[MIPS] time: Helpers to compute clocksource/event shift and mult values. (93c846f9) · Commits · e / devices / android_kernel_fairphone_FP3

arch/mips/kernel/time.c

+31 −8

Original line number	Diff line number	Diff line
		@@ -171,25 +171,48 @@ struct clocksource clocksource_mips = {
		.flags = CLOCK_SOURCE_IS_CONTINUOUS,
		};

		static void __init init_mips_clocksource(void)
		void __init clocksource_set_clock(struct clocksource *cs, unsigned int clock)
		{
		u64 temp;
		u32 shift;

		if (!mips_hpt_frequency \|\| clocksource_mips.read == null_hpt_read)
		return;
		/* Find a shift value */
		for (shift = 32; shift > 0; shift--) {
		temp = (u64) NSEC_PER_SEC << shift;
		do_div(temp, clock);
		if ((temp >> 32) == 0)
		break;
		}
		cs->shift = shift;
		cs->mult = (u32) temp;
		}

		void __cpuinit clockevent_set_clock(struct clock_event_device *cd,
		unsigned int clock)
		{
		u64 temp;
		u32 shift;

		/* Calclate a somewhat reasonable rating value */
		clocksource_mips.rating = 200 + mips_hpt_frequency / 10000000;
		/* Find a shift value */
		for (shift = 32; shift > 0; shift--) {
		temp = (u64) NSEC_PER_SEC << shift;
		do_div(temp, mips_hpt_frequency);
		do_div(temp, clock);
		if ((temp >> 32) == 0)
		break;
		}
		clocksource_mips.shift = shift;
		clocksource_mips.mult = (u32)temp;
		cd->shift = shift;
		cd->mult = (u32) temp;
		}

		static void __init init_mips_clocksource(void)
		{
		if (!mips_hpt_frequency \|\| clocksource_mips.read == null_hpt_read)
		return;

		/* Calclate a somewhat reasonable rating value */
		clocksource_mips.rating = 200 + mips_hpt_frequency / 10000000;

		clocksource_set_clock(&clocksource_mips, mips_hpt_frequency);

		clocksource_register(&clocksource_mips);
		}

+5 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@
		#include <linux/ptrace.h>
		#include <linux/rtc.h>
		#include <linux/spinlock.h>
		#include <linux/clockchips.h>
		#include <linux/clocksource.h>

		extern spinlock_t rtc_lock;
		@@ -83,4 +84,8 @@ static inline void mips_clockevent_init(void)
		}
		#endif

		extern void clocksource_set_clock(struct clocksource *cs, unsigned int clock);
		extern void clockevent_set_clock(struct clock_event_device *cd,
		unsigned int clock);

		#endif /* _ASM_TIME_H */