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From: John Stultz <john.stultz@linaro.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: John Stultz <john.stultz@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Alessandro Zummo <a.zummo@towertech.it>,
	Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>,
	rtc-linux@googlegroups.com
Subject: [PATCH 10/10] RTC: Fix up rtc.txt documentation to reflect changes to generic rtc layer
Date: Mon, 21 Feb 2011 15:55:38 -0800	[thread overview]
Message-ID: <1298332538-31216-11-git-send-email-john.stultz@linaro.org> (raw)
In-Reply-To: <1298332538-31216-1-git-send-email-john.stultz@linaro.org>

Now that the genric RTC layer handles much of the RTC functionality,
the rtc.txt documentation needs to be updated to remove outdated information.

CC: Thomas Gleixner <tglx@linutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
CC: rtc-linux@googlegroups.com
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 Documentation/rtc.txt |   29 ++++++++++-------------------
 1 files changed, 10 insertions(+), 19 deletions(-)

diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt
index 9104c10..2501604 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!
 
-- 
1.7.3.2.146.gca209


      parent reply	other threads:[~2011-02-21 23:58 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-21 23:55 [PATCH 00/10] [RFC] RTC: Cleanups for 2.6.39 John Stultz
2011-02-21 23:55 ` [PATCH 01/10] RTC: Cleanup rtc_class_ops->irq_set_state John Stultz
2011-02-21 23:55 ` [PATCH 02/10] RTC: Cleanup rtc_class_ops->irq_set_freq() John Stultz
2011-02-21 23:55 ` [PATCH 03/10] RTC: Cleanup rtc_class_ops->update_irq_enable() John Stultz
2011-02-21 23:55 ` [PATCH 04/10] RTC: Cleanup rtc_class_ops->read_alarm() John Stultz
2011-02-22  2:34   ` [rtc-linux] " Mark Brown
2011-02-22  2:55     ` John Stultz
2011-02-22  8:09       ` john stultz
2011-02-22 12:51         ` Marcelo Roberto Jimenez
2011-02-22 19:35           ` john stultz
2011-02-22 19:51             ` Mark Brown
2011-02-22 19:58               ` john stultz
2011-02-22 21:26                 ` Marcelo Roberto Jimenez
2011-02-22 18:16         ` Mark Brown
2011-02-22 19:51           ` john stultz
2011-02-22 20:00             ` Mark Brown
2011-02-22 20:22               ` john stultz
2011-02-22 21:05                 ` Mark Brown
2011-02-22 21:21                   ` john stultz
2011-02-22 21:27                     ` Thomas Gleixner
2011-02-22 21:40                       ` Mark Brown
2011-02-22 21:33                     ` Mark Brown
2011-02-22 22:10                       ` john stultz
2011-02-22 23:07                         ` Mark Brown
2011-02-22 19:53           ` john stultz
2011-02-22 20:31             ` Mark Brown
2011-02-21 23:55 ` [PATCH 05/10] RTC: Clean out UIE icotl implementations John Stultz
2011-02-21 23:55 ` [PATCH 06/10] RTC: Include information about UIE and PIE in RTC driver proc John Stultz
2011-02-21 23:55 ` [PATCH 07/10] RTC: Remove UIE and PIE information from the sa1100 " John Stultz
2011-02-21 23:55 ` [PATCH 08/10] RTC: Fix the cross interrupt issue on rtc-test John Stultz
2011-02-21 23:55 ` [PATCH 09/10] RTC: sa1100: Update the sa1100 RTC driver John Stultz
2011-02-21 23:55 ` John Stultz [this message]

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