X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Frtc%2Frtc-bfin.c;h=d90ba860d21678863610a69a3dc9a74f5b9e53bd;hb=4db8a5f21e5149e09949516eef98b78b68880075;hp=260ead95991898b0f89f57f2838464263cdb1abd;hpb=6ec129c3a2f8b38bc37e42348470ccfcb7460146;p=linux-2.6-omap-h63xx.git diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c index 260ead95991..d90ba860d21 100644 --- a/drivers/rtc/rtc-bfin.c +++ b/drivers/rtc/rtc-bfin.c @@ -1,6 +1,6 @@ /* * Blackfin On-Chip Real Time Clock Driver - * Supports BF531/BF532/BF533/BF534/BF536/BF537 + * Supports BF52[257]/BF53[123]/BF53[467]/BF54[24789] * * Copyright 2004-2007 Analog Devices Inc. * @@ -32,26 +32,25 @@ * writes to clear status registers complete immediately. */ -#include -#include #include -#include +#include +#include #include +#include +#include +#include #include +#include #include -#include -#include -#include #include -#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __FUNCTION__, __LINE__, ## args) -#define stampit() stamp("here i am") +#define dev_dbg_stamp(dev) dev_dbg(dev, "%s:%i: here i am\n", __func__, __LINE__) struct bfin_rtc { struct rtc_device *rtc_dev; struct rtc_time rtc_alarm; - spinlock_t lock; + u16 rtc_wrote_regs; }; /* Bit values for the ISTAT / ICTL registers */ @@ -72,7 +71,7 @@ struct bfin_rtc { #define SEC_BITS_OFF 0 /* Some helper functions to convert between the common RTC notion of time - * and the internal Blackfin notion that is stored in 32bits. + * and the internal Blackfin notion that is encoded in 32bits. */ static inline u32 rtc_time_to_bfin(unsigned long now) { @@ -97,7 +96,10 @@ static inline void rtc_bfin_to_tm(u32 rtc_bfin, struct rtc_time *tm) rtc_time_to_tm(rtc_bfin_to_time(rtc_bfin), tm); } -/* Wait for the previous write to a RTC register to complete. +/** + * bfin_rtc_sync_pending - make sure pending writes have complete + * + * Wait for the previous write to a RTC register to complete. * Unfortunately, we can't sleep here as that introduces a race condition when * turning on interrupt events. Consider this: * - process sets alarm @@ -112,188 +114,202 @@ static inline void rtc_bfin_to_tm(u32 rtc_bfin, struct rtc_time *tm) * If anyone can point out the obvious solution here, i'm listening :). This * shouldn't be an issue on an SMP or preempt system as this function should * only be called with the rtc lock held. + * + * Other options: + * - disable PREN so the sync happens at 32.768kHZ ... but this changes the + * inc rate for all RTC registers from 1HZ to 32.768kHZ ... + * - use the write complete IRQ */ -static void rtc_bfin_sync_pending(void) +/* +static void bfin_rtc_sync_pending_polled(void) { - stampit(); - while (!(bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_COMPLETE)) { + while (!(bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_COMPLETE)) if (!(bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_PENDING)) break; - } bfin_write_RTC_ISTAT(RTC_ISTAT_WRITE_COMPLETE); } +*/ +static DECLARE_COMPLETION(bfin_write_complete); +static void bfin_rtc_sync_pending(struct device *dev) +{ + dev_dbg_stamp(dev); + while (bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_PENDING) + wait_for_completion_timeout(&bfin_write_complete, HZ * 5); + dev_dbg_stamp(dev); +} -static void rtc_bfin_reset(struct bfin_rtc *rtc) +/** + * bfin_rtc_reset - set RTC to sane/known state + * + * Initialize the RTC. Enable pre-scaler to scale RTC clock + * to 1Hz and clear interrupt/status registers. + */ +static void bfin_rtc_reset(struct device *dev) { - /* Initialize the RTC. Enable pre-scaler to scale RTC clock - * to 1Hz and clear interrupt/status registers. */ - spin_lock_irq(&rtc->lock); - rtc_bfin_sync_pending(); + struct bfin_rtc *rtc = dev_get_drvdata(dev); + dev_dbg_stamp(dev); + bfin_rtc_sync_pending(dev); bfin_write_RTC_PREN(0x1); - bfin_write_RTC_ICTL(0); + bfin_write_RTC_ICTL(RTC_ISTAT_WRITE_COMPLETE); bfin_write_RTC_SWCNT(0); bfin_write_RTC_ALARM(0); bfin_write_RTC_ISTAT(0xFFFF); - spin_unlock_irq(&rtc->lock); + rtc->rtc_wrote_regs = 0; } +/** + * bfin_rtc_interrupt - handle interrupt from RTC + * + * Since we handle all RTC events here, we have to make sure the requested + * interrupt is enabled (in RTC_ICTL) as the event status register (RTC_ISTAT) + * always gets updated regardless of the interrupt being enabled. So when one + * even we care about (e.g. stopwatch) goes off, we don't want to turn around + * and say that other events have happened as well (e.g. second). We do not + * have to worry about pending writes to the RTC_ICTL register as interrupts + * only fire if they are enabled in the RTC_ICTL register. + */ static irqreturn_t bfin_rtc_interrupt(int irq, void *dev_id) { - struct platform_device *pdev = to_platform_device(dev_id); - struct bfin_rtc *rtc = platform_get_drvdata(pdev); + struct device *dev = dev_id; + struct bfin_rtc *rtc = dev_get_drvdata(dev); unsigned long events = 0; - u16 rtc_istat; - - stampit(); + bool write_complete = false; + u16 rtc_istat, rtc_ictl; - spin_lock_irq(&rtc->lock); + dev_dbg_stamp(dev); rtc_istat = bfin_read_RTC_ISTAT(); + rtc_ictl = bfin_read_RTC_ICTL(); - if (rtc_istat & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)) { - bfin_write_RTC_ISTAT(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY); - events |= RTC_AF | RTC_IRQF; + if (rtc_istat & RTC_ISTAT_WRITE_COMPLETE) { + bfin_write_RTC_ISTAT(RTC_ISTAT_WRITE_COMPLETE); + write_complete = true; + complete(&bfin_write_complete); } - if (rtc_istat & RTC_ISTAT_STOPWATCH) { - bfin_write_RTC_ISTAT(RTC_ISTAT_STOPWATCH); - events |= RTC_PF | RTC_IRQF; - bfin_write_RTC_SWCNT(rtc->rtc_dev->irq_freq); + if (rtc_ictl & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)) { + if (rtc_istat & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)) { + bfin_write_RTC_ISTAT(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY); + events |= RTC_AF | RTC_IRQF; + } } - if (rtc_istat & RTC_ISTAT_SEC) { - bfin_write_RTC_ISTAT(RTC_ISTAT_SEC); - events |= RTC_UF | RTC_IRQF; + if (rtc_ictl & RTC_ISTAT_STOPWATCH) { + if (rtc_istat & RTC_ISTAT_STOPWATCH) { + bfin_write_RTC_ISTAT(RTC_ISTAT_STOPWATCH); + events |= RTC_PF | RTC_IRQF; + bfin_write_RTC_SWCNT(rtc->rtc_dev->irq_freq); + } } - rtc_update_irq(rtc->rtc_dev, 1, events); + if (rtc_ictl & RTC_ISTAT_SEC) { + if (rtc_istat & RTC_ISTAT_SEC) { + bfin_write_RTC_ISTAT(RTC_ISTAT_SEC); + events |= RTC_UF | RTC_IRQF; + } + } - spin_unlock_irq(&rtc->lock); + if (events) + rtc_update_irq(rtc->rtc_dev, 1, events); - return IRQ_HANDLED; + if (write_complete || events) + return IRQ_HANDLED; + else + return IRQ_NONE; } static int bfin_rtc_open(struct device *dev) { - struct bfin_rtc *rtc = dev_get_drvdata(dev); int ret; - stampit(); + dev_dbg_stamp(dev); - ret = request_irq(IRQ_RTC, bfin_rtc_interrupt, IRQF_DISABLED, "rtc-bfin", dev); - if (unlikely(ret)) { - dev_err(dev, "request RTC IRQ failed with %d\n", ret); - return ret; - } - - rtc_bfin_reset(rtc); + ret = request_irq(IRQ_RTC, bfin_rtc_interrupt, IRQF_SHARED, to_platform_device(dev)->name, dev); + if (!ret) + bfin_rtc_reset(dev); return ret; } static void bfin_rtc_release(struct device *dev) { - struct bfin_rtc *rtc = dev_get_drvdata(dev); - stampit(); - rtc_bfin_reset(rtc); + dev_dbg_stamp(dev); + bfin_rtc_reset(dev); free_irq(IRQ_RTC, dev); } +static void bfin_rtc_int_set(struct bfin_rtc *rtc, u16 rtc_int) +{ + bfin_write_RTC_ISTAT(rtc_int); + bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() | rtc_int); +} +static void bfin_rtc_int_clear(struct bfin_rtc *rtc, u16 rtc_int) +{ + bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & rtc_int); +} +static void bfin_rtc_int_set_alarm(struct bfin_rtc *rtc) +{ + /* Blackfin has different bits for whether the alarm is + * more than 24 hours away. + */ + bfin_rtc_int_set(rtc, (rtc->rtc_alarm.tm_yday == -1 ? RTC_ISTAT_ALARM : RTC_ISTAT_ALARM_DAY)); +} static int bfin_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { struct bfin_rtc *rtc = dev_get_drvdata(dev); + int ret = 0; + + dev_dbg_stamp(dev); - stampit(); + bfin_rtc_sync_pending(dev); switch (cmd) { case RTC_PIE_ON: - stampit(); - spin_lock_irq(&rtc->lock); - rtc_bfin_sync_pending(); - bfin_write_RTC_ISTAT(RTC_ISTAT_STOPWATCH); + dev_dbg_stamp(dev); + bfin_rtc_int_set(rtc, RTC_ISTAT_STOPWATCH); bfin_write_RTC_SWCNT(rtc->rtc_dev->irq_freq); - bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() | RTC_ISTAT_STOPWATCH); - spin_unlock_irq(&rtc->lock); - return 0; + break; case RTC_PIE_OFF: - stampit(); - spin_lock_irq(&rtc->lock); - rtc_bfin_sync_pending(); - bfin_write_RTC_SWCNT(0); - bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & ~RTC_ISTAT_STOPWATCH); - spin_unlock_irq(&rtc->lock); - return 0; + dev_dbg_stamp(dev); + bfin_rtc_int_clear(rtc, ~RTC_ISTAT_STOPWATCH); + break; case RTC_UIE_ON: - stampit(); - spin_lock_irq(&rtc->lock); - rtc_bfin_sync_pending(); - bfin_write_RTC_ISTAT(RTC_ISTAT_SEC); - bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() | RTC_ISTAT_SEC); - spin_unlock_irq(&rtc->lock); - return 0; + dev_dbg_stamp(dev); + bfin_rtc_int_set(rtc, RTC_ISTAT_SEC); + break; case RTC_UIE_OFF: - stampit(); - spin_lock_irq(&rtc->lock); - rtc_bfin_sync_pending(); - bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & ~RTC_ISTAT_SEC); - spin_unlock_irq(&rtc->lock); - return 0; - - case RTC_AIE_ON: { - unsigned long rtc_alarm; - u16 which_alarm; - int ret = 0; - - stampit(); - - spin_lock_irq(&rtc->lock); - - rtc_bfin_sync_pending(); - if (rtc->rtc_alarm.tm_yday == -1) { - struct rtc_time now; - rtc_bfin_to_tm(bfin_read_RTC_STAT(), &now); - now.tm_sec = rtc->rtc_alarm.tm_sec; - now.tm_min = rtc->rtc_alarm.tm_min; - now.tm_hour = rtc->rtc_alarm.tm_hour; - ret = rtc_tm_to_time(&now, &rtc_alarm); - which_alarm = RTC_ISTAT_ALARM; - } else { - ret = rtc_tm_to_time(&rtc->rtc_alarm, &rtc_alarm); - which_alarm = RTC_ISTAT_ALARM_DAY; - } - if (ret == 0) { - bfin_write_RTC_ISTAT(which_alarm); - bfin_write_RTC_ALARM(rtc_time_to_bfin(rtc_alarm)); - bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() | which_alarm); - } - - spin_unlock_irq(&rtc->lock); - - return ret; - } + dev_dbg_stamp(dev); + bfin_rtc_int_clear(rtc, ~RTC_ISTAT_SEC); + break; + + case RTC_AIE_ON: + dev_dbg_stamp(dev); + bfin_rtc_int_set_alarm(rtc); + break; case RTC_AIE_OFF: - stampit(); - spin_lock_irq(&rtc->lock); - rtc_bfin_sync_pending(); - bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & ~(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)); - spin_unlock_irq(&rtc->lock); - return 0; + dev_dbg_stamp(dev); + bfin_rtc_int_clear(rtc, ~(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)); + break; + + default: + dev_dbg_stamp(dev); + ret = -ENOIOCTLCMD; } - return -ENOIOCTLCMD; + return ret; } static int bfin_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct bfin_rtc *rtc = dev_get_drvdata(dev); - stampit(); + dev_dbg_stamp(dev); + + if (rtc->rtc_wrote_regs & 0x1) + bfin_rtc_sync_pending(dev); - spin_lock_irq(&rtc->lock); - rtc_bfin_sync_pending(); rtc_bfin_to_tm(bfin_read_RTC_STAT(), tm); - spin_unlock_irq(&rtc->lock); return 0; } @@ -304,64 +320,79 @@ static int bfin_rtc_set_time(struct device *dev, struct rtc_time *tm) int ret; unsigned long now; - stampit(); - - spin_lock_irq(&rtc->lock); + dev_dbg_stamp(dev); ret = rtc_tm_to_time(tm, &now); if (ret == 0) { - rtc_bfin_sync_pending(); + if (rtc->rtc_wrote_regs & 0x1) + bfin_rtc_sync_pending(dev); bfin_write_RTC_STAT(rtc_time_to_bfin(now)); + rtc->rtc_wrote_regs = 0x1; } - spin_unlock_irq(&rtc->lock); - return ret; } static int bfin_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct bfin_rtc *rtc = dev_get_drvdata(dev); - stampit(); - memcpy(&alrm->time, &rtc->rtc_alarm, sizeof(struct rtc_time)); - alrm->pending = !!(bfin_read_RTC_ICTL() & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)); + dev_dbg_stamp(dev); + alrm->time = rtc->rtc_alarm; + bfin_rtc_sync_pending(dev); + alrm->enabled = !!(bfin_read_RTC_ICTL() & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)); return 0; } static int bfin_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct bfin_rtc *rtc = dev_get_drvdata(dev); - stampit(); - memcpy(&rtc->rtc_alarm, &alrm->time, sizeof(struct rtc_time)); + unsigned long rtc_alarm; + + dev_dbg_stamp(dev); + + if (rtc_tm_to_time(&alrm->time, &rtc_alarm)) + return -EINVAL; + + rtc->rtc_alarm = alrm->time; + + bfin_rtc_sync_pending(dev); + bfin_write_RTC_ALARM(rtc_time_to_bfin(rtc_alarm)); + if (alrm->enabled) + bfin_rtc_int_set_alarm(rtc); + return 0; } static int bfin_rtc_proc(struct device *dev, struct seq_file *seq) { -#define yesno(x) (x ? "yes" : "no") +#define yesno(x) ((x) ? "yes" : "no") u16 ictl = bfin_read_RTC_ICTL(); - stampit(); - seq_printf(seq, "alarm_IRQ\t: %s\n", yesno(ictl & RTC_ISTAT_ALARM)); - seq_printf(seq, "wkalarm_IRQ\t: %s\n", yesno(ictl & RTC_ISTAT_ALARM_DAY)); - seq_printf(seq, "seconds_IRQ\t: %s\n", yesno(ictl & RTC_ISTAT_SEC)); - seq_printf(seq, "periodic_IRQ\t: %s\n", yesno(ictl & RTC_ISTAT_STOPWATCH)); -#ifdef DEBUG - seq_printf(seq, "RTC_STAT\t: 0x%08X\n", bfin_read_RTC_STAT()); - seq_printf(seq, "RTC_ICTL\t: 0x%04X\n", bfin_read_RTC_ICTL()); - seq_printf(seq, "RTC_ISTAT\t: 0x%04X\n", bfin_read_RTC_ISTAT()); - seq_printf(seq, "RTC_SWCNT\t: 0x%04X\n", bfin_read_RTC_SWCNT()); - seq_printf(seq, "RTC_ALARM\t: 0x%08X\n", bfin_read_RTC_ALARM()); - seq_printf(seq, "RTC_PREN\t: 0x%04X\n", bfin_read_RTC_PREN()); -#endif + dev_dbg_stamp(dev); + seq_printf(seq, + "alarm_IRQ\t: %s\n" + "wkalarm_IRQ\t: %s\n" + "seconds_IRQ\t: %s\n" + "periodic_IRQ\t: %s\n", + yesno(ictl & RTC_ISTAT_ALARM), + yesno(ictl & RTC_ISTAT_ALARM_DAY), + yesno(ictl & RTC_ISTAT_SEC), + yesno(ictl & RTC_ISTAT_STOPWATCH)); return 0; +#undef yesno } +/** + * bfin_irq_set_freq - make sure hardware supports requested freq + * @dev: pointer to RTC device structure + * @freq: requested frequency rate + * + * The Blackfin RTC can only generate periodic events at 1 per + * second (1 Hz), so reject any attempt at changing it. + */ static int bfin_irq_set_freq(struct device *dev, int freq) { - struct bfin_rtc *rtc = dev_get_drvdata(dev); - stampit(); - rtc->rtc_dev->irq_freq = freq; - return 0; + dev_dbg_stamp(dev); + return -ENOTTY; } static struct rtc_class_ops bfin_rtc_ops = { @@ -381,27 +412,24 @@ static int __devinit bfin_rtc_probe(struct platform_device *pdev) struct bfin_rtc *rtc; int ret = 0; - stampit(); + dev_dbg_stamp(&pdev->dev); rtc = kzalloc(sizeof(*rtc), GFP_KERNEL); if (unlikely(!rtc)) return -ENOMEM; - spin_lock_init(&rtc->lock); - rtc->rtc_dev = rtc_device_register(pdev->name, &pdev->dev, &bfin_rtc_ops, THIS_MODULE); if (unlikely(IS_ERR(rtc))) { ret = PTR_ERR(rtc->rtc_dev); goto err; } - rtc->rtc_dev->irq_freq = 0; - rtc->rtc_dev->max_user_freq = (2 << 16); /* stopwatch is an unsigned 16 bit reg */ + rtc->rtc_dev->irq_freq = 1; platform_set_drvdata(pdev, rtc); return 0; -err: + err: kfree(rtc); return ret; } @@ -428,7 +456,6 @@ static struct platform_driver bfin_rtc_driver = { static int __init bfin_rtc_init(void) { - stampit(); return platform_driver_register(&bfin_rtc_driver); }