linux/drivers/hwmon/iio_hwmon.c
Linus Torvalds e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00

191 lines
4.7 KiB
C

/* Hwmon client for industrial I/O devices
*
* 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/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/hwmon.h>
#include <linux/of.h>
#include <linux/hwmon-sysfs.h>
#include <linux/iio/consumer.h>
#include <linux/iio/types.h>
/**
* struct iio_hwmon_state - device instance state
* @channels: filled with array of channels from iio
* @num_channels: number of channels in channels (saves counting twice)
* @hwmon_dev: associated hwmon device
* @attr_group: the group of attributes
* @attrs: null terminated array of attribute pointers.
*/
struct iio_hwmon_state {
struct iio_channel *channels;
int num_channels;
struct device *hwmon_dev;
struct attribute_group attr_group;
const struct attribute_group *groups[2];
struct attribute **attrs;
};
/*
* Assumes that IIO and hwmon operate in the same base units.
* This is supposed to be true, but needs verification for
* new channel types.
*/
static ssize_t iio_hwmon_read_val(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int result;
int ret;
struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
struct iio_hwmon_state *state = dev_get_drvdata(dev);
ret = iio_read_channel_processed(&state->channels[sattr->index],
&result);
if (ret < 0)
return ret;
return sprintf(buf, "%d\n", result);
}
static int iio_hwmon_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct iio_hwmon_state *st;
struct sensor_device_attribute *a;
int ret, i;
int in_i = 1, temp_i = 1, curr_i = 1, humidity_i = 1;
enum iio_chan_type type;
struct iio_channel *channels;
const char *name = "iio_hwmon";
if (dev->of_node && dev->of_node->name)
name = dev->of_node->name;
channels = iio_channel_get_all(dev);
if (IS_ERR(channels))
return PTR_ERR(channels);
st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
if (st == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
st->channels = channels;
/* count how many attributes we have */
while (st->channels[st->num_channels].indio_dev)
st->num_channels++;
st->attrs = devm_kzalloc(dev,
sizeof(*st->attrs) * (st->num_channels + 1),
GFP_KERNEL);
if (st->attrs == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
for (i = 0; i < st->num_channels; i++) {
a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
if (a == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
sysfs_attr_init(&a->dev_attr.attr);
ret = iio_get_channel_type(&st->channels[i], &type);
if (ret < 0)
goto error_release_channels;
switch (type) {
case IIO_VOLTAGE:
a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
"in%d_input",
in_i++);
break;
case IIO_TEMP:
a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
"temp%d_input",
temp_i++);
break;
case IIO_CURRENT:
a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
"curr%d_input",
curr_i++);
break;
case IIO_HUMIDITYRELATIVE:
a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
"humidity%d_input",
humidity_i++);
break;
default:
ret = -EINVAL;
goto error_release_channels;
}
if (a->dev_attr.attr.name == NULL) {
ret = -ENOMEM;
goto error_release_channels;
}
a->dev_attr.show = iio_hwmon_read_val;
a->dev_attr.attr.mode = S_IRUGO;
a->index = i;
st->attrs[i] = &a->dev_attr.attr;
}
st->attr_group.attrs = st->attrs;
st->groups[0] = &st->attr_group;
st->hwmon_dev = hwmon_device_register_with_groups(dev, name, st,
st->groups);
if (IS_ERR(st->hwmon_dev)) {
ret = PTR_ERR(st->hwmon_dev);
goto error_release_channels;
}
platform_set_drvdata(pdev, st);
return 0;
error_release_channels:
iio_channel_release_all(channels);
return ret;
}
static int iio_hwmon_remove(struct platform_device *pdev)
{
struct iio_hwmon_state *st = platform_get_drvdata(pdev);
hwmon_device_unregister(st->hwmon_dev);
iio_channel_release_all(st->channels);
return 0;
}
static const struct of_device_id iio_hwmon_of_match[] = {
{ .compatible = "iio-hwmon", },
{ }
};
MODULE_DEVICE_TABLE(of, iio_hwmon_of_match);
static struct platform_driver __refdata iio_hwmon_driver = {
.driver = {
.name = "iio_hwmon",
.of_match_table = iio_hwmon_of_match,
},
.probe = iio_hwmon_probe,
.remove = iio_hwmon_remove,
};
module_platform_driver(iio_hwmon_driver);
MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
MODULE_DESCRIPTION("IIO to hwmon driver");
MODULE_LICENSE("GPL v2");