1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright 2017 Analog Devices Inc.
  4 *  Author: Lars-Peter Clausen <lars@metafoo.de>
  5 */
  6
  7#include <linux/err.h>
  8#include <linux/export.h>
  9#include <linux/slab.h>
 10#include <linux/module.h>
 11
 12#include <linux/iio/iio.h>
 13#include <linux/iio/consumer.h>
 14#include <linux/iio/hw-consumer.h>
 15#include <linux/iio/buffer_impl.h>
 16
 17/**
 18 * struct iio_hw_consumer - IIO hw consumer block
 19 * @buffers: hardware buffers list head.
 20 * @channels: IIO provider channels.
 21 */
 22struct iio_hw_consumer {
 23	struct list_head buffers;
 24	struct iio_channel *channels;
 25};
 26
 27struct hw_consumer_buffer {
 28	struct list_head head;
 29	struct iio_dev *indio_dev;
 30	struct iio_buffer buffer;
 31	long scan_mask[];
 32};
 33
 34static struct hw_consumer_buffer *iio_buffer_to_hw_consumer_buffer(
 35	struct iio_buffer *buffer)
 36{
 37	return container_of(buffer, struct hw_consumer_buffer, buffer);
 38}
 39
 40static void iio_hw_buf_release(struct iio_buffer *buffer)
 41{
 42	struct hw_consumer_buffer *hw_buf =
 43		iio_buffer_to_hw_consumer_buffer(buffer);
 44	kfree(hw_buf);
 45}
 46
 47static const struct iio_buffer_access_funcs iio_hw_buf_access = {
 48	.release = &iio_hw_buf_release,
 49	.modes = INDIO_BUFFER_HARDWARE,
 50};
 51
 52static struct hw_consumer_buffer *iio_hw_consumer_get_buffer(
 53	struct iio_hw_consumer *hwc, struct iio_dev *indio_dev)
 54{
 55	struct hw_consumer_buffer *buf;
 56
 57	list_for_each_entry(buf, &hwc->buffers, head) {
 58		if (buf->indio_dev == indio_dev)
 59			return buf;
 60	}
 61
 62	buf = kzalloc(struct_size(buf, scan_mask, BITS_TO_LONGS(indio_dev->masklength)),
 63		      GFP_KERNEL);
 64	if (!buf)
 65		return NULL;
 66
 67	buf->buffer.access = &iio_hw_buf_access;
 68	buf->indio_dev = indio_dev;
 69	buf->buffer.scan_mask = buf->scan_mask;
 70
 71	iio_buffer_init(&buf->buffer);
 72	list_add_tail(&buf->head, &hwc->buffers);
 73
 74	return buf;
 75}
 76
 77/**
 78 * iio_hw_consumer_alloc() - Allocate IIO hardware consumer
 79 * @dev: Pointer to consumer device.
 80 *
 81 * Returns a valid iio_hw_consumer on success or a ERR_PTR() on failure.
 82 */
 83struct iio_hw_consumer *iio_hw_consumer_alloc(struct device *dev)
 84{
 85	struct hw_consumer_buffer *buf;
 86	struct iio_hw_consumer *hwc;
 87	struct iio_channel *chan;
 88	int ret;
 89
 90	hwc = kzalloc(sizeof(*hwc), GFP_KERNEL);
 91	if (!hwc)
 92		return ERR_PTR(-ENOMEM);
 93
 94	INIT_LIST_HEAD(&hwc->buffers);
 95
 96	hwc->channels = iio_channel_get_all(dev);
 97	if (IS_ERR(hwc->channels)) {
 98		ret = PTR_ERR(hwc->channels);
 99		goto err_free_hwc;
100	}
101
102	chan = &hwc->channels[0];
103	while (chan->indio_dev) {
104		buf = iio_hw_consumer_get_buffer(hwc, chan->indio_dev);
105		if (!buf) {
106			ret = -ENOMEM;
107			goto err_put_buffers;
108		}
109		set_bit(chan->channel->scan_index, buf->buffer.scan_mask);
110		chan++;
111	}
112
113	return hwc;
114
115err_put_buffers:
116	list_for_each_entry(buf, &hwc->buffers, head)
117		iio_buffer_put(&buf->buffer);
118	iio_channel_release_all(hwc->channels);
119err_free_hwc:
120	kfree(hwc);
121	return ERR_PTR(ret);
122}
123EXPORT_SYMBOL_GPL(iio_hw_consumer_alloc);
124
125/**
126 * iio_hw_consumer_free() - Free IIO hardware consumer
127 * @hwc: hw consumer to free.
128 */
129void iio_hw_consumer_free(struct iio_hw_consumer *hwc)
130{
131	struct hw_consumer_buffer *buf, *n;
132
133	iio_channel_release_all(hwc->channels);
134	list_for_each_entry_safe(buf, n, &hwc->buffers, head)
135		iio_buffer_put(&buf->buffer);
136	kfree(hwc);
137}
138EXPORT_SYMBOL_GPL(iio_hw_consumer_free);
139
140static void devm_iio_hw_consumer_release(void *iio_hwc)
141{
142	iio_hw_consumer_free(iio_hwc);
143}
144
145/**
146 * devm_iio_hw_consumer_alloc - Resource-managed iio_hw_consumer_alloc()
147 * @dev: Pointer to consumer device.
148 *
149 * Managed iio_hw_consumer_alloc. iio_hw_consumer allocated with this function
150 * is automatically freed on driver detach.
151 *
152 * returns pointer to allocated iio_hw_consumer on success, NULL on failure.
153 */
154struct iio_hw_consumer *devm_iio_hw_consumer_alloc(struct device *dev)
155{
156	struct iio_hw_consumer *iio_hwc;
157	int ret;
158
159	iio_hwc = iio_hw_consumer_alloc(dev);
160	if (IS_ERR(iio_hwc))
161		return iio_hwc;
162
163	ret = devm_add_action_or_reset(dev, devm_iio_hw_consumer_release,
164				       iio_hwc);
165	if (ret)
166		return ERR_PTR(ret);
167
168	return iio_hwc;
169}
170EXPORT_SYMBOL_GPL(devm_iio_hw_consumer_alloc);
171
172/**
173 * iio_hw_consumer_enable() - Enable IIO hardware consumer
174 * @hwc: iio_hw_consumer to enable.
175 *
176 * Returns 0 on success.
177 */
178int iio_hw_consumer_enable(struct iio_hw_consumer *hwc)
179{
180	struct hw_consumer_buffer *buf;
181	int ret;
182
183	list_for_each_entry(buf, &hwc->buffers, head) {
184		ret = iio_update_buffers(buf->indio_dev, &buf->buffer, NULL);
185		if (ret)
186			goto err_disable_buffers;
187	}
188
189	return 0;
190
191err_disable_buffers:
192	list_for_each_entry_continue_reverse(buf, &hwc->buffers, head)
193		iio_update_buffers(buf->indio_dev, NULL, &buf->buffer);
194	return ret;
195}
196EXPORT_SYMBOL_GPL(iio_hw_consumer_enable);
197
198/**
199 * iio_hw_consumer_disable() - Disable IIO hardware consumer
200 * @hwc: iio_hw_consumer to disable.
201 */
202void iio_hw_consumer_disable(struct iio_hw_consumer *hwc)
203{
204	struct hw_consumer_buffer *buf;
205
206	list_for_each_entry(buf, &hwc->buffers, head)
207		iio_update_buffers(buf->indio_dev, NULL, &buf->buffer);
208}
209EXPORT_SYMBOL_GPL(iio_hw_consumer_disable);
210
211MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
212MODULE_DESCRIPTION("Hardware consumer buffer the IIO framework");
213MODULE_LICENSE("GPL v2");