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!