diff options
| author |   Wan ZongShun <mcuos.com@gmail.com> | 2010-08-10 18:02:05 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-11 08:59:06 -0700 |
| commit | 0a89b55364e0a4fd4be9bc2c9a697f9b027eb395 (patch) | |
| tree | 6586428d02fe9365201eb28518d93ea27aa0b5da /drivers/rtc/rtc-nuc900.c | |
| parent | autofs4: remove unneeded null check in try_to_fill_dentry() (diff) | |
| download | linux-dev-0a89b55364e0a4fd4be9bc2c9a697f9b027eb395.tar.xz linux-dev-0a89b55364e0a4fd4be9bc2c9a697f9b027eb395.zip | |
nuc900/rtc: change the waiting for device ready implement
- add an mdelay(1) to the polling loop to cause less frequent access to
the hardware register.
- change the return value from ENODEV to EPERM if the loop timed out. I
think the 'Operation not permitted' description is more suitable for the
meaning of 'check_rtc_access_enable()' function, it just be used to
judge rtc access operation is permitted or not.
Signed-off-by: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.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/rtc-nuc900.c')
| -rw-r--r-- | drivers/rtc/rtc-nuc900.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/rtc/rtc-nuc900.c b/drivers/rtc/rtc-nuc900.c index a351bd5d8176..21d13309fb20 100644 --- a/drivers/rtc/rtc-nuc900.c +++ b/drivers/rtc/rtc-nuc900.c @@ -85,22 +85,21 @@ static irqreturn_t nuc900_rtc_interrupt(int irq, void *_rtc) static int *check_rtc_access_enable(struct nuc900_rtc *nuc900_rtc) { - unsigned int i; + unsigned int i, timeout = 0x1000; __raw_writel(INIRRESET, nuc900_rtc->rtc_reg + REG_RTC_INIR); mdelay(10); __raw_writel(AERPOWERON, nuc900_rtc->rtc_reg + REG_RTC_AER); - for (i = 0; i < 1000; i++) { - if (__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB) - return 0; - } + while (!(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB) + && timeout--) + mdelay(1); - if ((__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB) == 0x0) - return ERR_PTR(-ENODEV); + if (!timeout) + return ERR_PTR(-EPERM); - return ERR_PTR(-EPERM); + return 0; } static void nuc900_rtc_bcd2bin(unsigned int timereg, |