diff options
Diffstat (limited to 'drivers/input/misc/mma8450.c')
| -rw-r--r-- | drivers/input/misc/mma8450.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c new file mode 100644 index 000000000..1b5a5e192 --- /dev/null +++ b/drivers/input/misc/mma8450.c @@ -0,0 +1,214 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Driver for Freescale's 3-Axis Accelerometer MMA8450 + * + * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/input.h> +#include <linux/of_device.h> + +#define MMA8450_DRV_NAME "mma8450" + +#define MODE_CHANGE_DELAY_MS 100 +#define POLL_INTERVAL 100 +#define POLL_INTERVAL_MAX 500 + +/* register definitions */ +#define MMA8450_STATUS 0x00 +#define MMA8450_STATUS_ZXYDR 0x08 + +#define MMA8450_OUT_X8 0x01 +#define MMA8450_OUT_Y8 0x02 +#define MMA8450_OUT_Z8 0x03 + +#define MMA8450_OUT_X_LSB 0x05 +#define MMA8450_OUT_X_MSB 0x06 +#define MMA8450_OUT_Y_LSB 0x07 +#define MMA8450_OUT_Y_MSB 0x08 +#define MMA8450_OUT_Z_LSB 0x09 +#define MMA8450_OUT_Z_MSB 0x0a + +#define MMA8450_XYZ_DATA_CFG 0x16 + +#define MMA8450_CTRL_REG1 0x38 +#define MMA8450_CTRL_REG2 0x39 + +static int mma8450_read(struct i2c_client *c, unsigned int off) +{ + int ret; + + ret = i2c_smbus_read_byte_data(c, off); + if (ret < 0) + dev_err(&c->dev, + "failed to read register 0x%02x, error %d\n", + off, ret); + + return ret; +} + +static int mma8450_write(struct i2c_client *c, unsigned int off, u8 v) +{ + int error; + + error = i2c_smbus_write_byte_data(c, off, v); + if (error < 0) { + dev_err(&c->dev, + "failed to write to register 0x%02x, error %d\n", + off, error); + return error; + } + + return 0; +} + +static int mma8450_read_block(struct i2c_client *c, unsigned int off, + u8 *buf, size_t size) +{ + int err; + + err = i2c_smbus_read_i2c_block_data(c, off, size, buf); + if (err < 0) { + dev_err(&c->dev, + "failed to read block data at 0x%02x, error %d\n", + MMA8450_OUT_X_LSB, err); + return err; + } + + return 0; +} + +static void mma8450_poll(struct input_dev *input) +{ + struct i2c_client *c = input_get_drvdata(input); + int x, y, z; + int ret; + u8 buf[6]; + + ret = mma8450_read(c, MMA8450_STATUS); + if (ret < 0) + return; + + if (!(ret & MMA8450_STATUS_ZXYDR)) + return; + + ret = mma8450_read_block(c, MMA8450_OUT_X_LSB, buf, sizeof(buf)); + if (ret < 0) + return; + + x = ((int)(s8)buf[1] << 4) | (buf[0] & 0xf); + y = ((int)(s8)buf[3] << 4) | (buf[2] & 0xf); + z = ((int)(s8)buf[5] << 4) | (buf[4] & 0xf); + + input_report_abs(input, ABS_X, x); + input_report_abs(input, ABS_Y, y); + input_report_abs(input, ABS_Z, z); + input_sync(input); +} + +/* Initialize the MMA8450 chip */ +static int mma8450_open(struct input_dev *input) +{ + struct i2c_client *c = input_get_drvdata(input); + int err; + + /* enable all events from X/Y/Z, no FIFO */ + err = mma8450_write(c, MMA8450_XYZ_DATA_CFG, 0x07); + if (err) + return err; + + /* + * Sleep mode poll rate - 50Hz + * System output data rate - 400Hz + * Full scale selection - Active, +/- 2G + */ + err = mma8450_write(c, MMA8450_CTRL_REG1, 0x01); + if (err) + return err; + + msleep(MODE_CHANGE_DELAY_MS); + return 0; +} + +static void mma8450_close(struct input_dev *input) +{ + struct i2c_client *c = input_get_drvdata(input); + + mma8450_write(c, MMA8450_CTRL_REG1, 0x00); + mma8450_write(c, MMA8450_CTRL_REG2, 0x01); +} + +/* + * I2C init/probing/exit functions + */ +static int mma8450_probe(struct i2c_client *c, + const struct i2c_device_id *id) +{ + struct input_dev *input; + int err; + + input = devm_input_allocate_device(&c->dev); + if (!input) + return -ENOMEM; + + input_set_drvdata(input, c); + + input->name = MMA8450_DRV_NAME; + input->id.bustype = BUS_I2C; + + input->open = mma8450_open; + input->close = mma8450_close; + + input_set_abs_params(input, ABS_X, -2048, 2047, 32, 32); + input_set_abs_params(input, ABS_Y, -2048, 2047, 32, 32); + input_set_abs_params(input, ABS_Z, -2048, 2047, 32, 32); + + err = input_setup_polling(input, mma8450_poll); + if (err) { + dev_err(&c->dev, "failed to set up polling\n"); + return err; + } + + input_set_poll_interval(input, POLL_INTERVAL); + input_set_max_poll_interval(input, POLL_INTERVAL_MAX); + + err = input_register_device(input); + if (err) { + dev_err(&c->dev, "failed to register input device\n"); + return err; + } + + return 0; +} + +static const struct i2c_device_id mma8450_id[] = { + { MMA8450_DRV_NAME, 0 }, + { }, +}; +MODULE_DEVICE_TABLE(i2c, mma8450_id); + +static const struct of_device_id mma8450_dt_ids[] = { + { .compatible = "fsl,mma8450", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mma8450_dt_ids); + +static struct i2c_driver mma8450_driver = { + .driver = { + .name = MMA8450_DRV_NAME, + .of_match_table = mma8450_dt_ids, + }, + .probe = mma8450_probe, + .id_table = mma8450_id, +}; + +module_i2c_driver(mma8450_driver); + +MODULE_AUTHOR("Freescale Semiconductor, Inc."); +MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver"); +MODULE_LICENSE("GPL"); |