pca9698.c
2.39 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
124
125
126
127
/*
* (C) Copyright 2011
* Dirk Eibach, Guntermann & Drunck GmbH, eibach@gdsys.de
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* Driver for NXP's pca9698 40 bit I2C gpio expander
*/
#include <common.h>
#include <i2c.h>
#include <asm/errno.h>
#include <pca9698.h>
/*
* The pca9698 registers
*/
#define PCA9698_REG_INPUT 0x00
#define PCA9698_REG_OUTPUT 0x08
#define PCA9698_REG_POLARITY 0x10
#define PCA9698_REG_CONFIG 0x18
#define PCA9698_BUFFER_SIZE 5
#define PCA9698_GPIO_COUNT 40
static int pca9698_read40(u8 addr, u8 offset, u8 *buffer)
{
u8 command = offset | 0x80; /* autoincrement */
return i2c_read(addr, command, 1, buffer, PCA9698_BUFFER_SIZE);
}
static int pca9698_write40(u8 addr, u8 offset, u8 *buffer)
{
u8 command = offset | 0x80; /* autoincrement */
return i2c_write(addr, command, 1, buffer, PCA9698_BUFFER_SIZE);
}
static void pca9698_set_bit(unsigned gpio, u8 *buffer, unsigned value)
{
unsigned byte = gpio / 8;
unsigned bit = gpio % 8;
if (value)
buffer[byte] |= (1 << bit);
else
buffer[byte] &= ~(1 << bit);
}
int pca9698_request(unsigned gpio, const char *label)
{
if (gpio >= PCA9698_GPIO_COUNT)
return -EINVAL;
return 0;
}
void pca9698_free(unsigned gpio)
{
}
int pca9698_direction_input(u8 addr, unsigned gpio)
{
u8 data[PCA9698_BUFFER_SIZE];
int res;
res = pca9698_read40(addr, PCA9698_REG_CONFIG, data);
if (res)
return res;
pca9698_set_bit(gpio, data, 1);
return pca9698_write40(addr, PCA9698_REG_CONFIG, data);
}
int pca9698_direction_output(u8 addr, unsigned gpio, int value)
{
u8 data[PCA9698_BUFFER_SIZE];
int res;
res = pca9698_set_value(addr, gpio, value);
if (res)
return res;
res = pca9698_read40(addr, PCA9698_REG_CONFIG, data);
if (res)
return res;
pca9698_set_bit(gpio, data, 0);
return pca9698_write40(addr, PCA9698_REG_CONFIG, data);
}
int pca9698_get_value(u8 addr, unsigned gpio)
{
unsigned config_byte = gpio / 8;
unsigned config_bit = gpio % 8;
unsigned value;
u8 data[PCA9698_BUFFER_SIZE];
int res;
res = pca9698_read40(addr, PCA9698_REG_INPUT, data);
if (res)
return -1;
value = data[config_byte] & (1 << config_bit);
return !!value;
}
int pca9698_set_value(u8 addr, unsigned gpio, int value)
{
u8 data[PCA9698_BUFFER_SIZE];
int res;
res = pca9698_read40(addr, PCA9698_REG_OUTPUT, data);
if (res)
return res;
pca9698_set_bit(gpio, data, value);
return pca9698_write40(addr, PCA9698_REG_OUTPUT, data);
}