1 // SPDX-License-Identifier: GPL-2.0-only
3  * Framework to handle complex IIO aggregate devices.
6  * can be "linked" against one or multiple backend devices. All the IIO and
11  *                                           -------------------------------------------------------
12  * ------------------                        | ------------         ------------      -------  FPGA|
13  * |     ADC        |------------------------| | ADC CORE |---------| DMA CORE |------| RAM |      |
14  * | (Frontend/IIO) | Serial Data (eg: LVDS) | |(backend) |---------|          |------|     |      |
15  * |                |------------------------| ------------         ------------      -------      |
16  * ------------------                        -------------------------------------------------------
19  *   - Backends should register themselves with devm_iio_backend_register()
20  *   - Frontend devices should get backends with devm_iio_backend_get()
24  * devices. On top of that, this is "generic" for all IIO which means any kind
27  * the industrialio-backend.c is only left with the really generic stuff. Then,
30  * Copyright (C) 2023-2024 Analog Devices Inc.
32 #define dev_fmt(fmt) "iio-backend: " fmt
45 #include <linux/iio/backend.h>
74 	if (!____back->ops->op)						\
75 		____ret = -EOPNOTSUPP;					\
86 		__ret = __back->ops->op(__back, ##args);	\
100 		ptr_err = __back->ops->op(__back, ##args);	\
111 		__back->ops->op(__back, ##args);		\
115  * iio_backend_chan_enable - Enable a backend channel
129  * iio_backend_chan_disable - Disable a backend channel
148  * devm_iio_backend_enable - Device managed backend enable
149  * @dev:	Consumer device for the backend
168  * iio_backend_data_format_set - Configure the channel data format
182 	if (!data || data->type >= IIO_BACKEND_DATA_TYPE_MAX)  in iio_backend_data_format_set()
183 		return -EINVAL;  in iio_backend_data_format_set()
193 	iio_backend_void_op_call(pair->back, free_buffer, pair->buffer);  in iio_backend_free_buffer()
197  * devm_iio_backend_request_buffer - Device managed buffer request
198  * @dev:	Consumer device for the backend
200  * @indio_dev:	IIO device
202  * Request an IIO buffer from the backend. The type of the buffer (typically
220 		return -ENOMEM;  in devm_iio_backend_request_buffer()
227 	pair->back = back;  in devm_iio_backend_request_buffer()
228 	pair->buffer = buffer;  in devm_iio_backend_request_buffer()
238 	module_put(back->owner);  in iio_backend_release()
247 	 * Make sure the provider cannot be unloaded before the consumer module.  in __devm_iio_backend_get()
249 	 * accessible (and breaks) but this makes it explicit that the consumer  in __devm_iio_backend_get()
252 	if (!try_module_get(back->owner))  in __devm_iio_backend_get()
253 		return dev_err_probe(dev, -ENODEV,  in __devm_iio_backend_get()
260 	link = device_link_add(dev, back->dev, DL_FLAG_AUTOREMOVE_CONSUMER);  in __devm_iio_backend_get()
262 		return dev_err_probe(dev, -EINVAL,  in __devm_iio_backend_get()
264 				     dev_name(back->dev));  in __devm_iio_backend_get()
266 	dev_dbg(dev, "Found backend(%s) device\n", dev_name(back->dev));  in __devm_iio_backend_get()
272  * devm_iio_backend_get - Device managed backend device get
273  * @dev:	Consumer device for the backend
289 		ret = device_property_match_string(dev, "io-backend-names",  in devm_iio_backend_get()
298 	fwnode = fwnode_find_reference(dev_fwnode(dev), "io-backends", index);  in devm_iio_backend_get()
307 		if (!device_match_fwnode(back->dev, fwnode))  in devm_iio_backend_get()
319 	return ERR_PTR(-EPROBE_DEFER);  in devm_iio_backend_get()
324  * __devm_iio_backend_get_from_fwnode_lookup - Device managed fwnode backend device get
325  * @dev:	Consumer device for the backend
344 		if (!device_match_fwnode(back->dev, fwnode))  in __devm_iio_backend_get_from_fwnode_lookup()
354 	return ERR_PTR(-EPROBE_DEFER);  in __devm_iio_backend_get_from_fwnode_lookup()
359  * iio_backend_get_priv - Get driver private data
364 	return back->priv;  in iio_backend_get_priv()
373 	list_del(&back->entry);  in iio_backend_unregister()
377  * devm_iio_backend_register - Device managed backend device register
382  * @ops is mandatory. Not providing it results in -EINVAL.
393 		return dev_err_probe(dev, -EINVAL, "No backend ops given\n");  in devm_iio_backend_register()
399 	 * removing it will tear the frontend/consumer down.  in devm_iio_backend_register()
403 		return -ENOMEM;  in devm_iio_backend_register()
405 	back->ops = ops;  in devm_iio_backend_register()
406 	back->owner = dev->driver->owner;  in devm_iio_backend_register()
407 	back->dev = dev;  in devm_iio_backend_register()
408 	back->priv = priv;  in devm_iio_backend_register()
410 		list_add(&back->entry, &iio_back_list);  in devm_iio_backend_register()
417 MODULE_DESCRIPTION("Framework to handle complex IIO aggregate devices");