1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Freescale MMA7660FC 3-Axis Accelerometer
4 *
5 * Copyright (c) 2016, Intel Corporation.
6 *
7 * IIO driver for Freescale MMA7660FC; 7-bit I2C address: 0x4c.
8 */
9
10 #include <linux/i2c.h>
11 #include <linux/mod_devicetable.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 * The accelerometer has one measurement range:
31 *
32 * -1.5g - +1.5g (6-bit, signed)
33 *
34 * scale = (1.5 + 1.5) * 9.81 / (2^6 - 1) = 0.467142857
35 */
36
37 #define MMA7660_SCALE_AVAIL "0.467142857"
38
39 static const int mma7660_nscale = 467142857;
40
41 enum mma7660_mode {
42 MMA7660_MODE_STANDBY,
43 MMA7660_MODE_ACTIVE
44 };
45
46 struct mma7660_data {
47 struct i2c_client *client;
48 struct mutex lock;
49 enum mma7660_mode mode;
50 struct iio_mount_matrix orientation;
51 };
52
53 static const struct iio_mount_matrix *
mma7660_get_mount_matrix(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)54 mma7660_get_mount_matrix(const struct iio_dev *indio_dev,
55 const struct iio_chan_spec *chan)
56 {
57 struct mma7660_data *data = iio_priv(indio_dev);
58
59 return &data->orientation;
60 }
61
62 static const struct iio_chan_spec_ext_info mma7660_ext_info[] = {
63 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, mma7660_get_mount_matrix),
64 { }
65 };
66
67 static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL);
68
69 static struct attribute *mma7660_attributes[] = {
70 &iio_const_attr_in_accel_scale_available.dev_attr.attr,
71 NULL,
72 };
73
74 static const struct attribute_group mma7660_attribute_group = {
75 .attrs = mma7660_attributes
76 };
77
78 #define MMA7660_CHANNEL(reg, axis) { \
79 .type = IIO_ACCEL, \
80 .address = reg, \
81 .modified = 1, \
82 .channel2 = IIO_MOD_##axis, \
83 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
84 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
85 .ext_info = mma7660_ext_info, \
86 }
87
88 static const struct iio_chan_spec mma7660_channels[] = {
89 MMA7660_CHANNEL(MMA7660_REG_XOUT, X),
90 MMA7660_CHANNEL(MMA7660_REG_YOUT, Y),
91 MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z),
92 };
93
mma7660_set_mode(struct mma7660_data * data,enum mma7660_mode mode)94 static int mma7660_set_mode(struct mma7660_data *data,
95 enum mma7660_mode mode)
96 {
97 int ret;
98 struct i2c_client *client = data->client;
99
100 if (mode == data->mode)
101 return 0;
102
103 ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE);
104 if (ret < 0) {
105 dev_err(&client->dev, "failed to read sensor mode\n");
106 return ret;
107 }
108
109 if (mode == MMA7660_MODE_ACTIVE) {
110 ret &= ~MMA7660_REG_MODE_BIT_TON;
111 ret |= MMA7660_REG_MODE_BIT_MODE;
112 } else {
113 ret &= ~MMA7660_REG_MODE_BIT_TON;
114 ret &= ~MMA7660_REG_MODE_BIT_MODE;
115 }
116
117 ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret);
118 if (ret < 0) {
119 dev_err(&client->dev, "failed to change sensor mode\n");
120 return ret;
121 }
122
123 data->mode = mode;
124
125 return ret;
126 }
127
mma7660_read_accel(struct mma7660_data * data,u8 address)128 static int mma7660_read_accel(struct mma7660_data *data, u8 address)
129 {
130 int ret, retries = MMA7660_I2C_READ_RETRIES;
131 struct i2c_client *client = data->client;
132
133 /*
134 * Read data. If the Alert bit is set, the register was read at
135 * the same time as the device was attempting to update the content.
136 * The solution is to read the register again. Do this only
137 * MMA7660_I2C_READ_RETRIES times to avoid spending too much time
138 * in the kernel.
139 */
140 do {
141 ret = i2c_smbus_read_byte_data(client, address);
142 if (ret < 0) {
143 dev_err(&client->dev, "register read failed\n");
144 return ret;
145 }
146 } while (retries-- > 0 && ret & MMA7660_REG_OUT_BIT_ALERT);
147
148 if (ret & MMA7660_REG_OUT_BIT_ALERT) {
149 dev_err(&client->dev, "all register read retries failed\n");
150 return -ETIMEDOUT;
151 }
152
153 return ret;
154 }
155
mma7660_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)156 static int mma7660_read_raw(struct iio_dev *indio_dev,
157 struct iio_chan_spec const *chan,
158 int *val, int *val2, long mask)
159 {
160 struct mma7660_data *data = iio_priv(indio_dev);
161 int ret;
162
163 switch (mask) {
164 case IIO_CHAN_INFO_RAW:
165 mutex_lock(&data->lock);
166 ret = mma7660_read_accel(data, chan->address);
167 mutex_unlock(&data->lock);
168 if (ret < 0)
169 return ret;
170 *val = sign_extend32(ret, 5);
171 return IIO_VAL_INT;
172 case IIO_CHAN_INFO_SCALE:
173 *val = 0;
174 *val2 = mma7660_nscale;
175 return IIO_VAL_INT_PLUS_NANO;
176 default:
177 return -EINVAL;
178 }
179
180 return -EINVAL;
181 }
182
183 static const struct iio_info mma7660_info = {
184 .read_raw = mma7660_read_raw,
185 .attrs = &mma7660_attribute_group,
186 };
187
mma7660_probe(struct i2c_client * client)188 static int mma7660_probe(struct i2c_client *client)
189 {
190 int ret;
191 struct iio_dev *indio_dev;
192 struct mma7660_data *data;
193
194 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
195 if (!indio_dev) {
196 dev_err(&client->dev, "iio allocation failed!\n");
197 return -ENOMEM;
198 }
199
200 data = iio_priv(indio_dev);
201 data->client = client;
202 i2c_set_clientdata(client, indio_dev);
203 mutex_init(&data->lock);
204 data->mode = MMA7660_MODE_STANDBY;
205
206 ret = iio_read_mount_matrix(&client->dev, &data->orientation);
207 if (ret)
208 return ret;
209
210 indio_dev->info = &mma7660_info;
211 indio_dev->name = MMA7660_DRIVER_NAME;
212 indio_dev->modes = INDIO_DIRECT_MODE;
213 indio_dev->channels = mma7660_channels;
214 indio_dev->num_channels = ARRAY_SIZE(mma7660_channels);
215
216 ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
217 if (ret < 0)
218 return ret;
219
220 ret = iio_device_register(indio_dev);
221 if (ret < 0) {
222 dev_err(&client->dev, "device_register failed\n");
223 mma7660_set_mode(data, MMA7660_MODE_STANDBY);
224 }
225
226 return ret;
227 }
228
mma7660_remove(struct i2c_client * client)229 static void mma7660_remove(struct i2c_client *client)
230 {
231 struct iio_dev *indio_dev = i2c_get_clientdata(client);
232 int ret;
233
234 iio_device_unregister(indio_dev);
235
236 ret = mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY);
237 if (ret)
238 dev_warn(&client->dev, "Failed to put device in stand-by mode (%pe), ignoring\n",
239 ERR_PTR(ret));
240 }
241
mma7660_suspend(struct device * dev)242 static int mma7660_suspend(struct device *dev)
243 {
244 struct mma7660_data *data;
245
246 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
247
248 return mma7660_set_mode(data, MMA7660_MODE_STANDBY);
249 }
250
mma7660_resume(struct device * dev)251 static int mma7660_resume(struct device *dev)
252 {
253 struct mma7660_data *data;
254
255 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
256
257 return mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
258 }
259
260 static DEFINE_SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend,
261 mma7660_resume);
262
263 static const struct i2c_device_id mma7660_i2c_id[] = {
264 { "mma7660" },
265 {}
266 };
267 MODULE_DEVICE_TABLE(i2c, mma7660_i2c_id);
268
269 static const struct of_device_id mma7660_of_match[] = {
270 { .compatible = "fsl,mma7660" },
271 { }
272 };
273 MODULE_DEVICE_TABLE(of, mma7660_of_match);
274
275 static const struct acpi_device_id mma7660_acpi_id[] = {
276 {"MMA7660", 0},
277 {}
278 };
279
280 MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);
281
282 static struct i2c_driver mma7660_driver = {
283 .driver = {
284 .name = "mma7660",
285 .pm = pm_sleep_ptr(&mma7660_pm_ops),
286 .of_match_table = mma7660_of_match,
287 .acpi_match_table = mma7660_acpi_id,
288 },
289 .probe = mma7660_probe,
290 .remove = mma7660_remove,
291 .id_table = mma7660_i2c_id,
292 };
293
294 module_i2c_driver(mma7660_driver);
295
296 MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>");
297 MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
298 MODULE_LICENSE("GPL v2");
299