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Subject[PATCH] input: add support for mma8450 accelerometer
Date
Signed-off-by: Sammy He <r62914@freescale.com>
Signed-off-by: Eric Miao <eric.miao@linaro.org>
---
drivers/input/misc/Kconfig | 10 ++
drivers/input/misc/Makefile | 1 +
drivers/input/misc/mma8450.c | 256 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 267 insertions(+), 0 deletions(-)
create mode 100644 drivers/input/misc/mma8450.c
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 45dc6aa..faf7e0c 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -478,4 +478,14 @@ config INPUT_XEN_KBDDEV_FRONTEND
To compile this driver as a module, choose M here: the
module will be called xen-kbdfront.

+config INPUT_MMA8450
+ tristate "MMA8450 - Freescale's 3-Axis, 8/12-bit Digital Accelerometer"
+ depends on I2C
+ help
+ Say Y here if you want to support Freescale's MMA8450 Accelerometer
+ through I2C interface.
+
+ To compile this driver as a module, choose M here: the
+ module will be called mma8450.
+
endif
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 38efb2c..5239e29 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -45,4 +45,5 @@ obj-$(CONFIG_INPUT_WISTRON_BTNS) += wistron_btns.o
obj-$(CONFIG_INPUT_WM831X_ON) += wm831x-on.o
obj-$(CONFIG_INPUT_XEN_KBDDEV_FRONTEND) += xen-kbdfront.o
obj-$(CONFIG_INPUT_YEALINK) += yealink.o
+obj-$(CONFIG_INPUT_MMA8450) += mma8450.o

diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c
new file mode 100644
index 0000000..11ba3af
--- /dev/null
+++ b/drivers/input/misc/mma8450.c
@@ -0,0 +1,256 @@
+/*
+ * mma8450.c - driver for Freescale's 3-Axis Accelerometer
+ *
+ * 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/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.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_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, uint8_t *v)
+{
+ 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\n", off);
+ return ret;
+ }
+
+ *v = (uint8_t)ret;
+ return 0;
+}
+
+static int mma8450_write(struct mma8450 *m, unsigned off, uint8_t v)
+{
+ struct i2c_client *c = m->client;
+ int ret;
+
+ ret = i2c_smbus_write_byte_data(c, off, v);
+ if (ret < 0) {
+ dev_err(&c->dev, "failed to write to register 0x%02x\n", off);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int mma8450_init_client(struct mma8450 *m)
+{
+ int err;
+
+ /* 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 err;
+
+ msleep(MODE_CHANGE_DELAY_MS);
+ return 0;
+}
+
+static int mma8450_read_xyz(struct mma8450 *m, int *x, int *y, int *z)
+{
+ struct i2c_client *c = m->client;
+ uint8_t buff[6];
+ int ret;
+
+ ret = i2c_smbus_read_i2c_block_data(c, MMA8450_OUT_X_LSB, 6, buff);
+ if (ret < 0) {
+ dev_err(&c->dev, "failed to read block data at 0x%02x\n",
+ MMA8450_OUT_X_LSB);
+ return ret;
+ }
+
+ *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 *pdev)
+{
+ struct input_dev *dev = pdev->input;
+ struct mma8450 *m = input_get_drvdata(dev);
+ uint8_t status;
+ int x, y, z, err;
+
+ err = mma8450_read(m, MMA8450_STATUS, &status);
+ if (err)
+ return;
+
+ /* check new data */
+ if ((status & MMA8450_STATUS_ZXYDR) == 0)
+ return;
+
+ err = mma8450_read_xyz(m, &x, &y, &z);
+ if (err)
+ return;
+
+ input_report_abs(dev, ABS_X, x);
+ input_report_abs(dev, ABS_Y, y);
+ input_report_abs(dev, ABS_Z, z);
+ input_sync(dev);
+}
+
+/*
+ * 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;
+
+ err = i2c_check_functionality(c->adapter, I2C_FUNC_SMBUS_BYTE |
+ I2C_FUNC_SMBUS_BYTE_DATA);
+ if (err)
+ return -ENODEV;
+
+ m = kzalloc(sizeof(struct mma8450), GFP_KERNEL);
+ if (m == NULL)
+ return -ENOMEM;
+
+ m->client = c;
+
+ /* Initialize the MMA8450 chip */
+ err = mma8450_init_client(m);
+ if (err)
+ goto exit_free;
+
+ /*input poll device register */
+ idev = input_allocate_polled_device();
+ if (idev == NULL) {
+ dev_err(&c->dev, "failed to allocate polled input device\n");
+ goto exit_free;
+ }
+
+ 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;
+ __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);
+
+ input_set_drvdata(idev->input, m);
+
+ err = input_register_polled_device(idev);
+ if (err) {
+ dev_err(&c->dev, "failed to register polled input device\n");
+ goto exit_free_input;
+ }
+
+ dev_info(&c->dev, "polled input device registered\n");
+ return 0;
+
+exit_free_input:
+ input_free_polled_device(idev);
+exit_free:
+ kfree(m);
+ return err;
+}
+
+static int __devexit mma8450_remove(struct i2c_client *c)
+{
+ struct mma8450 *m = i2c_get_clientdata(c);
+
+ mma8450_write(m, MMA8450_CTRL_REG1, 0x00);
+ mma8450_write(m, MMA8450_CTRL_REG2, 0x01);
+
+ 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");
--
1.7.4.1


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