iio: accel: add Freescale MMA7455L/MMA7456L 3-axis accelerometer driver

Add support for Freescale MMA7455L/MMA7456L 3-axis in 10-bit mode for
I2C and SPI bus. This rather simple driver that currently doesn't
support all the hardware features of MMA7455L/MMA7456L.

Tested on Embedded Artist's LPC4357 Dev Kit with MMA7455L on I2C bus.

Data sheets for the two devices can be found here:
http://cache.freescale.com/files/sensors/doc/data_sheet/MMA7455L.pdf
http://cache.freescale.com/files/sensors/doc/data_sheet/MMA7456L.pdf

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/accel/mma7455_i2c.c

@@ -0,0 +1,56 @@
+/*
+ * IIO accel I2C driver for Freescale MMA7455L 3-axis 10-bit accelerometer
+ * Copyright 2015 Joachim Eastwood <manabian@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "mma7455.h"
+
+static int mma7455_i2c_probe(struct i2c_client *i2c,
+			     const struct i2c_device_id *id)
+{
+	struct regmap *regmap;
+	const char *name = NULL;
+
+	regmap = devm_regmap_init_i2c(i2c, &mma7455_core_regmap);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	if (id)
+		name = id->name;
+
+	return mma7455_core_probe(&i2c->dev, regmap, name);
+}
+
+static int mma7455_i2c_remove(struct i2c_client *i2c)
+{
+	return mma7455_core_remove(&i2c->dev);
+}
+
+static const struct i2c_device_id mma7455_i2c_ids[] = {
+	{ "mma7455", 0 },
+	{ "mma7456", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mma7455_i2c_ids);
+
+static struct i2c_driver mma7455_i2c_driver = {
+	.probe = mma7455_i2c_probe,
+	.remove = mma7455_i2c_remove,
+	.id_table = mma7455_i2c_ids,
+	.driver = {
+		.name	= "mma7455-i2c",
+	},
+};
+module_i2c_driver(mma7455_i2c_driver);
+
+MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
+MODULE_DESCRIPTION("Freescale MMA7455L I2C accelerometer driver");
+MODULE_LICENSE("GPL v2");