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#define MMA8450_ID 0xc6
42#define MMA8450_WHO_AM_I 0x0f
43
44static int mma8450_read(struct i2c_client *c, unsigned int off)
45{
46 int ret;
47
48 ret = i2c_smbus_read_byte_data(client: c, command: off);
49 if (ret < 0)
50 dev_err(&c->dev,
51 "failed to read register 0x%02x, error %d\n",
52 off, ret);
53
54 return ret;
55}
56
57static int mma8450_write(struct i2c_client *c, unsigned int off, u8 v)
58{
59 int error;
60
61 error = i2c_smbus_write_byte_data(client: c, command: off, value: v);
62 if (error < 0) {
63 dev_err(&c->dev,
64 "failed to write to register 0x%02x, error %d\n",
65 off, error);
66 return error;
67 }
68
69 return 0;
70}
71
72static int mma8450_read_block(struct i2c_client *c, unsigned int off,
73 u8 *buf, size_t size)
74{
75 int err;
76
77 err = i2c_smbus_read_i2c_block_data(client: c, command: off, length: size, values: buf);
78 if (err < 0) {
79 dev_err(&c->dev,
80 "failed to read block data at 0x%02x, error %d\n",
81 MMA8450_OUT_X_LSB, err);
82 return err;
83 }
84
85 return 0;
86}
87
88static void mma8450_poll(struct input_dev *input)
89{
90 struct i2c_client *c = input_get_drvdata(dev: input);
91 int x, y, z;
92 int ret;
93 u8 buf[6];
94
95 ret = mma8450_read(c, MMA8450_STATUS);
96 if (ret < 0)
97 return;
98
99 if (!(ret & MMA8450_STATUS_ZXYDR))
100 return;
101
102 ret = mma8450_read_block(c, MMA8450_OUT_X_LSB, buf, size: sizeof(buf));
103 if (ret < 0)
104 return;
105
106 x = ((int)(s8)buf[1] << 4) | (buf[0] & 0xf);
107 y = ((int)(s8)buf[3] << 4) | (buf[2] & 0xf);
108 z = ((int)(s8)buf[5] << 4) | (buf[4] & 0xf);
109
110 input_report_abs(dev: input, ABS_X, value: x);
111 input_report_abs(dev: input, ABS_Y, value: y);
112 input_report_abs(dev: input, ABS_Z, value: z);
113 input_sync(dev: input);
114}
115
116/* Initialize the MMA8450 chip */
117static int mma8450_open(struct input_dev *input)
118{
119 struct i2c_client *c = input_get_drvdata(dev: input);
120 int err;
121
122 /* enable all events from X/Y/Z, no FIFO */
123 err = mma8450_write(c, MMA8450_XYZ_DATA_CFG, v: 0x07);
124 if (err)
125 return err;
126
127 /*
128 * Sleep mode poll rate - 50Hz
129 * System output data rate - 400Hz
130 * Full scale selection - Active, +/- 2G
131 */
132 err = mma8450_write(c, MMA8450_CTRL_REG1, v: 0x01);
133 if (err)
134 return err;
135
136 msleep(MODE_CHANGE_DELAY_MS);
137 return 0;
138}
139
140static void mma8450_close(struct input_dev *input)
141{
142 struct i2c_client *c = input_get_drvdata(dev: input);
143
144 mma8450_write(c, MMA8450_CTRL_REG1, v: 0x00);
145 mma8450_write(c, MMA8450_CTRL_REG2, v: 0x01);
146}
147
148/*
149 * I2C init/probing/exit functions
150 */
151static int mma8450_probe(struct i2c_client *c)
152{
153 struct i2c_adapter *adapter = c->adapter;
154 struct input_dev *input;
155 int err, client_id;
156
157 if (!i2c_check_functionality(adap: adapter, I2C_FUNC_SMBUS_BYTE |
158 I2C_FUNC_SMBUS_BYTE_DATA))
159 return dev_err_probe(dev: &c->dev, err: -EINVAL,
160 fmt: "I2C adapter doesn't support SMBUS BYTE");
161
162 client_id = i2c_smbus_read_byte_data(client: c, MMA8450_WHO_AM_I);
163 if (client_id != MMA8450_ID)
164 return dev_err_probe(dev: &c->dev, err: -EINVAL,
165 fmt: "unexpected chip ID 0x%x (vs 0x%x)\n",
166 client_id, MMA8450_ID);
167
168 input = devm_input_allocate_device(&c->dev);
169 if (!input)
170 return -ENOMEM;
171
172 input_set_drvdata(dev: input, data: c);
173
174 input->name = MMA8450_DRV_NAME;
175 input->id.bustype = BUS_I2C;
176
177 input->open = mma8450_open;
178 input->close = mma8450_close;
179
180 input_set_abs_params(dev: input, ABS_X, min: -2048, max: 2047, fuzz: 32, flat: 32);
181 input_set_abs_params(dev: input, ABS_Y, min: -2048, max: 2047, fuzz: 32, flat: 32);
182 input_set_abs_params(dev: input, ABS_Z, min: -2048, max: 2047, fuzz: 32, flat: 32);
183
184 err = input_setup_polling(dev: input, poll_fn: mma8450_poll);
185 if (err) {
186 dev_err(&c->dev, "failed to set up polling\n");
187 return err;
188 }
189
190 input_set_poll_interval(dev: input, POLL_INTERVAL);
191 input_set_max_poll_interval(dev: input, POLL_INTERVAL_MAX);
192
193 err = input_register_device(input);
194 if (err) {
195 dev_err(&c->dev, "failed to register input device\n");
196 return err;
197 }
198
199 return 0;
200}
201
202static const struct i2c_device_id mma8450_id[] = {
203 { MMA8450_DRV_NAME },
204 { }
205};
206MODULE_DEVICE_TABLE(i2c, mma8450_id);
207
208static const struct of_device_id mma8450_dt_ids[] = {
209 { .compatible = "fsl,mma8450", },
210 { /* sentinel */ }
211};
212MODULE_DEVICE_TABLE(of, mma8450_dt_ids);
213
214static struct i2c_driver mma8450_driver = {
215 .driver = {
216 .name = MMA8450_DRV_NAME,
217 .of_match_table = mma8450_dt_ids,
218 },
219 .probe = mma8450_probe,
220 .id_table = mma8450_id,
221};
222
223module_i2c_driver(mma8450_driver);
224
225MODULE_AUTHOR("Freescale Semiconductor, Inc.");
226MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver");
227MODULE_LICENSE("GPL");
228

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