Staging/IIO driver fixes for 4.6-rc7

Well, it's really just IIO drivers here, some small fixes that resolve
 some "crash on boot" errors that have shown up in the -rc series, and
 other bugfixes that are required.
 
 All have been in linux-next with no reported problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iEYEABECAAYFAlcuKBgACgkQMUfUDdst+ynALgCgh4QWOZ/vnLQvx/r1ZOIW1xqm
 QdAAn1eJ1/KzwbM+WmmfXu1dKykfs7YS
 =tGM3
 -----END PGP SIGNATURE-----

Merge tag 'staging-4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull IIO driver fixes from Grek KH:
 "It's really just IIO drivers here, some small fixes that resolve some
  'crash on boot' errors that have shown up in the -rc series, and other
  bugfixes that are required.

  All have been in linux-next with no reported problems"

* tag 'staging-4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: imu: mpu6050: Fix name/chip_id when using ACPI
  iio: imu: mpu6050: fix possible NULL dereferences
  iio:adc:at91-sama5d2: Repair crash on module removal
  iio: ak8975: fix maybe-uninitialized warning
  iio: ak8975: Fix NULL pointer exception on early interrupt

drivers/iio/adc/at91-sama5d2_adc.c

@@ -451,6 +451,8 @@ static int at91_adc_probe(struct platform_device *pdev)
 	if (ret)
 		goto vref_disable;
 
+	platform_set_drvdata(pdev, indio_dev);
+
 	ret = iio_device_register(indio_dev);
 	if (ret < 0)
 		goto per_clk_disable_unprepare;

drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c

@@ -104,6 +104,19 @@ static int inv_mpu6050_deselect_bypass(struct i2c_adapter *adap,
 	return 0;
 }
 
+static const char *inv_mpu_match_acpi_device(struct device *dev, int *chip_id)
+{
+	const struct acpi_device_id *id;
+
+	id = acpi_match_device(dev->driver->acpi_match_table, dev);
+	if (!id)
+		return NULL;
+
+	*chip_id = (int)id->driver_data;
+
+	return dev_name(dev);
+}
+
 /**
  *  inv_mpu_probe() - probe function.
  *  @client:          i2c client.
@@ -115,14 +128,25 @@ static int inv_mpu_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct inv_mpu6050_state *st;
-	int result;
-	const char *name = id ? id->name : NULL;
+	int result, chip_type;
 	struct regmap *regmap;
+	const char *name;
 
 	if (!i2c_check_functionality(client->adapter,
 				     I2C_FUNC_SMBUS_I2C_BLOCK))
 		return -EOPNOTSUPP;
 
+	if (id) {
+		chip_type = (int)id->driver_data;
+		name = id->name;
+	} else if (ACPI_HANDLE(&client->dev)) {
+		name = inv_mpu_match_acpi_device(&client->dev, &chip_type);
+		if (!name)
+			return -ENODEV;
+	} else {
+		return -ENOSYS;
+	}
+
 	regmap = devm_regmap_init_i2c(client, &inv_mpu_regmap_config);
 	if (IS_ERR(regmap)) {
 		dev_err(&client->dev, "Failed to register i2c regmap %d\n",
@@ -131,7 +155,7 @@ static int inv_mpu_probe(struct i2c_client *client,
 	}
 
 	result = inv_mpu_core_probe(regmap, client->irq, name,
-				    NULL, id->driver_data);
+				    NULL, chip_type);
 	if (result < 0)
 		return result;
 

drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c

@@ -46,6 +46,7 @@ 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;
+	const int chip_type = id ? id->driver_data : 0;
 
 	regmap = devm_regmap_init_spi(spi, &inv_mpu_regmap_config);
 	if (IS_ERR(regmap)) {
@@ -55,7 +56,7 @@ static int inv_mpu_probe(struct spi_device *spi)
 	}
 
 	return inv_mpu_core_probe(regmap, spi->irq, name,
-				  inv_mpu_i2c_disable, id->driver_data);
+				  inv_mpu_i2c_disable, chip_type);
 }
 
 static int inv_mpu_remove(struct spi_device *spi)

drivers/iio/magnetometer/ak8975.c

@@ -462,6 +462,8 @@ static int ak8975_setup_irq(struct ak8975_data *data)
 	int rc;
 	int irq;
 
+	init_waitqueue_head(&data->data_ready_queue);
+	clear_bit(0, &data->flags);
 	if (client->irq)
 		irq = client->irq;
 	else
@@ -477,8 +479,6 @@ static int ak8975_setup_irq(struct ak8975_data *data)
 		return rc;
 	}
 
-	init_waitqueue_head(&data->data_ready_queue);
-	clear_bit(0, &data->flags);
 	data->eoc_irq = irq;
 
 	return rc;
@@ -732,7 +732,7 @@ static int ak8975_probe(struct i2c_client *client,
 	int eoc_gpio;
 	int err;
 	const char *name = NULL;
-	enum asahi_compass_chipset chipset;
+	enum asahi_compass_chipset chipset = AK_MAX_TYPE;
 
 	/* Grab and set up the supplied GPIO. */
 	if (client->dev.platform_data)