Fix wrong udelay logic that made it be way off.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25770 a1c6a512-1295-4272-9138-f99709370657

2 files changed, 8 insertions, 8 deletions

diff --git a/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c b/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c
index 4129d34ec7..d23fb432d6 100644
--- a/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c
+++ b/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c
@@ -233,12 +233,12 @@ int button_read_device(void)
     CCU_IO &= ~(1<<12);
 
     GPIOB_PIN(0) = 1<<0;
-    udelay(10);
+    udelay(4);
 
     gpiod6 = GPIOD_PIN(6);
 
     GPIOB_PIN(0) = 0;
-    udelay(5);
+    udelay(2);
 
     if (GPIOC_PIN(1) & 1<<1)
         btn |= BUTTON_DOWN;
diff --git a/firmware/target/arm/as3525/system-target.h b/firmware/target/arm/as3525/system-target.h
index ee46e7c7a5..38e2028f65 100644
--- a/firmware/target/arm/as3525/system-target.h
+++ b/firmware/target/arm/as3525/system-target.h
@@ -66,15 +66,15 @@ static inline void udelay(unsigned usecs)
     int end;
     
     /**
-     * we're limited to 1.5us multiplies due to the odd timer frequency (1.5MHz),
+     * we're limited to 0.666us multiplies due to the odd timer frequency (1.5MHz),
      * to avoid calculating which is safer (need to round up for small values)
      * and saves spending time in the divider we have a lut for
-     * small us values, it should be roughly us*2/3
+     * small us values, it should be roughly us*3/2
      **/
     static const unsigned char udelay_lut[] =
     {
-        0, 1, 2, 2,  3,  4,  4,  5,  6,  6,
-        7, 8, 8, 9, 10, 10, 11, 12, 12, 13,
+         0,  2,  3,  5,  6,  8,  9, 11, 12, 14,
+        15, 17, 18, 20, 21, 23, 24, 26, 27, 29,
     };
 
 
@@ -82,7 +82,7 @@ static inline void udelay(unsigned usecs)
     /* we don't want to handle multiple overflows, so limit the numbers
      * (if you want to wait more than a tick just poll current_tick, or
      * call sleep()) */
-    if (UNLIKELY(usecs >= TIMER_PERIOD))
+    if (UNLIKELY(usecs >= (TIMER_PERIOD*2/3)))
         panicf("%s(): %d too high!", __func__, usecs);
     if (UNLIKELY(usecs <= 0))
         return;
@@ -92,7 +92,7 @@ static inline void udelay(unsigned usecs)
     }
     else
     {   /* to usecs */
-        int delay = usecs * 2 / 3; /* us * 1.5 = us*timer_period */
+        int delay = usecs * 3 / 2; /* us * 0.666 = us*timer_period */
         end = now - delay;
     }