![Andrey Smirnov](/assets/img/avatar_default.png)
Since every call to devm_kasprintf() in the switch statement is mostly the same, we can move all of the shared code outside and capture differencies with two helper variables. No functional change intended. Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
176 lines
4.2 KiB
C
176 lines
4.2 KiB
C
/* Hwmon client for industrial I/O devices
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*
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* Copyright (c) 2011 Jonathan Cameron
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/err.h>
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#include <linux/platform_device.h>
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#include <linux/hwmon.h>
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#include <linux/of.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/iio/consumer.h>
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#include <linux/iio/types.h>
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/**
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* struct iio_hwmon_state - device instance state
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* @channels: filled with array of channels from iio
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* @num_channels: number of channels in channels (saves counting twice)
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* @attr_group: the group of attributes
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* @groups: null terminated array of attribute groups
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* @attrs: null terminated array of attribute pointers.
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*/
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struct iio_hwmon_state {
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struct iio_channel *channels;
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int num_channels;
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struct attribute_group attr_group;
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const struct attribute_group *groups[2];
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struct attribute **attrs;
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};
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/*
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* Assumes that IIO and hwmon operate in the same base units.
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* This is supposed to be true, but needs verification for
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* new channel types.
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*/
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static ssize_t iio_hwmon_read_val(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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int result;
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int ret;
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struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
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struct iio_hwmon_state *state = dev_get_drvdata(dev);
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ret = iio_read_channel_processed(&state->channels[sattr->index],
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&result);
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if (ret < 0)
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return ret;
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return sprintf(buf, "%d\n", result);
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}
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static int iio_hwmon_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct iio_hwmon_state *st;
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struct sensor_device_attribute *a;
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int ret, i;
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int in_i = 1, temp_i = 1, curr_i = 1, humidity_i = 1;
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enum iio_chan_type type;
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struct iio_channel *channels;
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struct device *hwmon_dev;
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char *sname;
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channels = devm_iio_channel_get_all(dev);
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if (IS_ERR(channels)) {
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if (PTR_ERR(channels) == -ENODEV)
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return -EPROBE_DEFER;
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return PTR_ERR(channels);
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}
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st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
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if (st == NULL)
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return -ENOMEM;
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st->channels = channels;
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/* count how many attributes we have */
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while (st->channels[st->num_channels].indio_dev)
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st->num_channels++;
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st->attrs = devm_kcalloc(dev,
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st->num_channels + 1, sizeof(*st->attrs),
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GFP_KERNEL);
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if (st->attrs == NULL)
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return -ENOMEM;
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for (i = 0; i < st->num_channels; i++) {
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const char *prefix;
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int n;
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a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
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if (a == NULL)
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return -ENOMEM;
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sysfs_attr_init(&a->dev_attr.attr);
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ret = iio_get_channel_type(&st->channels[i], &type);
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if (ret < 0)
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return ret;
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switch (type) {
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case IIO_VOLTAGE:
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n = in_i++;
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prefix = "in";
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break;
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case IIO_TEMP:
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n = temp_i++;
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prefix = "temp";
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break;
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case IIO_CURRENT:
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n = curr_i++;
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prefix = "curr";
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break;
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case IIO_HUMIDITYRELATIVE:
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n = humidity_i++;
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prefix = "humidity";
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break;
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default:
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return -EINVAL;
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}
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a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
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"%s%d_input",
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prefix, n);
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if (a->dev_attr.attr.name == NULL)
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return -ENOMEM;
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a->dev_attr.show = iio_hwmon_read_val;
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a->dev_attr.attr.mode = 0444;
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a->index = i;
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st->attrs[i] = &a->dev_attr.attr;
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}
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st->attr_group.attrs = st->attrs;
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st->groups[0] = &st->attr_group;
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if (dev->of_node) {
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sname = devm_kasprintf(dev, GFP_KERNEL, "%pOFn", dev->of_node);
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if (!sname)
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return -ENOMEM;
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strreplace(sname, '-', '_');
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} else {
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sname = "iio_hwmon";
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}
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hwmon_dev = devm_hwmon_device_register_with_groups(dev, sname, st,
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st->groups);
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return PTR_ERR_OR_ZERO(hwmon_dev);
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}
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static const struct of_device_id iio_hwmon_of_match[] = {
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{ .compatible = "iio-hwmon", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, iio_hwmon_of_match);
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static struct platform_driver __refdata iio_hwmon_driver = {
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.driver = {
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.name = "iio_hwmon",
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.of_match_table = iio_hwmon_of_match,
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},
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.probe = iio_hwmon_probe,
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};
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module_platform_driver(iio_hwmon_driver);
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MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
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MODULE_DESCRIPTION("IIO to hwmon driver");
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MODULE_LICENSE("GPL v2");
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