diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-versatile.c')
-rw-r--r-- | drivers/i2c/busses/i2c-versatile.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-versatile.c b/drivers/i2c/busses/i2c-versatile.c new file mode 100644 index 000000000000..081d9578ce10 --- /dev/null +++ b/drivers/i2c/busses/i2c-versatile.c | |||
@@ -0,0 +1,153 @@ | |||
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> | ||
17 | |||
18 | #include <asm/io.h> | ||
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 | |||
79 | if (!request_mem_region(r->start, r->end - r->start + 1, "versatile-i2c")) { | ||
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 | |||
90 | i2c->base = ioremap(r->start, r->end - r->start + 1); | ||
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; | ||
102 | i2c->algo = i2c_versatile_algo; | ||
103 | i2c->algo.data = i2c; | ||
104 | |||
105 | ret = i2c_bit_add_bus(&i2c->adap); | ||
106 | if (ret >= 0) { | ||
107 | platform_set_drvdata(dev, i2c); | ||
108 | return 0; | ||
109 | } | ||
110 | |||
111 | iounmap(i2c->base); | ||
112 | err_free: | ||
113 | kfree(i2c); | ||
114 | err_release: | ||
115 | release_mem_region(r->start, r->end - r->start + 1); | ||
116 | err_out: | ||
117 | return ret; | ||
118 | } | ||
119 | |||
120 | static int i2c_versatile_remove(struct platform_device *dev) | ||
121 | { | ||
122 | struct i2c_versatile *i2c = platform_get_drvdata(dev); | ||
123 | |||
124 | platform_set_drvdata(dev, NULL); | ||
125 | |||
126 | i2c_del_adapter(&i2c->adap); | ||
127 | return 0; | ||
128 | } | ||
129 | |||
130 | static struct platform_driver i2c_versatile_driver = { | ||
131 | .probe = i2c_versatile_probe, | ||
132 | .remove = i2c_versatile_remove, | ||
133 | .driver = { | ||
134 | .name = "versatile-i2c", | ||
135 | .owner = THIS_MODULE, | ||
136 | }, | ||
137 | }; | ||
138 | |||
139 | static int __init i2c_versatile_init(void) | ||
140 | { | ||
141 | return platform_driver_register(&i2c_versatile_driver); | ||
142 | } | ||
143 | |||
144 | static void __exit i2c_versatile_exit(void) | ||
145 | { | ||
146 | platform_driver_unregister(&i2c_versatile_driver); | ||
147 | } | ||
148 | |||
149 | module_init(i2c_versatile_init); | ||
150 | module_exit(i2c_versatile_exit); | ||
151 | |||
152 | MODULE_DESCRIPTION("ARM Versatile I2C bus driver"); | ||
153 | MODULE_LICENSE("GPL"); | ||