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
128
129
130
131
132
133
134
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* i2c-versatile.c
*
* Copyright (C) 2006 ARM Ltd.
* written by Russell King, Deep Blue Solutions Ltd.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/io.h>
#define I2C_CONTROL 0x00
#define I2C_CONTROLS 0x00
#define I2C_CONTROLC 0x04
#define SCL (1 << 0)
#define SDA (1 << 1)
struct i2c_versatile {
struct i2c_adapter adap;
struct i2c_algo_bit_data algo;
void __iomem *base;
};
static void i2c_versatile_setsda(void *data, int state)
{
struct i2c_versatile *i2c = data;
writel(SDA, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC));
}
static void i2c_versatile_setscl(void *data, int state)
{
struct i2c_versatile *i2c = data;
writel(SCL, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC));
}
static int i2c_versatile_getsda(void *data)
{
struct i2c_versatile *i2c = data;
return !!(readl(i2c->base + I2C_CONTROL) & SDA);
}
static int i2c_versatile_getscl(void *data)
{
struct i2c_versatile *i2c = data;
return !!(readl(i2c->base + I2C_CONTROL) & SCL);
}
static const struct i2c_algo_bit_data i2c_versatile_algo = {
.setsda = i2c_versatile_setsda,
.setscl = i2c_versatile_setscl,
.getsda = i2c_versatile_getsda,
.getscl = i2c_versatile_getscl,
.udelay = 30,
.timeout = HZ,
};
static int i2c_versatile_probe(struct platform_device *dev)
{
struct i2c_versatile *i2c;
int ret;
i2c = devm_kzalloc(&dev->dev, sizeof(struct i2c_versatile), GFP_KERNEL);
if (!i2c)
return -ENOMEM;
i2c->base = devm_platform_get_and_ioremap_resource(dev, 0, NULL);
if (IS_ERR(i2c->base))
return PTR_ERR(i2c->base);
writel(SCL | SDA, i2c->base + I2C_CONTROLS);
i2c->adap.owner = THIS_MODULE;
strscpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name));
i2c->adap.algo_data = &i2c->algo;
i2c->adap.dev.parent = &dev->dev;
i2c->adap.dev.of_node = dev->dev.of_node;
i2c->algo = i2c_versatile_algo;
i2c->algo.data = i2c;
i2c->adap.nr = dev->id;
ret = i2c_bit_add_numbered_bus(&i2c->adap);
if (ret < 0)
return ret;
platform_set_drvdata(dev, i2c);
return 0;
}
static void i2c_versatile_remove(struct platform_device *dev)
{
struct i2c_versatile *i2c = platform_get_drvdata(dev);
i2c_del_adapter(&i2c->adap);
}
static const struct of_device_id i2c_versatile_match[] = {
{ .compatible = "arm,versatile-i2c", },
{},
};
MODULE_DEVICE_TABLE(of, i2c_versatile_match);
static struct platform_driver i2c_versatile_driver = {
.probe = i2c_versatile_probe,
.remove = i2c_versatile_remove,
.driver = {
.name = "versatile-i2c",
.of_match_table = i2c_versatile_match,
},
};
static int __init i2c_versatile_init(void)
{
return platform_driver_register(&i2c_versatile_driver);
}
static void __exit i2c_versatile_exit(void)
{
platform_driver_unregister(&i2c_versatile_driver);
}
subsys_initcall(i2c_versatile_init);
module_exit(i2c_versatile_exit);
MODULE_DESCRIPTION("ARM Versatile I2C bus driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:versatile-i2c");
|
