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
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for Freescale's 3-Axis Accelerometer MMA8450
*
* Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/input-polldev.h>
#include <linux/of_device.h>
#define MMA8450_DRV_NAME "mma8450"
#define MODE_CHANGE_DELAY_MS 100
#define POLL_INTERVAL 100
#define POLL_INTERVAL_MAX 500
/* register definitions */
#define MMA8450_STATUS 0x00
#define MMA8450_STATUS_ZXYDR 0x08
#define MMA8450_OUT_X8 0x01
#define MMA8450_OUT_Y8 0x02
#define MMA8450_OUT_Z8 0x03
#define MMA8450_OUT_X_LSB 0x05
#define MMA8450_OUT_X_MSB 0x06
#define MMA8450_OUT_Y_LSB 0x07
#define MMA8450_OUT_Y_MSB 0x08
#define MMA8450_OUT_Z_LSB 0x09
#define MMA8450_OUT_Z_MSB 0x0a
#define MMA8450_XYZ_DATA_CFG 0x16
#define MMA8450_CTRL_REG1 0x38
#define MMA8450_CTRL_REG2 0x39
/* mma8450 status */
struct mma8450 {
struct i2c_client *client;
struct input_polled_dev *idev;
};
static int mma8450_read(struct mma8450 *m, unsigned off)
{
struct i2c_client *c = m->client;
int ret;
ret = i2c_smbus_read_byte_data(c, off);
if (ret < 0)
dev_err(&c->dev,
"failed to read register 0x%02x, error %d\n",
off, ret);
return ret;
}
static int mma8450_write(struct mma8450 *m, unsigned off, u8 v)
{
struct i2c_client *c = m->client;
int error;
error = i2c_smbus_write_byte_data(c, off, v);
if (error < 0) {
dev_err(&c->dev,
"failed to write to register 0x%02x, error %d\n",
off, error);
return error;
}
return 0;
}
static int mma8450_read_block(struct mma8450 *m, unsigned off,
u8 *buf, size_t size)
{
struct i2c_client *c = m->client;
int err;
err = i2c_smbus_read_i2c_block_data(c, off, size, buf);
if (err < 0) {
dev_err(&c->dev,
"failed to read block data at 0x%02x, error %d\n",
MMA8450_OUT_X_LSB, err);
return err;
}
return 0;
}
static void mma8450_poll(struct input_polled_dev *dev)
{
struct mma8450 *m = dev->private;
int x, y, z;
int ret;
u8 buf[6];
ret = mma8450_read(m, MMA8450_STATUS);
if (ret < 0)
return;
if (!(ret & MMA8450_STATUS_ZXYDR))
return;
ret = mma8450_read_block(m, MMA8450_OUT_X_LSB, buf, sizeof(buf));
if (ret < 0)
return;
x = ((int)(s8)buf[1] << 4) | (buf[0] & 0xf);
y = ((int)(s8)buf[3] << 4) | (buf[2] & 0xf);
z = ((int)(s8)buf[5] << 4) | (buf[4] & 0xf);
input_report_abs(dev->input, ABS_X, x);
input_report_abs(dev->input, ABS_Y, y);
input_report_abs(dev->input, ABS_Z, z);
input_sync(dev->input);
}
/* Initialize the MMA8450 chip */
static void mma8450_open(struct input_polled_dev *dev)
{
struct mma8450 *m = dev->private;
int err;
/* enable all events from X/Y/Z, no FIFO */
err = mma8450_write(m, MMA8450_XYZ_DATA_CFG, 0x07);
if (err)
return;
/*
* Sleep mode poll rate - 50Hz
* System output data rate - 400Hz
* Full scale selection - Active, +/- 2G
*/
err = mma8450_write(m, MMA8450_CTRL_REG1, 0x01);
if (err < 0)
return;
msleep(MODE_CHANGE_DELAY_MS);
}
static void mma8450_close(struct input_polled_dev *dev)
{
struct mma8450 *m = dev->private;
mma8450_write(m, MMA8450_CTRL_REG1, 0x00);
mma8450_write(m, MMA8450_CTRL_REG2, 0x01);
}
/*
* I2C init/probing/exit functions
*/
static int mma8450_probe(struct i2c_client *c,
const struct i2c_device_id *id)
{
struct input_polled_dev *idev;
struct mma8450 *m;
int err;
m = devm_kzalloc(&c->dev, sizeof(*m), GFP_KERNEL);
if (!m)
return -ENOMEM;
idev = devm_input_allocate_polled_device(&c->dev);
if (!idev)
return -ENOMEM;
m->client = c;
m->idev = idev;
idev->private = m;
idev->input->name = MMA8450_DRV_NAME;
idev->input->id.bustype = BUS_I2C;
idev->poll = mma8450_poll;
idev->poll_interval = POLL_INTERVAL;
idev->poll_interval_max = POLL_INTERVAL_MAX;
idev->open = mma8450_open;
idev->close = mma8450_close;
__set_bit(EV_ABS, idev->input->evbit);
input_set_abs_params(idev->input, ABS_X, -2048, 2047, 32, 32);
input_set_abs_params(idev->input, ABS_Y, -2048, 2047, 32, 32);
input_set_abs_params(idev->input, ABS_Z, -2048, 2047, 32, 32);
err = input_register_polled_device(idev);
if (err) {
dev_err(&c->dev, "failed to register polled input device\n");
return err;
}
return 0;
}
static const struct i2c_device_id mma8450_id[] = {
{ MMA8450_DRV_NAME, 0 },
{ },
};
MODULE_DEVICE_TABLE(i2c, mma8450_id);
static const struct of_device_id mma8450_dt_ids[] = {
{ .compatible = "fsl,mma8450", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mma8450_dt_ids);
static struct i2c_driver mma8450_driver = {
.driver = {
.name = MMA8450_DRV_NAME,
.of_match_table = mma8450_dt_ids,
},
.probe = mma8450_probe,
.id_table = mma8450_id,
};
module_i2c_driver(mma8450_driver);
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver");
MODULE_LICENSE("GPL");
|
