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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 /include/i2c.h | |
| 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 'include/i2c.h')
| -rw-r--r-- | include/i2c.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/i2c.h b/include/i2c.h index 701992e35e..22ab18adcf 100644 --- a/include/i2c.h +++ b/include/i2c.h @@ -1,4 +1,4 @@ -/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved. +/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved. * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ @@ -16,6 +16,9 @@ /* Initializes the module. */ int i2c_init(void); +/* Notifies the module the system clock frequency has changed to <freq>. */ +void i2c_clock_changed(int freq); + /* Reads a 16-bit register from the slave at 8-bit slave address * <slaveaddr>, at the specified 8-bit <offset> in the slave's address * space. */ |