mma8450.c

  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(c, 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(c, off, 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(c, off, size, 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(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, 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(input, ABS_X, x);
111	input_report_abs(input, ABS_Y, y);
112	input_report_abs(input, ABS_Z, z);
113	input_sync(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(input);
120	int err;
121
122	/* enable all events from X/Y/Z, no FIFO */
123	err = mma8450_write(c, MMA8450_XYZ_DATA_CFG, 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, 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(input);
143
144	mma8450_write(c, MMA8450_CTRL_REG1, 0x00);
145	mma8450_write(c, MMA8450_CTRL_REG2, 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(adapter, I2C_FUNC_SMBUS_BYTE |
158						I2C_FUNC_SMBUS_BYTE_DATA))
159		return dev_err_probe(&c->dev, -EINVAL,
160				     "I2C adapter doesn't support SMBUS BYTE");
161
162	client_id = i2c_smbus_read_byte_data(c, MMA8450_WHO_AM_I);
163	if (client_id != MMA8450_ID)
164		return dev_err_probe(&c->dev, -EINVAL,
165				     "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(input, 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(input, ABS_X, -2048, 2047, 32, 32);
181	input_set_abs_params(input, ABS_Y, -2048, 2047, 32, 32);
182	input_set_abs_params(input, ABS_Z, -2048, 2047, 32, 32);
183
184	err = input_setup_polling(input, 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(input, POLL_INTERVAL);
191	input_set_max_poll_interval(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");