From: Jonathan Cameron <jic23@xxxxxxxxx>
Lifted from proposal for in kernel interface built on the out of staging
branch.
Two elements here:
* Map as defined in "inkern.h"
* Matching code to actually get the iio_dev and channel
that we want from the global list of IIO devices.
V2: As per Greg KH suggestion, move over to registration by passing
the tables into the provider drivers (how regulator does it).
This does not prevent us using the original more flexible approach
if at a later date there is a usecase that demands it.
Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxxx>
---
drivers/staging/iio/Kconfig | 7 +-
drivers/staging/iio/Makefile | 2 +-
drivers/staging/iio/consumer.h | 103 +++++++++++++
drivers/staging/iio/driver.h | 34 ++++
drivers/staging/iio/iio_core.h | 3 +
drivers/staging/iio/industrialio-core.c | 2 +-
drivers/staging/iio/inkern.c | 256 +++++++++++++++++++++++++++++++
drivers/staging/iio/machine.h | 30 ++++
8 files changed, 434 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/iio/Kconfig b/drivers/staging/iio/Kconfig
index 90162aa..65c2a8e 100644
--- a/drivers/staging/iio/Kconfig
+++ b/drivers/staging/iio/Kconfig
@@ -10,8 +10,14 @@ menuconfig IIO
drivers for many different types of embedded sensors using a
number of different physical interfaces (i2c, spi, etc). See
drivers/staging/iio/Documentation for more information.
+
if IIO
+config IIO_INKERN
+ bool "In kernel support for IIO"
+ help
+ Support in kernel users of IIO device drivers.
+
config IIO_BUFFER
bool "Enable buffer support within IIO"
help
@@ -96,5 +102,4 @@ config IIO_SIMPLE_DUMMY_BUFFER
Add buffered data capture to the simple dummy driver.
endif # IIO_SIMPLE_DUMMY
-
endif # IIO
diff --git a/drivers/staging/iio/Makefile b/drivers/staging/iio/Makefile
index 657710b..5da4c78 100644
--- a/drivers/staging/iio/Makefile
+++ b/drivers/staging/iio/Makefile
@@ -1,9 +1,9 @@
#
# Makefile for the industrial I/O core.
#
-
obj-$(CONFIG_IIO) += industrialio.o
industrialio-y := industrialio-core.o industrialio-event.o
+industrialio-$(CONFIG_IIO_INKERN) += inkern.o
industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o
industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
diff --git a/drivers/staging/iio/consumer.h b/drivers/staging/iio/consumer.h
new file mode 100644
index 0000000..4ac320b
--- /dev/null
+++ b/drivers/staging/iio/consumer.h
@@ -0,0 +1,103 @@
+/*
+ * 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
+
+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.
+ * @dev: Pointer to the struct device for this device as provided
+ * in the iio_map with which the desired provider to
+ * consumer mapping was registered.
+ * Null if the mapping was registered against consumer
+ * device name.
+ * @name: Unique name of the device as provided in the iio_map
+ * with which the desired provider to consumer mapping
+ * was registered.
+ * Null if the mapping was instead registered by a struct
+ * device pointer.
+ * @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 struct device *dev,
+ 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
+ * @dev: consumer device structure (null if name to be used)
+ * @name: name of consuemr device (null if dev pointer to be used)
+ *
+ * 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 struct device *dev,
+ 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.
+ *
+ * returns the enum iio_chan_type of the channel
+ */
+enum iio_chan_type iio_st_get_channel_type(struct iio_channel *channel);
+
+/**
+ * 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
diff --git a/drivers/staging/iio/driver.h b/drivers/staging/iio/driver.h
new file mode 100644
index 0000000..cea8bcd
--- /dev/null
+++ b/drivers/staging/iio/driver.h
@@ -0,0 +1,34 @@
+/*
+ * Industrial I/O in kernel access map 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_H_
+#define _IIO_INKERN_H_
+
+struct iio_map;
+
+/**
+ * iio_map_array_register() - tell the core about inkernel consumers
+ * @indio_dev: provider device
+ * @map: array of mappings specifying association of channel with client
+ */
+int iio_map_array_register(struct iio_dev *indio_dev,
+ struct iio_map *map);
+
+/**
+ * iio_map_array_unregister() - tell the core to remove consumer mappings
+ * @indio_dev: provider device
+ * @map: array of mappings to remove. Note these must have same memory
+ * addresses as those originally added not just equal parameter
+ * values.
+ */
+int iio_map_array_unregister(struct iio_dev *indio_dev,
+ struct iio_map *map);
+
+#endif
diff --git a/drivers/staging/iio/iio_core.h b/drivers/staging/iio/iio_core.h
index c9dfcba..a45bb43 100644
--- a/drivers/staging/iio/iio_core.h
+++ b/drivers/staging/iio/iio_core.h
@@ -12,6 +12,9 @@
#ifndef _IIO_CORE_H_
#define _IIO_CORE_H_
+#include <linux/device.h>
+
+extern struct device_type iio_dev_type;
int __iio_add_chan_devattr(const char *postfix,
struct iio_chan_spec const *chan,
diff --git a/drivers/staging/iio/industrialio-core.c b/drivers/staging/iio/industrialio-core.c
index e4824fe..876ea17 100644
--- a/drivers/staging/iio/industrialio-core.c
+++ b/drivers/staging/iio/industrialio-core.c
@@ -567,7 +567,7 @@ static void iio_dev_release(struct device *device)
iio_device_unregister_sysfs(indio_dev);
}
-static struct device_type iio_dev_type = {
+struct device_type iio_dev_type = {
.name = "iio_device",
.release = iio_dev_release,
};
diff --git a/drivers/staging/iio/inkern.c b/drivers/staging/iio/inkern.c
new file mode 100644
index 0000000..634d421
--- /dev/null
+++ b/drivers/staging/iio/inkern.c
@@ -0,0 +1,256 @@
+/* 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 != NULL) ||
+ (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 != NULL) ||
+ (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 struct device *dev,
+ const char *name,
+ const char *channel_name)
+{
+ struct iio_map_internal *c_i = NULL, *c = NULL;
+ struct iio_channel *channel;
+
+ if (dev == NULL && 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 ((dev && dev != c_i->map->consumer_dev) ||
+ (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 struct device *dev,
+ const char *name)
+{
+ struct iio_channel *chans;
+ struct iio_map_internal *c = NULL;
+ int nummaps = 0;
+ int mapind = 0;
+ int i, ret;
+
+ if (dev == NULL && name == NULL)
+ return ERR_PTR(-EINVAL);
+ /* first count the matching maps */
+ list_for_each_entry(c, &iio_map_list, l)
+ if ((dev && dev != c->map->consumer_dev) ||
+ (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 (dev && dev != c->map->consumer_dev)
+ continue;
+ 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;
+ return chan->indio_dev->info->read_raw(chan->indio_dev, chan->channel,
+ val, &val2, 0);
+}
+EXPORT_SYMBOL_GPL(iio_st_read_channel_raw);
+
+int iio_st_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
+{
+ return chan->indio_dev->info->read_raw(chan->indio_dev,
+ chan->channel,
+ val, val2,
+ IIO_CHAN_INFO_SCALE);
+}
+EXPORT_SYMBOL_GPL(iio_st_read_channel_scale);
+
+enum iio_chan_type iio_st_get_channel_type(struct iio_channel *channel)
+{
+ return channel->channel->type;
+}
+EXPORT_SYMBOL_GPL(iio_st_get_channel_type);
diff --git a/drivers/staging/iio/machine.h b/drivers/staging/iio/machine.h
new file mode 100644
index 0000000..7c7da30
--- /dev/null
+++ b/drivers/staging/iio/machine.h
@@ -0,0 +1,30 @@
+/*
+ * Industrial I/O in kernel access map definitions for board files.
+ *
+ * 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.
+ */
+
+/**
+ * struct iio_map - description of link between consumer and device channels
+ * @adc_channel_label: Label used to identify the channel on the provider.
+ * This is matched against the datasheet_name element
+ * of struct iio_chan_spec.
+ * @consumer_dev: Pointer to device structure for the consumer.
+ * Either this or consumer_dev_name must be supplied
+ * to allow the consumer to be identified.
+ * @consumer_dev_name: Name to uniquely identify the consumer if the
+ * device pointer is not available when registering this
+ * mapping.
+ * @consumer_channel: Unique name used to idenitify the channel on the
+ * consumer side.
+ */
+struct iio_map {
+ const char *adc_channel_label;
+ struct device *consumer_dev;
+ const char *consumer_dev_name;
+ const char *consumer_channel;
+};
--
1.7.8.4
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