Staging/IIO fixes for 4.7-rc6

Here are a few small staging and iio driver fixes for 4.7-rc6.
 
 Nothing major here, just a number of small fixes, all have been in
 linux-next for a while, and the full details are in the shortlog.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-4.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging and IIO fixes from Greg KH:
 "Here are a few small staging and iio driver fixes for 4.7-rc6.

  Nothing major here, just a number of small fixes, all have been in
  linux-next for a while, and the full details are in the shortlog"

* tag 'staging-4.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio:ad7266: Fix probe deferral for vref
  iio:ad7266: Fix support for optional regulators
  iio:ad7266: Fix broken regulator error handling
  iio: accel: kxsd9: fix the usage of spi_w8r8()
  staging: iio: accel: fix error check
  staging: iio: ad5933: fix order of cycle conditions
  staging: iio: fix ad7606_spi regression
  iio: inv_mpu6050: Fix use-after-free in ACPI code

drivers/iio/accel/kxsd9.c

@@ -81,7 +81,7 @@ static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
 
 	mutex_lock(&st->buf_lock);
 	ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
-	if (ret)
+	if (ret < 0)
 		goto error_ret;
 	st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);
 	st->tx[1] = (ret & ~KXSD9_FS_MASK) | i;
@@ -163,7 +163,7 @@ static int kxsd9_read_raw(struct iio_dev *indio_dev,
 		break;
 	case IIO_CHAN_INFO_SCALE:
 		ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
-		if (ret)
+		if (ret < 0)
 			goto error_ret;
 		*val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
 		ret = IIO_VAL_INT_PLUS_MICRO;

drivers/iio/adc/ad7266.c

@@ -396,8 +396,8 @@ static int ad7266_probe(struct spi_device *spi)
 
 	st = iio_priv(indio_dev);
 
-	st->reg = devm_regulator_get(&spi->dev, "vref");
-	if (!IS_ERR_OR_NULL(st->reg)) {
+	st->reg = devm_regulator_get_optional(&spi->dev, "vref");
+	if (!IS_ERR(st->reg)) {
 		ret = regulator_enable(st->reg);
 		if (ret)
 			return ret;
@@ -408,6 +408,9 @@ static int ad7266_probe(struct spi_device *spi)
 
 		st->vref_mv = ret / 1000;
 	} else {
+		/* Any other error indicates that the regulator does exist */
+		if (PTR_ERR(st->reg) != -ENODEV)
+			return PTR_ERR(st->reg);
 		/* Use internal reference */
 		st->vref_mv = 2500;
 	}

drivers/iio/imu/inv_mpu6050/inv_mpu_acpi.c

@@ -56,6 +56,7 @@ static int asus_acpi_get_sensor_info(struct acpi_device *adev,
 	int i;
 	acpi_status status;
 	union acpi_object *cpm;
+	int ret;
 
 	status = acpi_evaluate_object(adev->handle, "CNF0", NULL, &buffer);
 	if (ACPI_FAILURE(status))
@@ -82,10 +83,10 @@ static int asus_acpi_get_sensor_info(struct acpi_device *adev,
 			}
 		}
 	}
-
+	ret = cpm->package.count;
 	kfree(buffer.pointer);
 
-	return cpm->package.count;
+	return ret;
 }
 
 static int acpi_i2c_check_resource(struct acpi_resource *ares, void *data)

drivers/staging/iio/accel/sca3000_core.c

@@ -594,7 +594,7 @@ static ssize_t sca3000_read_frequency(struct device *dev,
 		goto error_ret_mut;
 	ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);
 	mutex_unlock(&st->lock);
-	if (ret)
+	if (ret < 0)
 		goto error_ret;
 	val = ret;
 	if (base_freq > 0)

drivers/staging/iio/adc/ad7606_spi.c

@@ -21,7 +21,7 @@ static int ad7606_spi_read_block(struct device *dev,
 {
 	struct spi_device *spi = to_spi_device(dev);
 	int i, ret;
-	unsigned short *data;
+	unsigned short *data = buf;
 	__be16 *bdata = buf;
 
 	ret = spi_read(spi, buf, count * 2);

drivers/staging/iio/impedance-analyzer/ad5933.c

@@ -444,10 +444,10 @@ static ssize_t ad5933_store(struct device *dev,
 		st->settling_cycles = val;
 
 		/* 2x, 4x handling, see datasheet */
-		if (val > 511)
-			val = (val >> 1) | (1 << 9);
-		else if (val > 1022)
+		if (val > 1022)
 			val = (val >> 2) | (3 << 9);
+		else if (val > 511)
+			val = (val >> 1) | (1 << 9);
 
 		dat = cpu_to_be16(val);
 		ret = ad5933_i2c_write(st->client,