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authorBryan Wu <cooloney@kernel.org>2008-08-26 22:51:02 -0400
committerBryan Wu <cooloney@kernel.org>2008-08-26 22:51:02 -0400
commit639f6571458948b5112be2cf00c0c2c04db2897d (patch)
treea4dd7af33d0e92c935ba1e904f6fb7e923ac825e /arch/blackfin/include/asm/time.h
parent3d9b7a5ce534f3963afcf8f4777267e5899fe007 (diff)
Blackfin arch: move include/asm-blackfin header files to arch/blackfin
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Diffstat (limited to 'arch/blackfin/include/asm/time.h')
-rw-r--r--arch/blackfin/include/asm/time.h40
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/time.h b/arch/blackfin/include/asm/time.h
new file mode 100644
index 000000000000..ddc43ce38533
--- /dev/null
+++ b/arch/blackfin/include/asm/time.h
@@ -0,0 +1,40 @@
1/*
2 * asm-blackfin/time.h:
3 *
4 * Copyright 2004-2008 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 */
8
9#ifndef _ASM_BLACKFIN_TIME_H
10#define _ASM_BLACKFIN_TIME_H
11
12/*
13 * The way that the Blackfin core timer works is:
14 * - CCLK is divided by a programmable 8-bit pre-scaler (TSCALE)
15 * - Every time TSCALE ticks, a 32bit is counted down (TCOUNT)
16 *
17 * If you take the fastest clock (1ns, or 1GHz to make the math work easier)
18 * 10ms is 10,000,000 clock ticks, which fits easy into a 32-bit counter
19 * (32 bit counter is 4,294,967,296ns or 4.2 seconds) so, we don't need
20 * to use TSCALE, and program it to zero (which is pass CCLK through).
21 * If you feel like using it, try to keep HZ * TIMESCALE to some
22 * value that divides easy (like power of 2).
23 */
24
25#ifndef CONFIG_CPU_FREQ
26#define TIME_SCALE 1
27#define __bfin_cycles_off (0)
28#define __bfin_cycles_mod (0)
29#else
30/*
31 * Blackfin CPU frequency scaling supports max Core Clock 1, 1/2 and 1/4 .
32 * Whenever we change the Core Clock frequency changes we immediately
33 * adjust the Core Timer Presale Register. This way we don't lose time.
34 */
35#define TIME_SCALE 4
36extern unsigned long long __bfin_cycles_off;
37extern unsigned int __bfin_cycles_mod;
38#endif
39
40#endif