diff options
author | Michael Hennerich <michael.hennerich@analog.com> | 2008-04-24 16:58:29 -0400 |
---|---|---|
committer | Bryan Wu <cooloney@kernel.org> | 2008-04-24 16:58:29 -0400 |
commit | e6c91b64dd6e4c3adf39483c85a936eef9465e19 (patch) | |
tree | fb21af3166c55866dd587dd30c3807e9218054a9 /arch/blackfin/kernel/time.c | |
parent | fe44193c55e26b9b835722b5ee2519972f59c540 (diff) |
[Blackfin] arch: Functional power management support: Add support for cpu frequency scaling
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Diffstat (limited to 'arch/blackfin/kernel/time.c')
-rw-r--r-- | arch/blackfin/kernel/time.c | 19 |
1 files changed, 3 insertions, 16 deletions
diff --git a/arch/blackfin/kernel/time.c b/arch/blackfin/kernel/time.c index 715b3945e4c7..eb2352320454 100644 --- a/arch/blackfin/kernel/time.c +++ b/arch/blackfin/kernel/time.c | |||
@@ -6,9 +6,10 @@ | |||
6 | * Created: | 6 | * Created: |
7 | * Description: This file contains the bfin-specific time handling details. | 7 | * Description: This file contains the bfin-specific time handling details. |
8 | * Most of the stuff is located in the machine specific files. | 8 | * Most of the stuff is located in the machine specific files. |
9 | * FIXME: (This file is subject for removal) | ||
9 | * | 10 | * |
10 | * Modified: | 11 | * Modified: |
11 | * Copyright 2004-2006 Analog Devices Inc. | 12 | * Copyright 2004-2008 Analog Devices Inc. |
12 | * | 13 | * |
13 | * Bugs: Enter bugs at http://blackfin.uclinux.org/ | 14 | * Bugs: Enter bugs at http://blackfin.uclinux.org/ |
14 | * | 15 | * |
@@ -35,6 +36,7 @@ | |||
35 | #include <linux/irq.h> | 36 | #include <linux/irq.h> |
36 | 37 | ||
37 | #include <asm/blackfin.h> | 38 | #include <asm/blackfin.h> |
39 | #include <asm/time.h> | ||
38 | 40 | ||
39 | /* This is an NTP setting */ | 41 | /* This is an NTP setting */ |
40 | #define TICK_SIZE (tick_nsec / 1000) | 42 | #define TICK_SIZE (tick_nsec / 1000) |
@@ -47,21 +49,6 @@ static struct irqaction bfin_timer_irq = { | |||
47 | .flags = IRQF_DISABLED | 49 | .flags = IRQF_DISABLED |
48 | }; | 50 | }; |
49 | 51 | ||
50 | /* | ||
51 | * The way that the Blackfin core timer works is: | ||
52 | * - CCLK is divided by a programmable 8-bit pre-scaler (TSCALE) | ||
53 | * - Every time TSCALE ticks, a 32bit is counted down (TCOUNT) | ||
54 | * | ||
55 | * If you take the fastest clock (1ns, or 1GHz to make the math work easier) | ||
56 | * 10ms is 10,000,000 clock ticks, which fits easy into a 32-bit counter | ||
57 | * (32 bit counter is 4,294,967,296ns or 4.2 seconds) so, we don't need | ||
58 | * to use TSCALE, and program it to zero (which is pass CCLK through). | ||
59 | * If you feel like using it, try to keep HZ * TIMESCALE to some | ||
60 | * value that divides easy (like power of 2). | ||
61 | */ | ||
62 | |||
63 | #define TIME_SCALE 1 | ||
64 | |||
65 | static void | 52 | static void |
66 | time_sched_init(irq_handler_t timer_routine) | 53 | time_sched_init(irq_handler_t timer_routine) |
67 | { | 54 | { |