/* * Copyright (C) 2018 bzt (bztsrc@github) * * Permission is hereby granted, free of charge, to any person * obtaining a copy of this software and associated documentation * files (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, copy, * modify, merge, publish, distribute, sublicense, and/or sell copies * of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. * */ #include "gpio.h" #define SYSTMR_LO ((volatile unsigned int*)(MMIO_BASE+0x00003004)) #define SYSTMR_HI ((volatile unsigned int*)(MMIO_BASE+0x00003008)) /** * Wait N CPU cycles (ARM CPU only) */ void wait_cycles(unsigned int n) { if(n) while(n--) { asm volatile("nop"); } } /** * Wait N microsec (ARM CPU only) */ void wait_msec(unsigned int n) { register unsigned long f, t, r; // get the current counter frequency asm volatile ("mrs %0, cntfrq_el0" : "=r"(f)); // read the current counter asm volatile ("mrs %0, cntpct_el0" : "=r"(t)); // calculate expire value for counter t+=((f/1000)*n)/1000; do{asm volatile ("mrs %0, cntpct_el0" : "=r"(r));}while(r