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 #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
50 static 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
56 enum mma7660_mode {
57 MMA7660_MODE_STANDBY,
58 MMA7660_MODE_ACTIVE
59 };
60
61 struct mma7660_data {
62 struct i2c_client *client;
63 struct mutex lock;
64 enum mma7660_mode mode;
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
mma7660_set_mode(struct mma7660_data * data,enum mma7660_mode mode)78 static 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
mma7660_read_accel(struct mma7660_data * data,u8 address)112 static 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 * Read data. If the Alert bit is set, the register was read at
119 * the same time as the device was attempting to update the content.
120 * The solution is to read the register again. Do this only
121 * MMA7660_I2C_READ_RETRIES times to avoid spending too much time
122 * in the kernel.
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
mma7660_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)140 static 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
167 static const struct iio_info mma7660_info = {
168 .read_raw = mma7660_read_raw,
169 .attrs = &mma7660_attribute_group,
170 };
171
mma7660_probe(struct i2c_client * client)172 static int mma7660_probe(struct i2c_client *client)
173 {
174 int ret;
175 struct iio_dev *indio_dev;
176 struct mma7660_data *data;
177
178 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
179 if (!indio_dev) {
180 dev_err(&client->dev, "iio allocation failed!\n");
181 return -ENOMEM;
182 }
183
184 data = iio_priv(indio_dev);
185 data->client = client;
186 i2c_set_clientdata(client, indio_dev);
187 mutex_init(&data->lock);
188 data->mode = MMA7660_MODE_STANDBY;
189
190 indio_dev->info = &mma7660_info;
191 indio_dev->name = MMA7660_DRIVER_NAME;
192 indio_dev->modes = INDIO_DIRECT_MODE;
193 indio_dev->channels = mma7660_channels;
194 indio_dev->num_channels = ARRAY_SIZE(mma7660_channels);
195
196 ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
197 if (ret < 0)
198 return ret;
199
200 ret = iio_device_register(indio_dev);
201 if (ret < 0) {
202 dev_err(&client->dev, "device_register failed\n");
203 mma7660_set_mode(data, MMA7660_MODE_STANDBY);
204 }
205
206 return ret;
207 }
208
mma7660_remove(struct i2c_client * client)209 static void mma7660_remove(struct i2c_client *client)
210 {
211 struct iio_dev *indio_dev = i2c_get_clientdata(client);
212 int ret;
213
214 iio_device_unregister(indio_dev);
215
216 ret = mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY);
217 if (ret)
218 dev_warn(&client->dev, "Failed to put device in stand-by mode (%pe), ignoring\n",
219 ERR_PTR(ret));
220 }
221
mma7660_suspend(struct device * dev)222 static int mma7660_suspend(struct device *dev)
223 {
224 struct mma7660_data *data;
225
226 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
227
228 return mma7660_set_mode(data, MMA7660_MODE_STANDBY);
229 }
230
mma7660_resume(struct device * dev)231 static int mma7660_resume(struct device *dev)
232 {
233 struct mma7660_data *data;
234
235 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
236
237 return mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
238 }
239
240 static DEFINE_SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend,
241 mma7660_resume);
242
243 static const struct i2c_device_id mma7660_i2c_id[] = {
244 {"mma7660", 0},
245 {}
246 };
247 MODULE_DEVICE_TABLE(i2c, mma7660_i2c_id);
248
249 static const struct of_device_id mma7660_of_match[] = {
250 { .compatible = "fsl,mma7660" },
251 { }
252 };
253 MODULE_DEVICE_TABLE(of, mma7660_of_match);
254
255 static const struct acpi_device_id mma7660_acpi_id[] = {
256 {"MMA7660", 0},
257 {}
258 };
259
260 MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);
261
262 static struct i2c_driver mma7660_driver = {
263 .driver = {
264 .name = "mma7660",
265 .pm = pm_sleep_ptr(&mma7660_pm_ops),
266 .of_match_table = mma7660_of_match,
267 .acpi_match_table = mma7660_acpi_id,
268 },
269 .probe = mma7660_probe,
270 .remove = mma7660_remove,
271 .id_table = mma7660_i2c_id,
272 };
273
274 module_i2c_driver(mma7660_driver);
275
276 MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>");
277 MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
278 MODULE_LICENSE("GPL v2");
279