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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
|
/*
* bh1780gli.c
* ROHM Ambient Light Sensor Driver
*
* Copyright (C) 2010 Texas Instruments
* Author: Hemanth V <hemanthv@ti.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.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/module.h>
#define BH1780_REG_CONTROL 0x80
#define BH1780_REG_PARTID 0x8A
#define BH1780_REG_MANFID 0x8B
#define BH1780_REG_DLOW 0x8C
#define BH1780_REG_DHIGH 0x8D
#define BH1780_REVMASK (0xf)
#define BH1780_POWMASK (0x3)
#define BH1780_POFF (0x0)
#define BH1780_PON (0x3)
/* power on settling time in ms */
#define BH1780_PON_DELAY 2
struct bh1780_data {
struct i2c_client *client;
int power_state;
/* lock for sysfs operations */
struct mutex lock;
};
static int bh1780_write(struct bh1780_data *ddata, u8 reg, u8 val, char *msg)
{
int ret = i2c_smbus_write_byte_data(ddata->client, reg, val);
if (ret < 0)
dev_err(&ddata->client->dev,
"i2c_smbus_write_byte_data failed error %d Register (%s)\n",
ret, msg);
return ret;
}
static int bh1780_read(struct bh1780_data *ddata, u8 reg, char *msg)
{
int ret = i2c_smbus_read_byte_data(ddata->client, reg);
if (ret < 0)
dev_err(&ddata->client->dev,
"i2c_smbus_read_byte_data failed error %d Register (%s)\n",
ret, msg);
return ret;
}
static ssize_t bh1780_show_lux(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
struct bh1780_data *ddata = platform_get_drvdata(pdev);
int lsb, msb;
lsb = bh1780_read(ddata, BH1780_REG_DLOW, "DLOW");
if (lsb < 0)
return lsb;
msb = bh1780_read(ddata, BH1780_REG_DHIGH, "DHIGH");
if (msb < 0)
return msb;
return sprintf(buf, "%d\n", (msb << 8) | lsb);
}
static ssize_t bh1780_show_power_state(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct platform_device *pdev = to_platform_device(dev);
struct bh1780_data *ddata = platform_get_drvdata(pdev);
int state;
state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
if (state < 0)
return state;
return sprintf(buf, "%d\n", state & BH1780_POWMASK);
}
static ssize_t bh1780_store_power_state(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct platform_device *pdev = to_platform_device(dev);
struct bh1780_data *ddata = platform_get_drvdata(pdev);
unsigned long val;
int error;
error = strict_strtoul(buf, 0, &val);
if (error)
return error;
if (val < BH1780_POFF || val > BH1780_PON)
return -EINVAL;
mutex_lock(&ddata->lock);
error = bh1780_write(ddata, BH1780_REG_CONTROL, val, "CONTROL");
if (error < 0) {
mutex_unlock(&ddata->lock);
return error;
}
msleep(BH1780_PON_DELAY);
ddata->power_state = val;
mutex_unlock(&ddata->lock);
return count;
}
static DEVICE_ATTR(lux, S_IRUGO, bh1780_show_lux, NULL);
static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
bh1780_show_power_state, bh1780_store_power_state);
static struct attribute *bh1780_attributes[] = {
&dev_attr_power_state.attr,
&dev_attr_lux.attr,
NULL
};
static const struct attribute_group bh1780_attr_group = {
.attrs = bh1780_attributes,
};
static int __devinit bh1780_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct bh1780_data *ddata = NULL;
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) {
ret = -EIO;
goto err_op_failed;
}
ddata = kzalloc(sizeof(struct bh1780_data), GFP_KERNEL);
if (ddata == NULL) {
ret = -ENOMEM;
goto err_op_failed;
}
ddata->client = client;
i2c_set_clientdata(client, ddata);
ret = bh1780_read(ddata, BH1780_REG_PARTID, "PART ID");
if (ret < 0)
goto err_op_failed;
dev_info(&client->dev, "Ambient Light Sensor, Rev : %d\n",
(ret & BH1780_REVMASK));
mutex_init(&ddata->lock);
ret = sysfs_create_group(&client->dev.kobj, &bh1780_attr_group);
if (ret)
goto err_op_failed;
return 0;
err_op_failed:
kfree(ddata);
return ret;
}
static int __devexit bh1780_remove(struct i2c_client *client)
{
struct bh1780_data *ddata;
ddata = i2c_get_clientdata(client);
sysfs_remove_group(&client->dev.kobj, &bh1780_attr_group);
kfree(ddata);
return 0;
}
#ifdef CONFIG_PM
static int bh1780_suspend(struct device *dev)
{
struct bh1780_data *ddata;
int state, ret;
struct i2c_client *client = to_i2c_client(dev);
ddata = i2c_get_clientdata(client);
state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
if (state < 0)
return state;
ddata->power_state = state & BH1780_POWMASK;
ret = bh1780_write(ddata, BH1780_REG_CONTROL, BH1780_POFF,
"CONTROL");
if (ret < 0)
return ret;
return 0;
}
static int bh1780_resume(struct device *dev)
{
struct bh1780_data *ddata;
int state, ret;
struct i2c_client *client = to_i2c_client(dev);
ddata = i2c_get_clientdata(client);
state = ddata->power_state;
ret = bh1780_write(ddata, BH1780_REG_CONTROL, state,
"CONTROL");
if (ret < 0)
return ret;
return 0;
}
static SIMPLE_DEV_PM_OPS(bh1780_pm, bh1780_suspend, bh1780_resume);
#define BH1780_PMOPS (&bh1780_pm)
#else
#define BH1780_PMOPS NULL
#endif /* CONFIG_PM */
static const struct i2c_device_id bh1780_id[] = {
{ "bh1780", 0 },
{ },
};
static struct i2c_driver bh1780_driver = {
.probe = bh1780_probe,
.remove = bh1780_remove,
.id_table = bh1780_id,
.driver = {
.name = "bh1780",
.pm = BH1780_PMOPS,
},
};
module_i2c_driver(bh1780_driver);
MODULE_DESCRIPTION("BH1780GLI Ambient Light Sensor Driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");
|
