1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
|
// SPDX-License-Identifier: GPL-2.0-only
/**
* IIO driver for the 3-axis accelerometer Domintech ARD10.
*
* Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
* Copyright (c) 2012 Domintech Technology Co., Ltd
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/byteorder/generic.h>
#define DMARD10_REG_ACTR 0x00
#define DMARD10_REG_AFEM 0x0c
#define DMARD10_REG_STADR 0x12
#define DMARD10_REG_STAINT 0x1c
#define DMARD10_REG_MISC2 0x1f
#define DMARD10_REG_PD 0x21
#define DMARD10_MODE_OFF 0x00
#define DMARD10_MODE_STANDBY 0x02
#define DMARD10_MODE_ACTIVE 0x06
#define DMARD10_MODE_READ_OTP 0x12
#define DMARD10_MODE_RESET_DATA_PATH 0x82
/* AFEN set 1, ATM[2:0]=b'000 (normal), EN_Z/Y/X/T=1 */
#define DMARD10_VALUE_AFEM_AFEN_NORMAL 0x8f
/* ODR[3:0]=b'0111 (100Hz), CCK[3:0]=b'0100 (204.8kHZ) */
#define DMARD10_VALUE_CKSEL_ODR_100_204 0x74
/* INTC[6:5]=b'00 */
#define DMARD10_VALUE_INTC 0x00
/* TAP1/TAP2 Average 2 */
#define DMARD10_VALUE_TAPNS_AVE_2 0x11
#define DMARD10_VALUE_STADR 0x55
#define DMARD10_VALUE_STAINT 0xaa
#define DMARD10_VALUE_MISC2_OSCA_EN 0x08
#define DMARD10_VALUE_PD_RST 0x52
/* Offsets into the buffer read in dmard10_read_raw() */
#define DMARD10_X_OFFSET 1
#define DMARD10_Y_OFFSET 2
#define DMARD10_Z_OFFSET 3
/*
* a value of + or -128 corresponds to + or - 1G
* scale = 9.81 / 128 = 0.076640625
*/
static const int dmard10_nscale = 76640625;
#define DMARD10_CHANNEL(reg, axis) { \
.type = IIO_ACCEL, \
.address = reg, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
}
static const struct iio_chan_spec dmard10_channels[] = {
DMARD10_CHANNEL(DMARD10_X_OFFSET, X),
DMARD10_CHANNEL(DMARD10_Y_OFFSET, Y),
DMARD10_CHANNEL(DMARD10_Z_OFFSET, Z),
};
struct dmard10_data {
struct i2c_client *client;
};
/* Init sequence taken from the android driver */
static int dmard10_reset(struct i2c_client *client)
{
unsigned char buffer[7];
int ret;
/* 1. Powerdown reset */
ret = i2c_smbus_write_byte_data(client, DMARD10_REG_PD,
DMARD10_VALUE_PD_RST);
if (ret < 0)
return ret;
/*
* 2. ACTR => Standby mode => Download OTP to parameter reg =>
* Standby mode => Reset data path => Standby mode
*/
buffer[0] = DMARD10_REG_ACTR;
buffer[1] = DMARD10_MODE_STANDBY;
buffer[2] = DMARD10_MODE_READ_OTP;
buffer[3] = DMARD10_MODE_STANDBY;
buffer[4] = DMARD10_MODE_RESET_DATA_PATH;
buffer[5] = DMARD10_MODE_STANDBY;
ret = i2c_master_send(client, buffer, 6);
if (ret < 0)
return ret;
/* 3. OSCA_EN = 1, TSTO = b'000 (INT1 = normal, TEST0 = normal) */
ret = i2c_smbus_write_byte_data(client, DMARD10_REG_MISC2,
DMARD10_VALUE_MISC2_OSCA_EN);
if (ret < 0)
return ret;
/* 4. AFEN = 1 (AFE will powerdown after ADC) */
buffer[0] = DMARD10_REG_AFEM;
buffer[1] = DMARD10_VALUE_AFEM_AFEN_NORMAL;
buffer[2] = DMARD10_VALUE_CKSEL_ODR_100_204;
buffer[3] = DMARD10_VALUE_INTC;
buffer[4] = DMARD10_VALUE_TAPNS_AVE_2;
buffer[5] = 0x00; /* DLYC, no delay timing */
buffer[6] = 0x07; /* INTD=1 push-pull, INTA=1 active high, AUTOT=1 */
ret = i2c_master_send(client, buffer, 7);
if (ret < 0)
return ret;
/* 5. Activation mode */
ret = i2c_smbus_write_byte_data(client, DMARD10_REG_ACTR,
DMARD10_MODE_ACTIVE);
if (ret < 0)
return ret;
return 0;
}
/* Shutdown sequence taken from the android driver */
static int dmard10_shutdown(struct i2c_client *client)
{
unsigned char buffer[3];
buffer[0] = DMARD10_REG_ACTR;
buffer[1] = DMARD10_MODE_STANDBY;
buffer[2] = DMARD10_MODE_OFF;
return i2c_master_send(client, buffer, 3);
}
static int dmard10_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct dmard10_data *data = iio_priv(indio_dev);
__le16 buf[4];
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
/*
* Read 8 bytes starting at the REG_STADR register, trying to
* read the individual X, Y, Z registers will always read 0.
*/
ret = i2c_smbus_read_i2c_block_data(data->client,
DMARD10_REG_STADR,
sizeof(buf), (u8 *)buf);
if (ret < 0)
return ret;
ret = le16_to_cpu(buf[chan->address]);
*val = sign_extend32(ret, 12);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = dmard10_nscale;
return IIO_VAL_INT_PLUS_NANO;
default:
return -EINVAL;
}
}
static const struct iio_info dmard10_info = {
.read_raw = dmard10_read_raw,
};
static int dmard10_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct iio_dev *indio_dev;
struct dmard10_data *data;
/* These 2 registers have special POR reset values used for id */
ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STADR);
if (ret != DMARD10_VALUE_STADR)
return (ret < 0) ? ret : -ENODEV;
ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STAINT);
if (ret != DMARD10_VALUE_STAINT)
return (ret < 0) ? ret : -ENODEV;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev) {
dev_err(&client->dev, "iio allocation failed!\n");
return -ENOMEM;
}
data = iio_priv(indio_dev);
data->client = client;
i2c_set_clientdata(client, indio_dev);
indio_dev->info = &dmard10_info;
indio_dev->name = "dmard10";
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = dmard10_channels;
indio_dev->num_channels = ARRAY_SIZE(dmard10_channels);
ret = dmard10_reset(client);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(&client->dev, "device_register failed\n");
dmard10_shutdown(client);
}
return ret;
}
static int dmard10_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
return dmard10_shutdown(client);
}
#ifdef CONFIG_PM_SLEEP
static int dmard10_suspend(struct device *dev)
{
return dmard10_shutdown(to_i2c_client(dev));
}
static int dmard10_resume(struct device *dev)
{
return dmard10_reset(to_i2c_client(dev));
}
#endif
static SIMPLE_DEV_PM_OPS(dmard10_pm_ops, dmard10_suspend, dmard10_resume);
static const struct i2c_device_id dmard10_i2c_id[] = {
{"dmard10", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, dmard10_i2c_id);
static struct i2c_driver dmard10_driver = {
.driver = {
.name = "dmard10",
.pm = &dmard10_pm_ops,
},
.probe = dmard10_probe,
.remove = dmard10_remove,
.id_table = dmard10_i2c_id,
};
module_i2c_driver(dmard10_driver);
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("Domintech ARD10 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");
|
