/* * 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); |