I2C.hpp
3.76 KB
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
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file i2c.h
*
* Base class for devices connected via I2C.
*/
#ifndef _DEVICE_I2C_H
#define _DEVICE_I2C_H
#include "../CDev.hpp"
#include <px4_platform_common/i2c.h>
#include <nuttx/i2c/i2c_master.h>
#if !defined(CONFIG_I2C)
# error I2C support requires CONFIG_I2C
#endif
namespace device __EXPORT
{
/**
* Abstract class for character device on I2C
*/
class __EXPORT I2C : public CDev
{
public:
// no copy, assignment, move, move assignment
I2C(const I2C &) = delete;
I2C &operator=(const I2C &) = delete;
I2C(I2C &&) = delete;
I2C &operator=(I2C &&) = delete;
virtual int init() override;
static int set_bus_clock(unsigned bus, unsigned clock_hz);
protected:
/**
* The number of times a read or write operation will be retried on
* error.
*/
uint8_t _retries{0};
/**
* @ Constructor
*
* @param device_type The device type (see drv_sensor.h)
* @param name Driver name
* @param bus I2C bus on which the device lives
* @param address I2C bus address, or zero if set_address will be used
* @param frequency I2C bus frequency for the device (currently not used)
*/
I2C(uint8_t device_type, const char *name, const int bus, const uint16_t address, const uint32_t frequency);
virtual ~I2C();
/**
* Check for the presence of the device on the bus.
*/
virtual int probe() { return PX4_OK; }
/**
* Perform an I2C transaction to the device.
*
* At least one of send_len and recv_len must be non-zero.
*
* @param send Pointer to bytes to send.
* @param send_len Number of bytes to send.
* @param recv Pointer to buffer for bytes received.
* @param recv_len Number of bytes to receive.
* @return OK if the transfer was successful, -errno
* otherwise.
*/
int transfer(const uint8_t *send, const unsigned send_len, uint8_t *recv, const unsigned recv_len);
bool external() const override { return px4_i2c_bus_external(_device_id.devid_s.bus); }
private:
static unsigned int _bus_clocks[PX4_NUMBER_I2C_BUSES];
const uint32_t _frequency;
i2c_master_s *_dev{nullptr};
};
} // namespace device
#endif /* _DEVICE_I2C_H */