90 lines
3.1 KiB
C
90 lines
3.1 KiB
C
/* Copyright 2021 QMK
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#ifndef __OPTIMIZE__
|
|
# pragma message "Compiler optimizations disabled; wait_cpuclock() won't work as designed"
|
|
#endif
|
|
|
|
#define CLOCK_DELAY_NOP8 "nop\n\t nop\n\t nop\n\t nop\n\t nop\n\t nop\n\t nop\n\t nop\n\t"
|
|
|
|
__attribute__((always_inline)) static inline void wait_cpuclock(unsigned int n) { /* n: 1..135 */
|
|
/* The argument n must be a constant expression.
|
|
* That way, compiler optimization will remove unnecessary code. */
|
|
if (n < 1) {
|
|
return;
|
|
}
|
|
if (n > 8) {
|
|
unsigned int n8 = n / 8;
|
|
n = n - n8 * 8;
|
|
switch (n8) {
|
|
case 16:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 15:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 14:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 13:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 12:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 11:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 10:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 9:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 8:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 7:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 6:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 5:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 4:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 3:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 2:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 1:
|
|
asm volatile(CLOCK_DELAY_NOP8::: "memory");
|
|
case 0:
|
|
break;
|
|
}
|
|
}
|
|
switch (n) {
|
|
case 8:
|
|
asm volatile("nop" ::: "memory");
|
|
case 7:
|
|
asm volatile("nop" ::: "memory");
|
|
case 6:
|
|
asm volatile("nop" ::: "memory");
|
|
case 5:
|
|
asm volatile("nop" ::: "memory");
|
|
case 4:
|
|
asm volatile("nop" ::: "memory");
|
|
case 3:
|
|
asm volatile("nop" ::: "memory");
|
|
case 2:
|
|
asm volatile("nop" ::: "memory");
|
|
case 1:
|
|
asm volatile("nop" ::: "memory");
|
|
case 0:
|
|
break;
|
|
}
|
|
}
|