tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/**
2 * mCube MC3230 3-Axis Accelerometer
3 *
4 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * IIO driver for mCube MC3230; 7-bit I2C address: 0x4c.
12 */
13
14#include <linux/i2c.h>
15#include <linux/module.h>
16#include <linux/iio/iio.h>
17#include <linux/iio/sysfs.h>
18
19#define MC3230_REG_XOUT 0x00
20#define MC3230_REG_YOUT 0x01
21#define MC3230_REG_ZOUT 0x02
22
23#define MC3230_REG_MODE 0x07
24#define MC3230_MODE_OPCON_MASK 0x03
25#define MC3230_MODE_OPCON_WAKE 0x01
26#define MC3230_MODE_OPCON_STANDBY 0x03
27
28#define MC3230_REG_CHIP_ID 0x18
29#define MC3230_CHIP_ID 0x01
30
31#define MC3230_REG_PRODUCT_CODE 0x3b
32#define MC3230_PRODUCT_CODE 0x19
33
34/*
35 * The accelerometer has one measurement range:
36 *
37 * -1.5g - +1.5g (8-bit, signed)
38 *
39 * scale = (1.5 + 1.5) * 9.81 / (2^8 - 1) = 0.115411765
40 */
41
42static const int mc3230_nscale = 115411765;
43
44#define MC3230_CHANNEL(reg, axis) { \
45 .type = IIO_ACCEL, \
46 .address = reg, \
47 .modified = 1, \
48 .channel2 = IIO_MOD_##axis, \
49 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
50 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
51}
52
53static const struct iio_chan_spec mc3230_channels[] = {
54 MC3230_CHANNEL(MC3230_REG_XOUT, X),
55 MC3230_CHANNEL(MC3230_REG_YOUT, Y),
56 MC3230_CHANNEL(MC3230_REG_ZOUT, Z),
57};
58
59struct mc3230_data {
60 struct i2c_client *client;
61};
62
63static int mc3230_set_opcon(struct mc3230_data *data, int opcon)
64{
65 int ret;
66 struct i2c_client *client = data->client;
67
68 ret = i2c_smbus_read_byte_data(client, MC3230_REG_MODE);
69 if (ret < 0) {
70 dev_err(&client->dev, "failed to read mode reg: %d\n", ret);
71 return ret;
72 }
73
74 ret &= ~MC3230_MODE_OPCON_MASK;
75 ret |= opcon;
76
77 ret = i2c_smbus_write_byte_data(client, MC3230_REG_MODE, ret);
78 if (ret < 0) {
79 dev_err(&client->dev, "failed to write mode reg: %d\n", ret);
80 return ret;
81 }
82
83 return 0;
84}
85
86static int mc3230_read_raw(struct iio_dev *indio_dev,
87 struct iio_chan_spec const *chan,
88 int *val, int *val2, long mask)
89{
90 struct mc3230_data *data = iio_priv(indio_dev);
91 int ret;
92
93 switch (mask) {
94 case IIO_CHAN_INFO_RAW:
95 ret = i2c_smbus_read_byte_data(data->client, chan->address);
96 if (ret < 0)
97 return ret;
98 *val = sign_extend32(ret, 7);
99 return IIO_VAL_INT;
100 case IIO_CHAN_INFO_SCALE:
101 *val = 0;
102 *val2 = mc3230_nscale;
103 return IIO_VAL_INT_PLUS_NANO;
104 default:
105 return -EINVAL;
106 }
107}
108
109static const struct iio_info mc3230_info = {
110 .read_raw = mc3230_read_raw,
111};
112
113static int mc3230_probe(struct i2c_client *client,
114 const struct i2c_device_id *id)
115{
116 int ret;
117 struct iio_dev *indio_dev;
118 struct mc3230_data *data;
119
120 /* First check chip-id and product-id */
121 ret = i2c_smbus_read_byte_data(client, MC3230_REG_CHIP_ID);
122 if (ret != MC3230_CHIP_ID)
123 return (ret < 0) ? ret : -ENODEV;
124
125 ret = i2c_smbus_read_byte_data(client, MC3230_REG_PRODUCT_CODE);
126 if (ret != MC3230_PRODUCT_CODE)
127 return (ret < 0) ? ret : -ENODEV;
128
129 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
130 if (!indio_dev) {
131 dev_err(&client->dev, "iio allocation failed!\n");
132 return -ENOMEM;
133 }
134
135 data = iio_priv(indio_dev);
136 data->client = client;
137 i2c_set_clientdata(client, indio_dev);
138
139 indio_dev->dev.parent = &client->dev;
140 indio_dev->info = &mc3230_info;
141 indio_dev->name = "mc3230";
142 indio_dev->modes = INDIO_DIRECT_MODE;
143 indio_dev->channels = mc3230_channels;
144 indio_dev->num_channels = ARRAY_SIZE(mc3230_channels);
145
146 ret = mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
147 if (ret < 0)
148 return ret;
149
150 ret = iio_device_register(indio_dev);
151 if (ret < 0) {
152 dev_err(&client->dev, "device_register failed\n");
153 mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
154 }
155
156 return ret;
157}
158
159static int mc3230_remove(struct i2c_client *client)
160{
161 struct iio_dev *indio_dev = i2c_get_clientdata(client);
162
163 iio_device_unregister(indio_dev);
164
165 return mc3230_set_opcon(iio_priv(indio_dev), MC3230_MODE_OPCON_STANDBY);
166}
167
168#ifdef CONFIG_PM_SLEEP
169static int mc3230_suspend(struct device *dev)
170{
171 struct mc3230_data *data;
172
173 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
174
175 return mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
176}
177
178static int mc3230_resume(struct device *dev)
179{
180 struct mc3230_data *data;
181
182 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
183
184 return mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
185}
186#endif
187
188static SIMPLE_DEV_PM_OPS(mc3230_pm_ops, mc3230_suspend, mc3230_resume);
189
190static const struct i2c_device_id mc3230_i2c_id[] = {
191 {"mc3230", 0},
192 {}
193};
194MODULE_DEVICE_TABLE(i2c, mc3230_i2c_id);
195
196static struct i2c_driver mc3230_driver = {
197 .driver = {
198 .name = "mc3230",
199 .pm = &mc3230_pm_ops,
200 },
201 .probe = mc3230_probe,
202 .remove = mc3230_remove,
203 .id_table = mc3230_i2c_id,
204};
205
206module_i2c_driver(mc3230_driver);
207
208MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
209MODULE_DESCRIPTION("mCube MC3230 3-Axis Accelerometer driver");
210MODULE_LICENSE("GPL v2");