tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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-polldev.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
42/* mma8450 status */
43struct mma8450 {
44 struct i2c_client *client;
45 struct input_polled_dev *idev;
46};
47
48static int mma8450_read(struct mma8450 *m, unsigned off)
49{
50 struct i2c_client *c = m->client;
51 int ret;
52
53 ret = i2c_smbus_read_byte_data(c, off);
54 if (ret < 0)
55 dev_err(&c->dev,
56 "failed to read register 0x%02x, error %d\n",
57 off, ret);
58
59 return ret;
60}
61
62static int mma8450_write(struct mma8450 *m, unsigned off, u8 v)
63{
64 struct i2c_client *c = m->client;
65 int error;
66
67 error = i2c_smbus_write_byte_data(c, off, v);
68 if (error < 0) {
69 dev_err(&c->dev,
70 "failed to write to register 0x%02x, error %d\n",
71 off, error);
72 return error;
73 }
74
75 return 0;
76}
77
78static int mma8450_read_block(struct mma8450 *m, unsigned off,
79 u8 *buf, size_t size)
80{
81 struct i2c_client *c = m->client;
82 int err;
83
84 err = i2c_smbus_read_i2c_block_data(c, off, size, buf);
85 if (err < 0) {
86 dev_err(&c->dev,
87 "failed to read block data at 0x%02x, error %d\n",
88 MMA8450_OUT_X_LSB, err);
89 return err;
90 }
91
92 return 0;
93}
94
95static void mma8450_poll(struct input_polled_dev *dev)
96{
97 struct mma8450 *m = dev->private;
98 int x, y, z;
99 int ret;
100 u8 buf[6];
101
102 ret = mma8450_read(m, MMA8450_STATUS);
103 if (ret < 0)
104 return;
105
106 if (!(ret & MMA8450_STATUS_ZXYDR))
107 return;
108
109 ret = mma8450_read_block(m, MMA8450_OUT_X_LSB, buf, sizeof(buf));
110 if (ret < 0)
111 return;
112
113 x = ((int)(s8)buf[1] << 4) | (buf[0] & 0xf);
114 y = ((int)(s8)buf[3] << 4) | (buf[2] & 0xf);
115 z = ((int)(s8)buf[5] << 4) | (buf[4] & 0xf);
116
117 input_report_abs(dev->input, ABS_X, x);
118 input_report_abs(dev->input, ABS_Y, y);
119 input_report_abs(dev->input, ABS_Z, z);
120 input_sync(dev->input);
121}
122
123/* Initialize the MMA8450 chip */
124static void mma8450_open(struct input_polled_dev *dev)
125{
126 struct mma8450 *m = dev->private;
127 int err;
128
129 /* enable all events from X/Y/Z, no FIFO */
130 err = mma8450_write(m, MMA8450_XYZ_DATA_CFG, 0x07);
131 if (err)
132 return;
133
134 /*
135 * Sleep mode poll rate - 50Hz
136 * System output data rate - 400Hz
137 * Full scale selection - Active, +/- 2G
138 */
139 err = mma8450_write(m, MMA8450_CTRL_REG1, 0x01);
140 if (err < 0)
141 return;
142
143 msleep(MODE_CHANGE_DELAY_MS);
144}
145
146static void mma8450_close(struct input_polled_dev *dev)
147{
148 struct mma8450 *m = dev->private;
149
150 mma8450_write(m, MMA8450_CTRL_REG1, 0x00);
151 mma8450_write(m, MMA8450_CTRL_REG2, 0x01);
152}
153
154/*
155 * I2C init/probing/exit functions
156 */
157static int mma8450_probe(struct i2c_client *c,
158 const struct i2c_device_id *id)
159{
160 struct input_polled_dev *idev;
161 struct mma8450 *m;
162 int err;
163
164 m = devm_kzalloc(&c->dev, sizeof(*m), GFP_KERNEL);
165 if (!m)
166 return -ENOMEM;
167
168 idev = devm_input_allocate_polled_device(&c->dev);
169 if (!idev)
170 return -ENOMEM;
171
172 m->client = c;
173 m->idev = idev;
174
175 idev->private = m;
176 idev->input->name = MMA8450_DRV_NAME;
177 idev->input->id.bustype = BUS_I2C;
178 idev->poll = mma8450_poll;
179 idev->poll_interval = POLL_INTERVAL;
180 idev->poll_interval_max = POLL_INTERVAL_MAX;
181 idev->open = mma8450_open;
182 idev->close = mma8450_close;
183
184 __set_bit(EV_ABS, idev->input->evbit);
185 input_set_abs_params(idev->input, ABS_X, -2048, 2047, 32, 32);
186 input_set_abs_params(idev->input, ABS_Y, -2048, 2047, 32, 32);
187 input_set_abs_params(idev->input, ABS_Z, -2048, 2047, 32, 32);
188
189 err = input_register_polled_device(idev);
190 if (err) {
191 dev_err(&c->dev, "failed to register polled input device\n");
192 return err;
193 }
194
195 return 0;
196}
197
198static const struct i2c_device_id mma8450_id[] = {
199 { MMA8450_DRV_NAME, 0 },
200 { },
201};
202MODULE_DEVICE_TABLE(i2c, mma8450_id);
203
204static const struct of_device_id mma8450_dt_ids[] = {
205 { .compatible = "fsl,mma8450", },
206 { /* sentinel */ }
207};
208MODULE_DEVICE_TABLE(of, mma8450_dt_ids);
209
210static struct i2c_driver mma8450_driver = {
211 .driver = {
212 .name = MMA8450_DRV_NAME,
213 .of_match_table = mma8450_dt_ids,
214 },
215 .probe = mma8450_probe,
216 .id_table = mma8450_id,
217};
218
219module_i2c_driver(mma8450_driver);
220
221MODULE_AUTHOR("Freescale Semiconductor, Inc.");
222MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver");
223MODULE_LICENSE("GPL");