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| author | Randall Spangler <rspangler@chromium.org> | 2012-04-06 09:33:41 -0700 |
|---|---|---|
| committer | Randall Spangler <rspangler@chromium.org> | 2012-04-09 10:33:35 -0700 |
| commit | e9328ac4f63351b4282916034270aa86b7e74922 (patch) | |
| tree | d0fde5840594c33709927a5a4d1fabfe0f858c26 /test | |
| parent | 1a9a415cf68c6e8e3b31972c072c81ed886290ab (diff) | |
| download | chrome-ec-e9328ac4f63351b4282916034270aa86b7e74922.tar.gz | |
Support dynamically changing the system clock
Add nopll command to turn off the PLL, reducing the system clock to 16Mhz.
Signed-off-by: Randall Spangler <rspangler@chromium.org>
BUG=chrome-os-partner:8798
TEST=manual
boot system
press power button to boot x86
temps // should print all temperatures
timerinfo
timerinfo
timerinfo // convince yourself this is counting up at about 1MHz
nopll // this drops the system clock to 16MHz
temps // should still print all temperatures
timerinfo
timerinfo
timerinfo // should still be counting up at about 1MHz
Change-Id: Ie29ceb17af348148bffadf63d60c1b731f4c3f6d
Diffstat (limited to 'test')
| -rw-r--r-- | test/powerdemo.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/test/powerdemo.c b/test/powerdemo.c index aabe4c8825..496459f9f7 100644 --- a/test/powerdemo.c +++ b/test/powerdemo.c @@ -6,16 +6,14 @@ /* Power state machine demo module for Chrome EC */ #include "board.h" +#include "clock.h" #include "powerdemo.h" #include "task.h" #include "timer.h" #include "uart.h" #include "registers.h" - #define US_PER_SECOND 1000000 -/* Divider to get microsecond for the clock */ -#define CLOCKSOURCE_DIVIDER (CPU_CLOCK/US_PER_SECOND) static volatile enum { POWER_STATE_IDLE = 0, /* Idle */ @@ -77,7 +75,7 @@ int power_demo_init(void) /* 32-bit timer mode */ LM4_TIMER_CFG(7) = 4; /* Set the prescaler to increment every microsecond */ - LM4_TIMER_TAPR(7) = CLOCKSOURCE_DIVIDER; + LM4_TIMER_TAPR(7) = clock_get_freq() / US_PER_SECOND; /* One-shot, counting down */ LM4_TIMER_TAMR(7) = 0x01; /* Set overflow interrupt */ |