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/of_device.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
mma8450_read(struct i2c_client * c,unsigned int off)42 static int mma8450_read(struct i2c_client *c, unsigned int off)
43 {
44 int ret;
45
46 ret = i2c_smbus_read_byte_data(c, 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
mma8450_write(struct i2c_client * c,unsigned int off,u8 v)55 static int mma8450_write(struct i2c_client *c, unsigned int off, u8 v)
56 {
57 int error;
58
59 error = i2c_smbus_write_byte_data(c, off, 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
mma8450_read_block(struct i2c_client * c,unsigned int off,u8 * buf,size_t size)70 static 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(c, off, size, 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
mma8450_poll(struct input_dev * input)86 static void mma8450_poll(struct input_dev *input)
87 {
88 struct i2c_client *c = input_get_drvdata(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, 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(input, ABS_X, x);
109 input_report_abs(input, ABS_Y, y);
110 input_report_abs(input, ABS_Z, z);
111 input_sync(input);
112 }
113
114 /* Initialize the MMA8450 chip */
mma8450_open(struct input_dev * input)115 static int mma8450_open(struct input_dev *input)
116 {
117 struct i2c_client *c = input_get_drvdata(input);
118 int err;
119
120 /* enable all events from X/Y/Z, no FIFO */
121 err = mma8450_write(c, MMA8450_XYZ_DATA_CFG, 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, 0x01);
131 if (err)
132 return err;
133
134 msleep(MODE_CHANGE_DELAY_MS);
135 return 0;
136 }
137
mma8450_close(struct input_dev * input)138 static void mma8450_close(struct input_dev *input)
139 {
140 struct i2c_client *c = input_get_drvdata(input);
141
142 mma8450_write(c, MMA8450_CTRL_REG1, 0x00);
143 mma8450_write(c, MMA8450_CTRL_REG2, 0x01);
144 }
145
146 /*
147 * I2C init/probing/exit functions
148 */
mma8450_probe(struct i2c_client * c,const struct i2c_device_id * id)149 static int mma8450_probe(struct i2c_client *c,
150 const struct i2c_device_id *id)
151 {
152 struct input_dev *input;
153 int err;
154
155 input = devm_input_allocate_device(&c->dev);
156 if (!input)
157 return -ENOMEM;
158
159 input_set_drvdata(input, c);
160
161 input->name = MMA8450_DRV_NAME;
162 input->id.bustype = BUS_I2C;
163
164 input->open = mma8450_open;
165 input->close = mma8450_close;
166
167 input_set_abs_params(input, ABS_X, -2048, 2047, 32, 32);
168 input_set_abs_params(input, ABS_Y, -2048, 2047, 32, 32);
169 input_set_abs_params(input, ABS_Z, -2048, 2047, 32, 32);
170
171 err = input_setup_polling(input, mma8450_poll);
172 if (err) {
173 dev_err(&c->dev, "failed to set up polling\n");
174 return err;
175 }
176
177 input_set_poll_interval(input, POLL_INTERVAL);
178 input_set_max_poll_interval(input, POLL_INTERVAL_MAX);
179
180 err = input_register_device(input);
181 if (err) {
182 dev_err(&c->dev, "failed to register input device\n");
183 return err;
184 }
185
186 return 0;
187 }
188
189 static const struct i2c_device_id mma8450_id[] = {
190 { MMA8450_DRV_NAME, 0 },
191 { },
192 };
193 MODULE_DEVICE_TABLE(i2c, mma8450_id);
194
195 static const struct of_device_id mma8450_dt_ids[] = {
196 { .compatible = "fsl,mma8450", },
197 { /* sentinel */ }
198 };
199 MODULE_DEVICE_TABLE(of, mma8450_dt_ids);
200
201 static struct i2c_driver mma8450_driver = {
202 .driver = {
203 .name = MMA8450_DRV_NAME,
204 .of_match_table = mma8450_dt_ids,
205 },
206 .probe = mma8450_probe,
207 .id_table = mma8450_id,
208 };
209
210 module_i2c_driver(mma8450_driver);
211
212 MODULE_AUTHOR("Freescale Semiconductor, Inc.");
213 MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver");
214 MODULE_LICENSE("GPL");
215