diff options
| author | Vineet Gupta <vgupta@synopsys.com> | 2013-11-07 10:27:16 +0100 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2015-06-22 10:36:56 +0200 |
| commit | aa93e8ef98471277cfedacd68604bb28b5a35aa7 (patch) | |
| tree | 40b78e1eb7d72320e33638bb6850d90fc57c02c2 /arch/arc/kernel | |
| parent | ARCv2: extable: Enable sorting at build time (diff) | |
| download | linux-aa93e8ef98471277cfedacd68604bb28b5a35aa7.tar.xz linux-aa93e8ef98471277cfedacd68604bb28b5a35aa7.zip | |
ARCv2: clocksource: Introduce 64bit local RTC counter
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/kernel')
| -rw-r--r-- | arch/arc/kernel/setup.c | 9 | ||||
| -rw-r--r-- | arch/arc/kernel/time.c | 50 |
2 files changed, 57 insertions, 2 deletions
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c index ca71cef4bafd..a3d186211ed3 100644 --- a/arch/arc/kernel/setup.c +++ b/arch/arc/kernel/setup.c @@ -200,9 +200,11 @@ static char *arc_cpu_mumbojumbo(int cpu_id, char *buf, int len) (unsigned int)(arc_get_core_freq() / 1000000), (unsigned int)(arc_get_core_freq() / 10000) % 100); - n += scnprintf(buf + n, len - n, "Timers\t\t: %s%s\nISA Extn\t: ", + n += scnprintf(buf + n, len - n, "Timers\t\t: %s%s%s%s\nISA Extn\t: ", IS_AVAIL1(cpu->timers.t0, "Timer0 "), - IS_AVAIL1(cpu->timers.t1, "Timer1 ")); + IS_AVAIL1(cpu->timers.t1, "Timer1 "), + IS_AVAIL2(cpu->timers.rtc, "64-bit RTC ", + CONFIG_ARC_HAS_RTC)); n += i = scnprintf(buf + n, len - n, "%s%s%s%s%s", IS_AVAIL2(atomic, "atomic ", CONFIG_ARC_HAS_LLSC), @@ -290,6 +292,9 @@ static void arc_chk_core_config(void) if (!cpu->timers.t1) panic("Timer1 is not present!\n"); + if (IS_ENABLED(CONFIG_ARC_HAS_RTC) && !cpu->timers.rtc) + panic("RTC is not present\n"); + #ifdef CONFIG_ARC_HAS_DCCM /* * DCCM can be arbit placed in hardware. 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 *********/ /* |