1// SPDX-License-Identifier: GPL-2.0-only
2/**
3 * IIO driver for the MiraMEMS DA280 3-axis accelerometer and
4 * IIO driver for the MiraMEMS DA226 2-axis accelerometer
5 *
6 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
7 */
8
9#include <linux/module.h>
10#include <linux/i2c.h>
11#include <linux/acpi.h>
12#include <linux/iio/iio.h>
13#include <linux/iio/sysfs.h>
14#include <linux/byteorder/generic.h>
15
16#define DA280_REG_CHIP_ID		0x01
17#define DA280_REG_ACC_X_LSB		0x02
18#define DA280_REG_ACC_Y_LSB		0x04
19#define DA280_REG_ACC_Z_LSB		0x06
20#define DA280_REG_MODE_BW		0x11
21
22#define DA280_CHIP_ID			0x13
23#define DA280_MODE_ENABLE		0x1e
24#define DA280_MODE_DISABLE		0x9e
25
26enum da280_chipset { da226, da280 };
27
28/*
29 * a value of + or -4096 corresponds to + or - 1G
30 * scale = 9.81 / 4096 = 0.002395019
31 */
32
33static const int da280_nscale = 2395019;
34
35#define DA280_CHANNEL(reg, axis) {	\
36	.type = IIO_ACCEL,	\
37	.address = reg,	\
38	.modified = 1,	\
39	.channel2 = IIO_MOD_##axis,	\
40	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
41	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
42}
43
44static const struct iio_chan_spec da280_channels[] = {
45	DA280_CHANNEL(DA280_REG_ACC_X_LSB, X),
46	DA280_CHANNEL(DA280_REG_ACC_Y_LSB, Y),
47	DA280_CHANNEL(DA280_REG_ACC_Z_LSB, Z),
48};
49
50struct da280_data {
51	struct i2c_client *client;
52};
53
54static int da280_enable(struct i2c_client *client, bool enable)
55{
56	u8 data = enable ? DA280_MODE_ENABLE : DA280_MODE_DISABLE;
57
58	return i2c_smbus_write_byte_data(client, DA280_REG_MODE_BW, data);
59}
60
61static int da280_read_raw(struct iio_dev *indio_dev,
62				struct iio_chan_spec const *chan,
63				int *val, int *val2, long mask)
64{
65	struct da280_data *data = iio_priv(indio_dev);
66	int ret;
67
68	switch (mask) {
69	case IIO_CHAN_INFO_RAW:
70		ret = i2c_smbus_read_word_data(data->client, chan->address);
71		if (ret < 0)
72			return ret;
73		/*
74		 * Values are 14 bits, stored as 16 bits with the 2
75		 * least significant bits always 0.
76		 */
77		*val = (short)ret >> 2;
78		return IIO_VAL_INT;
79	case IIO_CHAN_INFO_SCALE:
80		*val = 0;
81		*val2 = da280_nscale;
82		return IIO_VAL_INT_PLUS_NANO;
83	default:
84		return -EINVAL;
85	}
86}
87
88static const struct iio_info da280_info = {
89	.read_raw	= da280_read_raw,
90};
91
92static enum da280_chipset da280_match_acpi_device(struct device *dev)
93{
94	const struct acpi_device_id *id;
95
96	id = acpi_match_device(dev->driver->acpi_match_table, dev);
97	if (!id)
98		return -EINVAL;
99
100	return (enum da280_chipset) id->driver_data;
101}
102
103static int da280_probe(struct i2c_client *client,
104			const struct i2c_device_id *id)
105{
106	int ret;
107	struct iio_dev *indio_dev;
108	struct da280_data *data;
109	enum da280_chipset chip;
110
111	ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID);
112	if (ret != DA280_CHIP_ID)
113		return (ret < 0) ? ret : -ENODEV;
114
115	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
116	if (!indio_dev)
117		return -ENOMEM;
118
119	data = iio_priv(indio_dev);
120	data->client = client;
121	i2c_set_clientdata(client, indio_dev);
122
123	indio_dev->info = &da280_info;
124	indio_dev->modes = INDIO_DIRECT_MODE;
125	indio_dev->channels = da280_channels;
126
127	if (ACPI_HANDLE(&client->dev)) {
128		chip = da280_match_acpi_device(&client->dev);
129	} else {
130		chip = id->driver_data;
131	}
132
133	if (chip == da226) {
134		indio_dev->name = "da226";
135		indio_dev->num_channels = 2;
136	} else {
137		indio_dev->name = "da280";
138		indio_dev->num_channels = 3;
139	}
140
141	ret = da280_enable(client, true);
142	if (ret < 0)
143		return ret;
144
145	ret = iio_device_register(indio_dev);
146	if (ret < 0) {
147		dev_err(&client->dev, "device_register failed\n");
148		da280_enable(client, false);
149	}
150
151	return ret;
152}
153
154static int da280_remove(struct i2c_client *client)
155{
156	struct iio_dev *indio_dev = i2c_get_clientdata(client);
157
158	iio_device_unregister(indio_dev);
159
160	return da280_enable(client, false);
161}
162
163#ifdef CONFIG_PM_SLEEP
164static int da280_suspend(struct device *dev)
165{
166	return da280_enable(to_i2c_client(dev), false);
167}
168
169static int da280_resume(struct device *dev)
170{
171	return da280_enable(to_i2c_client(dev), true);
172}
173#endif
174
175static SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume);
176
177static const struct acpi_device_id da280_acpi_match[] = {
178	{"MIRAACC", da280},
179	{},
180};
181MODULE_DEVICE_TABLE(acpi, da280_acpi_match);
182
183static const struct i2c_device_id da280_i2c_id[] = {
184	{ "da226", da226 },
185	{ "da280", da280 },
186	{}
187};
188MODULE_DEVICE_TABLE(i2c, da280_i2c_id);
189
190static struct i2c_driver da280_driver = {
191	.driver = {
192		.name = "da280",
193		.acpi_match_table = ACPI_PTR(da280_acpi_match),
194		.pm = &da280_pm_ops,
195	},
196	.probe		= da280_probe,
197	.remove		= da280_remove,
198	.id_table	= da280_i2c_id,
199};
200
201module_i2c_driver(da280_driver);
202
203MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
204MODULE_DESCRIPTION("MiraMEMS DA280 3-Axis Accelerometer driver");
205MODULE_LICENSE("GPL v2");
206