arch: m68k: Introduce trivial PIT based timer
The QEMU emulation of m68k does not support DMA timer, the only
timer that is supported is the PIT timer. Implement trivial PIT
timer support for m68k.
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/arch/m68k/lib/time.c b/arch/m68k/lib/time.c
index 500e4db..61db1e6 100644
--- a/arch/m68k/lib/time.c
+++ b/arch/m68k/lib/time.c
@@ -111,8 +111,6 @@
return (timestamp - base);
}
-#endif /* CONFIG_MCFTMR */
-
/*
* This function is derived from PowerPC code (read timebase as long long).
* On M68K it just returns the timer value.
@@ -121,7 +119,41 @@
{
return get_timer(0);
}
+#else
+static u64 timer64 __section(".data");
+static u16 timer16 __section(".data");
+
+uint64_t __weak get_ticks(void)
+{
+ volatile pit_t *timerp = (pit_t *) (CFG_SYS_UDELAY_BASE);
+ u16 val = ~timerp->pcntr;
+
+ if (timer16 > val)
+ timer64 += 0xffff - timer16 + val;
+ else
+ timer64 += val - timer16;
+
+ timer16 = val;
+
+ return timer64;
+}
+/* PIT timer */
+int timer_init(void)
+{
+ volatile pit_t *timerp = (pit_t *) (CFG_SYS_UDELAY_BASE);
+
+ timer16 = 0;
+ timer64 = 0;
+
+ /* Set up PIT as timebase clock */
+ timerp->pmr = 0xffff;
+ timerp->pcsr = PIT_PCSR_EN | PIT_PCSR_OVW;
+
+ return 0;
+}
+#endif /* CONFIG_MCFTMR */
+
unsigned long usec2ticks(unsigned long usec)
{
return get_timer(usec);