2 * Copyright (C) 2005 Simtec Electronics
3 * Ben Dooks <ben@simtec.co.uk>
5 * Simtec Generic I2C Controller
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/delay.h>
24 #include <linux/platform_device.h>
25 #include <linux/slab.h>
28 #include <linux/i2c.h>
29 #include <linux/i2c-algo-bit.h>
31 struct simtec_i2c_data {
32 struct resource *ioarea;
34 struct i2c_adapter adap;
35 struct i2c_algo_bit_data bit;
38 #define CMD_SET_SDA (1<<2)
39 #define CMD_SET_SCL (1<<3)
41 #define STATE_SDA (1<<0)
42 #define STATE_SCL (1<<1)
44 /* i2c bit-bus functions */
46 static void simtec_i2c_setsda(void *pw, int state)
48 struct simtec_i2c_data *pd = pw;
49 writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg);
52 static void simtec_i2c_setscl(void *pw, int state)
54 struct simtec_i2c_data *pd = pw;
55 writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg);
58 static int simtec_i2c_getsda(void *pw)
60 struct simtec_i2c_data *pd = pw;
61 return readb(pd->reg) & STATE_SDA ? 1 : 0;
64 static int simtec_i2c_getscl(void *pw)
66 struct simtec_i2c_data *pd = pw;
67 return readb(pd->reg) & STATE_SCL ? 1 : 0;
70 /* device registration */
72 static int simtec_i2c_probe(struct platform_device *dev)
74 struct simtec_i2c_data *pd;
79 pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL);
83 platform_set_drvdata(dev, pd);
85 res = platform_get_resource(dev, IORESOURCE_MEM, 0);
87 dev_err(&dev->dev, "cannot find IO resource\n");
92 size = resource_size(res);
94 pd->ioarea = request_mem_region(res->start, size, dev->name);
95 if (pd->ioarea == NULL) {
96 dev_err(&dev->dev, "cannot request IO\n");
101 pd->reg = ioremap(res->start, size);
102 if (pd->reg == NULL) {
103 dev_err(&dev->dev, "cannot map IO\n");
108 /* setup the private data */
110 pd->adap.owner = THIS_MODULE;
111 pd->adap.algo_data = &pd->bit;
112 pd->adap.dev.parent = &dev->dev;
114 strlcpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name));
117 pd->bit.setsda = simtec_i2c_setsda;
118 pd->bit.setscl = simtec_i2c_setscl;
119 pd->bit.getsda = simtec_i2c_getsda;
120 pd->bit.getscl = simtec_i2c_getscl;
121 pd->bit.timeout = HZ;
124 ret = i2c_bit_add_bus(&pd->adap);
134 release_resource(pd->ioarea);
142 static int simtec_i2c_remove(struct platform_device *dev)
144 struct simtec_i2c_data *pd = platform_get_drvdata(dev);
146 i2c_del_adapter(&pd->adap);
149 release_resource(pd->ioarea);
158 static struct platform_driver simtec_i2c_driver = {
160 .name = "simtec-i2c",
161 .owner = THIS_MODULE,
163 .probe = simtec_i2c_probe,
164 .remove = simtec_i2c_remove,
167 module_platform_driver(simtec_i2c_driver);
169 MODULE_DESCRIPTION("Simtec Generic I2C Bus driver");
170 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
171 MODULE_LICENSE("GPL");
172 MODULE_ALIAS("platform:simtec-i2c");