12504ba9fSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
2bcda9f1eSBen Dooks /*
3bcda9f1eSBen Dooks * Copyright (C) 2005 Simtec Electronics
4bcda9f1eSBen Dooks * Ben Dooks <ben@simtec.co.uk>
5bcda9f1eSBen Dooks *
6bcda9f1eSBen Dooks * Simtec Generic I2C Controller
7bcda9f1eSBen Dooks */
8bcda9f1eSBen Dooks
9bcda9f1eSBen Dooks #include <linux/kernel.h>
10bcda9f1eSBen Dooks #include <linux/module.h>
11bcda9f1eSBen Dooks #include <linux/delay.h>
12bcda9f1eSBen Dooks #include <linux/platform_device.h>
135a0e3ad6STejun Heo #include <linux/slab.h>
1421782180SH Hartley Sweeten #include <linux/io.h>
15bcda9f1eSBen Dooks
16bcda9f1eSBen Dooks #include <linux/i2c.h>
17bcda9f1eSBen Dooks #include <linux/i2c-algo-bit.h>
18bcda9f1eSBen Dooks
19bcda9f1eSBen Dooks struct simtec_i2c_data {
20bcda9f1eSBen Dooks struct resource *ioarea;
21bcda9f1eSBen Dooks void __iomem *reg;
22bcda9f1eSBen Dooks struct i2c_adapter adap;
23bcda9f1eSBen Dooks struct i2c_algo_bit_data bit;
24bcda9f1eSBen Dooks };
25bcda9f1eSBen Dooks
26bcda9f1eSBen Dooks #define CMD_SET_SDA (1<<2)
27bcda9f1eSBen Dooks #define CMD_SET_SCL (1<<3)
28bcda9f1eSBen Dooks
29bcda9f1eSBen Dooks #define STATE_SDA (1<<0)
30bcda9f1eSBen Dooks #define STATE_SCL (1<<1)
31bcda9f1eSBen Dooks
32bcda9f1eSBen Dooks /* i2c bit-bus functions */
33bcda9f1eSBen Dooks
simtec_i2c_setsda(void * pw,int state)34bcda9f1eSBen Dooks static void simtec_i2c_setsda(void *pw, int state)
35bcda9f1eSBen Dooks {
36bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw;
37bcda9f1eSBen Dooks writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg);
38bcda9f1eSBen Dooks }
39bcda9f1eSBen Dooks
simtec_i2c_setscl(void * pw,int state)40bcda9f1eSBen Dooks static void simtec_i2c_setscl(void *pw, int state)
41bcda9f1eSBen Dooks {
42bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw;
43bcda9f1eSBen Dooks writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg);
44bcda9f1eSBen Dooks }
45bcda9f1eSBen Dooks
simtec_i2c_getsda(void * pw)46bcda9f1eSBen Dooks static int simtec_i2c_getsda(void *pw)
47bcda9f1eSBen Dooks {
48bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw;
49bcda9f1eSBen Dooks return readb(pd->reg) & STATE_SDA ? 1 : 0;
50bcda9f1eSBen Dooks }
51bcda9f1eSBen Dooks
simtec_i2c_getscl(void * pw)52bcda9f1eSBen Dooks static int simtec_i2c_getscl(void *pw)
53bcda9f1eSBen Dooks {
54bcda9f1eSBen Dooks struct simtec_i2c_data *pd = pw;
55bcda9f1eSBen Dooks return readb(pd->reg) & STATE_SCL ? 1 : 0;
56bcda9f1eSBen Dooks }
57bcda9f1eSBen Dooks
58bcda9f1eSBen Dooks /* device registration */
59bcda9f1eSBen Dooks
simtec_i2c_probe(struct platform_device * dev)60bcda9f1eSBen Dooks static int simtec_i2c_probe(struct platform_device *dev)
61bcda9f1eSBen Dooks {
62bcda9f1eSBen Dooks struct simtec_i2c_data *pd;
63bcda9f1eSBen Dooks struct resource *res;
64bcda9f1eSBen Dooks int size;
65bcda9f1eSBen Dooks int ret;
66bcda9f1eSBen Dooks
67bcda9f1eSBen Dooks pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL);
6846797a2aSJingoo Han if (pd == NULL)
69bcda9f1eSBen Dooks return -ENOMEM;
70bcda9f1eSBen Dooks
71bcda9f1eSBen Dooks platform_set_drvdata(dev, pd);
72bcda9f1eSBen Dooks
73bcda9f1eSBen Dooks res = platform_get_resource(dev, IORESOURCE_MEM, 0);
74bcda9f1eSBen Dooks if (res == NULL) {
75bcda9f1eSBen Dooks dev_err(&dev->dev, "cannot find IO resource\n");
76bcda9f1eSBen Dooks ret = -ENOENT;
77bcda9f1eSBen Dooks goto err;
78bcda9f1eSBen Dooks }
79bcda9f1eSBen Dooks
8059330825SJulia Lawall size = resource_size(res);
81bcda9f1eSBen Dooks
82bcda9f1eSBen Dooks pd->ioarea = request_mem_region(res->start, size, dev->name);
83bcda9f1eSBen Dooks if (pd->ioarea == NULL) {
84bcda9f1eSBen Dooks dev_err(&dev->dev, "cannot request IO\n");
85bcda9f1eSBen Dooks ret = -ENXIO;
86bcda9f1eSBen Dooks goto err;
87bcda9f1eSBen Dooks }
88bcda9f1eSBen Dooks
89bcda9f1eSBen Dooks pd->reg = ioremap(res->start, size);
90bcda9f1eSBen Dooks if (pd->reg == NULL) {
91bcda9f1eSBen Dooks dev_err(&dev->dev, "cannot map IO\n");
92bcda9f1eSBen Dooks ret = -ENXIO;
93bcda9f1eSBen Dooks goto err_res;
94bcda9f1eSBen Dooks }
95bcda9f1eSBen Dooks
96bcda9f1eSBen Dooks /* setup the private data */
97bcda9f1eSBen Dooks
98bcda9f1eSBen Dooks pd->adap.owner = THIS_MODULE;
99bcda9f1eSBen Dooks pd->adap.algo_data = &pd->bit;
100bcda9f1eSBen Dooks pd->adap.dev.parent = &dev->dev;
101bcda9f1eSBen Dooks
102ea1558ceSWolfram Sang strscpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name));
103bcda9f1eSBen Dooks
104bcda9f1eSBen Dooks pd->bit.data = pd;
105bcda9f1eSBen Dooks pd->bit.setsda = simtec_i2c_setsda;
106bcda9f1eSBen Dooks pd->bit.setscl = simtec_i2c_setscl;
107bcda9f1eSBen Dooks pd->bit.getsda = simtec_i2c_getsda;
108bcda9f1eSBen Dooks pd->bit.getscl = simtec_i2c_getscl;
109bcda9f1eSBen Dooks pd->bit.timeout = HZ;
110bcda9f1eSBen Dooks pd->bit.udelay = 20;
111bcda9f1eSBen Dooks
112bcda9f1eSBen Dooks ret = i2c_bit_add_bus(&pd->adap);
113bcda9f1eSBen Dooks if (ret)
114bcda9f1eSBen Dooks goto err_all;
115bcda9f1eSBen Dooks
116bcda9f1eSBen Dooks return 0;
117bcda9f1eSBen Dooks
118bcda9f1eSBen Dooks err_all:
119bcda9f1eSBen Dooks iounmap(pd->reg);
120bcda9f1eSBen Dooks
121bcda9f1eSBen Dooks err_res:
12242543aebSAnton Vasilyev release_mem_region(pd->ioarea->start, size);
123bcda9f1eSBen Dooks
124bcda9f1eSBen Dooks err:
125bcda9f1eSBen Dooks kfree(pd);
126bcda9f1eSBen Dooks return ret;
127bcda9f1eSBen Dooks }
128bcda9f1eSBen Dooks
simtec_i2c_remove(struct platform_device * dev)129*e190a0c3SUwe Kleine-König static void simtec_i2c_remove(struct platform_device *dev)
130bcda9f1eSBen Dooks {
131bcda9f1eSBen Dooks struct simtec_i2c_data *pd = platform_get_drvdata(dev);
132bcda9f1eSBen Dooks
133bcda9f1eSBen Dooks i2c_del_adapter(&pd->adap);
134bcda9f1eSBen Dooks
135bcda9f1eSBen Dooks iounmap(pd->reg);
13642543aebSAnton Vasilyev release_mem_region(pd->ioarea->start, resource_size(pd->ioarea));
137bcda9f1eSBen Dooks kfree(pd);
138bcda9f1eSBen Dooks }
139bcda9f1eSBen Dooks
140bcda9f1eSBen Dooks /* device driver */
141bcda9f1eSBen Dooks
142bcda9f1eSBen Dooks static struct platform_driver simtec_i2c_driver = {
143bcda9f1eSBen Dooks .driver = {
144bcda9f1eSBen Dooks .name = "simtec-i2c",
145bcda9f1eSBen Dooks },
146bcda9f1eSBen Dooks .probe = simtec_i2c_probe,
147*e190a0c3SUwe Kleine-König .remove_new = simtec_i2c_remove,
148bcda9f1eSBen Dooks };
149bcda9f1eSBen Dooks
150a3664b51SAxel Lin module_platform_driver(simtec_i2c_driver);
151bcda9f1eSBen Dooks
152bcda9f1eSBen Dooks MODULE_DESCRIPTION("Simtec Generic I2C Bus driver");
153bcda9f1eSBen Dooks MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
154bcda9f1eSBen Dooks MODULE_LICENSE("GPL");
155a3664b51SAxel Lin MODULE_ALIAS("platform:simtec-i2c");
156