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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-15 18:59:21 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-15 18:59:21 -0700 |
commit | 21a32816b2e13eafb6d8a4589a84c6e629adc392 (patch) | |
tree | 8cfd2b8ffd355ef0954d6fef36aaffbc6fd53215 /Documentation | |
parent | 420c1c572d4ceaa2f37b6311b7017ac6cf049fe2 (diff) | |
parent | ea04683f592e6200b52e191b7e2842aedcfd88b6 (diff) | |
download | linux-21a32816b2e13eafb6d8a4589a84c6e629adc392.tar.bz2 |
Merge branch 'timers-rtc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-rtc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
RTC: Fix up rtc.txt documentation to reflect changes to generic rtc layer
RTC: sa1100: Update the sa1100 RTC driver.
RTC: Fix the cross interrupt issue on rtc-test.
RTC: Remove UIE and PIE information from the sa1100 driver proc.
RTC: Include information about UIE and PIE in RTC driver proc.
RTC: Clean out UIE icotl implementations
RTC: Cleanup rtc_class_ops->update_irq_enable()
RTC: Cleanup rtc_class_ops->irq_set_freq()
RTC: Cleanup rtc_class_ops->irq_set_state
RTC: Initialize kernel state from RTC
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/rtc.txt | 29 |
1 files changed, 10 insertions, 19 deletions
diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt index 9104c1062084..250160469d83 100644 --- a/Documentation/rtc.txt +++ b/Documentation/rtc.txt @@ -178,38 +178,29 @@ RTC class framework, but can't be supported by the older driver. setting the longer alarm time and enabling its IRQ using a single request (using the same model as EFI firmware). - * RTC_UIE_ON, RTC_UIE_OFF ... if the RTC offers IRQs, it probably - also offers update IRQs whenever the "seconds" counter changes. - If needed, the RTC framework can emulate this mechanism. + * RTC_UIE_ON, RTC_UIE_OFF ... if the RTC offers IRQs, the RTC framework + will emulate this mechanism. - * RTC_PIE_ON, RTC_PIE_OFF, RTC_IRQP_SET, RTC_IRQP_READ ... another - feature often accessible with an IRQ line is a periodic IRQ, issued - at settable frequencies (usually 2^N Hz). + * RTC_PIE_ON, RTC_PIE_OFF, RTC_IRQP_SET, RTC_IRQP_READ ... these icotls + are emulated via a kernel hrtimer. In many cases, the RTC alarm can be a system wake event, used to force Linux out of a low power sleep state (or hibernation) back to a fully operational state. For example, a system could enter a deep power saving state until it's time to execute some scheduled tasks. -Note that many of these ioctls need not actually be implemented by your -driver. The common rtc-dev interface handles many of these nicely if your -driver returns ENOIOCTLCMD. Some common examples: +Note that many of these ioctls are handled by the common rtc-dev interface. +Some common examples: * RTC_RD_TIME, RTC_SET_TIME: the read_time/set_time functions will be called with appropriate values. - * RTC_ALM_SET, RTC_ALM_READ, RTC_WKALM_SET, RTC_WKALM_RD: the - set_alarm/read_alarm functions will be called. + * RTC_ALM_SET, RTC_ALM_READ, RTC_WKALM_SET, RTC_WKALM_RD: gets or sets + the alarm rtc_timer. May call the set_alarm driver function. - * RTC_IRQP_SET, RTC_IRQP_READ: the irq_set_freq function will be called - to set the frequency while the framework will handle the read for you - since the frequency is stored in the irq_freq member of the rtc_device - structure. Your driver needs to initialize the irq_freq member during - init. Make sure you check the requested frequency is in range of your - hardware in the irq_set_freq function. If it isn't, return -EINVAL. If - you cannot actually change the frequency, do not define irq_set_freq. + * RTC_IRQP_SET, RTC_IRQP_READ: These are emulated by the generic code. - * RTC_PIE_ON, RTC_PIE_OFF: the irq_set_state function will be called. + * RTC_PIE_ON, RTC_PIE_OFF: These are also emulated by the generic code. If all else fails, check out the rtc-test.c driver! |