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| author | Mike Frysinger <michael.frysinger@analog.com> | 2008-02-06 01:38:47 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-06 10:41:13 -0800 |
| commit | 5c236343eb558e3cf3bbffd0688f5518f8b9028a (patch) | |
| tree | fd56732063f8a223c589ca46ab4b0de7c25fc0ab /drivers/rtc | |
| parent | 8f26795a22b12880bb07be688df72b4266f67be8 (diff) | |
| download | linux-3.10-5c236343eb558e3cf3bbffd0688f5518f8b9028a.tar.gz linux-3.10-5c236343eb558e3cf3bbffd0688f5518f8b9028a.tar.bz2 linux-3.10-5c236343eb558e3cf3bbffd0688f5518f8b9028a.zip | |
Blackfin RTC driver: the frequency function is in units of Hz, not units of seconds, so lock our driver down to 1 Hz
Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-bfin.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c index 1aa709dda0d..303ed6e91d3 100644 --- a/drivers/rtc/rtc-bfin.c +++ b/drivers/rtc/rtc-bfin.c @@ -72,7 +72,7 @@ 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) { @@ -112,6 +112,11 @@ 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) { @@ -356,12 +361,18 @@ static int bfin_rtc_proc(struct device *dev, struct seq_file *seq) return 0; } +/** + * 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; + return -ENOTTY; } static struct rtc_class_ops bfin_rtc_ops = { @@ -394,14 +405,13 @@ static int __devinit bfin_rtc_probe(struct platform_device *pdev) 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; } |