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  */
22 struct iio_hw_consumer {
23 	struct list_head buffers;
24 	struct iio_channel *channels;
25 };
26 
27 struct 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 
iio_buffer_to_hw_consumer_buffer(struct iio_buffer * buffer)34 static 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 
iio_hw_buf_release(struct iio_buffer * buffer)40 static 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 
47 static const struct iio_buffer_access_funcs iio_hw_buf_access = {
48 	.release = &iio_hw_buf_release,
49 	.modes = INDIO_BUFFER_HARDWARE,
50 };
51 
iio_hw_consumer_get_buffer(struct iio_hw_consumer * hwc,struct iio_dev * indio_dev)52 static struct hw_consumer_buffer *iio_hw_consumer_get_buffer(
53 	struct iio_hw_consumer *hwc, struct iio_dev *indio_dev)
54 {
55 	size_t mask_size = BITS_TO_LONGS(indio_dev->masklength) * sizeof(long);
56 	struct hw_consumer_buffer *buf;
57 
58 	list_for_each_entry(buf, &hwc->buffers, head) {
59 		if (buf->indio_dev == indio_dev)
60 			return buf;
61 	}
62 
63 	buf = kzalloc(sizeof(*buf) + mask_size, 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  */
iio_hw_consumer_alloc(struct device * dev)83 struct 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 
115 err_put_buffers:
116 	list_for_each_entry(buf, &hwc->buffers, head)
117 		iio_buffer_put(&buf->buffer);
118 	iio_channel_release_all(hwc->channels);
119 err_free_hwc:
120 	kfree(hwc);
121 	return ERR_PTR(ret);
122 }
123 EXPORT_SYMBOL_GPL(iio_hw_consumer_alloc);
124 
125 /**
126  * iio_hw_consumer_free() - Free IIO hardware consumer
127  * @hwc: hw consumer to free.
128  */
iio_hw_consumer_free(struct iio_hw_consumer * hwc)129 void 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 }
138 EXPORT_SYMBOL_GPL(iio_hw_consumer_free);
139 
devm_iio_hw_consumer_release(void * iio_hwc)140 static 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  */
devm_iio_hw_consumer_alloc(struct device * dev)154 struct 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 }
170 EXPORT_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  */
iio_hw_consumer_enable(struct iio_hw_consumer * hwc)178 int 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 
191 err_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 }
196 EXPORT_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  */
iio_hw_consumer_disable(struct iio_hw_consumer * hwc)202 void 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 }
209 EXPORT_SYMBOL_GPL(iio_hw_consumer_disable);
210 
211 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
212 MODULE_DESCRIPTION("Hardware consumer buffer the IIO framework");
213 MODULE_LICENSE("GPL v2");
214