Some of kernel driver uses the IIO framework to get the sensor
value via ADC or IIO HW driver. The client driver get iio channel
by iio_channel_get() and release it by calling iio_channel_release().
Add resource managed version (devm_*) of these APIs so that if client
calls the devm_iio_channel_get() then it need not to release it explicitly,
it can be done by managed device framework when driver get un-binded.
This reduces the code in error path and also need of .remove callback in
some cases.
Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
---
drivers/iio/inkern.c | 48 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/iio/consumer.h | 27 +++++++++++++++++++++++++
2 files changed, 75 insertions(+)
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 734a004..18e623f 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -356,6 +356,54 @@ void iio_channel_release(struct iio_channel *channel)
}
EXPORT_SYMBOL_GPL(iio_channel_release);
+static void devm_iio_channel_free(struct device *dev, void *res)
+{
+ struct iio_channel *channel = *(struct iio_channel **)res;
+
+ iio_channel_release(channel);
+}
+
+static int devm_iio_channel_match(struct device *dev, void *res, void *data)
+{
+ struct iio_channel **r = res;
+
+ if (!r || !*r) {
+ WARN_ON(!r || !*r);
+ return 0;
+ }
+
+ return *r == data;
+}
+
+struct iio_channel *devm_iio_channel_get(struct device *dev,
+ const char *channel_name)
+{
+ struct iio_channel **ptr, *channel;
+
+ ptr = devres_alloc(devm_iio_channel_free, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ channel = iio_channel_get(dev, channel_name);
+ if (IS_ERR(channel)) {
+ devres_free(ptr);
+ return channel;
+ }
+
+ *ptr = channel;
+ devres_add(dev, ptr);
+
+ return channel;
+}
+EXPORT_SYMBOL_GPL(devm_iio_channel_get);
+
+void devm_iio_channel_release(struct device *dev, struct iio_channel *channel)
+{
+ WARN_ON(devres_release(dev, devm_iio_channel_free,
+ devm_iio_channel_match, channel));
+}
+EXPORT_SYMBOL_GPL(devm_iio_channel_release);
+
struct iio_channel *iio_channel_get_all(struct device *dev)
{
const char *name;
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index fad5867..e1e033d 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -49,6 +49,33 @@ struct iio_channel *iio_channel_get(struct device *dev,
void iio_channel_release(struct iio_channel *chan);
/**
+ * devm_iio_channel_get() - Resource managed version of iio_channel_get().
+ * @dev: Pointer to consumer device. Device name must match
+ * the name of the device as provided in the iio_map
+ * with which the desired provider to consumer mapping
+ * was registered.
+ * @consumer_channel: Unique name to identify the channel on the consumer
+ * side. This typically describes the channels use within
+ * the consumer. E.g. 'battery_voltage'
+ *
+ * Returns a pointer to negative errno if it is not able to get the iio channel
+ * otherwise returns valid pointer for iio channel.
+ *
+ * The allocated iio channel is automatically released when the device is
+ * unbound.
+ */
+struct iio_channel *devm_iio_channel_get(struct device *dev,
+ const char *consumer_channel);
+/**
+ * devm_iio_channel_release() - Resource managed version of
+ * iio_channel_release().
+ * @dev: Pointer to consumer device for which resource
+ * is allocared.
+ * @chan: The channel to be released.
+ */
+void devm_iio_channel_release(struct device *dev, struct iio_channel *chan);
+
+/**
* iio_channel_get_all() - get all channels associated with a client
* @dev: Pointer to consumer device.
*
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
