Merge branch 'omap-clks3' into devel
[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         if (dev->id >= 0) {
106                 /* static bus numbering */
107                 i2c->adap.nr = dev->id;
108                 ret = i2c_bit_add_numbered_bus(&i2c->adap);
109         } else
110                 /* dynamic bus numbering */
111                 ret = i2c_bit_add_bus(&i2c->adap);
112         if (ret >= 0) {
113                 platform_set_drvdata(dev, i2c);
114                 return 0;
115         }
116
117         iounmap(i2c->base);
118  err_free:
119         kfree(i2c);
120  err_release:
121         release_mem_region(r->start, r->end - r->start + 1);
122  err_out:
123         return ret;
124 }
125
126 static int i2c_versatile_remove(struct platform_device *dev)
127 {
128         struct i2c_versatile *i2c = platform_get_drvdata(dev);
129
130         platform_set_drvdata(dev, NULL);
131
132         i2c_del_adapter(&i2c->adap);
133         return 0;
134 }
135
136 static struct platform_driver i2c_versatile_driver = {
137         .probe          = i2c_versatile_probe,
138         .remove         = i2c_versatile_remove,
139         .driver         = {
140                 .name   = "versatile-i2c",
141                 .owner  = THIS_MODULE,
142         },
143 };
144
145 static int __init i2c_versatile_init(void)
146 {
147         return platform_driver_register(&i2c_versatile_driver);
148 }
149
150 static void __exit i2c_versatile_exit(void)
151 {
152         platform_driver_unregister(&i2c_versatile_driver);
153 }
154
155 subsys_initcall(i2c_versatile_init);
156 module_exit(i2c_versatile_exit);
157
158 MODULE_DESCRIPTION("ARM Versatile I2C bus driver");
159 MODULE_LICENSE("GPL");
160 MODULE_ALIAS("platform:versatile-i2c");