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
|
/*
* AL3320A - Dyna Image Ambient Light Sensor
*
* Copyright (c) 2014, Intel Corporation.
*
* This file is subject to the terms and conditions of version 2 of
* the GNU General Public License. See the file COPYING in the main
* directory of this archive for more details.
*
* IIO driver for AL3320A (7-bit I2C slave address 0x1C).
*
* TODO: interrupt support, thresholds
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#define AL3320A_DRV_NAME "al3320a"
#define AL3320A_REG_CONFIG 0x00
#define AL3320A_REG_STATUS 0x01
#define AL3320A_REG_INT 0x02
#define AL3320A_REG_WAIT 0x06
#define AL3320A_REG_CONFIG_RANGE 0x07
#define AL3320A_REG_PERSIST 0x08
#define AL3320A_REG_MEAN_TIME 0x09
#define AL3320A_REG_ADUMMY 0x0A
#define AL3320A_REG_DATA_LOW 0x22
#define AL3320A_REG_LOW_THRESH_LOW 0x30
#define AL3320A_REG_LOW_THRESH_HIGH 0x31
#define AL3320A_REG_HIGH_THRESH_LOW 0x32
#define AL3320A_REG_HIGH_THRESH_HIGH 0x33
#define AL3320A_CONFIG_DISABLE 0x00
#define AL3320A_CONFIG_ENABLE 0x01
#define AL3320A_GAIN_SHIFT 1
#define AL3320A_GAIN_MASK (BIT(2) | BIT(1))
/* chip params default values */
#define AL3320A_DEFAULT_MEAN_TIME 4
#define AL3320A_DEFAULT_WAIT_TIME 0 /* no waiting */
#define AL3320A_SCALE_AVAILABLE "0.512 0.128 0.032 0.01"
enum al3320a_range {
AL3320A_RANGE_1, /* 33.28 Klx */
AL3320A_RANGE_2, /* 8.32 Klx */
AL3320A_RANGE_3, /* 2.08 Klx */
AL3320A_RANGE_4 /* 0.65 Klx */
};
static const int al3320a_scales[][2] = {
{0, 512000}, {0, 128000}, {0, 32000}, {0, 10000}
};
struct al3320a_data {
struct i2c_client *client;
};
static const struct iio_chan_spec al3320a_channels[] = {
{
.type = IIO_LIGHT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
}
};
static IIO_CONST_ATTR(in_illuminance_scale_available, AL3320A_SCALE_AVAILABLE);
static struct attribute *al3320a_attributes[] = {
&iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
NULL,
};
static const struct attribute_group al3320a_attribute_group = {
.attrs = al3320a_attributes,
};
static int al3320a_init(struct al3320a_data *data)
{
int ret;
/* power on */
ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG,
AL3320A_CONFIG_ENABLE);
if (ret < 0)
return ret;
ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG_RANGE,
AL3320A_RANGE_3 << AL3320A_GAIN_SHIFT);
if (ret < 0)
return ret;
ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_MEAN_TIME,
AL3320A_DEFAULT_MEAN_TIME);
if (ret < 0)
return ret;
ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_WAIT,
AL3320A_DEFAULT_WAIT_TIME);
if (ret < 0)
return ret;
return 0;
}
static int al3320a_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
{
struct al3320a_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
/*
* ALS ADC value is stored in two adjacent registers:
* - low byte of output is stored at AL3320A_REG_DATA_LOW
* - high byte of output is stored at AL3320A_REG_DATA_LOW + 1
*/
ret = i2c_smbus_read_word_data(data->client,
AL3320A_REG_DATA_LOW);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
ret = i2c_smbus_read_byte_data(data->client,
AL3320A_REG_CONFIG_RANGE);
if (ret < 0)
return ret;
ret = (ret & AL3320A_GAIN_MASK) >> AL3320A_GAIN_SHIFT;
*val = al3320a_scales[ret][0];
*val2 = al3320a_scales[ret][1];
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
static int al3320a_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val,
int val2, long mask)
{
struct al3320a_data *data = iio_priv(indio_dev);
int i;
switch (mask) {
case IIO_CHAN_INFO_SCALE:
for (i = 0; i < ARRAY_SIZE(al3320a_scales); i++) {
if (val == al3320a_scales[i][0] &&
val2 == al3320a_scales[i][1])
return i2c_smbus_write_byte_data(data->client,
AL3320A_REG_CONFIG_RANGE,
i << AL3320A_GAIN_SHIFT);
}
break;
}
return -EINVAL;
}
static const struct iio_info al3320a_info = {
.read_raw = al3320a_read_raw,
.write_raw = al3320a_write_raw,
.attrs = &al3320a_attribute_group,
};
static int al3320a_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct al3320a_data *data;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
indio_dev->dev.parent = &client->dev;
indio_dev->info = &al3320a_info;
indio_dev->name = AL3320A_DRV_NAME;
indio_dev->channels = al3320a_channels;
indio_dev->num_channels = ARRAY_SIZE(al3320a_channels);
indio_dev->modes = INDIO_DIRECT_MODE;
ret = al3320a_init(data);
if (ret < 0) {
dev_err(&client->dev, "al3320a chip init failed\n");
return ret;
}
return devm_iio_device_register(&client->dev, indio_dev);
}
static int al3320a_remove(struct i2c_client *client)
{
return i2c_smbus_write_byte_data(client, AL3320A_REG_CONFIG,
AL3320A_CONFIG_DISABLE);
}
static const struct i2c_device_id al3320a_id[] = {
{"al3320a", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, al3320a_id);
static struct i2c_driver al3320a_driver = {
.driver = {
.name = AL3320A_DRV_NAME,
},
.probe = al3320a_probe,
.remove = al3320a_remove,
.id_table = al3320a_id,
};
module_i2c_driver(al3320a_driver);
MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
MODULE_DESCRIPTION("AL3320A Ambient Light Sensor driver");
MODULE_LICENSE("GPL v2");
|
