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
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	 * 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
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{
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
209static 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
222static 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
231static 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
240static DEFINE_SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend,
241				mma7660_resume);
242
243static const struct i2c_device_id mma7660_i2c_id[] = {
244	{"mma7660", 0},
245	{}
246};
247MODULE_DEVICE_TABLE(i2c, mma7660_i2c_id);
248
249static const struct of_device_id mma7660_of_match[] = {
250	{ .compatible = "fsl,mma7660" },
251	{ }
252};
253MODULE_DEVICE_TABLE(of, mma7660_of_match);
254
255static const struct acpi_device_id mma7660_acpi_id[] = {
256	{"MMA7660", 0},
257	{}
258};
259
260MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);
261
262static 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
274module_i2c_driver(mma7660_driver);
275
276MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>");
277MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
278MODULE_LICENSE("GPL v2");
279