Merge tag 'iio-for-3.19a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

First round of new drivers, features and cleanups for IIO in the 3.19 cycle.

New drivers / supported parts
* rockchip - rk3066-tsadc variant
* si7020 humidity and temperature sensor
* mcp320x - add mcp3001, mcp3002, mcp3004, mcp3008, mcp3201, mcp3202
* bmp280 pressure and temperature sensor
* Qualcomm SPMI PMIC current ADC driver
* Exynos_adc - support exynos7

New features
* vf610-adc - add temperature sensor support
* Documentation of current attributes, scaled pressure, offset and
  scaled humidity, RGBC intensity gain factor and scale applied to
  differential voltage channels.
* Bring iio_event_monitor up to date with newer modifiers.
* Add of_xlate function to allow for complex channel mappings from the
  device tree.
* Add -g parameter to generic_buffer example to allow for devices with
  directly fed (no trigger) buffers.
* Move exynos driver over to syscon for PMU register access.

Cleanups, fixes for new drivers
* lis3l02dq drop an unneeded else.
* st sensors - renam st_sensors to st_sensor_settings (for clarity)
* st sensors - drop an unused parameter from all the probe utility
  functions.
* vf610 better error handling and tidy up.
* si7020 - cleanups following merge
* as3935 - drop some unnecessary semicolons.
* bmp280 - fix the pressure calculation.

drivers/iio/inkern.c

@@ -100,6 +100,28 @@ static int iio_dev_node_match(struct device *dev, void *data)
 	return dev->of_node == data && dev->type == &iio_device_type;
 }
 
+/**
+ * __of_iio_simple_xlate - translate iiospec to the IIO channel index
+ * @indio_dev:	pointer to the iio_dev structure
+ * @iiospec:	IIO specifier as found in the device tree
+ *
+ * This is simple translation function, suitable for the most 1:1 mapped
+ * channels in IIO chips. This function performs only one sanity check:
+ * whether IIO index is less than num_channels (that is specified in the
+ * iio_dev).
+ */
+static int __of_iio_simple_xlate(struct iio_dev *indio_dev,
+				const struct of_phandle_args *iiospec)
+{
+	if (!iiospec->args_count)
+		return 0;
+
+	if (iiospec->args[0] >= indio_dev->num_channels)
+		return -EINVAL;
+
+	return iiospec->args[0];
+}
+
 static int __of_iio_channel_get(struct iio_channel *channel,
 				struct device_node *np, int index)
 {
@@ -122,18 +144,19 @@ static int __of_iio_channel_get(struct iio_channel *channel,
 
 	indio_dev = dev_to_iio_dev(idev);
 	channel->indio_dev = indio_dev;
-	index = iiospec.args_count ? iiospec.args[0] : 0;
-	if (index >= indio_dev->num_channels) {
-		err = -EINVAL;
+	if (indio_dev->info->of_xlate)
+		index = indio_dev->info->of_xlate(indio_dev, &iiospec);
+	else
+		index = __of_iio_simple_xlate(indio_dev, &iiospec);
+	if (index < 0)
 		goto err_put;
-	}
 	channel->channel = &indio_dev->channels[index];
 
 	return 0;
 
 err_put:
 	iio_device_put(indio_dev);
-	return err;
+	return index;
 }
 
 static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)