/* * 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 #include #include #include #include #include #include #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 = ((buf[1] << 4) & 0xff0) | (buf[0] & 0xf); y = ((buf[3] << 4) & 0xff0) | (buf[2] & 0xf); z = ((buf[5] << 4) & 0xff0) | (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 __devinit mma8450_probe(struct i2c_client *c, const struct i2c_device_id *id) { struct input_polled_dev *idev; struct mma8450 *m; int err; m = kzalloc(sizeof(struct mma8450), GFP_KERNEL); idev = input_allocate_polled_device(); if (!m || !idev) { err = -ENOMEM; goto err_free_mem; } 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"); goto err_free_mem; } return 0; err_free_mem: input_free_polled_device(idev); kfree(m); return err; } static int __devexit mma8450_remove(struct i2c_client *c) { struct mma8450 *m = i2c_get_clientdata(c); struct input_polled_dev *idev = m->idev; input_unregister_polled_device(idev); input_free_polled_device(idev); kfree(m); 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, .owner = THIS_MODULE, .of_match_table = mma8450_dt_ids, }, .probe = mma8450_probe, .remove = __devexit_p(mma8450_remove), .id_table = mma8450_id, }; static int __init mma8450_init(void) { return i2c_add_driver(&mma8450_driver); } module_init(mma8450_init); static void __exit mma8450_exit(void) { i2c_del_driver(&mma8450_driver); } module_exit(mma8450_exit); MODULE_AUTHOR("Freescale Semiconductor, Inc."); MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver"); MODULE_LICENSE("GPL");