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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 void da280_disable(void *client)
104{
105 da280_enable(client, false);
106}
107
108static int da280_probe(struct i2c_client *client)
109{
110 const struct i2c_device_id *id = i2c_client_get_device_id(client);
111 int ret;
112 struct iio_dev *indio_dev;
113 struct da280_data *data;
114 enum da280_chipset chip;
115
116 ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID);
117 if (ret != DA280_CHIP_ID)
118 return (ret < 0) ? ret : -ENODEV;
119
120 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
121 if (!indio_dev)
122 return -ENOMEM;
123
124 data = iio_priv(indio_dev);
125 data->client = client;
126
127 indio_dev->info = &da280_info;
128 indio_dev->modes = INDIO_DIRECT_MODE;
129 indio_dev->channels = da280_channels;
130
131 if (ACPI_HANDLE(&client->dev)) {
132 chip = da280_match_acpi_device(&client->dev);
133 } else {
134 chip = id->driver_data;
135 }
136
137 if (chip == da226) {
138 indio_dev->name = "da226";
139 indio_dev->num_channels = 2;
140 } else {
141 indio_dev->name = "da280";
142 indio_dev->num_channels = 3;
143 }
144
145 ret = da280_enable(client, true);
146 if (ret < 0)
147 return ret;
148
149 ret = devm_add_action_or_reset(&client->dev, da280_disable, client);
150 if (ret)
151 return ret;
152
153 return devm_iio_device_register(&client->dev, indio_dev);
154}
155
156static int da280_suspend(struct device *dev)
157{
158 return da280_enable(to_i2c_client(dev), false);
159}
160
161static int da280_resume(struct device *dev)
162{
163 return da280_enable(to_i2c_client(dev), true);
164}
165
166static DEFINE_SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume);
167
168static const struct acpi_device_id da280_acpi_match[] = {
169 {"MIRAACC", da280},
170 {},
171};
172MODULE_DEVICE_TABLE(acpi, da280_acpi_match);
173
174static const struct i2c_device_id da280_i2c_id[] = {
175 { "da226", da226 },
176 { "da280", da280 },
177 {}
178};
179MODULE_DEVICE_TABLE(i2c, da280_i2c_id);
180
181static struct i2c_driver da280_driver = {
182 .driver = {
183 .name = "da280",
184 .acpi_match_table = ACPI_PTR(da280_acpi_match),
185 .pm = pm_sleep_ptr(&da280_pm_ops),
186 },
187 .probe_new = da280_probe,
188 .id_table = da280_i2c_id,
189};
190
191module_i2c_driver(da280_driver);
192
193MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
194MODULE_DESCRIPTION("MiraMEMS DA280 3-Axis Accelerometer driver");
195MODULE_LICENSE("GPL v2");