--- /dev/null
+/*
+ * 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>
+
+#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_xyz(struct mma8450 *m, int *x, int *y, int *z)
+{
+ struct i2c_client *c = m->client;
+ u8 buff[6];
+ int err;
+
+ err = i2c_smbus_read_i2c_block_data(c, MMA8450_OUT_X_LSB, 6, buff);
+ 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;
+ }
+
+ *x = ((buff[1] << 4) & 0xff0) | (buff[0] & 0xf);
+ *y = ((buff[3] << 4) & 0xff0) | (buff[2] & 0xf);
+ *z = ((buff[5] << 4) & 0xff0) | (buff[4] & 0xf);
+
+ return 0;
+}
+
+static void mma8450_poll(struct input_polled_dev *dev)
+{
+ struct mma8450 *m = dev->private;
+ int x, y, z;
+ int ret;
+ int err;
+
+ ret = mma8450_read(m, MMA8450_STATUS);
+ if (ret < 0)
+ return;
+
+ if (!(ret & MMA8450_STATUS_ZXYDR))
+ return;
+
+ err = mma8450_read_xyz(m, &x, &y, &z);
+ if (err)
+ return;
+
+ 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 struct i2c_driver mma8450_driver = {
+ .driver = {
+ .name = MMA8450_DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .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");
projects / openwrt / staging / blogic.git / commitdiff