Commit c464cc61 authored by Olivier Moysan's avatar Olivier Moysan Committed by Jonathan Cameron
Browse files

iio: add child nodes support in iio backend framework 

Add an API to support IIO generic channels binding:
http://devicetree.org/schemas/iio/adc/adc.yaml#


This new API is needed, as generic channel DT node isn't populated as a
device.
Add devm_iio_backend_fwnode_get() to allow an IIO device backend
consumer to reference backend phandles in its child nodes.

Signed-off-by: default avatarOlivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: default avatarNuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20240730084640.1307938-4-olivier.moysan@foss.st.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 2530d7d4

drivers/iio/industrialio-backend.c

+41 −16
Original line number Diff line number Diff line
@@ -718,19 +718,10 @@ static int __devm_iio_backend_get(struct device *dev, struct iio_backend *back) 
	return 0;

}



/**

 * devm_iio_backend_get - Device managed backend device get

 * @dev: Consumer device for the backend

 * @name: Backend name

 *

 * Get's the backend associated with @dev.

 *

 * RETURNS:

 * A backend pointer, negative error pointer otherwise.

 */

struct iio_backend *devm_iio_backend_get(struct device *dev, const char *name)

static struct iio_backend *__devm_iio_backend_fwnode_get(struct device *dev, const char *name,

							 struct fwnode_handle *fwnode)

{

	struct fwnode_handle *fwnode;

	struct fwnode_handle *fwnode_back;

	struct iio_backend *back;

	unsigned int index;

	int ret;
@@ -745,17 +736,17 @@ struct iio_backend *devm_iio_backend_get(struct device *dev, const char *name) 
		index = 0;

	}



	fwnode = fwnode_find_reference(dev_fwnode(dev), "io-backends", index);

	fwnode_back = fwnode_find_reference(fwnode, "io-backends", index);

	if (IS_ERR(fwnode))

		return dev_err_cast_probe(dev, fwnode,

					  "Cannot get Firmware reference\n");



	guard(mutex)(&iio_back_lock);

	list_for_each_entry(back, &iio_back_list, entry) {

		if (!device_match_fwnode(back->dev, fwnode))

		if (!device_match_fwnode(back->dev, fwnode_back))

			continue;



		fwnode_handle_put(fwnode);

		fwnode_handle_put(fwnode_back);

		ret = __devm_iio_backend_get(dev, back);

		if (ret)

			return ERR_PTR(ret);
@@ -766,11 +757,45 @@ struct iio_backend *devm_iio_backend_get(struct device *dev, const char *name) 
		return back;

	}



	fwnode_handle_put(fwnode);

	fwnode_handle_put(fwnode_back);

	return ERR_PTR(-EPROBE_DEFER);

}



/**

 * devm_iio_backend_get - Device managed backend device get

 * @dev: Consumer device for the backend

 * @name: Backend name

 *

 * Get's the backend associated with @dev.

 *

 * RETURNS:

 * A backend pointer, negative error pointer otherwise.

 */

struct iio_backend *devm_iio_backend_get(struct device *dev, const char *name)

{

	return __devm_iio_backend_fwnode_get(dev, name, dev_fwnode(dev));

}

EXPORT_SYMBOL_NS_GPL(devm_iio_backend_get, IIO_BACKEND);



/**

 * devm_iio_backend_fwnode_get - Device managed backend firmware node get

 * @dev: Consumer device for the backend

 * @name: Backend name

 * @fwnode: Firmware node of the backend consumer

 *

 * Get's the backend associated with a firmware node.

 *

 * RETURNS:

 * A backend pointer, negative error pointer otherwise.

 */

struct iio_backend *devm_iio_backend_fwnode_get(struct device *dev,

						const char *name,

						struct fwnode_handle *fwnode)

{

	return __devm_iio_backend_fwnode_get(dev, name, fwnode);

}

EXPORT_SYMBOL_NS_GPL(devm_iio_backend_fwnode_get, IIO_BACKEND);



/**

 * __devm_iio_backend_get_from_fwnode_lookup - Device managed fwnode backend device get

 * @dev: Consumer device for the backend

include/linux/iio/backend.h

+3 −0
Original line number Diff line number Diff line
@@ -176,6 +176,9 @@ int iio_backend_extend_chan_spec(struct iio_backend *back, 
				 struct iio_chan_spec *chan);

void *iio_backend_get_priv(const struct iio_backend *conv);

struct iio_backend *devm_iio_backend_get(struct device *dev, const char *name);

struct iio_backend *devm_iio_backend_fwnode_get(struct device *dev,

						const char *name,

						struct fwnode_handle *fwnode);

struct iio_backend *

__devm_iio_backend_get_from_fwnode_lookup(struct device *dev,

					  struct fwnode_handle *fwnode);