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 | |
23 | struct i2c_versatile { |
24 | struct i2c_adapter adap; |
25 | struct i2c_algo_bit_data algo; |
26 | void __iomem *base; |
27 | }; |
28 | |
29 | static void i2c_versatile_setsda(void *data, int state) |
30 | { |
31 | struct i2c_versatile *i2c = data; |
32 | |
33 | writel(SDA, addr: i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); |
34 | } |
35 | |
36 | static void i2c_versatile_setscl(void *data, int state) |
37 | { |
38 | struct i2c_versatile *i2c = data; |
39 | |
40 | writel(SCL, addr: i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); |
41 | } |
42 | |
43 | static int i2c_versatile_getsda(void *data) |
44 | { |
45 | struct i2c_versatile *i2c = data; |
46 | return !!(readl(addr: i2c->base + I2C_CONTROL) & SDA); |
47 | } |
48 | |
49 | static int i2c_versatile_getscl(void *data) |
50 | { |
51 | struct i2c_versatile *i2c = data; |
52 | return !!(readl(addr: i2c->base + I2C_CONTROL) & SCL); |
53 | } |
54 | |
55 | static 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 | |
64 | static int i2c_versatile_probe(struct platform_device *dev) |
65 | { |
66 | struct i2c_versatile *i2c; |
67 | int ret; |
68 | |
69 | i2c = devm_kzalloc(dev: &dev->dev, size: sizeof(struct i2c_versatile), GFP_KERNEL); |
70 | if (!i2c) |
71 | return -ENOMEM; |
72 | |
73 | i2c->base = devm_platform_get_and_ioremap_resource(pdev: dev, index: 0, NULL); |
74 | if (IS_ERR(ptr: i2c->base)) |
75 | return PTR_ERR(ptr: i2c->base); |
76 | |
77 | writel(SCL | SDA, addr: i2c->base + I2C_CONTROLS); |
78 | |
79 | i2c->adap.owner = THIS_MODULE; |
80 | strscpy(p: i2c->adap.name, q: "Versatile I2C adapter" , size: sizeof(i2c->adap.name)); |
81 | i2c->adap.algo_data = &i2c->algo; |
82 | i2c->adap.dev.parent = &dev->dev; |
83 | i2c->adap.dev.of_node = dev->dev.of_node; |
84 | i2c->algo = i2c_versatile_algo; |
85 | i2c->algo.data = i2c; |
86 | |
87 | i2c->adap.nr = dev->id; |
88 | ret = i2c_bit_add_numbered_bus(&i2c->adap); |
89 | if (ret < 0) |
90 | return ret; |
91 | |
92 | platform_set_drvdata(pdev: dev, data: i2c); |
93 | |
94 | return 0; |
95 | } |
96 | |
97 | static void i2c_versatile_remove(struct platform_device *dev) |
98 | { |
99 | struct i2c_versatile *i2c = platform_get_drvdata(pdev: dev); |
100 | |
101 | i2c_del_adapter(adap: &i2c->adap); |
102 | } |
103 | |
104 | static const struct of_device_id i2c_versatile_match[] = { |
105 | { .compatible = "arm,versatile-i2c" , }, |
106 | {}, |
107 | }; |
108 | MODULE_DEVICE_TABLE(of, i2c_versatile_match); |
109 | |
110 | static struct platform_driver i2c_versatile_driver = { |
111 | .probe = i2c_versatile_probe, |
112 | .remove_new = i2c_versatile_remove, |
113 | .driver = { |
114 | .name = "versatile-i2c" , |
115 | .of_match_table = i2c_versatile_match, |
116 | }, |
117 | }; |
118 | |
119 | static int __init i2c_versatile_init(void) |
120 | { |
121 | return platform_driver_register(&i2c_versatile_driver); |
122 | } |
123 | |
124 | static void __exit i2c_versatile_exit(void) |
125 | { |
126 | platform_driver_unregister(&i2c_versatile_driver); |
127 | } |
128 | |
129 | subsys_initcall(i2c_versatile_init); |
130 | module_exit(i2c_versatile_exit); |
131 | |
132 | MODULE_DESCRIPTION("ARM Versatile I2C bus driver" ); |
133 | MODULE_LICENSE("GPL" ); |
134 | MODULE_ALIAS("platform:versatile-i2c" ); |
135 | |