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authorVineet Gupta <vgupta@synopsys.com>2013-11-07 14:57:16 +0530
committerVineet Gupta <vgupta@synopsys.com>2015-06-22 14:06:56 +0530
commitaa93e8ef98471277cfedacd68604bb28b5a35aa7 (patch)
tree40b78e1eb7d72320e33638bb6850d90fc57c02c2
parentb3210d141f5ec32d3b29d0cf4f33d922a739602f (diff)
downloadop-kernel-dev-aa93e8ef98471277cfedacd68604bb28b5a35aa7.zip
op-kernel-dev-aa93e8ef98471277cfedacd68604bb28b5a35aa7.tar.gz
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>
-rw-r--r--arch/arc/Kconfig5
-rw-r--r--arch/arc/kernel/setup.c9
-rw-r--r--arch/arc/kernel/time.c50
3 files changed, 62 insertions, 2 deletions
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 974ed90..f09e03a 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -372,6 +372,11 @@ config ARC_HAS_LL64
dest operands with 2 possible source operands.
default y
+config ARC_HAS_RTC
+ bool "Local 64-bit r/o cycle counter"
+ default n
+ depends on !SMP
+
config ARC_NUMBER_OF_INTERRUPTS
int "Number of interrupts"
range 8 240
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index ca71cef..a3d1862 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 71493f7..da49547 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 *********/
/*
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