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Commit aa93e8ef authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARCv2: clocksource: Introduce 64bit local RTC counter 



Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent b3210d14

arch/arc/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -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

arch/arc/kernel/setup.c

+7 −2
Original line number Diff line number Diff line
@@ -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.

arch/arc/kernel/time.c

+50 −0
Original line number Diff line number Diff line
@@ -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 *********/



/*