iio:imu:mpu6050 add explicit mpu9250 support

The mpu9250 is a SIP containing an mpu6500 and an ak8975.  If this was all
there was too it there would be no need for explicit handling in the driver.
Arguably the bindings would also only reflect the presence of an mpu6500 with
the ak8975 hanging off it, as the kernel doesn't care that they are in one
package.

However, the WHOAMI value changes as well so best to add explicit support.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt

@@ -7,6 +7,7 @@ Required properties:
 		"invensense,mpu6050"
  		"invensense,mpu6500"
 		"invensense,mpu9150"
+		"invensense,mpu9250"
 		"invensense,icm20608"
  - reg : the I2C address of the sensor
  - interrupt-parent : should be the phandle for the interrupt controller

drivers/iio/imu/inv_mpu6050/inv_mpu_core.c

@@ -113,6 +113,12 @@ static const struct inv_mpu6050_hw hw_info[] = {
 		.reg = &reg_set_6050,
 		.config = &chip_config_6050,
 	},
+	{
+		.whoami = INV_MPU9250_WHOAMI_VALUE,
+		.name = "MPU9250",
+		.reg = &reg_set_6500,
+		.config = &chip_config_6050,
+	},
 	{
 		.whoami = INV_ICM20608_WHOAMI_VALUE,
 		.name = "ICM20608",

drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c

@@ -178,6 +178,7 @@ static const struct i2c_device_id inv_mpu_id[] = {
 	{"mpu6050", INV_MPU6050},
 	{"mpu6500", INV_MPU6500},
 	{"mpu9150", INV_MPU9150},
+	{"mpu9250", INV_MPU9250},
 	{"icm20608", INV_ICM20608},
 	{}
 };
@@ -197,6 +198,10 @@ static const struct of_device_id inv_of_match[] = {
 		.compatible = "invensense,mpu9150",
 		.data = (void *)INV_MPU9150
 	},
+	{
+		.compatible = "invensense,mpu9250",
+		.data = (void *)INV_MPU9250
+	},
 	{
 		.compatible = "invensense,icm20608",
 		.data = (void *)INV_ICM20608

drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h

@@ -70,6 +70,7 @@ enum inv_devices {
 	INV_MPU6500,
 	INV_MPU6000,
 	INV_MPU9150,
+	INV_MPU9250,
 	INV_ICM20608,
 	INV_NUM_PARTS
 };
@@ -226,6 +227,7 @@ struct inv_mpu6050_state {
 #define INV_MPU6050_WHOAMI_VALUE		0x68
 #define INV_MPU6500_WHOAMI_VALUE		0x70
 #define INV_MPU9150_WHOAMI_VALUE		0x68
+#define INV_MPU9250_WHOAMI_VALUE		0x71
 #define INV_ICM20608_WHOAMI_VALUE		0xAF
 
 /* scan element definition */

drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c

@@ -82,6 +82,7 @@ static const struct spi_device_id inv_mpu_id[] = {
 	{"mpu6000", INV_MPU6000},
 	{"mpu6500", INV_MPU6500},
 	{"mpu9150", INV_MPU9150},
+	{"mpu9250", INV_MPU9250},
 	{"icm20608", INV_ICM20608},
 	{}
 };