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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> |
6b65cd74 RK |
18 | |
19 | #include <asm/io.h> | |
20 | ||
21 | #define I2C_CONTROL 0x00 | |
22 | #define I2C_CONTROLS 0x00 | |
23 | #define I2C_CONTROLC 0x04 | |
24 | #define SCL (1 << 0) | |
25 | #define SDA (1 << 1) | |
26 | ||
27 | struct i2c_versatile { | |
28 | struct i2c_adapter adap; | |
29 | struct i2c_algo_bit_data algo; | |
30 | void __iomem *base; | |
31 | }; | |
32 | ||
33 | static void i2c_versatile_setsda(void *data, int state) | |
34 | { | |
35 | struct i2c_versatile *i2c = data; | |
36 | ||
37 | writel(SDA, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); | |
38 | } | |
39 | ||
40 | static void i2c_versatile_setscl(void *data, int state) | |
41 | { | |
42 | struct i2c_versatile *i2c = data; | |
43 | ||
44 | writel(SCL, i2c->base + (state ? I2C_CONTROLS : I2C_CONTROLC)); | |
45 | } | |
46 | ||
47 | static int i2c_versatile_getsda(void *data) | |
48 | { | |
49 | struct i2c_versatile *i2c = data; | |
50 | return !!(readl(i2c->base + I2C_CONTROL) & SDA); | |
51 | } | |
52 | ||
53 | static int i2c_versatile_getscl(void *data) | |
54 | { | |
55 | struct i2c_versatile *i2c = data; | |
56 | return !!(readl(i2c->base + I2C_CONTROL) & SCL); | |
57 | } | |
58 | ||
59 | static struct i2c_algo_bit_data i2c_versatile_algo = { | |
60 | .setsda = i2c_versatile_setsda, | |
61 | .setscl = i2c_versatile_setscl, | |
62 | .getsda = i2c_versatile_getsda, | |
63 | .getscl = i2c_versatile_getscl, | |
64 | .udelay = 30, | |
65 | .timeout = HZ, | |
66 | }; | |
67 | ||
68 | static int i2c_versatile_probe(struct platform_device *dev) | |
69 | { | |
70 | struct i2c_versatile *i2c; | |
71 | struct resource *r; | |
72 | int ret; | |
73 | ||
74 | r = platform_get_resource(dev, IORESOURCE_MEM, 0); | |
75 | if (!r) { | |
76 | ret = -EINVAL; | |
77 | goto err_out; | |
78 | } | |
79 | ||
c6ffddea | 80 | if (!request_mem_region(r->start, resource_size(r), "versatile-i2c")) { |
6b65cd74 RK |
81 | ret = -EBUSY; |
82 | goto err_out; | |
83 | } | |
84 | ||
85 | i2c = kzalloc(sizeof(struct i2c_versatile), GFP_KERNEL); | |
86 | if (!i2c) { | |
87 | ret = -ENOMEM; | |
88 | goto err_release; | |
89 | } | |
90 | ||
c6ffddea | 91 | i2c->base = ioremap(r->start, resource_size(r)); |
6b65cd74 RK |
92 | if (!i2c->base) { |
93 | ret = -ENOMEM; | |
94 | goto err_free; | |
95 | } | |
96 | ||
97 | writel(SCL | SDA, i2c->base + I2C_CONTROLS); | |
98 | ||
99 | i2c->adap.owner = THIS_MODULE; | |
100 | strlcpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name)); | |
101 | i2c->adap.algo_data = &i2c->algo; | |
102 | i2c->adap.dev.parent = &dev->dev; | |
103 | i2c->algo = i2c_versatile_algo; | |
104 | i2c->algo.data = i2c; | |
105 | ||
2514cca0 CM |
106 | if (dev->id >= 0) { |
107 | /* static bus numbering */ | |
108 | i2c->adap.nr = dev->id; | |
109 | ret = i2c_bit_add_numbered_bus(&i2c->adap); | |
110 | } else | |
111 | /* dynamic bus numbering */ | |
112 | ret = i2c_bit_add_bus(&i2c->adap); | |
6b65cd74 RK |
113 | if (ret >= 0) { |
114 | platform_set_drvdata(dev, i2c); | |
115 | return 0; | |
116 | } | |
117 | ||
118 | iounmap(i2c->base); | |
119 | err_free: | |
120 | kfree(i2c); | |
121 | err_release: | |
c6ffddea | 122 | release_mem_region(r->start, resource_size(r)); |
6b65cd74 RK |
123 | err_out: |
124 | return ret; | |
125 | } | |
126 | ||
127 | static int i2c_versatile_remove(struct platform_device *dev) | |
128 | { | |
129 | struct i2c_versatile *i2c = platform_get_drvdata(dev); | |
130 | ||
131 | platform_set_drvdata(dev, NULL); | |
132 | ||
133 | i2c_del_adapter(&i2c->adap); | |
134 | return 0; | |
135 | } | |
136 | ||
137 | static struct platform_driver i2c_versatile_driver = { | |
138 | .probe = i2c_versatile_probe, | |
139 | .remove = i2c_versatile_remove, | |
140 | .driver = { | |
141 | .name = "versatile-i2c", | |
142 | .owner = THIS_MODULE, | |
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"); |