/arch/xtensa/variants/s6000/delay.c
https://bitbucket.org/thekraven/iscream_thunderc-2.6.35 · C · 27 lines · 26 code · 1 blank · 0 comment · 3 complexity · 18c8ab6ef9fca56120a4d30253054c02 MD5 · raw file
- #include <asm/delay.h>
- #include <asm/timex.h>
- #include <asm/io.h>
- #include <variant/hardware.h>
- #define LOOPS 10
- void platform_calibrate_ccount(void)
- {
- u32 uninitialized_var(a);
- u32 uninitialized_var(u);
- u32 b;
- u32 tstamp = S6_REG_GREG1 + S6_GREG1_GLOBAL_TIMER;
- int i = LOOPS+1;
- do {
- u32 t = u;
- asm volatile(
- "1: l32i %0, %2, 0 ;"
- " beq %0, %1, 1b ;"
- : "=&a"(u) : "a"(t), "a"(tstamp));
- b = xtensa_get_ccount();
- if (i == LOOPS)
- a = b;
- } while (--i >= 0);
- b -= a;
- nsec_per_ccount = (LOOPS * 10000) / b;
- ccount_per_jiffy = b * (100000UL / (LOOPS * HZ));
- }