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
|
/*
* Copyright 2021 Advanced Micro Devices, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
*/
#include "amdgpu_eeprom.h"
#include "amdgpu.h"
#define EEPROM_OFFSET_LENGTH 2
int amdgpu_eeprom_xfer(struct i2c_adapter *i2c_adap,
u16 slave_addr, u16 eeprom_addr,
u8 *eeprom_buf, u16 bytes, bool read)
{
u8 eeprom_offset_buf[2];
u16 bytes_transferred;
struct i2c_msg msgs[] = {
{
.addr = slave_addr,
.flags = 0,
.len = EEPROM_OFFSET_LENGTH,
.buf = eeprom_offset_buf,
},
{
.addr = slave_addr,
.flags = read ? I2C_M_RD : 0,
.len = bytes,
.buf = eeprom_buf,
},
};
int r;
msgs[0].buf[0] = ((eeprom_addr >> 8) & 0xff);
msgs[0].buf[1] = (eeprom_addr & 0xff);
while (msgs[1].len) {
r = i2c_transfer(i2c_adap, msgs, ARRAY_SIZE(msgs));
if (r <= 0)
return r;
/* Only for write data */
if (!msgs[1].flags)
/*
* According to EEPROM spec there is a MAX of 10 ms required for
* EEPROM to flush internal RX buffer after STOP was issued at the
* end of write transaction. During this time the EEPROM will not be
* responsive to any more commands - so wait a bit more.
*
* TODO Improve to wait for first ACK for slave address after
* internal write cycle done.
*/
msleep(10);
bytes_transferred = r - EEPROM_OFFSET_LENGTH;
eeprom_addr += bytes_transferred;
msgs[0].buf[0] = ((eeprom_addr >> 8) & 0xff);
msgs[0].buf[1] = (eeprom_addr & 0xff);
msgs[1].buf += bytes_transferred;
msgs[1].len -= bytes_transferred;
}
return 0;
}
|
