On Mon, Dec 3, 2012 at 9:39 AM, Chao Xie <xiechao.m...@gmail.com> wrote: > On Fri, Nov 30, 2012 at 3:04 PM, Haojian Zhuang > <haojian.zhu...@gmail.com> wrote: >> On Thu, Nov 29, 2012 at 6:25 PM, Russell King - ARM Linux >> <li...@arm.linux.org.uk> wrote: >>> On Wed, Nov 28, 2012 at 09:21:07PM -0500, Chao Xie wrote: >>>> The original sa1100_rtc_open/sa1100_rtc_release will be called >>>> when the /dev/rtc0 is opened or closed. >>>> In fact, these two functions will enable/disable the clock, and >>>> register/unregister the irqs. >>>> User application will use /dev/rtc0 to read the rtc time or set >>>> the alarm. The rtc should still run indepent of open/close the >>>> rtc device. >>>> So only enable clock and register the irqs when probe the device, >>>> and disable clock and unregister the irqs when remove the device. >>> >>> NAK. I don't think you properly understand what's going on here if you >>> think moving the entire open and release functions into the probe and >>> remove functions is the right thing to do. >> >> Since PXA27x & PXA3xx supports dual rtc device at the same time, >> user could choose use either of rtc at run time. Then clk & irq are setup >> in open(). >> >> Chao, >> So you shouldn't remove them into probe(). > > How can user to choose one RTC? > The user API, for example "date" will open the device, get the time > and then close the device. > WHen set a alarm, it is the same routine. open->set->close. > The open routine will enable clock and register irq, close will > disable the clock and unregister irq. It means that if only open is > invoked, rtc begins to work, and after close is invoked rtc stops > working. It means that the user can not get correct time and can not > get right alarm.
hi I want to correct what i said. For the irq register/unregister i think can be done at open/release. But for clock enable/disable, i do not think so. If clock is disabled, as i think RTC will not work. User API still use open->get_time->close for "date" command. It means that RTC will not return correct date to user. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
