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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* MXC6255 - MEMSIC orientation sensing accelerometer
*
* Copyright (c) 2015, Intel Corporation.
*
* IIO driver for MXC6255 (7-bit I2C slave address 0x15).
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/iio/iio.h>
#include <linux/delay.h>
#include <linux/acpi.h>
#include <linux/regmap.h>
#include <linux/iio/sysfs.h>
#define MXC6255_DRV_NAME "mxc6255"
#define MXC6255_REGMAP_NAME "mxc6255_regmap"
#define MXC6255_REG_XOUT 0x00
#define MXC6255_REG_YOUT 0x01
#define MXC6255_REG_CHIP_ID 0x08
#define MXC6255_CHIP_ID 0x05
/*
* MXC6255 has only one measurement range: +/- 2G.
* The acceleration output is an 8-bit value.
*
* Scale is calculated as follows:
* (2 + 2) * 9.80665 / (2^8 - 1) = 0.153829
*
* Scale value for +/- 2G measurement range
*/
#define MXC6255_SCALE 153829
enum mxc6255_axis {
AXIS_X,
AXIS_Y,
};
struct mxc6255_data {
struct i2c_client *client;
struct regmap *regmap;
};
static int mxc6255_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mxc6255_data *data = iio_priv(indio_dev);
unsigned int reg;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = regmap_read(data->regmap, chan->address, ®);
if (ret < 0) {
dev_err(&data->client->dev,
"Error reading reg %lu\n", chan->address);
return ret;
}
*val = sign_extend32(reg, 7);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = MXC6255_SCALE;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
static const struct iio_info mxc6255_info = {
.read_raw = mxc6255_read_raw,
};
#define MXC6255_CHANNEL(_axis, reg) { \
.type = IIO_ACCEL, \
.modified = 1, \
.channel2 = IIO_MOD_##_axis, \
.address = reg, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
}
static const struct iio_chan_spec mxc6255_channels[] = {
MXC6255_CHANNEL(X, MXC6255_REG_XOUT),
MXC6255_CHANNEL(Y, MXC6255_REG_YOUT),
};
static bool mxc6255_is_readable_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case MXC6255_REG_XOUT:
case MXC6255_REG_YOUT:
case MXC6255_REG_CHIP_ID:
return true;
default:
return false;
}
}
static const struct regmap_config mxc6255_regmap_config = {
.name = MXC6255_REGMAP_NAME,
.reg_bits = 8,
.val_bits = 8,
.readable_reg = mxc6255_is_readable_reg,
};
static int mxc6255_probe(struct i2c_client *client)
{
struct mxc6255_data *data;
struct iio_dev *indio_dev;
struct regmap *regmap;
unsigned int chip_id;
int ret;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
regmap = devm_regmap_init_i2c(client, &mxc6255_regmap_config);
if (IS_ERR(regmap)) {
dev_err(&client->dev, "Error initializing regmap\n");
return PTR_ERR(regmap);
}
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
data->regmap = regmap;
indio_dev->name = MXC6255_DRV_NAME;
indio_dev->channels = mxc6255_channels;
indio_dev->num_channels = ARRAY_SIZE(mxc6255_channels);
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &mxc6255_info;
ret = regmap_read(data->regmap, MXC6255_REG_CHIP_ID, &chip_id);
if (ret < 0) {
dev_err(&client->dev, "Error reading chip id %d\n", ret);
return ret;
}
if ((chip_id & 0x1f) != MXC6255_CHIP_ID) {
dev_err(&client->dev, "Invalid chip id %x\n", chip_id);
return -ENODEV;
}
dev_dbg(&client->dev, "Chip id %x\n", chip_id);
ret = devm_iio_device_register(&client->dev, indio_dev);
if (ret < 0) {
dev_err(&client->dev, "Could not register IIO device\n");
return ret;
}
return 0;
}
static const struct acpi_device_id mxc6255_acpi_match[] = {
{"MXC6225", 0},
{"MXC6255", 0},
{ }
};
MODULE_DEVICE_TABLE(acpi, mxc6255_acpi_match);
static const struct i2c_device_id mxc6255_id[] = {
{"mxc6225", 0},
{"mxc6255", 0},
{ }
};
MODULE_DEVICE_TABLE(i2c, mxc6255_id);
static struct i2c_driver mxc6255_driver = {
.driver = {
.name = MXC6255_DRV_NAME,
.acpi_match_table = ACPI_PTR(mxc6255_acpi_match),
},
.probe = mxc6255_probe,
.id_table = mxc6255_id,
};
module_i2c_driver(mxc6255_driver);
MODULE_AUTHOR("Teodora Baluta <teodora.baluta@intel.com>");
MODULE_DESCRIPTION("MEMSIC MXC6255 orientation sensing accelerometer driver");
MODULE_LICENSE("GPL v2");
|
