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https://github.com/Telecominfraproject/OpenCellular.git
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e9328ac4f6
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
55 lines
1.9 KiB
C
55 lines
1.9 KiB
C
/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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/* I2C interface for Chrome EC */
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#ifndef __CROS_EC_I2C_H
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#define __CROS_EC_I2C_H
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#include "common.h"
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/* Flags for slave address field, in addition to the 8-bit address */
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#define I2C_FLAG_BIG_ENDIAN 0x100 /* 16 byte values are MSB-first */
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/* Initializes the module. */
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int i2c_init(void);
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/* Notifies the module the system clock frequency has changed to <freq>. */
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void i2c_clock_changed(int freq);
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/* Reads a 16-bit register from the slave at 8-bit slave address
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* <slaveaddr>, at the specified 8-bit <offset> in the slave's address
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* space. */
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int i2c_read16(int port, int slave_addr, int offset, int* data);
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/* Writes a 16-bit register to the slave at 8-bit slave address
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* <slaveaddr>, at the specified 8-bit <offset> in the slave's address
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* space. */
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int i2c_write16(int port, int slave_addr, int offset, int data);
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/* Reads an 8-bit register from the slave at 8-bit slave address
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* <slaveaddr>, at the specified 8-bit <offset> in the slave's address
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* space. */
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int i2c_read8(int port, int slave_addr, int offset, int* data);
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/* Writes an 8-bit register to the slave at 8-bit slave address
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* <slaveaddr>, at the specified 8-bit <offset> in the slave's address
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* space. */
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int i2c_write8(int port, int slave_addr, int offset, int data);
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/* Read ascii string using smbus read block protocol.
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* Read bytestream from <slaveaddr>:<offset> with format:
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* [length_N] [byte_0] [byte_1] ... [byte_N-1]
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*
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* <len> : the max length of receving buffer. to read N bytes
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* ascii, len should be at least N+1 to include the
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* terminating 0.
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* <len> == 0 : buffer size > 255
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*/
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int i2c_read_string(int port, int slave_addr, int offset, uint8_t *data,
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int len);
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#endif /* __CROS_EC_I2C_H */
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