iio: imu: inv_mpu6050: Add SPI support for MPU6000

The only difference between the MPU6000 and the
MPU6050 is that the first also supports SPI.
Add SPI driver for this chip.

Signed-off-by: Adriana Reus <adriana.reus@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/imu/inv_mpu6050/Kconfig

@@ -20,3 +20,14 @@ config INV_MPU6050_I2C
 	  It is a gyroscope/accelerometer combo device.
 	  This driver can be built as a module. The module will be called
 	  inv-mpu6050-i2c.
+
+config INV_MPU6050_SPI
+	tristate "Invensense MPU6050 devices (SPI)"
+	depends on SPI_MASTER
+	select INV_MPU6050_IIO
+	select REGMAP_SPI
+	help
+	  This driver supports the Invensense MPU6050 devices.
+	  It is a gyroscope/accelerometer combo device.
+	  This driver can be built as a module. The module will be called
+	  inv-mpu6050-spi.

drivers/iio/imu/inv_mpu6050/Makefile

@@ -7,3 +7,6 @@ inv-mpu6050-objs := inv_mpu_core.o inv_mpu_ring.o inv_mpu_trigger.o
 
 obj-$(CONFIG_INV_MPU6050_I2C) += inv-mpu6050-i2c.o
 inv-mpu6050-i2c-objs := inv_mpu_i2c.o inv_mpu_acpi.o
+
+obj-$(CONFIG_INV_MPU6050_SPI) += inv-mpu6050-spi.o
+inv-mpu6050-spi-objs := inv_mpu_spi.o

drivers/iio/imu/inv_mpu6050/inv_mpu_core.c

@@ -152,6 +152,7 @@ int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st, bool power_on)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(inv_mpu6050_set_power_itg);
 
 /**
  *  inv_mpu6050_init_config() - Initialize hardware, disable FIFO.
@@ -676,7 +677,8 @@ static int inv_check_and_setup_chip(struct inv_mpu6050_state *st)
 	return 0;
 }
 
-int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name)
+int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
+		       int (*inv_mpu_bus_setup)(struct iio_dev *))
 {
 	struct inv_mpu6050_state *st;
 	struct iio_dev *indio_dev;
@@ -700,6 +702,9 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name)
 	if (result)
 		return result;
 
+	if (inv_mpu_bus_setup)
+		inv_mpu_bus_setup(indio_dev);
+
 	result = inv_mpu6050_init_config(indio_dev);
 	if (result) {
 		dev_err(dev, "Could not initialize device.\n");

drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c

@@ -129,7 +129,7 @@ static int inv_mpu_probe(struct i2c_client *client,
 		return PTR_ERR(regmap);
 	}
 
-	result = inv_mpu_core_probe(regmap, client->irq, name);
+	result = inv_mpu_core_probe(regmap, client->irq, name, NULL);
 	if (result < 0)
 		return result;
 

drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h

@@ -62,6 +62,7 @@ struct inv_mpu6050_reg_map {
 enum inv_devices {
 	INV_MPU6050,
 	INV_MPU6500,
+	INV_MPU6000,
 	INV_NUM_PARTS
 };
 
@@ -154,6 +155,7 @@ struct inv_mpu6050_state {
 #define INV_MPU6050_BIT_I2C_MST_EN          0x20
 #define INV_MPU6050_BIT_FIFO_EN             0x40
 #define INV_MPU6050_BIT_DMP_EN              0x80
+#define INV_MPU6050_BIT_I2C_IF_DIS          0x10
 
 #define INV_MPU6050_REG_PWR_MGMT_1          0x6B
 #define INV_MPU6050_BIT_H_RESET             0x80
@@ -258,6 +260,8 @@ int inv_mpu6050_write_reg(struct inv_mpu6050_state *st, int reg, u8 val);
 int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st, bool power_on);
 int inv_mpu_acpi_create_mux_client(struct i2c_client *client);
 void inv_mpu_acpi_delete_mux_client(struct i2c_client *client);
-int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name);
+int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
+		      int (*inv_mpu_bus_setup)(struct iio_dev *));
 int inv_mpu_core_remove(struct device *dev);
+int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st, bool power_on);
 extern const struct dev_pm_ops inv_mpu_pmops;

drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c

@@ -0,0 +1,97 @@
+/*
+* Copyright (C) 2015 Intel Corporation Inc.
+*
+* This software is licensed under the terms of the GNU General Public
+* License version 2, as published by the Free Software Foundation, and
+* may be copied, distributed, and modified under those terms.
+*
+* 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.
+*/
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/spi/spi.h>
+#include <linux/regmap.h>
+#include <linux/iio/iio.h>
+#include "inv_mpu_iio.h"
+
+static const struct regmap_config inv_mpu_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int inv_mpu_i2c_disable(struct iio_dev *indio_dev)
+{
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+	int ret = 0;
+
+	ret = inv_mpu6050_set_power_itg(st, true);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(st->map, INV_MPU6050_REG_USER_CTRL,
+			   INV_MPU6050_BIT_I2C_IF_DIS);
+	if (ret) {
+		inv_mpu6050_set_power_itg(st, false);
+		return ret;
+	}
+
+	return inv_mpu6050_set_power_itg(st, false);
+}
+
+static int inv_mpu_probe(struct spi_device *spi)
+{
+	struct regmap *regmap;
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	const char *name = id ? id->name : NULL;
+
+	regmap = devm_regmap_init_spi(spi, &inv_mpu_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&spi->dev, "Failed to register spi regmap %d\n",
+			(int)PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return inv_mpu_core_probe(regmap, spi->irq, name, inv_mpu_i2c_disable);
+}
+
+static int inv_mpu_remove(struct spi_device *spi)
+{
+	return inv_mpu_core_remove(&spi->dev);
+}
+
+/*
+ * device id table is used to identify what device can be
+ * supported by this driver
+ */
+static const struct spi_device_id inv_mpu_id[] = {
+	{"mpu6000", INV_MPU6000},
+	{}
+};
+
+MODULE_DEVICE_TABLE(spi, inv_mpu_id);
+
+static const struct acpi_device_id inv_acpi_match[] = {
+	{"INVN6000", 0},
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, inv_acpi_match);
+
+static struct spi_driver inv_mpu_driver = {
+	.probe		=	inv_mpu_probe,
+	.remove		=	inv_mpu_remove,
+	.id_table	=	inv_mpu_id,
+	.driver = {
+		.acpi_match_table = ACPI_PTR(inv_acpi_match),
+		.name	=	"inv-mpu6000-spi",
+		.pm     =       &inv_mpu_pmops,
+	},
+};
+
+module_spi_driver(inv_mpu_driver);
+
+MODULE_AUTHOR("Adriana Reus <adriana.reus@intel.com>");
+MODULE_DESCRIPTION("Invensense device MPU6000 driver");
+MODULE_LICENSE("GPL");