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6b65cd74 RK |
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> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
21782180 | 18 | #include <linux/io.h> |
6b65cd74 RK |
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 | ||
c6ffddea | 79 | if (!request_mem_region(r->start, resource_size(r), "versatile-i2c")) { |
6b65cd74 RK |
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 | ||
c6ffddea | 90 | i2c->base = ioremap(r->start, resource_size(r)); |
6b65cd74 RK |
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; | |
237ab406 | 102 | i2c->adap.dev.of_node = dev->dev.of_node; |
6b65cd74 RK |
103 | i2c->algo = i2c_versatile_algo; |
104 | i2c->algo.data = i2c; | |
105 | ||
44454baa KL |
106 | i2c->adap.nr = dev->id; |
107 | ret = i2c_bit_add_numbered_bus(&i2c->adap); | |
6b65cd74 RK |
108 | if (ret >= 0) { |
109 | platform_set_drvdata(dev, i2c); | |
110 | return 0; | |
111 | } | |
112 | ||
113 | iounmap(i2c->base); | |
114 | err_free: | |
115 | kfree(i2c); | |
116 | err_release: | |
c6ffddea | 117 | release_mem_region(r->start, resource_size(r)); |
6b65cd74 RK |
118 | err_out: |
119 | return ret; | |
120 | } | |
121 | ||
122 | static int i2c_versatile_remove(struct platform_device *dev) | |
123 | { | |
124 | struct i2c_versatile *i2c = platform_get_drvdata(dev); | |
125 | ||
6b65cd74 RK |
126 | i2c_del_adapter(&i2c->adap); |
127 | return 0; | |
128 | } | |
129 | ||
237ab406 PM |
130 | static const struct of_device_id i2c_versatile_match[] = { |
131 | { .compatible = "arm,versatile-i2c", }, | |
132 | {}, | |
133 | }; | |
134 | MODULE_DEVICE_TABLE(of, i2c_versatile_match); | |
135 | ||
6b65cd74 RK |
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, | |
237ab406 | 142 | .of_match_table = i2c_versatile_match, |
6b65cd74 RK |
143 | }, |
144 | }; | |
145 | ||
146 | static int __init i2c_versatile_init(void) | |
147 | { | |
148 | return platform_driver_register(&i2c_versatile_driver); | |
149 | } | |
150 | ||
151 | static void __exit i2c_versatile_exit(void) | |
152 | { | |
153 | platform_driver_unregister(&i2c_versatile_driver); | |
154 | } | |
155 | ||
2514cca0 | 156 | subsys_initcall(i2c_versatile_init); |
6b65cd74 RK |
157 | module_exit(i2c_versatile_exit); |
158 | ||
159 | MODULE_DESCRIPTION("ARM Versatile I2C bus driver"); | |
160 | MODULE_LICENSE("GPL"); | |
add8eda7 | 161 | MODULE_ALIAS("platform:versatile-i2c"); |