From: Will Sowerbutts <will@sowerbutts.com>
Date: Thu, 1 Jan 2015 14:37:48 +0000 (+0000)
Subject: Kernel: Optionally call rtc_secs() less frequently
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=4cb1397f416bd89530635c2db3289e7232af5a86;p=FUZIX.git

Kernel: Optionally call rtc_secs() less frequently
---

diff --git a/Kernel/platform-n8vem-mark4/config.h b/Kernel/platform-n8vem-mark4/config.h
index 3b6fb756..28a47cf2 100644
--- a/Kernel/platform-n8vem-mark4/config.h
+++ b/Kernel/platform-n8vem-mark4/config.h
@@ -60,3 +60,4 @@
 
 /* We have a DS1302, we can read the time of day from it */
 #define CONFIG_RTC
+#define CONFIG_RTC_INTERVAL 30 /* deciseconds between reading RTC seconds counter */
diff --git a/Kernel/platform-p112/config.h b/Kernel/platform-p112/config.h
index 316ee2a0..dc464760 100644
--- a/Kernel/platform-p112/config.h
+++ b/Kernel/platform-p112/config.h
@@ -57,3 +57,4 @@
 
 /* We have a DS1302, we can read the time of day from it */
 #define CONFIG_RTC
+#define CONFIG_RTC_INTERVAL 30 /* deciseconds between reading RTC seconds counter */
diff --git a/Kernel/timer.c b/Kernel/timer.c
index e9b8a3c3..d97ec406 100644
--- a/Kernel/timer.c
+++ b/Kernel/timer.c
@@ -65,6 +65,9 @@ void updatetod(void)
 #else
 
 static uint8_t rtcsec;
+#ifdef CONFIG_RTC_INTERVAL
+static uint8_t tod_deci;
+#endif
 
 /*
  *	We use the seconds counter on the RTC as a time counter and lock our
@@ -77,9 +80,19 @@ static uint8_t rtcsec;
  */
 void updatetod(void)
 {
-	uint8_t rtcnew = rtc_secs();	/* platform function */
+	uint8_t rtcnew;
 	int8_t slide;
 
+#ifdef CONFIG_RTC_INTERVAL
+	/* on some platforms reading the RTC is expensive so we don't do it
+	   every decisecond. */
+	if(++tod_deci != CONFIG_RTC_INTERVAL)
+	    return;
+	tod_deci = 0;
+#endif
+
+	rtcnew = rtc_secs();		/* platform function */
+
 	if (rtcnew == rtcsec)
 		return;
 	slide = rtcnew - rtcsec;	/* Seconds elapsed */