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Commit 922cc171 authored by Vineet Gupta's avatar Vineet Gupta
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ARC: timer: rtc: implement read loop in "C" vs. inline asm 



The current code doesn't even compile as somehow the inline assembly
can't see the register names defined as ARC_RTC_*
I'm pretty sure It worked when I first got it merged, but the tools were
definitely different then.

So better to write this in "C" anyways.

CC: stable@vger.kernel.org	#4.2+
Acked-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent e6e335bf

arch/arc/kernel/time.c

+11 −8
Original line number Diff line number Diff line
@@ -152,14 +152,17 @@ static cycle_t arc_read_rtc(struct clocksource *cs) 
		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));

	/*

	 * hardware has an internal state machine which tracks readout of

	 * low/high and updates the CTRL.status if

	 *  - interrupt/exception taken between the two reads

	 *  - high increments after low has been read

	 */

	do {

		stamp.low = read_aux_reg(AUX_RTC_LOW);

		stamp.high = read_aux_reg(AUX_RTC_HIGH);

		status = read_aux_reg(AUX_RTC_CTRL);

	} while (!(status & _BITUL(31)));



	return stamp.full;

}