--- /dev/null
+/*
+ * Industrial I/O in kernel consumer interface
+ *
+ * Copyright (c) 2011 Jonathan Cameron
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+#ifndef _IIO_INKERN_CONSUMER_H_
+#define _IIO_INKERN_CONSUMER_H
+#include "types.h"
+
+struct iio_dev;
+struct iio_chan_spec;
+
+/**
+ * struct iio_channel - everything needed for a consumer to use a channel
+ * @indio_dev: Device on which the channel exists.
+ * @channel: Full description of the channel.
+ */
+struct iio_channel {
+ struct iio_dev *indio_dev;
+ const struct iio_chan_spec *channel;
+};
+
+/**
+ * iio_channel_get() - get description of all that is needed to access channel.
+ * @name: Unique name of the device as provided in the iio_map
+ * with which the desired provider to consumer mapping
+ * was registered.
+ * @consumer_channel: Unique name to identify the channel on the consumer
+ * side. This typically describes the channels use within
+ * the consumer. E.g. 'battery_voltage'
+ */
+struct iio_channel *iio_st_channel_get(const char *name,
+ const char *consumer_channel);
+
+/**
+ * iio_st_channel_release() - release channels obtained via iio_st_channel_get
+ * @chan: The channel to be released.
+ */
+void iio_st_channel_release(struct iio_channel *chan);
+
+/**
+ * iio_st_channel_get_all() - get all channels associated with a client
+ * @name: name of consumer device.
+ *
+ * Returns an array of iio_channel structures terminated with one with
+ * null iio_dev pointer.
+ * This function is used by fairly generic consumers to get all the
+ * channels registered as having this consumer.
+ */
+struct iio_channel *iio_st_channel_get_all(const char *name);
+
+/**
+ * iio_st_channel_release_all() - reverse iio_st_get_all
+ * @chan: Array of channels to be released.
+ */
+void iio_st_channel_release_all(struct iio_channel *chan);
+
+/**
+ * iio_st_read_channel_raw() - read from a given channel
+ * @channel: The channel being queried.
+ * @val: Value read back.
+ *
+ * Note raw reads from iio channels are in adc counts and hence
+ * scale will need to be applied if standard units required.
+ */
+int iio_st_read_channel_raw(struct iio_channel *chan,
+ int *val);
+
+/**
+ * iio_st_get_channel_type() - get the type of a channel
+ * @channel: The channel being queried.
+ * @type: The type of the channel.
+ *
+ * returns the enum iio_chan_type of the channel
+ */
+int iio_st_get_channel_type(struct iio_channel *channel,
+ enum iio_chan_type *type);
+
+/**
+ * iio_st_read_channel_scale() - read the scale value for a channel
+ * @channel: The channel being queried.
+ * @val: First part of value read back.
+ * @val2: Second part of value read back.
+ *
+ * Note returns a description of what is in val and val2, such
+ * as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val
+ * + val2/1e6
+ */
+int iio_st_read_channel_scale(struct iio_channel *chan, int *val,
+ int *val2);
+
+#endif
--- /dev/null
+/* The industrial I/O core in kernel channel mapping
+ *
+ * Copyright (c) 2011 Jonathan Cameron
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+
+#include "iio.h"
+#include "iio_core.h"
+#include "machine.h"
+#include "driver.h"
+#include "consumer.h"
+
+struct iio_map_internal {
+ struct iio_dev *indio_dev;
+ struct iio_map *map;
+ struct list_head l;
+};
+
+static LIST_HEAD(iio_map_list);
+static DEFINE_MUTEX(iio_map_list_lock);
+
+int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps)
+{
+ int i = 0, ret = 0;
+ struct iio_map_internal *mapi;
+
+ if (maps == NULL)
+ return 0;
+
+ mutex_lock(&iio_map_list_lock);
+ while (maps[i].consumer_dev_name != NULL) {
+ mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
+ if (mapi == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+ mapi->map = &maps[i];
+ mapi->indio_dev = indio_dev;
+ list_add(&mapi->l, &iio_map_list);
+ i++;
+ }
+error_ret:
+ mutex_unlock(&iio_map_list_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iio_map_array_register);
+
+
+/* Assumes the exact same array (e.g. memory locations)
+ * used at unregistration as used at registration rather than
+ * more complex checking of contents.
+ */
+int iio_map_array_unregister(struct iio_dev *indio_dev,
+ struct iio_map *maps)
+{
+ int i = 0, ret = 0;
+ bool found_it;
+ struct iio_map_internal *mapi;
+
+ if (maps == NULL)
+ return 0;
+
+ mutex_lock(&iio_map_list_lock);
+ while (maps[i].consumer_dev_name != NULL) {
+ found_it = false;
+ list_for_each_entry(mapi, &iio_map_list, l)
+ if (&maps[i] == mapi->map) {
+ list_del(&mapi->l);
+ kfree(mapi);
+ found_it = true;
+ break;
+ }
+ if (found_it == false) {
+ ret = -ENODEV;
+ goto error_ret;
+ }
+ }
+error_ret:
+ mutex_unlock(&iio_map_list_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iio_map_array_unregister);
+
+static const struct iio_chan_spec
+*iio_chan_spec_from_name(const struct iio_dev *indio_dev,
+ const char *name)
+{
+ int i;
+ const struct iio_chan_spec *chan = NULL;
+
+ for (i = 0; i < indio_dev->num_channels; i++)
+ if (indio_dev->channels[i].datasheet_name &&
+ strcmp(name, indio_dev->channels[i].datasheet_name) == 0) {
+ chan = &indio_dev->channels[i];
+ break;
+ }
+ return chan;
+}
+
+
+struct iio_channel *iio_st_channel_get(const char *name,
+ const char *channel_name)
+{
+ struct iio_map_internal *c_i = NULL, *c = NULL;
+ struct iio_channel *channel;
+
+ if (name == NULL && channel_name == NULL)
+ return ERR_PTR(-ENODEV);
+
+ /* first find matching entry the channel map */
+ mutex_lock(&iio_map_list_lock);
+ list_for_each_entry(c_i, &iio_map_list, l) {
+ if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) ||
+ (channel_name &&
+ strcmp(channel_name, c_i->map->consumer_channel) != 0))
+ continue;
+ c = c_i;
+ get_device(&c->indio_dev->dev);
+ break;
+ }
+ mutex_unlock(&iio_map_list_lock);
+ if (c == NULL)
+ return ERR_PTR(-ENODEV);
+
+ channel = kmalloc(sizeof(*channel), GFP_KERNEL);
+ if (channel == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ channel->indio_dev = c->indio_dev;
+
+ if (c->map->adc_channel_label)
+ channel->channel =
+ iio_chan_spec_from_name(channel->indio_dev,
+ c->map->adc_channel_label);
+
+ return channel;
+}
+EXPORT_SYMBOL_GPL(iio_st_channel_get);
+
+void iio_st_channel_release(struct iio_channel *channel)
+{
+ put_device(&channel->indio_dev->dev);
+ kfree(channel);
+}
+EXPORT_SYMBOL_GPL(iio_st_channel_release);
+
+struct iio_channel *iio_st_channel_get_all(const char *name)
+{
+ struct iio_channel *chans;
+ struct iio_map_internal *c = NULL;
+ int nummaps = 0;
+ int mapind = 0;
+ int i, ret;
+
+ if (name == NULL)
+ return ERR_PTR(-EINVAL);
+
+ mutex_lock(&iio_map_list_lock);
+ /* first count the matching maps */
+ list_for_each_entry(c, &iio_map_list, l)
+ if (name && strcmp(name, c->map->consumer_dev_name) != 0)
+ continue;
+ else
+ nummaps++;
+
+ if (nummaps == 0) {
+ ret = -ENODEV;
+ goto error_ret;
+ }
+
+ /* NULL terminated array to save passing size */
+ chans = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL);
+ if (chans == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ /* for each map fill in the chans element */
+ list_for_each_entry(c, &iio_map_list, l) {
+ if (name && strcmp(name, c->map->consumer_dev_name) != 0)
+ continue;
+ chans[mapind].indio_dev = c->indio_dev;
+ chans[mapind].channel =
+ iio_chan_spec_from_name(chans[mapind].indio_dev,
+ c->map->adc_channel_label);
+ if (chans[mapind].channel == NULL) {
+ ret = -EINVAL;
+ put_device(&chans[mapind].indio_dev->dev);
+ goto error_free_chans;
+ }
+ get_device(&chans[mapind].indio_dev->dev);
+ mapind++;
+ }
+ mutex_unlock(&iio_map_list_lock);
+ if (mapind == 0) {
+ ret = -ENODEV;
+ goto error_free_chans;
+ }
+ return chans;
+
+error_free_chans:
+ for (i = 0; i < nummaps; i++)
+ if (chans[i].indio_dev)
+ put_device(&chans[i].indio_dev->dev);
+ kfree(chans);
+error_ret:
+ mutex_unlock(&iio_map_list_lock);
+
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(iio_st_channel_get_all);
+
+void iio_st_channel_release_all(struct iio_channel *channels)
+{
+ struct iio_channel *chan = &channels[0];
+
+ while (chan->indio_dev) {
+ put_device(&chan->indio_dev->dev);
+ chan++;
+ }
+ kfree(channels);
+}
+EXPORT_SYMBOL_GPL(iio_st_channel_release_all);
+
+int iio_st_read_channel_raw(struct iio_channel *chan, int *val)
+{
+ int val2, ret;
+
+ mutex_lock(&chan->indio_dev->info_exist_lock);
+ if (chan->indio_dev->info == NULL) {
+ ret = -ENODEV;
+ goto err_unlock;
+ }
+
+ ret = chan->indio_dev->info->read_raw(chan->indio_dev, chan->channel,
+ val, &val2, 0);
+err_unlock:
+ mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iio_st_read_channel_raw);
+
+int iio_st_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
+{
+ int ret;
+
+ mutex_lock(&chan->indio_dev->info_exist_lock);
+ if (chan->indio_dev->info == NULL) {
+ ret = -ENODEV;
+ goto err_unlock;
+ }
+
+ ret = chan->indio_dev->info->read_raw(chan->indio_dev,
+ chan->channel,
+ val, val2,
+ IIO_CHAN_INFO_SCALE);
+err_unlock:
+ mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iio_st_read_channel_scale);
+
+int iio_st_get_channel_type(struct iio_channel *chan,
+ enum iio_chan_type *type)
+{
+ int ret = 0;
+ /* Need to verify underlying driver has not gone away */
+
+ mutex_lock(&chan->indio_dev->info_exist_lock);
+ if (chan->indio_dev->info == NULL) {
+ ret = -ENODEV;
+ goto err_unlock;
+ }
+
+ *type = chan->channel->type;
+err_unlock:
+ mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iio_st_get_channel_type);
projects / users / hch / dma-mapping.git / commitdiff