p->t->enabled) + cmos_irq_enable(p->cmos, RTC_AIE); +} + static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t) { struct cmos_rtc *cmos = dev_get_drvdata(dev); - unsigned char mon, mday, hrs, min, sec, rtc_control; + struct cmos_set_alarm_callback_param p = { + .cmos = cmos, + .t = t + }; + unsigned char rtc_control; int ret; /* This not only a rtc_op, but also called directly */ @@ -451,52 +531,33 @@ static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t) if (ret < 0) return ret; - mon = t->time.tm_mon + 1; - mday = t->time.tm_mday; - hrs = t->time.tm_hour; - min = t->time.tm_min; - sec = t->time.tm_sec; + p.mon = t->time.tm_mon + 1; + p.mday = t->time.tm_mday; + p.hrs = t->time.tm_hour; + p.min = t->time.tm_min; + p.sec = t->time.tm_sec; + spin_lock_irq(&rtc_lock); rtc_control = CMOS_READ(RTC_CONTROL); + spin_unlock_irq(&rtc_lock); + if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { /* Writing 0xff means "don't care" or "match all". */ - mon = (mon <= 12) ? bin2bcd(mon) : 0xff; - mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff; - hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff; - min = (min < 60) ? bin2bcd(min) : 0xff; - sec = (sec < 60) ? bin2bcd(sec) : 0xff; - } - - spin_lock_irq(&rtc_lock); - - /* next rtc irq must not be from previous alarm setting */ - cmos_irq_disable(cmos, RTC_AIE); - - /* update alarm */ - CMOS_WRITE(hrs, RTC_HOURS_ALARM); - CMOS_WRITE(min, RTC_MINUTES_ALARM); - CMOS_WRITE(sec, RTC_SECONDS_ALARM); - - /* the system may support an "enhanced" alarm */ - if (cmos->day_alrm) { - CMOS_WRITE(mday, cmos->day_alrm); - if (cmos->mon_alrm) - CMOS_WRITE(mon, cmos->mon_alrm); + p.mon = (p.mon <= 12) ? bin2bcd(p.mon) : 0xff; + p.mday = (p.mday >= 1 && p.mday <= 31) ? bin2bcd(p.mday) : 0xff; + p.hrs = (p.hrs < 24) ? bin2bcd(p.hrs) : 0xff; + p.min = (p.min < 60) ? bin2bcd(p.min) : 0xff; + p.sec = (p.sec < 60) ? bin2bcd(p.sec) : 0xff; } - if (use_hpet_alarm()) { - /* - * FIXME the HPET alarm glue currently ignores day_alrm - * and mon_alrm ... - */ - hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min, - t->time.tm_sec); - } - - if (t->enabled) - cmos_irq_enable(cmos, RTC_AIE); - - spin_unlock_irq(&rtc_lock); + /* + * Some Intel chipsets disconnect the alarm registers when the clock + * update is in progress - during this time writes fail silently. + * + * Use mc146818_avoid_UIP() to avoid this. + */ + if (!mc146818_avoid_UIP(cmos_set_alarm_callback, &p)) + return -EIO; cmos->alarm_expires = rtc_tm_to_time64(&t->time); @@ -790,16 +851,14 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) rename_region(ports, dev_name(&cmos_rtc.rtc->dev)); - spin_lock_irq(&rtc_lock); - - /* Ensure that the RTC is accessible. Bit 6 must be 0! */ - if ((CMOS_READ(RTC_VALID) & 0x40) != 0) { - spin_unlock_irq(&rtc_lock); - dev_warn(dev, "not accessible\n"); + if (!mc146818_does_rtc_work()) { + dev_warn(dev, "broken or not accessible\n"); retval = -ENXIO; goto cleanup1; } + spin_lock_irq(&rtc_lock); + if (!(flags & CMOS_RTC_FLAGS_NOFREQ)) { /* force periodic irq to CMOS reset default of 1024Hz; * |