1
2
3
4
5
6
7
8
9
10#include <linux/acpi.h>
11#include <linux/i2c.h>
12#include <linux/module.h>
13#include <linux/iio/iio.h>
14#include <linux/iio/sysfs.h>
15
16#define MMA7660_DRIVER_NAME "mma7660"
17
18#define MMA7660_REG_XOUT 0x00
19#define MMA7660_REG_YOUT 0x01
20#define MMA7660_REG_ZOUT 0x02
21#define MMA7660_REG_OUT_BIT_ALERT BIT(6)
22
23#define MMA7660_REG_MODE 0x07
24#define MMA7660_REG_MODE_BIT_MODE BIT(0)
25#define MMA7660_REG_MODE_BIT_TON BIT(2)
26
27#define MMA7660_I2C_READ_RETRIES 5
28
29
30
31
32
33
34
35
36
37#define MMA7660_SCALE_AVAIL "0.467142857"
38
39static const int mma7660_nscale = 467142857;
40
41#define MMA7660_CHANNEL(reg, axis) { \
42 .type = IIO_ACCEL, \
43 .address = reg, \
44 .modified = 1, \
45 .channel2 = IIO_MOD_##axis, \
46 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
47 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
48}
49
50static const struct iio_chan_spec mma7660_channels[] = {
51 MMA7660_CHANNEL(MMA7660_REG_XOUT, X),
52 MMA7660_CHANNEL(MMA7660_REG_YOUT, Y),
53 MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z),
54};
55
56enum mma7660_mode {
57 MMA7660_MODE_STANDBY,
58 MMA7660_MODE_ACTIVE
59};
60
61struct mma7660_data {
62 struct i2c_client *client;
63 struct mutex lock;
64 enum mma7660_mode mode;
65};
66
67static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL);
68
69static struct attribute *mma7660_attributes[] = {
70 &iio_const_attr_in_accel_scale_available.dev_attr.attr,
71 NULL,
72};
73
74static const struct attribute_group mma7660_attribute_group = {
75 .attrs = mma7660_attributes
76};
77
78static int mma7660_set_mode(struct mma7660_data *data,
79 enum mma7660_mode mode)
80{
81 int ret;
82 struct i2c_client *client = data->client;
83
84 if (mode == data->mode)
85 return 0;
86
87 ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE);
88 if (ret < 0) {
89 dev_err(&client->dev, "failed to read sensor mode\n");
90 return ret;
91 }
92
93 if (mode == MMA7660_MODE_ACTIVE) {
94 ret &= ~MMA7660_REG_MODE_BIT_TON;
95 ret |= MMA7660_REG_MODE_BIT_MODE;
96 } else {
97 ret &= ~MMA7660_REG_MODE_BIT_TON;
98 ret &= ~MMA7660_REG_MODE_BIT_MODE;
99 }
100
101 ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret);
102 if (ret < 0) {
103 dev_err(&client->dev, "failed to change sensor mode\n");
104 return ret;
105 }
106
107 data->mode = mode;
108
109 return ret;
110}
111
112static int mma7660_read_accel(struct mma7660_data *data, u8 address)
113{
114 int ret, retries = MMA7660_I2C_READ_RETRIES;
115 struct i2c_client *client = data->client;
116
117
118
119
120
121
122
123
124 do {
125 ret = i2c_smbus_read_byte_data(client, address);
126 if (ret < 0) {
127 dev_err(&client->dev, "register read failed\n");
128 return ret;
129 }
130 } while (retries-- > 0 && ret & MMA7660_REG_OUT_BIT_ALERT);
131
132 if (ret & MMA7660_REG_OUT_BIT_ALERT) {
133 dev_err(&client->dev, "all register read retries failed\n");
134 return -ETIMEDOUT;
135 }
136
137 return ret;
138}
139
140static int mma7660_read_raw(struct iio_dev *indio_dev,
141 struct iio_chan_spec const *chan,
142 int *val, int *val2, long mask)
143{
144 struct mma7660_data *data = iio_priv(indio_dev);
145 int ret;
146
147 switch (mask) {
148 case IIO_CHAN_INFO_RAW:
149 mutex_lock(&data->lock);
150 ret = mma7660_read_accel(data, chan->address);
151 mutex_unlock(&data->lock);
152 if (ret < 0)
153 return ret;
154 *val = sign_extend32(ret, 5);
155 return IIO_VAL_INT;
156 case IIO_CHAN_INFO_SCALE:
157 *val = 0;
158 *val2 = mma7660_nscale;
159 return IIO_VAL_INT_PLUS_NANO;
160 default:
161 return -EINVAL;
162 }
163
164 return -EINVAL;
165}
166
167static const struct iio_info mma7660_info = {
168 .read_raw = mma7660_read_raw,
169 .attrs = &mma7660_attribute_group,
170};
171
172static int mma7660_probe(struct i2c_client *client,
173 const struct i2c_device_id *id)
174{
175 int ret;
176 struct iio_dev *indio_dev;
177 struct mma7660_data *data;
178
179 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
180 if (!indio_dev) {
181 dev_err(&client->dev, "iio allocation failed!\n");
182 return -ENOMEM;
183 }
184
185 data = iio_priv(indio_dev);
186 data->client = client;
187 i2c_set_clientdata(client, indio_dev);
188 mutex_init(&data->lock);
189 data->mode = MMA7660_MODE_STANDBY;
190
191 indio_dev->dev.parent = &client->dev;
192 indio_dev->info = &mma7660_info;
193 indio_dev->name = MMA7660_DRIVER_NAME;
194 indio_dev->modes = INDIO_DIRECT_MODE;
195 indio_dev->channels = mma7660_channels;
196 indio_dev->num_channels = ARRAY_SIZE(mma7660_channels);
197
198 ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
199 if (ret < 0)
200 return ret;
201
202 ret = iio_device_register(indio_dev);
203 if (ret < 0) {
204 dev_err(&client->dev, "device_register failed\n");
205 mma7660_set_mode(data, MMA7660_MODE_STANDBY);
206 }
207
208 return ret;
209}
210
211static int mma7660_remove(struct i2c_client *client)
212{
213 struct iio_dev *indio_dev = i2c_get_clientdata(client);
214
215 iio_device_unregister(indio_dev);
216
217 return mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY);
218}
219
220#ifdef CONFIG_PM_SLEEP
221static int mma7660_suspend(struct device *dev)
222{
223 struct mma7660_data *data;
224
225 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
226
227 return mma7660_set_mode(data, MMA7660_MODE_STANDBY);
228}
229
230static int mma7660_resume(struct device *dev)
231{
232 struct mma7660_data *data;
233
234 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
235
236 return mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
237}
238
239static SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend, mma7660_resume);
240
241#define MMA7660_PM_OPS (&mma7660_pm_ops)
242#else
243#define MMA7660_PM_OPS NULL
244#endif
245
246static const struct i2c_device_id mma7660_i2c_id[] = {
247 {"mma7660", 0},
248 {}
249};
250MODULE_DEVICE_TABLE(i2c, mma7660_i2c_id);
251
252static const struct of_device_id mma7660_of_match[] = {
253 { .compatible = "fsl,mma7660" },
254 { }
255};
256MODULE_DEVICE_TABLE(of, mma7660_of_match);
257
258static const struct acpi_device_id mma7660_acpi_id[] = {
259 {"MMA7660", 0},
260 {}
261};
262
263MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);
264
265static struct i2c_driver mma7660_driver = {
266 .driver = {
267 .name = "mma7660",
268 .pm = MMA7660_PM_OPS,
269 .of_match_table = mma7660_of_match,
270 .acpi_match_table = ACPI_PTR(mma7660_acpi_id),
271 },
272 .probe = mma7660_probe,
273 .remove = mma7660_remove,
274 .id_table = mma7660_i2c_id,
275};
276
277module_i2c_driver(mma7660_driver);
278
279MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>");
280MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
281MODULE_LICENSE("GPL v2");
282
