arm: zynq: U-Boot udelay < 1000 FIX
Rework the __udelay function of U-Boot Zynq Arch to handle
delay < 1000 usec
Signed-off-by: David Andrey <david.andrey@netmodule.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Tom Rini <trini@ti.com>
diff --git a/arch/arm/cpu/armv7/zynq/timer.c b/arch/arm/cpu/armv7/zynq/timer.c
index 45b405a..5d8bb24 100644
--- a/arch/arm/cpu/armv7/zynq/timer.c
+++ b/arch/arm/cpu/armv7/zynq/timer.c
@@ -114,15 +114,43 @@
void __udelay(unsigned long usec)
{
- unsigned long long tmp;
- ulong tmo;
+ u32 countticks;
+ u32 timeend;
+ u32 timediff;
+ u32 timenow;
- tmo = usec / (1000000 / CONFIG_SYS_HZ);
- tmp = get_ticks() + tmo; /* Get current timestamp */
+ if (usec == 0)
+ return;
+
+ countticks = (u32) (((unsigned long long) TIMER_TICK_HZ * usec) /
+ 1000000);
+
+ /* decrementing timer */
+ timeend = readl(&timer_base->counter) - countticks;
+
+#if TIMER_LOAD_VAL != 0xFFFFFFFF
+ /* do not manage multiple overflow */
+ if (countticks >= TIMER_LOAD_VAL)
+ countticks = TIMER_LOAD_VAL - 1;
+#endif
+
+ do {
+ timenow = readl(&timer_base->counter);
- while (get_ticks() < tmp) { /* Loop till event */
- /* NOP */;
- }
+ if (timenow >= timeend) {
+ /* normal case */
+ timediff = timenow - timeend;
+ } else {
+ if ((TIMER_LOAD_VAL - timeend + timenow) <=
+ countticks) {
+ /* overflow */
+ timediff = TIMER_LOAD_VAL - timeend + timenow;
+ } else {
+ /* missed the exact match */
+ break;
+ }
+ }
+ } while (timediff > 0);
}
/* Timer without interrupts */