2 * Driver for Freescale's 3-Axis Accelerometer MMA8450
4 * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <linux/delay.h>
25 #include <linux/i2c.h>
26 #include <linux/input-polldev.h>
27 #include <linux/of_device.h>
29 #define MMA8450_DRV_NAME "mma8450"
31 #define MODE_CHANGE_DELAY_MS 100
32 #define POLL_INTERVAL 100
33 #define POLL_INTERVAL_MAX 500
35 /* register definitions */
36 #define MMA8450_STATUS 0x00
37 #define MMA8450_STATUS_ZXYDR 0x08
39 #define MMA8450_OUT_X8 0x01
40 #define MMA8450_OUT_Y8 0x02
41 #define MMA8450_OUT_Z8 0x03
43 #define MMA8450_OUT_X_LSB 0x05
44 #define MMA8450_OUT_X_MSB 0x06
45 #define MMA8450_OUT_Y_LSB 0x07
46 #define MMA8450_OUT_Y_MSB 0x08
47 #define MMA8450_OUT_Z_LSB 0x09
48 #define MMA8450_OUT_Z_MSB 0x0a
50 #define MMA8450_XYZ_DATA_CFG 0x16
52 #define MMA8450_CTRL_REG1 0x38
53 #define MMA8450_CTRL_REG2 0x39
57 struct i2c_client
*client
;
58 struct input_polled_dev
*idev
;
61 static int mma8450_read(struct mma8450
*m
, unsigned off
)
63 struct i2c_client
*c
= m
->client
;
66 ret
= i2c_smbus_read_byte_data(c
, off
);
69 "failed to read register 0x%02x, error %d\n",
75 static int mma8450_write(struct mma8450
*m
, unsigned off
, u8 v
)
77 struct i2c_client
*c
= m
->client
;
80 error
= i2c_smbus_write_byte_data(c
, off
, v
);
83 "failed to write to register 0x%02x, error %d\n",
91 static int mma8450_read_block(struct mma8450
*m
, unsigned off
,
94 struct i2c_client
*c
= m
->client
;
97 err
= i2c_smbus_read_i2c_block_data(c
, off
, size
, buf
);
100 "failed to read block data at 0x%02x, error %d\n",
101 MMA8450_OUT_X_LSB
, err
);
108 static void mma8450_poll(struct input_polled_dev
*dev
)
110 struct mma8450
*m
= dev
->private;
115 ret
= mma8450_read(m
, MMA8450_STATUS
);
119 if (!(ret
& MMA8450_STATUS_ZXYDR
))
122 ret
= mma8450_read_block(m
, MMA8450_OUT_X_LSB
, buf
, sizeof(buf
));
126 x
= ((int)(s8
)buf
[1] << 4) | (buf
[0] & 0xf);
127 y
= ((int)(s8
)buf
[3] << 4) | (buf
[2] & 0xf);
128 z
= ((int)(s8
)buf
[5] << 4) | (buf
[4] & 0xf);
130 input_report_abs(dev
->input
, ABS_X
, x
);
131 input_report_abs(dev
->input
, ABS_Y
, y
);
132 input_report_abs(dev
->input
, ABS_Z
, z
);
133 input_sync(dev
->input
);
136 /* Initialize the MMA8450 chip */
137 static void mma8450_open(struct input_polled_dev
*dev
)
139 struct mma8450
*m
= dev
->private;
142 /* enable all events from X/Y/Z, no FIFO */
143 err
= mma8450_write(m
, MMA8450_XYZ_DATA_CFG
, 0x07);
148 * Sleep mode poll rate - 50Hz
149 * System output data rate - 400Hz
150 * Full scale selection - Active, +/- 2G
152 err
= mma8450_write(m
, MMA8450_CTRL_REG1
, 0x01);
156 msleep(MODE_CHANGE_DELAY_MS
);
159 static void mma8450_close(struct input_polled_dev
*dev
)
161 struct mma8450
*m
= dev
->private;
163 mma8450_write(m
, MMA8450_CTRL_REG1
, 0x00);
164 mma8450_write(m
, MMA8450_CTRL_REG2
, 0x01);
168 * I2C init/probing/exit functions
170 static int mma8450_probe(struct i2c_client
*c
,
171 const struct i2c_device_id
*id
)
173 struct input_polled_dev
*idev
;
177 m
= kzalloc(sizeof(struct mma8450
), GFP_KERNEL
);
178 idev
= input_allocate_polled_device();
188 idev
->input
->name
= MMA8450_DRV_NAME
;
189 idev
->input
->id
.bustype
= BUS_I2C
;
190 idev
->poll
= mma8450_poll
;
191 idev
->poll_interval
= POLL_INTERVAL
;
192 idev
->poll_interval_max
= POLL_INTERVAL_MAX
;
193 idev
->open
= mma8450_open
;
194 idev
->close
= mma8450_close
;
196 __set_bit(EV_ABS
, idev
->input
->evbit
);
197 input_set_abs_params(idev
->input
, ABS_X
, -2048, 2047, 32, 32);
198 input_set_abs_params(idev
->input
, ABS_Y
, -2048, 2047, 32, 32);
199 input_set_abs_params(idev
->input
, ABS_Z
, -2048, 2047, 32, 32);
201 err
= input_register_polled_device(idev
);
203 dev_err(&c
->dev
, "failed to register polled input device\n");
210 input_free_polled_device(idev
);
215 static int mma8450_remove(struct i2c_client
*c
)
217 struct mma8450
*m
= i2c_get_clientdata(c
);
218 struct input_polled_dev
*idev
= m
->idev
;
220 input_unregister_polled_device(idev
);
221 input_free_polled_device(idev
);
227 static const struct i2c_device_id mma8450_id
[] = {
228 { MMA8450_DRV_NAME
, 0 },
231 MODULE_DEVICE_TABLE(i2c
, mma8450_id
);
233 static const struct of_device_id mma8450_dt_ids
[] = {
234 { .compatible
= "fsl,mma8450", },
237 MODULE_DEVICE_TABLE(of
, mma8450_dt_ids
);
239 static struct i2c_driver mma8450_driver
= {
241 .name
= MMA8450_DRV_NAME
,
242 .owner
= THIS_MODULE
,
243 .of_match_table
= mma8450_dt_ids
,
245 .probe
= mma8450_probe
,
246 .remove
= mma8450_remove
,
247 .id_table
= mma8450_id
,
250 module_i2c_driver(mma8450_driver
);
252 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
253 MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver");
254 MODULE_LICENSE("GPL");