From a23ad152c9696fcc3d711ac96a4faf9d92b682ad Mon Sep 17 00:00:00 2001
From: Mike Frysinger <michael.frysinger@analog.com>
Date: Wed, 6 Feb 2008 01:38:47 -0800
Subject: [PATCH] --- yaml --- r: 83531 b: refs/heads/master c:
 5c236343eb558e3cf3bbffd0688f5518f8b9028a h: refs/heads/master i:   83529:
 b38b5c2f3e1274d65ce3c2e0c7b989446d91a22b   83527:
 53053bf761b4d3a990b6321a21a9c3d891819cb7 v: v3

---
 [refs]                       |  2 +-
 trunk/drivers/rtc/rtc-bfin.c | 24 +++++++++++++++++-------
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/[refs] b/[refs]
index e1dfb2056abc..6e220621bf66 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8f26795a22b12880bb07be688df72b4266f67be8
+refs/heads/master: 5c236343eb558e3cf3bbffd0688f5518f8b9028a
diff --git a/trunk/drivers/rtc/rtc-bfin.c b/trunk/drivers/rtc/rtc-bfin.c
index 1aa709dda0d6..303ed6e91d3f 100644
--- a/trunk/drivers/rtc/rtc-bfin.c
+++ b/trunk/drivers/rtc/rtc-bfin.c
@@ -72,7 +72,7 @@ struct bfin_rtc {
 #define SEC_BITS_OFF    0
 
 /* Some helper functions to convert between the common RTC notion of time
- * and the internal Blackfin notion that is stored in 32bits.
+ * and the internal Blackfin notion that is encoded in 32bits.
  */
 static inline u32 rtc_time_to_bfin(unsigned long now)
 {
@@ -112,6 +112,11 @@ static inline void rtc_bfin_to_tm(u32 rtc_bfin, struct rtc_time *tm)
  * If anyone can point out the obvious solution here, i'm listening :).  This
  * shouldn't be an issue on an SMP or preempt system as this function should
  * only be called with the rtc lock held.
+ *
+ * Other options:
+ *  - disable PREN so the sync happens at 32.768kHZ ... but this changes the
+ *    inc rate for all RTC registers from 1HZ to 32.768kHZ ...
+ *  - use the write complete IRQ
  */
 static void rtc_bfin_sync_pending(void)
 {
@@ -356,12 +361,18 @@ static int bfin_rtc_proc(struct device *dev, struct seq_file *seq)
 	return 0;
 }
 
+/**
+ *	bfin_irq_set_freq - make sure hardware supports requested freq
+ *	@dev: pointer to RTC device structure
+ *	@freq: requested frequency rate
+ *
+ *	The Blackfin RTC can only generate periodic events at 1 per
+ *	second (1 Hz), so reject any attempt at changing it.
+ */
 static int bfin_irq_set_freq(struct device *dev, int freq)
 {
-	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 	stampit();
-	rtc->rtc_dev->irq_freq = freq;
-	return 0;
+	return -ENOTTY;
 }
 
 static struct rtc_class_ops bfin_rtc_ops = {
@@ -394,14 +405,13 @@ static int __devinit bfin_rtc_probe(struct platform_device *pdev)
 		ret = PTR_ERR(rtc->rtc_dev);
 		goto err;
 	}
-	rtc->rtc_dev->irq_freq = 0;
-	rtc->rtc_dev->max_user_freq = (2 << 16); /* stopwatch is an unsigned 16 bit reg */
+	rtc->rtc_dev->irq_freq = 1;
 
 	platform_set_drvdata(pdev, rtc);
 
 	return 0;
 
-err:
+ err:
 	kfree(rtc);
 	return ret;
 }