1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  i2c-versatile.c
4 *
5 *  Copyright (C) 2006 ARM Ltd.
6 *  written by Russell King, Deep Blue Solutions Ltd.
7 */
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/i2c.h>
11#include <linux/i2c-algo-bit.h>
12#include <linux/init.h>
13#include <linux/platform_device.h>
14#include <linux/slab.h>
15#include <linux/io.h>
16
17#define I2C_CONTROL	0x00
18#define I2C_CONTROLS	0x00
19#define I2C_CONTROLC	0x04
20#define SCL		(1 << 0)
21#define SDA		(1 << 1)
22
23struct i2c_versatile {
24	struct i2c_adapter	 adap;
25	struct i2c_algo_bit_data algo;
26	void __iomem		 *base;
27};
28
29static void i2c_versatile_setsda(void *data, int state)
30{
31	struct i2c_versatile *i2c = data;
32
33	writel(SDA, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC));
34}
35
36static void i2c_versatile_setscl(void *data, int state)
37{
38	struct i2c_versatile *i2c = data;
39
40	writel(SCL, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC));
41}
42
43static int i2c_versatile_getsda(void *data)
44{
45	struct i2c_versatile *i2c = data;
46	return !!(readl(i2c->base + I2C_CONTROL) & SDA);
47}
48
49static int i2c_versatile_getscl(void *data)
50{
51	struct i2c_versatile *i2c = data;
52	return !!(readl(i2c->base + I2C_CONTROL) & SCL);
53}
54
55static const struct i2c_algo_bit_data i2c_versatile_algo = {
56	.setsda	= i2c_versatile_setsda,
57	.setscl = i2c_versatile_setscl,
58	.getsda	= i2c_versatile_getsda,
59	.getscl = i2c_versatile_getscl,
60	.udelay	= 30,
61	.timeout = HZ,
62};
63
64static int i2c_versatile_probe(struct platform_device *dev)
65{
66	struct i2c_versatile *i2c;
67	struct resource *r;
68	int ret;
69
70	i2c = devm_kzalloc(&dev->dev, sizeof(struct i2c_versatile), GFP_KERNEL);
71	if (!i2c)
72		return -ENOMEM;
73
74	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
75	i2c->base = devm_ioremap_resource(&dev->dev, r);
76	if (IS_ERR(i2c->base))
77		return PTR_ERR(i2c->base);
78
79	writel(SCL | SDA, i2c->base + I2C_CONTROLS);
80
81	i2c->adap.owner = THIS_MODULE;
82	strlcpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name));
83	i2c->adap.algo_data = &i2c->algo;
84	i2c->adap.dev.parent = &dev->dev;
85	i2c->adap.dev.of_node = dev->dev.of_node;
86	i2c->algo = i2c_versatile_algo;
87	i2c->algo.data = i2c;
88
89	i2c->adap.nr = dev->id;
90	ret = i2c_bit_add_numbered_bus(&i2c->adap);
91	if (ret < 0)
92		return ret;
93
94	platform_set_drvdata(dev, i2c);
95
96	return 0;
97}
98
99static int i2c_versatile_remove(struct platform_device *dev)
100{
101	struct i2c_versatile *i2c = platform_get_drvdata(dev);
102
103	i2c_del_adapter(&i2c->adap);
104	return 0;
105}
106
107static const struct of_device_id i2c_versatile_match[] = {
108	{ .compatible = "arm,versatile-i2c", },
109	{},
110};
111MODULE_DEVICE_TABLE(of, i2c_versatile_match);
112
113static struct platform_driver i2c_versatile_driver = {
114	.probe		= i2c_versatile_probe,
115	.remove		= i2c_versatile_remove,
116	.driver		= {
117		.name	= "versatile-i2c",
118		.of_match_table = i2c_versatile_match,
119	},
120};
121
122static int __init i2c_versatile_init(void)
123{
124	return platform_driver_register(&i2c_versatile_driver);
125}
126
127static void __exit i2c_versatile_exit(void)
128{
129	platform_driver_unregister(&i2c_versatile_driver);
130}
131
132subsys_initcall(i2c_versatile_init);
133module_exit(i2c_versatile_exit);
134
135MODULE_DESCRIPTION("ARM Versatile I2C bus driver");
136MODULE_LICENSE("GPL");
137MODULE_ALIAS("platform:versatile-i2c");
138