diff options
Diffstat (limited to 'include/asm-generic/delay.h')
| -rw-r--r-- | include/asm-generic/delay.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/include/asm-generic/delay.h b/include/asm-generic/delay.h new file mode 100644 index 000000000..e448ac614 --- /dev/null +++ b/include/asm-generic/delay.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_GENERIC_DELAY_H +#define __ASM_GENERIC_DELAY_H + +/* Undefined functions to get compile-time errors */ +extern void __bad_udelay(void); +extern void __bad_ndelay(void); + +extern void __udelay(unsigned long usecs); +extern void __ndelay(unsigned long nsecs); +extern void __const_udelay(unsigned long xloops); +extern void __delay(unsigned long loops); + +/* + * The weird n/20000 thing suppresses a "comparison is always false due to + * limited range of data type" warning with non-const 8-bit arguments. + */ + +/* 0x10c7 is 2**32 / 1000000 (rounded up) */ +#define udelay(n) \ + ({ \ + if (__builtin_constant_p(n)) { \ + if ((n) / 20000 >= 1) \ + __bad_udelay(); \ + else \ + __const_udelay((n) * 0x10c7ul); \ + } else { \ + __udelay(n); \ + } \ + }) + +/* 0x5 is 2**32 / 1000000000 (rounded up) */ +#define ndelay(n) \ + ({ \ + if (__builtin_constant_p(n)) { \ + if ((n) / 20000 >= 1) \ + __bad_ndelay(); \ + else \ + __const_udelay((n) * 5ul); \ + } else { \ + __ndelay(n); \ + } \ + }) + +#endif /* __ASM_GENERIC_DELAY_H */ |