diff options
Diffstat (limited to 'arch/arc/kernel/time.c')
| -rw-r--r-- | arch/arc/kernel/time.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c index 71493f75ae6b..da495478a40b 100644 --- a/arch/arc/kernel/time.c +++ b/arch/arc/kernel/time.c @@ -60,6 +60,54 @@ /********** Clock Source Device *********/ +#ifdef CONFIG_ARC_HAS_RTC + +#define AUX_RTC_CTRL 0x103 +#define AUX_RTC_LOW 0x104 +#define AUX_RTC_HIGH 0x105 + +int arc_counter_setup(void) +{ + write_aux_reg(AUX_RTC_CTRL, 1); + + /* Not usable in SMP */ + return !IS_ENABLED(CONFIG_SMP); +} + +static cycle_t arc_counter_read(struct clocksource *cs) +{ + unsigned long status; + union { +#ifdef CONFIG_CPU_BIG_ENDIAN + struct { u32 high, low; }; +#else + struct { u32 low, high; }; +#endif + cycle_t full; + } stamp; + + + __asm__ __volatile( + "1: \n" + " lr %0, [AUX_RTC_LOW] \n" + " lr %1, [AUX_RTC_HIGH] \n" + " lr %2, [AUX_RTC_CTRL] \n" + " bbit0.nt %2, 31, 1b \n" + : "=r" (stamp.low), "=r" (stamp.high), "=r" (status)); + + return stamp.full; +} + +static struct clocksource arc_counter = { + .name = "ARCv2 RTC", + .rating = 350, + .read = arc_counter_read, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +#else /* !CONFIG_ARC_HAS_RTC */ + /* * set 32bit TIMER1 to keep counting monotonically and wraparound */ @@ -86,6 +134,8 @@ static struct clocksource arc_counter = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +#endif + /********** Clock Event Device *********/ /* |
