1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * mCube MC3230 3-Axis Accelerometer
4 *
5 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
6 *
7 * IIO driver for mCube MC3230; 7-bit I2C address: 0x4c.
8 */
9
10#include <linux/i2c.h>
11#include <linux/module.h>
12#include <linux/iio/iio.h>
13#include <linux/iio/sysfs.h>
14
15#define MC3230_REG_XOUT 0x00
16#define MC3230_REG_YOUT 0x01
17#define MC3230_REG_ZOUT 0x02
18
19#define MC3230_REG_MODE 0x07
20#define MC3230_MODE_OPCON_MASK 0x03
21#define MC3230_MODE_OPCON_WAKE 0x01
22#define MC3230_MODE_OPCON_STANDBY 0x03
23
24#define MC3230_REG_CHIP_ID 0x18
25#define MC3230_CHIP_ID 0x01
26
27#define MC3230_REG_PRODUCT_CODE 0x3b
28#define MC3230_PRODUCT_CODE 0x19
29
30/*
31 * The accelerometer has one measurement range:
32 *
33 * -1.5g - +1.5g (8-bit, signed)
34 *
35 * scale = (1.5 + 1.5) * 9.81 / (2^8 - 1) = 0.115411765
36 */
37
38static const int mc3230_nscale = 115411765;
39
40#define MC3230_CHANNEL(reg, axis) { \
41 .type = IIO_ACCEL, \
42 .address = reg, \
43 .modified = 1, \
44 .channel2 = IIO_MOD_##axis, \
45 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
46 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
47}
48
49static const struct iio_chan_spec mc3230_channels[] = {
50 MC3230_CHANNEL(MC3230_REG_XOUT, X),
51 MC3230_CHANNEL(MC3230_REG_YOUT, Y),
52 MC3230_CHANNEL(MC3230_REG_ZOUT, Z),
53};
54
55struct mc3230_data {
56 struct i2c_client *client;
57};
58
59static int mc3230_set_opcon(struct mc3230_data *data, int opcon)
60{
61 int ret;
62 struct i2c_client *client = data->client;
63
64 ret = i2c_smbus_read_byte_data(client, MC3230_REG_MODE);
65 if (ret < 0) {
66 dev_err(&client->dev, "failed to read mode reg: %d\n", ret);
67 return ret;
68 }
69
70 ret &= ~MC3230_MODE_OPCON_MASK;
71 ret |= opcon;
72
73 ret = i2c_smbus_write_byte_data(client, MC3230_REG_MODE, value: ret);
74 if (ret < 0) {
75 dev_err(&client->dev, "failed to write mode reg: %d\n", ret);
76 return ret;
77 }
78
79 return 0;
80}
81
82static int mc3230_read_raw(struct iio_dev *indio_dev,
83 struct iio_chan_spec const *chan,
84 int *val, int *val2, long mask)
85{
86 struct mc3230_data *data = iio_priv(indio_dev);
87 int ret;
88
89 switch (mask) {
90 case IIO_CHAN_INFO_RAW:
91 ret = i2c_smbus_read_byte_data(client: data->client, command: chan->address);
92 if (ret < 0)
93 return ret;
94 *val = sign_extend32(value: ret, index: 7);
95 return IIO_VAL_INT;
96 case IIO_CHAN_INFO_SCALE:
97 *val = 0;
98 *val2 = mc3230_nscale;
99 return IIO_VAL_INT_PLUS_NANO;
100 default:
101 return -EINVAL;
102 }
103}
104
105static const struct iio_info mc3230_info = {
106 .read_raw = mc3230_read_raw,
107};
108
109static int mc3230_probe(struct i2c_client *client)
110{
111 int ret;
112 struct iio_dev *indio_dev;
113 struct mc3230_data *data;
114
115 /* First check chip-id and product-id */
116 ret = i2c_smbus_read_byte_data(client, MC3230_REG_CHIP_ID);
117 if (ret != MC3230_CHIP_ID)
118 return (ret < 0) ? ret : -ENODEV;
119
120 ret = i2c_smbus_read_byte_data(client, MC3230_REG_PRODUCT_CODE);
121 if (ret != MC3230_PRODUCT_CODE)
122 return (ret < 0) ? ret : -ENODEV;
123
124 indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*data));
125 if (!indio_dev) {
126 dev_err(&client->dev, "iio allocation failed!\n");
127 return -ENOMEM;
128 }
129
130 data = iio_priv(indio_dev);
131 data->client = client;
132 i2c_set_clientdata(client, data: indio_dev);
133
134 indio_dev->info = &mc3230_info;
135 indio_dev->name = "mc3230";
136 indio_dev->modes = INDIO_DIRECT_MODE;
137 indio_dev->channels = mc3230_channels;
138 indio_dev->num_channels = ARRAY_SIZE(mc3230_channels);
139
140 ret = mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
141 if (ret < 0)
142 return ret;
143
144 ret = iio_device_register(indio_dev);
145 if (ret < 0) {
146 dev_err(&client->dev, "device_register failed\n");
147 mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
148 }
149
150 return ret;
151}
152
153static void mc3230_remove(struct i2c_client *client)
154{
155 struct iio_dev *indio_dev = i2c_get_clientdata(client);
156
157 iio_device_unregister(indio_dev);
158
159 mc3230_set_opcon(data: iio_priv(indio_dev), MC3230_MODE_OPCON_STANDBY);
160}
161
162static int mc3230_suspend(struct device *dev)
163{
164 struct mc3230_data *data;
165
166 data = iio_priv(indio_dev: i2c_get_clientdata(to_i2c_client(dev)));
167
168 return mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
169}
170
171static int mc3230_resume(struct device *dev)
172{
173 struct mc3230_data *data;
174
175 data = iio_priv(indio_dev: i2c_get_clientdata(to_i2c_client(dev)));
176
177 return mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
178}
179
180static DEFINE_SIMPLE_DEV_PM_OPS(mc3230_pm_ops, mc3230_suspend, mc3230_resume);
181
182static const struct i2c_device_id mc3230_i2c_id[] = {
183 {"mc3230", 0},
184 {}
185};
186MODULE_DEVICE_TABLE(i2c, mc3230_i2c_id);
187
188static struct i2c_driver mc3230_driver = {
189 .driver = {
190 .name = "mc3230",
191 .pm = pm_sleep_ptr(&mc3230_pm_ops),
192 },
193 .probe = mc3230_probe,
194 .remove = mc3230_remove,
195 .id_table = mc3230_i2c_id,
196};
197
198module_i2c_driver(mc3230_driver);
199
200MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
201MODULE_DESCRIPTION("mCube MC3230 3-Axis Accelerometer driver");
202MODULE_LICENSE("GPL v2");
203

source code of linux/drivers/iio/accel/mc3230.c