1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
/*
* Support for the Extra GPIOs on the Sharp SL-C1000 (Akita)
* (uses a Maxim MAX7310 8 Port IO Expander)
*
* Copyright 2005 Openedhand Ltd.
*
* Author: Richard Purdie <richard@openedhand.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <asm/arch/akita.h>
/* MAX7310 Regiser Map */
#define MAX7310_INPUT 0x00
#define MAX7310_OUTPUT 0x01
#define MAX7310_POLINV 0x02
#define MAX7310_IODIR 0x03 /* 1 = Input, 0 = Output */
#define MAX7310_TIMEOUT 0x04
/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x18, I2C_CLIENT_END };
/* I2C Magic */
I2C_CLIENT_INSMOD;
static int max7310_write(struct i2c_client *client, int address, int data);
static struct i2c_client max7310_template;
static void akita_ioexp_work(struct work_struct *private_);
static struct device *akita_ioexp_device;
static unsigned char ioexp_output_value = AKITA_IOEXP_IO_OUT;
DECLARE_WORK(akita_ioexp, akita_ioexp_work);
/*
* MAX7310 Access
*/
static int max7310_config(struct device *dev, int iomode, int polarity)
{
int ret;
struct i2c_client *client = to_i2c_client(dev);
ret = max7310_write(client, MAX7310_POLINV, polarity);
if (ret < 0)
return ret;
ret = max7310_write(client, MAX7310_IODIR, iomode);
return ret;
}
static int max7310_set_ouputs(struct device *dev, int outputs)
{
struct i2c_client *client = to_i2c_client(dev);
return max7310_write(client, MAX7310_OUTPUT, outputs);
}
/*
* I2C Functions
*/
static int max7310_write(struct i2c_client *client, int address, int value)
{
u8 data[2];
data[0] = address & 0xff;
data[1] = value & 0xff;
if (i2c_master_send(client, data, 2) == 2)
return 0;
return -1;
}
static int max7310_detect(struct i2c_adapter *adapter, int address, int kind)
{
struct i2c_client *new_client;
int err;
if (!(new_client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL)))
return -ENOMEM;
max7310_template.adapter = adapter;
max7310_template.addr = address;
memcpy(new_client, &max7310_template, sizeof(struct i2c_client));
if ((err = i2c_attach_client(new_client))) {
kfree(new_client);
return err;
}
max7310_config(&new_client->dev, AKITA_IOEXP_IO_DIR, 0);
akita_ioexp_device = &new_client->dev;
schedule_work(&akita_ioexp);
return 0;
}
static int max7310_attach_adapter(struct i2c_adapter *adapter)
{
return i2c_probe(adapter, &addr_data, max7310_detect);
}
static int max7310_detach_client(struct i2c_client *client)
{
int err;
akita_ioexp_device = NULL;
if ((err = i2c_detach_client(client)))
return err;
kfree(client);
return 0;
}
static struct i2c_driver max7310_i2c_driver = {
.driver = {
.name = "akita-max7310",
},
.id = I2C_DRIVERID_AKITAIOEXP,
.attach_adapter = max7310_attach_adapter,
.detach_client = max7310_detach_client,
};
static struct i2c_client max7310_template = {
name: "akita-max7310",
driver: &max7310_i2c_driver,
};
void akita_set_ioexp(struct device *dev, unsigned char bit)
{
ioexp_output_value |= bit;
if (akita_ioexp_device)
schedule_work(&akita_ioexp);
return;
}
void akita_reset_ioexp(struct device *dev, unsigned char bit)
{
ioexp_output_value &= ~bit;
if (akita_ioexp_device)
schedule_work(&akita_ioexp);
return;
}
EXPORT_SYMBOL(akita_set_ioexp);
EXPORT_SYMBOL(akita_reset_ioexp);
static void akita_ioexp_work(struct work_struct *private_)
{
if (akita_ioexp_device)
max7310_set_ouputs(akita_ioexp_device, ioexp_output_value);
}
#ifdef CONFIG_PM
static int akita_ioexp_suspend(struct platform_device *pdev, pm_message_t state)
{
flush_scheduled_work();
return 0;
}
static int akita_ioexp_resume(struct platform_device *pdev)
{
schedule_work(&akita_ioexp);
return 0;
}
#else
#define akita_ioexp_suspend NULL
#define akita_ioexp_resume NULL
#endif
static int __init akita_ioexp_probe(struct platform_device *pdev)
{
return i2c_add_driver(&max7310_i2c_driver);
}
static int akita_ioexp_remove(struct platform_device *pdev)
{
i2c_del_driver(&max7310_i2c_driver);
return 0;
}
static struct platform_driver akita_ioexp_driver = {
.probe = akita_ioexp_probe,
.remove = akita_ioexp_remove,
.suspend = akita_ioexp_suspend,
.resume = akita_ioexp_resume,
.driver = {
.name = "akita-ioexp",
},
};
static int __init akita_ioexp_init(void)
{
return platform_driver_register(&akita_ioexp_driver);
}
static void __exit akita_ioexp_exit(void)
{
platform_driver_unregister(&akita_ioexp_driver);
}
MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
MODULE_DESCRIPTION("Akita IO-Expander driver");
MODULE_LICENSE("GPL");
fs_initcall(akita_ioexp_init);
module_exit(akita_ioexp_exit);
|
