iio: magn: Split bmc150 driver in common/i2c parts

This is useful for easily adding SPI support in later patches.

Now bmc150_magn exports core functions to be used by I2C/SPI drivers
instances. For the moment only I2C driver is supported.
Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Acked-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/magnetometer/Kconfig

@@ -27,22 +27,25 @@ config AK09911
 	  Deprecated: AK09911 is now supported by AK8975 driver.
 
 config BMC150_MAGN
-	tristate "Bosch BMC150 Magnetometer Driver"
-	depends on I2C
-	select REGMAP_I2C
+	tristate
 	select IIO_BUFFER
 	select IIO_TRIGGERED_BUFFER
-	help
-	  Say yes here to build support for the BMC150 magnetometer.
 
-	  Currently this only supports the device via an i2c interface.
+config BMC150_MAGN_I2C
+	tristate "Bosch BMC150 I2C Magnetometer Driver"
+	depends on I2C
+	select BMC150_MAGN
+	select REGMAP_I2C
+	help
+	  Say yes here to build support for the BMC150 magnetometer with
+	  I2C interface.
 
 	  This is a combo module with both accelerometer and magnetometer.
 	  This driver is only implementing magnetometer part, which has
 	  its own address and register map.
 
 	  To compile this driver as a module, choose M here: the module will be
-	  called bmc150_magn.
+	  called bmc150_magn_i2c.
 
 config MAG3110
 	tristate "Freescale MAG3110 3-Axis Magnetometer"

drivers/iio/magnetometer/Makefile

@@ -5,6 +5,8 @@
 # When adding new entries keep the list in alphabetical order
 obj-$(CONFIG_AK8975)	+= ak8975.o
 obj-$(CONFIG_BMC150_MAGN) += bmc150_magn.o
+obj-$(CONFIG_BMC150_MAGN_I2C) += bmc150_magn_i2c.o
+
 obj-$(CONFIG_MAG3110)	+= mag3110.o
 obj-$(CONFIG_HID_SENSOR_MAGNETOMETER_3D) += hid-sensor-magn-3d.o
 obj-$(CONFIG_MMC35240)	+= mmc35240.o

drivers/iio/magnetometer/bmc150_magn.h

+#ifndef _BMC150_MAGN_H_
+#define _BMC150_MAGN_H_
+
+extern const struct regmap_config bmc150_magn_regmap_config;
+extern const struct dev_pm_ops bmc150_magn_pm_ops;
+
+int bmc150_magn_probe(struct device *dev, struct regmap *regmap, int irq,
+		      const char *name);
+int bmc150_magn_remove(struct device *dev);
+
+#endif /* _BMC150_MAGN_H_ */

drivers/iio/magnetometer/bmc150_magn_i2c.c

+/*
+ * 3-axis magnetometer driver supporting following I2C Bosch-Sensortec chips:
+ *  - BMC150
+ *  - BMC156
+ *
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ */
+#include <linux/device.h>
+#include <linux/mod_devicetable.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/regmap.h>
+
+#include "bmc150_magn.h"
+
+static int bmc150_magn_i2c_probe(struct i2c_client *client,
+				 const struct i2c_device_id *id)
+{
+	struct regmap *regmap;
+	const char *name = NULL;
+
+	regmap = devm_regmap_init_i2c(client, &bmc150_magn_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "Failed to initialize i2c regmap\n");
+		return PTR_ERR(regmap);
+	}
+
+	if (id)
+		name = id->name;
+
+	return bmc150_magn_probe(&client->dev, regmap, client->irq, name);
+}
+
+static int bmc150_magn_i2c_remove(struct i2c_client *client)
+{
+	return bmc150_magn_remove(&client->dev);
+}
+
+static const struct acpi_device_id bmc150_magn_acpi_match[] = {
+	{"BMC150B", 0},
+	{"BMC156B", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, bmc150_magn_acpi_match);
+
+static const struct i2c_device_id bmc150_magn_i2c_id[] = {
+	{"bmc150_magn",	0},
+	{"bmc156_magn", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, bmc150_magn_i2c_id);
+
+static struct i2c_driver bmc150_magn_driver = {
+	.driver = {
+		.name	= "bmc150_magn_i2c",
+		.acpi_match_table = ACPI_PTR(bmc150_magn_acpi_match),
+		.pm	= &bmc150_magn_pm_ops,
+	},
+	.probe		= bmc150_magn_i2c_probe,
+	.remove		= bmc150_magn_i2c_remove,
+	.id_table	= bmc150_magn_i2c_id,
+};
+module_i2c_driver(bmc150_magn_driver);
+
+MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("BMC150 I2C magnetometer driver");