diff options
Diffstat (limited to 'drivers/input/misc/mma8450.c')
| -rw-r--r-- | drivers/input/misc/mma8450.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c new file mode 100644 index 000000000..b60cdea73 --- /dev/null +++ b/drivers/input/misc/mma8450.c @@ -0,0 +1,236 @@ +/* + * Driver for Freescale's 3-Axis Accelerometer MMA8450 + * + * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/input-polldev.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 + +/* mma8450 status */ +struct mma8450 { + struct i2c_client *client; + struct input_polled_dev *idev; +}; + +static int mma8450_read(struct mma8450 *m, unsigned off) +{ + struct i2c_client *c = m->client; + 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 mma8450 *m, unsigned off, u8 v) +{ + struct i2c_client *c = m->client; + 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 mma8450 *m, unsigned off, + u8 *buf, size_t size) +{ + struct i2c_client *c = m->client; + 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_polled_dev *dev) +{ + struct mma8450 *m = dev->private; + int x, y, z; + int ret; + u8 buf[6]; + + ret = mma8450_read(m, MMA8450_STATUS); + if (ret < 0) + return; + + if (!(ret & MMA8450_STATUS_ZXYDR)) + return; + + ret = mma8450_read_block(m, 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(dev->input, ABS_X, x); + input_report_abs(dev->input, ABS_Y, y); + input_report_abs(dev->input, ABS_Z, z); + input_sync(dev->input); +} + +/* Initialize the MMA8450 chip */ +static void mma8450_open(struct input_polled_dev *dev) +{ + struct mma8450 *m = dev->private; + int err; + + /* enable all events from X/Y/Z, no FIFO */ + err = mma8450_write(m, MMA8450_XYZ_DATA_CFG, 0x07); + if (err) + return; + + /* + * Sleep mode poll rate - 50Hz + * System output data rate - 400Hz + * Full scale selection - Active, +/- 2G + */ + err = mma8450_write(m, MMA8450_CTRL_REG1, 0x01); + if (err < 0) + return; + + msleep(MODE_CHANGE_DELAY_MS); +} + +static void mma8450_close(struct input_polled_dev *dev) +{ + struct mma8450 *m = dev->private; + + mma8450_write(m, MMA8450_CTRL_REG1, 0x00); + mma8450_write(m, 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_polled_dev *idev; + struct mma8450 *m; + int err; + + m = devm_kzalloc(&c->dev, sizeof(*m), GFP_KERNEL); + if (!m) + return -ENOMEM; + + idev = devm_input_allocate_polled_device(&c->dev); + if (!idev) + return -ENOMEM; + + m->client = c; + m->idev = idev; + + idev->private = m; + idev->input->name = MMA8450_DRV_NAME; + idev->input->id.bustype = BUS_I2C; + idev->poll = mma8450_poll; + idev->poll_interval = POLL_INTERVAL; + idev->poll_interval_max = POLL_INTERVAL_MAX; + idev->open = mma8450_open; + idev->close = mma8450_close; + + __set_bit(EV_ABS, idev->input->evbit); + input_set_abs_params(idev->input, ABS_X, -2048, 2047, 32, 32); + input_set_abs_params(idev->input, ABS_Y, -2048, 2047, 32, 32); + input_set_abs_params(idev->input, ABS_Z, -2048, 2047, 32, 32); + + err = input_register_polled_device(idev); + if (err) { + dev_err(&c->dev, "failed to register polled 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"); |