| Oskar Schirmer | b070a03 | 2009-05-11 15:43:36 +0200 | [diff] [blame] | 1 | #include <asm/delay.h> |
| 2 | #include <asm/timex.h> |
| 3 | #include <asm/io.h> |
| 4 | #include <variant/hardware.h> |
| 5 | |
| 6 | #define LOOPS 10 |
| 7 | void platform_calibrate_ccount(void) |
| 8 | { |
| 9 | u32 uninitialized_var(a); |
| 10 | u32 uninitialized_var(u); |
| 11 | u32 b; |
| 12 | u32 tstamp = S6_REG_GREG1 + S6_GREG1_GLOBAL_TIMER; |
| 13 | int i = LOOPS+1; |
| 14 | do { |
| 15 | u32 t = u; |
| 16 | asm volatile( |
| 17 | "1: l32i %0, %2, 0 ;" |
| 18 | " beq %0, %1, 1b ;" |
| 19 | : "=&a"(u) : "a"(t), "a"(tstamp)); |
| 20 | b = xtensa_get_ccount(); |
| 21 | if (i == LOOPS) |
| 22 | a = b; |
| 23 | } while (--i >= 0); |
| 24 | b -= a; |
| 25 | nsec_per_ccount = (LOOPS * 10000) / b; |
| 26 | ccount_per_jiffy = b * (100000UL / (LOOPS * HZ)); |
| 27 | } |