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184 lines
4.3 KiB
184 lines
4.3 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* 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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#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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struct iio_channel *chan = &state->channels[sattr->index]; |
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enum iio_chan_type type; |
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ret = iio_read_channel_processed(chan, &result); |
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if (ret < 0) |
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return ret; |
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ret = iio_get_channel_type(chan, &type); |
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if (ret < 0) |
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return ret; |
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if (type == IIO_POWER) |
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result *= 1000; /* mili-Watts to micro-Watts conversion */ |
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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, power_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_POWER: |
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n = power_i++; |
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prefix = "power"; |
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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 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 <[email protected]>"); |
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MODULE_DESCRIPTION("IIO to hwmon driver"); |
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MODULE_LICENSE("GPL v2");
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