summaryrefslogtreecommitdiffstats
path: root/drivers/iio/accel/mc3230.c
blob: 679e69cd7657a4923a4a81fbe95646660a1cf826 (plain)
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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * mCube MC3230 3-Axis Accelerometer
 *
 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
 *
 * IIO driver for mCube MC3230; 7-bit I2C address: 0x4c.
 */

#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#define MC3230_REG_XOUT			0x00
#define MC3230_REG_YOUT			0x01
#define MC3230_REG_ZOUT			0x02

#define MC3230_REG_MODE			0x07
#define MC3230_MODE_OPCON_MASK		0x03
#define MC3230_MODE_OPCON_WAKE		0x01
#define MC3230_MODE_OPCON_STANDBY	0x03

#define MC3230_REG_CHIP_ID		0x18
#define MC3230_CHIP_ID			0x01

#define MC3230_REG_PRODUCT_CODE		0x3b
#define MC3230_PRODUCT_CODE		0x19

/*
 * The accelerometer has one measurement range:
 *
 * -1.5g - +1.5g (8-bit, signed)
 *
 * scale = (1.5 + 1.5) * 9.81 / (2^8 - 1)	= 0.115411765
 */

static const int mc3230_nscale = 115411765;

#define MC3230_CHANNEL(reg, axis) {	\
	.type = IIO_ACCEL,	\
	.address = reg,	\
	.modified = 1,	\
	.channel2 = IIO_MOD_##axis,	\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
}

static const struct iio_chan_spec mc3230_channels[] = {
	MC3230_CHANNEL(MC3230_REG_XOUT, X),
	MC3230_CHANNEL(MC3230_REG_YOUT, Y),
	MC3230_CHANNEL(MC3230_REG_ZOUT, Z),
};

struct mc3230_data {
	struct i2c_client *client;
};

static int mc3230_set_opcon(struct mc3230_data *data, int opcon)
{
	int ret;
	struct i2c_client *client = data->client;

	ret = i2c_smbus_read_byte_data(client, MC3230_REG_MODE);
	if (ret < 0) {
		dev_err(&client->dev, "failed to read mode reg: %d\n", ret);
		return ret;
	}

	ret &= ~MC3230_MODE_OPCON_MASK;
	ret |= opcon;

	ret = i2c_smbus_write_byte_data(client, MC3230_REG_MODE, ret);
	if (ret < 0) {
		dev_err(&client->dev, "failed to write mode reg: %d\n", ret);
		return ret;
	}

	return 0;
}

static int mc3230_read_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int *val, int *val2, long mask)
{
	struct mc3230_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = i2c_smbus_read_byte_data(data->client, chan->address);
		if (ret < 0)
			return ret;
		*val = sign_extend32(ret, 7);
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = 0;
		*val2 = mc3230_nscale;
		return IIO_VAL_INT_PLUS_NANO;
	default:
		return -EINVAL;
	}
}

static const struct iio_info mc3230_info = {
	.read_raw	= mc3230_read_raw,
};

static int mc3230_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	int ret;
	struct iio_dev *indio_dev;
	struct mc3230_data *data;

	/* First check chip-id and product-id */
	ret = i2c_smbus_read_byte_data(client, MC3230_REG_CHIP_ID);
	if (ret != MC3230_CHIP_ID)
		return (ret < 0) ? ret : -ENODEV;

	ret = i2c_smbus_read_byte_data(client, MC3230_REG_PRODUCT_CODE);
	if (ret != MC3230_PRODUCT_CODE)
		return (ret < 0) ? ret : -ENODEV;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	if (!indio_dev) {
		dev_err(&client->dev, "iio allocation failed!\n");
		return -ENOMEM;
	}

	data = iio_priv(indio_dev);
	data->client = client;
	i2c_set_clientdata(client, indio_dev);

	indio_dev->info = &mc3230_info;
	indio_dev->name = "mc3230";
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = mc3230_channels;
	indio_dev->num_channels = ARRAY_SIZE(mc3230_channels);

	ret = mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
	if (ret < 0)
		return ret;

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
		dev_err(&client->dev, "device_register failed\n");
		mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
	}

	return ret;
}

static int mc3230_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	iio_device_unregister(indio_dev);

	return mc3230_set_opcon(iio_priv(indio_dev), MC3230_MODE_OPCON_STANDBY);
}

static int mc3230_suspend(struct device *dev)
{
	struct mc3230_data *data;

	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

	return mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
}

static int mc3230_resume(struct device *dev)
{
	struct mc3230_data *data;

	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

	return mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
}

static DEFINE_SIMPLE_DEV_PM_OPS(mc3230_pm_ops, mc3230_suspend, mc3230_resume);

static const struct i2c_device_id mc3230_i2c_id[] = {
	{"mc3230", 0},
	{}
};
MODULE_DEVICE_TABLE(i2c, mc3230_i2c_id);

static struct i2c_driver mc3230_driver = {
	.driver = {
		.name = "mc3230",
		.pm = pm_sleep_ptr(&mc3230_pm_ops),
	},
	.probe		= mc3230_probe,
	.remove		= mc3230_remove,
	.id_table	= mc3230_i2c_id,
};

module_i2c_driver(mc3230_driver);

MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("mCube MC3230 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");