Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / drivers / i2c / busses / i2c-versatile.c
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
18 #include <asm/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
26 struct i2c_versatile {
27         struct i2c_adapter       adap;
28         struct i2c_algo_bit_data algo;
29         void __iomem             *base;
30 };
31
32 static 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
39 static 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
46 static int i2c_versatile_getsda(void *data)
47 {
48         struct i2c_versatile *i2c = data;
49         return !!(readl(i2c->base + I2C_CONTROL) & SDA);
50 }
51
52 static int i2c_versatile_getscl(void *data)
53 {
54         struct i2c_versatile *i2c = data;
55         return !!(readl(i2c->base + I2C_CONTROL) & SCL);
56 }
57
58 static 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
67 static int i2c_versatile_probe(struct platform_device *dev)
68 {
69         struct i2c_versatile *i2c;
70         struct resource *r;
71         int ret;
72
73         r = platform_get_resource(dev, IORESOURCE_MEM, 0);
74         if (!r) {
75                 ret = -EINVAL;
76                 goto err_out;
77         }
78
79         if (!request_mem_region(r->start, r->end - r->start + 1, "versatile-i2c")) {
80                 ret = -EBUSY;
81                 goto err_out;
82         }
83
84         i2c = kzalloc(sizeof(struct i2c_versatile), GFP_KERNEL);
85         if (!i2c) {
86                 ret = -ENOMEM;
87                 goto err_release;
88         }
89
90         i2c->base = ioremap(r->start, r->end - r->start + 1);
91         if (!i2c->base) {
92                 ret = -ENOMEM;
93                 goto err_free;
94         }
95
96         writel(SCL | SDA, i2c->base + I2C_CONTROLS);
97
98         i2c->adap.owner = THIS_MODULE;
99         strlcpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name));
100         i2c->adap.algo_data = &i2c->algo;
101         i2c->adap.dev.parent = &dev->dev;
102         i2c->algo = i2c_versatile_algo;
103         i2c->algo.data = i2c;
104
105         ret = i2c_bit_add_bus(&i2c->adap);
106         if (ret >= 0) {
107                 platform_set_drvdata(dev, i2c);
108                 return 0;
109         }
110
111         iounmap(i2c->base);
112  err_free:
113         kfree(i2c);
114  err_release:
115         release_mem_region(r->start, r->end - r->start + 1);
116  err_out:
117         return ret;
118 }
119
120 static int i2c_versatile_remove(struct platform_device *dev)
121 {
122         struct i2c_versatile *i2c = platform_get_drvdata(dev);
123
124         platform_set_drvdata(dev, NULL);
125
126         i2c_del_adapter(&i2c->adap);
127         return 0;
128 }
129
130 static struct platform_driver i2c_versatile_driver = {
131         .probe          = i2c_versatile_probe,
132         .remove         = i2c_versatile_remove,
133         .driver         = {
134                 .name   = "versatile-i2c",
135                 .owner  = THIS_MODULE,
136         },
137 };
138
139 static int __init i2c_versatile_init(void)
140 {
141         return platform_driver_register(&i2c_versatile_driver);
142 }
143
144 static void __exit i2c_versatile_exit(void)
145 {
146         platform_driver_unregister(&i2c_versatile_driver);
147 }
148
149 module_init(i2c_versatile_init);
150 module_exit(i2c_versatile_exit);
151
152 MODULE_DESCRIPTION("ARM Versatile I2C bus driver");
153 MODULE_LICENSE("GPL");
154 MODULE_ALIAS("platform:versatile-i2c");