tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * i2c-versatile.c
3 *
4 * Copyright (C) 2006 ARM Ltd.
5 * written by Russell King, Deep Blue Solutions Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/i2c.h>
14#include <linux/i2c-algo-bit.h>
15#include <linux/init.h>
16#include <linux/platform_device.h>
17#include <linux/slab.h>
18#include <linux/io.h>
19
20#define I2C_CONTROL 0x00
21#define I2C_CONTROLS 0x00
22#define I2C_CONTROLC 0x04
23#define SCL (1 << 0)
24#define SDA (1 << 1)
25
26struct i2c_versatile {
27 struct i2c_adapter adap;
28 struct i2c_algo_bit_data algo;
29 void __iomem *base;
30};
31
32static void i2c_versatile_setsda(void *data, int state)
33{
34 struct i2c_versatile *i2c = data;
35
36 writel(SDA, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC));
37}
38
39static void i2c_versatile_setscl(void *data, int state)
40{
41 struct i2c_versatile *i2c = data;
42
43 writel(SCL, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC));
44}
45
46static int i2c_versatile_getsda(void *data)
47{
48 struct i2c_versatile *i2c = data;
49 return !!(readl(i2c->base + I2C_CONTROL) & SDA);
50}
51
52static int i2c_versatile_getscl(void *data)
53{
54 struct i2c_versatile *i2c = data;
55 return !!(readl(i2c->base + I2C_CONTROL) & SCL);
56}
57
58static const struct i2c_algo_bit_data i2c_versatile_algo = {
59 .setsda = i2c_versatile_setsda,
60 .setscl = i2c_versatile_setscl,
61 .getsda = i2c_versatile_getsda,
62 .getscl = i2c_versatile_getscl,
63 .udelay = 30,
64 .timeout = HZ,
65};
66
67static int i2c_versatile_probe(struct platform_device *dev)
68{
69 struct i2c_versatile *i2c;
70 struct resource *r;
71 int ret;
72
73 i2c = devm_kzalloc(&dev->dev, sizeof(struct i2c_versatile), GFP_KERNEL);
74 if (!i2c)
75 return -ENOMEM;
76
77 r = platform_get_resource(dev, IORESOURCE_MEM, 0);
78 i2c->base = devm_ioremap_resource(&dev->dev, r);
79 if (IS_ERR(i2c->base))
80 return PTR_ERR(i2c->base);
81
82 writel(SCL | SDA, i2c->base + I2C_CONTROLS);
83
84 i2c->adap.owner = THIS_MODULE;
85 strlcpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name));
86 i2c->adap.algo_data = &i2c->algo;
87 i2c->adap.dev.parent = &dev->dev;
88 i2c->adap.dev.of_node = dev->dev.of_node;
89 i2c->algo = i2c_versatile_algo;
90 i2c->algo.data = i2c;
91
92 i2c->adap.nr = dev->id;
93 ret = i2c_bit_add_numbered_bus(&i2c->adap);
94 if (ret < 0)
95 return ret;
96
97 platform_set_drvdata(dev, i2c);
98
99 return 0;
100}
101
102static int i2c_versatile_remove(struct platform_device *dev)
103{
104 struct i2c_versatile *i2c = platform_get_drvdata(dev);
105
106 i2c_del_adapter(&i2c->adap);
107 return 0;
108}
109
110static const struct of_device_id i2c_versatile_match[] = {
111 { .compatible = "arm,versatile-i2c", },
112 {},
113};
114MODULE_DEVICE_TABLE(of, i2c_versatile_match);
115
116static struct platform_driver i2c_versatile_driver = {
117 .probe = i2c_versatile_probe,
118 .remove = i2c_versatile_remove,
119 .driver = {
120 .name = "versatile-i2c",
121 .of_match_table = i2c_versatile_match,
122 },
123};
124
125static int __init i2c_versatile_init(void)
126{
127 return platform_driver_register(&i2c_versatile_driver);
128}
129
130static void __exit i2c_versatile_exit(void)
131{
132 platform_driver_unregister(&i2c_versatile_driver);
133}
134
135subsys_initcall(i2c_versatile_init);
136module_exit(i2c_versatile_exit);
137
138MODULE_DESCRIPTION("ARM Versatile I2C bus driver");
139MODULE_LICENSE("GPL");
140MODULE_ALIAS("platform:versatile-i2c");