MIPS: use common code from lib/time.c

The common code just needs the C0_COUNT as free running counter,
without the need of writing and checking C0_COMPARE.

The function get_tbclk() is still implemented here instead of changing
all places of CONFIG_SYS_MIPS_TIMER_FREQ to CONFIG_SYS_TIMER_RATE.

The change was tested on a MIPS32 system, but as the MIPS64 code
was/is the same, this should be no problem.

Signed-off-by: Thomas Langer <thomas.langer@lantiq.com>
diff --git a/arch/mips/cpu/mips32/time.c b/arch/mips/cpu/mips32/time.c
index 386f45a..553da5f 100644
--- a/arch/mips/cpu/mips32/time.c
+++ b/arch/mips/cpu/mips32/time.c
@@ -8,63 +8,12 @@
 #include <common.h>
 #include <asm/mipsregs.h>
 
-static unsigned long timestamp;
-
-/* how many counter cycles in a jiffy */
-#define CYCLES_PER_JIFFY	\
-	(CONFIG_SYS_MIPS_TIMER_FREQ + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ
-
-/*
- * timer without interrupts
- */
-
-int timer_init(void)
+unsigned long notrace timer_read_counter(void)
 {
-	/* Set up the timer for the first expiration. */
-	write_c0_compare(read_c0_count() + CYCLES_PER_JIFFY);
-
-	return 0;
+	return read_c0_count();
 }
 
-ulong get_timer(ulong base)
+ulong notrace get_tbclk(void)
 {
-	unsigned int count;
-	unsigned int expirelo = read_c0_compare();
-
-	/* Check to see if we have missed any timestamps. */
-	count = read_c0_count();
-	while ((count - expirelo) < 0x7fffffff) {
-		expirelo += CYCLES_PER_JIFFY;
-		timestamp++;
-	}
-	write_c0_compare(expirelo);
-
-	return timestamp - base;
-}
-
-void __udelay(unsigned long usec)
-{
-	unsigned int tmo;
-
-	tmo = read_c0_count() + (usec * (CONFIG_SYS_MIPS_TIMER_FREQ / 1000000));
-	while ((tmo - read_c0_count()) < 0x7fffffff)
-		/*NOP*/;
-}
-
-/*
- * This function is derived from PowerPC code (read timebase as long long).
- * On MIPS it just returns the timer value.
- */
-unsigned long long get_ticks(void)
-{
-	return get_timer(0);
-}
-
-/*
- * This function is derived from PowerPC code (timebase clock frequency).
- * On MIPS it returns the number of timer ticks per second.
- */
-ulong get_tbclk(void)
-{
-	return CONFIG_SYS_HZ;
+	return CONFIG_SYS_MIPS_TIMER_FREQ;
 }