diff options
Diffstat (limited to 'include/asm-xtensa/delay.h')
-rw-r--r-- | include/asm-xtensa/delay.h | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/include/asm-xtensa/delay.h b/include/asm-xtensa/delay.h new file mode 100644 index 000000000000..6359c55e77a8 --- /dev/null +++ b/include/asm-xtensa/delay.h | |||
@@ -0,0 +1,50 @@ | |||
1 | /* | ||
2 | * include/asm-xtensa/delay.h | ||
3 | * | ||
4 | * This file is subject to the terms and conditions of the GNU General Public | ||
5 | * License. See the file "COPYING" in the main directory of this archive | ||
6 | * for more details. | ||
7 | * | ||
8 | * Copyright (C) 2001 - 2005 Tensilica Inc. | ||
9 | * | ||
10 | */ | ||
11 | |||
12 | #ifndef _XTENSA_DELAY_H | ||
13 | #define _XTENSA_DELAY_H | ||
14 | |||
15 | #include <linux/config.h> | ||
16 | #include <asm/processor.h> | ||
17 | #include <asm/param.h> | ||
18 | |||
19 | extern unsigned long loops_per_jiffy; | ||
20 | |||
21 | extern __inline__ void __delay(unsigned long loops) | ||
22 | { | ||
23 | /* 2 cycles per loop. */ | ||
24 | __asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 1, 1b" | ||
25 | : "=r" (loops) : "0" (loops)); | ||
26 | } | ||
27 | |||
28 | static __inline__ u32 xtensa_get_ccount(void) | ||
29 | { | ||
30 | u32 ccount; | ||
31 | asm volatile ("rsr %0, 234; # CCOUNT\n" : "=r" (ccount)); | ||
32 | return ccount; | ||
33 | } | ||
34 | |||
35 | /* For SMP/NUMA systems, change boot_cpu_data to something like | ||
36 | * local_cpu_data->... where local_cpu_data points to the current | ||
37 | * cpu. */ | ||
38 | |||
39 | static __inline__ void udelay (unsigned long usecs) | ||
40 | { | ||
41 | unsigned long start = xtensa_get_ccount(); | ||
42 | unsigned long cycles = usecs * (loops_per_jiffy / (1000000UL / HZ)); | ||
43 | |||
44 | /* Note: all variables are unsigned (can wrap around)! */ | ||
45 | while (((unsigned long)xtensa_get_ccount()) - start < cycles) | ||
46 | ; | ||
47 | } | ||
48 | |||
49 | #endif | ||
50 | |||