CRIS v32: Add precise delay loops for ETRAX FS and ARTPEC-3.

/*

 * Precise Delay Loops for ETRAX FS

 *

 * Copyright (C) 2006 Axis Communications AB.

 *

 */

#include <hwregs/reg_map.h>

#include <hwregs/reg_rdwr.h>

#include <hwregs/timer_defs.h>

#include <linux/types.h>

#include <linux/delay.h>

#include <linux/module.h>

/*

 * On ETRAX FS, we can check the free-running read-only 100MHz timer

 * getting 32-bit 10ns precision, theoretically good for 42.94967295

 * seconds.  Unsigned arithmetic and careful expression handles

 * wrapping.

 */

void cris_delay10ns(u32 n10ns)

{

	u32 t0 = REG_RD(timer, regi_timer0, r_time);

	while (REG_RD(timer, regi_timer0, r_time) - t0 < n10ns)

		;

}

EXPORT_SYMBOL(cris_delay10ns);