From 6668b65ef22c5ad6dd13b4a63de22763ff6f93da Mon Sep 17 00:00:00 2001
From: Brandon Low <lostlogic@rockbox.org>
Date: Sun, 5 Mar 2006 18:19:46 +0000
Subject: [PATCH] Move the RTC read throttling to a smarter place

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8912 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/common/timefuncs.c | 27 ++++++++++++++++-----------
 firmware/drivers/rtc.c      | 17 +++++------------
 2 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/firmware/common/timefuncs.c b/firmware/common/timefuncs.c
index 81d5c493ec..19033a504e 100644
--- a/firmware/common/timefuncs.c
+++ b/firmware/common/timefuncs.c
@@ -20,6 +20,7 @@
 #include <stdio.h> /* get NULL */
 #include "config.h"
 
+#include "kernel.h"
 #include "rtc.h"
 #include "timefuncs.h"
 #include "debug.h"
@@ -42,25 +43,29 @@ bool valid_time(const struct tm *tm)
         return true;
 }
 
+static int last_tick = 0;
 
 struct tm *get_time(void)
 {
 #ifndef SIMULATOR
 #ifdef CONFIG_RTC
-    char rtcbuf[7];
 
-    rtc_read_datetime(rtcbuf);
+    /* Don't read the RTC more than 4 times per second */
+    if (last_tick + HZ/4 < current_tick) {
+        char rtcbuf[7];
+        rtc_read_datetime(rtcbuf);
 
-    tm.tm_sec = ((rtcbuf[0] & 0x70) >> 4) * 10 + (rtcbuf[0] & 0x0f);
-    tm.tm_min = ((rtcbuf[1] & 0x70) >> 4) * 10 + (rtcbuf[1] & 0x0f);
-    tm.tm_hour = ((rtcbuf[2] & 0x30) >> 4) * 10 + (rtcbuf[2] & 0x0f);
-    tm.tm_wday = rtcbuf[3] & 0x07;
-    tm.tm_mday = ((rtcbuf[4] & 0x30) >> 4) * 10 + (rtcbuf[4] & 0x0f);
-    tm.tm_mon = ((rtcbuf[5] & 0x10) >> 4) * 10 + (rtcbuf[5] & 0x0f) - 1;
-    tm.tm_year = ((rtcbuf[6] & 0xf0) >> 4) * 10 + (rtcbuf[6] & 0x0f) + 100;
+        tm.tm_sec = ((rtcbuf[0] & 0x70) >> 4) * 10 + (rtcbuf[0] & 0x0f);
+        tm.tm_min = ((rtcbuf[1] & 0x70) >> 4) * 10 + (rtcbuf[1] & 0x0f);
+        tm.tm_hour = ((rtcbuf[2] & 0x30) >> 4) * 10 + (rtcbuf[2] & 0x0f);
+        tm.tm_wday = rtcbuf[3] & 0x07;
+        tm.tm_mday = ((rtcbuf[4] & 0x30) >> 4) * 10 + (rtcbuf[4] & 0x0f);
+        tm.tm_mon = ((rtcbuf[5] & 0x10) >> 4) * 10 + (rtcbuf[5] & 0x0f) - 1;
+        tm.tm_year = ((rtcbuf[6] & 0xf0) >> 4) * 10 + (rtcbuf[6] & 0x0f) + 100;
 
-    tm.tm_yday = 0; /* Not implemented for now */
-    tm.tm_isdst = -1; /* Not implemented for now */
+        tm.tm_yday = 0; /* Not implemented for now */
+        tm.tm_isdst = -1; /* Not implemented for now */
+    }
 #else
     tm.tm_sec = 0;
     tm.tm_min = 0;
diff --git a/firmware/drivers/rtc.c b/firmware/drivers/rtc.c
index 6458092348..ecfd2ac6ba 100644
--- a/firmware/drivers/rtc.c
+++ b/firmware/drivers/rtc.c
@@ -61,24 +61,17 @@ int rtc_write_datetime(unsigned char* buf)
     return 1;
 }
 #elif CONFIG_RTC == RTC_PCF50606
-static int last_tick;
-static char rtc_buf[7];
 void rtc_init(void)
 {
-    last_tick = 0;
 }
 
 int rtc_read_datetime(unsigned char* buf) {
     int rc;
-    if (last_tick + HZ/2 < current_tick) {
-        int oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
-        last_tick = current_tick;
-        rc  = pcf50606_read_multiple(0x0a, rtc_buf, 7);
-        set_irq_level(oldlevel);
-    } else {
-        rc = 7;
-    }
-    memcpy(buf, rtc_buf, 7);
+    int oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
+    
+    rc = pcf50606_read_multiple(0x0a, buf, 7);
+
+    set_irq_level(oldlevel);
     return rc;
 }