| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * 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); |
