iio: inkern: Add of_xlate function to struct iio_info
When #iio-cells is greater than '0', the driver could provide
a custom of_xlate function that reads the *args* and returns
the appropriate index in registered IIO channels array.
Add simple translation function, suitable for the most 1:1
mapped channels in IIO chips, and use it when driver did not
provide custom implementation.
Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index c749700..0cc505d 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -100,6 +100,28 @@
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 @@
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)