1 // SPDX-License-Identifier: GPL-2.0
3 * IIO multiplexer driver
5 * Copyright (C) 2017 Axentia Technologies AB
7 * Author: Peter Rosin <peda@axentia.se>
10 #include <linux/err.h>
11 #include <linux/iio/consumer.h>
12 #include <linux/iio/iio.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/mux/consumer.h>
17 #include <linux/platform_device.h>
19 struct mux_ext_info_cache {
25 struct mux_ext_info_cache *ext_info_cache;
30 struct mux_control *control;
31 struct iio_channel *parent;
32 struct iio_dev *indio_dev;
33 struct iio_chan_spec *chan;
34 struct iio_chan_spec_ext_info *ext_info;
35 struct mux_child *child;
39 static int iio_mux_select(struct mux *mux, int idx)
41 struct mux_child *child = &mux->child[idx];
42 struct iio_chan_spec const *chan = &mux->chan[idx];
46 ret = mux_control_select_delay(mux->control, chan->channel,
49 mux->cached_state = -1;
53 if (mux->cached_state == chan->channel)
57 for (i = 0; chan->ext_info[i].name; ++i) {
58 const char *attr = chan->ext_info[i].name;
59 struct mux_ext_info_cache *cache;
61 cache = &child->ext_info_cache[i];
66 ret = iio_write_channel_ext_info(mux->parent, attr,
71 mux_control_deselect(mux->control);
72 mux->cached_state = -1;
77 mux->cached_state = chan->channel;
82 static void iio_mux_deselect(struct mux *mux)
84 mux_control_deselect(mux->control);
87 static int mux_read_raw(struct iio_dev *indio_dev,
88 struct iio_chan_spec const *chan,
89 int *val, int *val2, long mask)
91 struct mux *mux = iio_priv(indio_dev);
92 int idx = chan - mux->chan;
95 ret = iio_mux_select(mux, idx);
100 case IIO_CHAN_INFO_RAW:
101 ret = iio_read_channel_raw(mux->parent, val);
104 case IIO_CHAN_INFO_SCALE:
105 ret = iio_read_channel_scale(mux->parent, val, val2);
112 iio_mux_deselect(mux);
117 static int mux_read_avail(struct iio_dev *indio_dev,
118 struct iio_chan_spec const *chan,
119 const int **vals, int *type, int *length,
122 struct mux *mux = iio_priv(indio_dev);
123 int idx = chan - mux->chan;
126 ret = iio_mux_select(mux, idx);
131 case IIO_CHAN_INFO_RAW:
133 ret = iio_read_avail_channel_raw(mux->parent, vals, length);
140 iio_mux_deselect(mux);
145 static int mux_write_raw(struct iio_dev *indio_dev,
146 struct iio_chan_spec const *chan,
147 int val, int val2, long mask)
149 struct mux *mux = iio_priv(indio_dev);
150 int idx = chan - mux->chan;
153 ret = iio_mux_select(mux, idx);
158 case IIO_CHAN_INFO_RAW:
159 ret = iio_write_channel_raw(mux->parent, val);
166 iio_mux_deselect(mux);
171 static const struct iio_info mux_info = {
172 .read_raw = mux_read_raw,
173 .read_avail = mux_read_avail,
174 .write_raw = mux_write_raw,
177 static ssize_t mux_read_ext_info(struct iio_dev *indio_dev, uintptr_t private,
178 struct iio_chan_spec const *chan, char *buf)
180 struct mux *mux = iio_priv(indio_dev);
181 int idx = chan - mux->chan;
184 ret = iio_mux_select(mux, idx);
188 ret = iio_read_channel_ext_info(mux->parent,
189 mux->ext_info[private].name,
192 iio_mux_deselect(mux);
197 static ssize_t mux_write_ext_info(struct iio_dev *indio_dev, uintptr_t private,
198 struct iio_chan_spec const *chan,
199 const char *buf, size_t len)
201 struct device *dev = indio_dev->dev.parent;
202 struct mux *mux = iio_priv(indio_dev);
203 int idx = chan - mux->chan;
207 if (len >= PAGE_SIZE)
210 ret = iio_mux_select(mux, idx);
214 new = devm_kmemdup(dev, buf, len + 1, GFP_KERNEL);
216 iio_mux_deselect(mux);
222 ret = iio_write_channel_ext_info(mux->parent,
223 mux->ext_info[private].name,
226 iio_mux_deselect(mux);
227 devm_kfree(dev, new);
231 devm_kfree(dev, mux->child[idx].ext_info_cache[private].data);
232 mux->child[idx].ext_info_cache[private].data = new;
233 mux->child[idx].ext_info_cache[private].size = len;
235 iio_mux_deselect(mux);
240 static int mux_configure_channel(struct device *dev, struct mux *mux,
241 u32 state, const char *label, int idx)
243 struct mux_child *child = &mux->child[idx];
244 struct iio_chan_spec *chan = &mux->chan[idx];
245 struct iio_chan_spec const *pchan = mux->parent->channel;
252 chan->output = pchan->output;
253 chan->datasheet_name = label;
254 chan->ext_info = mux->ext_info;
256 ret = iio_get_channel_type(mux->parent, &chan->type);
258 dev_err(dev, "failed to get parent channel type\n");
262 if (iio_channel_has_info(pchan, IIO_CHAN_INFO_RAW))
263 chan->info_mask_separate |= BIT(IIO_CHAN_INFO_RAW);
264 if (iio_channel_has_info(pchan, IIO_CHAN_INFO_SCALE))
265 chan->info_mask_separate |= BIT(IIO_CHAN_INFO_SCALE);
267 if (iio_channel_has_available(pchan, IIO_CHAN_INFO_RAW))
268 chan->info_mask_separate_available |= BIT(IIO_CHAN_INFO_RAW);
270 if (state >= mux_control_states(mux->control)) {
271 dev_err(dev, "too many channels\n");
275 chan->channel = state;
277 num_ext_info = iio_get_channel_ext_info_count(mux->parent);
279 page = devm_kzalloc(dev, PAGE_SIZE, GFP_KERNEL);
283 child->ext_info_cache = devm_kcalloc(dev,
285 sizeof(*child->ext_info_cache),
287 if (!child->ext_info_cache)
290 for (i = 0; i < num_ext_info; ++i) {
291 child->ext_info_cache[i].size = -1;
293 if (!pchan->ext_info[i].write)
295 if (!pchan->ext_info[i].read)
298 ret = iio_read_channel_ext_info(mux->parent,
299 mux->ext_info[i].name,
302 dev_err(dev, "failed to get ext_info '%s'\n",
303 pchan->ext_info[i].name);
306 if (ret >= PAGE_SIZE) {
307 dev_err(dev, "too large ext_info '%s'\n",
308 pchan->ext_info[i].name);
312 child->ext_info_cache[i].data = devm_kmemdup(dev, page, ret + 1,
314 if (!child->ext_info_cache[i].data)
317 child->ext_info_cache[i].data[ret] = 0;
318 child->ext_info_cache[i].size = ret;
322 devm_kfree(dev, page);
328 * Same as of_property_for_each_string(), but also keeps track of the
329 * index of each string.
331 #define of_property_for_each_string_index(np, propname, prop, s, i) \
332 for (prop = of_find_property(np, propname, NULL), \
333 s = of_prop_next_string(prop, NULL), \
336 s = of_prop_next_string(prop, s), \
339 static int mux_probe(struct platform_device *pdev)
341 struct device *dev = &pdev->dev;
342 struct device_node *np = pdev->dev.of_node;
343 struct iio_dev *indio_dev;
344 struct iio_channel *parent;
346 struct property *prop;
358 parent = devm_iio_channel_get(dev, "parent");
360 return dev_err_probe(dev, PTR_ERR(parent),
361 "failed to get parent channel\n");
363 sizeof_ext_info = iio_get_channel_ext_info_count(parent);
364 if (sizeof_ext_info) {
365 sizeof_ext_info += 1; /* one extra entry for the sentinel */
366 sizeof_ext_info *= sizeof(*mux->ext_info);
370 of_property_for_each_string(np, "channels", prop, label) {
375 dev_err(dev, "not even a single child\n");
379 sizeof_priv = sizeof(*mux);
380 sizeof_priv += sizeof(*mux->child) * children;
381 sizeof_priv += sizeof(*mux->chan) * children;
382 sizeof_priv += sizeof_ext_info;
384 indio_dev = devm_iio_device_alloc(dev, sizeof_priv);
388 mux = iio_priv(indio_dev);
389 mux->child = (struct mux_child *)(mux + 1);
390 mux->chan = (struct iio_chan_spec *)(mux->child + children);
392 platform_set_drvdata(pdev, indio_dev);
394 mux->parent = parent;
395 mux->cached_state = -1;
398 of_property_read_u32(np, "settle-time-us", &mux->delay_us);
400 indio_dev->name = dev_name(dev);
401 indio_dev->info = &mux_info;
402 indio_dev->modes = INDIO_DIRECT_MODE;
403 indio_dev->channels = mux->chan;
404 indio_dev->num_channels = children;
405 if (sizeof_ext_info) {
406 mux->ext_info = devm_kmemdup(dev,
407 parent->channel->ext_info,
408 sizeof_ext_info, GFP_KERNEL);
412 for (i = 0; mux->ext_info[i].name; ++i) {
413 if (parent->channel->ext_info[i].read)
414 mux->ext_info[i].read = mux_read_ext_info;
415 if (parent->channel->ext_info[i].write)
416 mux->ext_info[i].write = mux_write_ext_info;
417 mux->ext_info[i].private = i;
421 mux->control = devm_mux_control_get(dev, NULL);
422 if (IS_ERR(mux->control)) {
423 if (PTR_ERR(mux->control) != -EPROBE_DEFER)
424 dev_err(dev, "failed to get control-mux\n");
425 return PTR_ERR(mux->control);
429 of_property_for_each_string_index(np, "channels", prop, label, state) {
433 ret = mux_configure_channel(dev, mux, state, label, i++);
438 ret = devm_iio_device_register(dev, indio_dev);
440 dev_err(dev, "failed to register iio device\n");
447 static const struct of_device_id mux_match[] = {
448 { .compatible = "io-channel-mux" },
451 MODULE_DEVICE_TABLE(of, mux_match);
453 static struct platform_driver mux_driver = {
457 .of_match_table = mux_match,
460 module_platform_driver(mux_driver);
462 MODULE_DESCRIPTION("IIO multiplexer driver");
463 MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
464 MODULE_LICENSE("GPL v2");