1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Driver for Freescale's 3-Axis Accelerometer MMA8450
4 *
5 * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/slab.h>
11#include <linux/delay.h>
12#include <linux/i2c.h>
13#include <linux/input.h>
14#include <linux/mod_devicetable.h>
15
16#define MMA8450_DRV_NAME "mma8450"
17
18#define MODE_CHANGE_DELAY_MS 100
19#define POLL_INTERVAL 100
20#define POLL_INTERVAL_MAX 500
21
22/* register definitions */
23#define MMA8450_STATUS 0x00
24#define MMA8450_STATUS_ZXYDR 0x08
25
26#define MMA8450_OUT_X8 0x01
27#define MMA8450_OUT_Y8 0x02
28#define MMA8450_OUT_Z8 0x03
29
30#define MMA8450_OUT_X_LSB 0x05
31#define MMA8450_OUT_X_MSB 0x06
32#define MMA8450_OUT_Y_LSB 0x07
33#define MMA8450_OUT_Y_MSB 0x08
34#define MMA8450_OUT_Z_LSB 0x09
35#define MMA8450_OUT_Z_MSB 0x0a
36
37#define MMA8450_XYZ_DATA_CFG 0x16
38
39#define MMA8450_CTRL_REG1 0x38
40#define MMA8450_CTRL_REG2 0x39
41
42static int mma8450_read(struct i2c_client *c, unsigned int off)
43{
44 int ret;
45
46 ret = i2c_smbus_read_byte_data(client: c, command: off);
47 if (ret < 0)
48 dev_err(&c->dev,
49 "failed to read register 0x%02x, error %d\n",
50 off, ret);
51
52 return ret;
53}
54
55static int mma8450_write(struct i2c_client *c, unsigned int off, u8 v)
56{
57 int error;
58
59 error = i2c_smbus_write_byte_data(client: c, command: off, value: v);
60 if (error < 0) {
61 dev_err(&c->dev,
62 "failed to write to register 0x%02x, error %d\n",
63 off, error);
64 return error;
65 }
66
67 return 0;
68}
69
70static int mma8450_read_block(struct i2c_client *c, unsigned int off,
71 u8 *buf, size_t size)
72{
73 int err;
74
75 err = i2c_smbus_read_i2c_block_data(client: c, command: off, length: size, values: buf);
76 if (err < 0) {
77 dev_err(&c->dev,
78 "failed to read block data at 0x%02x, error %d\n",
79 MMA8450_OUT_X_LSB, err);
80 return err;
81 }
82
83 return 0;
84}
85
86static void mma8450_poll(struct input_dev *input)
87{
88 struct i2c_client *c = input_get_drvdata(dev: input);
89 int x, y, z;
90 int ret;
91 u8 buf[6];
92
93 ret = mma8450_read(c, MMA8450_STATUS);
94 if (ret < 0)
95 return;
96
97 if (!(ret & MMA8450_STATUS_ZXYDR))
98 return;
99
100 ret = mma8450_read_block(c, MMA8450_OUT_X_LSB, buf, size: sizeof(buf));
101 if (ret < 0)
102 return;
103
104 x = ((int)(s8)buf[1] << 4) | (buf[0] & 0xf);
105 y = ((int)(s8)buf[3] << 4) | (buf[2] & 0xf);
106 z = ((int)(s8)buf[5] << 4) | (buf[4] & 0xf);
107
108 input_report_abs(dev: input, ABS_X, value: x);
109 input_report_abs(dev: input, ABS_Y, value: y);
110 input_report_abs(dev: input, ABS_Z, value: z);
111 input_sync(dev: input);
112}
113
114/* Initialize the MMA8450 chip */
115static int mma8450_open(struct input_dev *input)
116{
117 struct i2c_client *c = input_get_drvdata(dev: input);
118 int err;
119
120 /* enable all events from X/Y/Z, no FIFO */
121 err = mma8450_write(c, MMA8450_XYZ_DATA_CFG, v: 0x07);
122 if (err)
123 return err;
124
125 /*
126 * Sleep mode poll rate - 50Hz
127 * System output data rate - 400Hz
128 * Full scale selection - Active, +/- 2G
129 */
130 err = mma8450_write(c, MMA8450_CTRL_REG1, v: 0x01);
131 if (err)
132 return err;
133
134 msleep(MODE_CHANGE_DELAY_MS);
135 return 0;
136}
137
138static void mma8450_close(struct input_dev *input)
139{
140 struct i2c_client *c = input_get_drvdata(dev: input);
141
142 mma8450_write(c, MMA8450_CTRL_REG1, v: 0x00);
143 mma8450_write(c, MMA8450_CTRL_REG2, v: 0x01);
144}
145
146/*
147 * I2C init/probing/exit functions
148 */
149static int mma8450_probe(struct i2c_client *c)
150{
151 struct input_dev *input;
152 int err;
153
154 input = devm_input_allocate_device(&c->dev);
155 if (!input)
156 return -ENOMEM;
157
158 input_set_drvdata(dev: input, data: c);
159
160 input->name = MMA8450_DRV_NAME;
161 input->id.bustype = BUS_I2C;
162
163 input->open = mma8450_open;
164 input->close = mma8450_close;
165
166 input_set_abs_params(dev: input, ABS_X, min: -2048, max: 2047, fuzz: 32, flat: 32);
167 input_set_abs_params(dev: input, ABS_Y, min: -2048, max: 2047, fuzz: 32, flat: 32);
168 input_set_abs_params(dev: input, ABS_Z, min: -2048, max: 2047, fuzz: 32, flat: 32);
169
170 err = input_setup_polling(dev: input, poll_fn: mma8450_poll);
171 if (err) {
172 dev_err(&c->dev, "failed to set up polling\n");
173 return err;
174 }
175
176 input_set_poll_interval(dev: input, POLL_INTERVAL);
177 input_set_max_poll_interval(dev: input, POLL_INTERVAL_MAX);
178
179 err = input_register_device(input);
180 if (err) {
181 dev_err(&c->dev, "failed to register input device\n");
182 return err;
183 }
184
185 return 0;
186}
187
188static const struct i2c_device_id mma8450_id[] = {
189 { MMA8450_DRV_NAME, 0 },
190 { },
191};
192MODULE_DEVICE_TABLE(i2c, mma8450_id);
193
194static const struct of_device_id mma8450_dt_ids[] = {
195 { .compatible = "fsl,mma8450", },
196 { /* sentinel */ }
197};
198MODULE_DEVICE_TABLE(of, mma8450_dt_ids);
199
200static struct i2c_driver mma8450_driver = {
201 .driver = {
202 .name = MMA8450_DRV_NAME,
203 .of_match_table = mma8450_dt_ids,
204 },
205 .probe = mma8450_probe,
206 .id_table = mma8450_id,
207};
208
209module_i2c_driver(mma8450_driver);
210
211MODULE_AUTHOR("Freescale Semiconductor, Inc.");
212MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver");
213MODULE_LICENSE("GPL");
214

source code of linux/drivers/input/misc/mma8450.c