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ARCv2: SMP: clocksource: Enable Global Real Time counter

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Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2014-12-24 18:41:55 +05:30
parent aa6083ed50
commit 72d7288061
4 changed files with 56 additions and 0 deletions
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5
arch/arc/Kconfig
View File

@ -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

3
arch/arc/include/asm/mcip.h
View File

@ -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

3
arch/arc/kernel/mcip.c
View File

@ -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");
}

45
arch/arc/kernel/time.c
View File

@ -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 *********/