1/*
 2 * Precise Delay Loops for ETRAX FS
 3 *
 4 * Copyright (C) 2006 Axis Communications AB.
 5 *
 6 */
 7
 8#include <hwregs/reg_map.h>
 9#include <hwregs/reg_rdwr.h>
10#include <hwregs/timer_defs.h>
11#include <linux/types.h>
12#include <linux/delay.h>
13#include <linux/module.h>
14
15/*
16 * On ETRAX FS, we can check the free-running read-only 100MHz timer
17 * getting 32-bit 10ns precision, theoretically good for 42.94967295
18 * seconds.  Unsigned arithmetic and careful expression handles
19 * wrapping.
20 */
21
22void cris_delay10ns(u32 n10ns)
23{
24	u32 t0 = REG_RD(timer, regi_timer0, r_time);
25	while (REG_RD(timer, regi_timer0, r_time) - t0 < n10ns)
26		;
27}
28EXPORT_SYMBOL(cris_delay10ns);