1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
/* Copyright (c) 2013 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.
*/
/* I2C interface for Chrome EC */
#ifndef __CROS_EC_I2C_H
#define __CROS_EC_I2C_H
#include "common.h"
/* Flags for slave address field, in addition to the 8-bit address */
#define I2C_FLAG_BIG_ENDIAN 0x100 /* 16 byte values are MSB-first */
/* Data structure to define I2C port configuration. */
struct i2c_port_t {
const char *name; /* Port name */
int port; /* Port */
int kbps; /* Speed in kbps */
};
extern const struct i2c_port_t i2c_ports[];
/* Flags for i2c_xfer() */
#define I2C_XFER_START (1 << 0) /* Start smbus session from idle state */
#define I2C_XFER_STOP (1 << 1) /* Terminate smbus session with stop bit */
#define I2C_XFER_SINGLE (I2C_XFER_START | I2C_XFER_STOP) /* One transaction */
/**
* Transmit one block of raw data, then receive one block of raw data.
*
* This is a low-level platform-dependent function used by the other functions
* below. It must be called between i2c_lock(port, 1) and i2c_lock(port, 0).
*
* @param port Port to access
* @param slave_addr Slave device address
* @param out Data to send
* @param out_size Number of bytes to send
* @param in Destination buffer for received data
* @param in_size Number of bytes to receive
* @param flags Flags (see I2C_XFER_* above)
* @return EC_SUCCESS, or non-zero if error.
*/
int i2c_xfer(int port, int slave_addr, const uint8_t *out, int out_size,
uint8_t *in, int in_size, int flags);
#define I2C_LINE_SCL_HIGH (1 << 0)
#define I2C_LINE_SDA_HIGH (1 << 1)
#define I2C_LINE_IDLE (I2C_LINE_SCL_HIGH | I2C_LINE_SDA_HIGH)
/**
* Return raw I/O line levels (I2C_LINE_*) for a port.
*
* @param port Port to check
*/
int i2c_get_line_levels(int port);
/**
* Lock / unlock an I2C port.
* @param port Port to lock
* @param lock 1 to lock, 0 to unlock
*/
void i2c_lock(int port, int lock);
/* Read 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. */
int i2c_read16(int port, int slave_addr, int offset, int* data);
/* Write a 16-bit register to the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space. */
int i2c_write16(int port, int slave_addr, int offset, int data);
/* Read an 8-bit register from the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space. */
int i2c_read8(int port, int slave_addr, int offset, int* data);
/* Write an 8-bit register to the slave at 8-bit slave address <slaveaddr>, at
* the specified 8-bit <offset> in the slave's address space. */
int i2c_write8(int port, int slave_addr, int offset, int data);
/* Read ascii string using smbus read block protocol.
* Read bytestream from <slaveaddr>:<offset> with format:
* [length_N] [byte_0] [byte_1] ... [byte_N-1]
*
* <len> : the max length of receving buffer. to read N bytes
* ascii, len should be at least N+1 to include the
* terminating 0.
* <len> == 0 : buffer size > 255
*/
int i2c_read_string(int port, int slave_addr, int offset, uint8_t *data,
int len);
#endif /* __CROS_EC_I2C_H */
|
