Commit 72d72880 authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARCv2: SMP: clocksource: Enable Global Real Time counter 



Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent aa6083ed

arch/arc/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -384,6 +384,11 @@ config ARC_HAS_RTC 
	default n

	depends on !SMP



config ARC_HAS_GRTC

	bool "SMP synchronized 64-bit cycle counter"

	default y

	depends on SMP



config ARC_NUMBER_OF_INTERRUPTS

	int "Number of interrupts"

	range 8 240

arch/arc/include/asm/mcip.h

+3 −0
Original line number Diff line number Diff line
@@ -39,6 +39,9 @@ struct mcip_cmd { 
#define CMD_DEBUG_SET_MASK		0x34

#define CMD_DEBUG_SET_SELECT		0x36



#define CMD_GRTC_READ_LO		0x42

#define CMD_GRTC_READ_HI		0x43



#define CMD_IDU_ENABLE			0x71

#define CMD_IDU_DISABLE			0x72

#define CMD_IDU_SET_MODE		0x74

arch/arc/kernel/mcip.c

+3 −0
Original line number Diff line number Diff line
@@ -154,4 +154,7 @@ void mcip_init_early_smp(void) 
		__mcip_cmd_data(CMD_DEBUG_SET_SELECT, 0, 0xf);

		__mcip_cmd_data(CMD_DEBUG_SET_MASK, 0xf, 0xf);

	}



	if (IS_ENABLED(CONFIG_ARC_HAS_GRTC) && !mp.grtc)

		panic("kernel trying to use non-existent GRTC\n");

}

arch/arc/kernel/time.c

+45 −0
Original line number Diff line number Diff line
@@ -45,6 +45,8 @@ 
#include <asm/clk.h>

#include <asm/mach_desc.h>



#include <asm/mcip.h>



/* Timer related Aux registers */

#define ARC_REG_TIMER0_LIMIT	0x23	/* timer 0 limit */

#define ARC_REG_TIMER0_CTRL	0x22	/* timer 0 control */
@@ -60,6 +62,48 @@ 


/********** Clock Source Device *********/



#ifdef CONFIG_ARC_HAS_GRTC



static int arc_counter_setup(void)

{

	return 1;

}



static cycle_t arc_counter_read(struct clocksource *cs)

{

	unsigned long flags;

	union {

#ifdef CONFIG_CPU_BIG_ENDIAN

		struct { u32 h, l; };

#else

		struct { u32 l, h; };

#endif

		cycle_t  full;

	} stamp;



	local_irq_save(flags);



	__mcip_cmd(CMD_GRTC_READ_LO, 0);

	stamp.l = read_aux_reg(ARC_REG_MCIP_READBACK);



	__mcip_cmd(CMD_GRTC_READ_HI, 0);

	stamp.h = read_aux_reg(ARC_REG_MCIP_READBACK);



	local_irq_restore(flags);



	return stamp.full;

}



static struct clocksource arc_counter = {

	.name   = "ARConnect GRTC",

	.rating = 400,

	.read   = arc_counter_read,

	.mask   = CLOCKSOURCE_MASK(64),

	.flags  = CLOCK_SOURCE_IS_CONTINUOUS,

};



#else



#ifdef CONFIG_ARC_HAS_RTC



#define AUX_RTC_CTRL	0x103
@@ -134,6 +178,7 @@ static struct clocksource arc_counter = { 
	.flags  = CLOCK_SOURCE_IS_CONTINUOUS,

};



#endif

#endif



/********** Clock Event Device *********/