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1// SPDX-License-Identifier: GPL-2.0-only2/* Hwmon client for industrial I/O devices3 *4 * Copyright (c) 2011 Jonathan Cameron5 */6 7#include <linux/kernel.h>8#include <linux/slab.h>9#include <linux/mod_devicetable.h>10#include <linux/module.h>11#include <linux/err.h>12#include <linux/platform_device.h>13#include <linux/property.h>14 15#include <linux/hwmon.h>16#include <linux/hwmon-sysfs.h>17#include <linux/iio/consumer.h>18#include <linux/iio/types.h>19 20/**21 * struct iio_hwmon_state - device instance state22 * @channels: filled with array of channels from iio23 * @num_channels: number of channels in channels (saves counting twice)24 * @attr_group: the group of attributes25 * @groups: null terminated array of attribute groups26 * @attrs: null terminated array of attribute pointers.27 */28struct iio_hwmon_state {29 struct iio_channel *channels;30 int num_channels;31 struct attribute_group attr_group;32 const struct attribute_group *groups[2];33 struct attribute **attrs;34};35 36static ssize_t iio_hwmon_read_label(struct device *dev,37 struct device_attribute *attr,38 char *buf)39{40 struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);41 struct iio_hwmon_state *state = dev_get_drvdata(dev);42 struct iio_channel *chan = &state->channels[sattr->index];43 44 return iio_read_channel_label(chan, buf);45}46 47/*48 * Assumes that IIO and hwmon operate in the same base units.49 * This is supposed to be true, but needs verification for50 * new channel types.51 */52static ssize_t iio_hwmon_read_val(struct device *dev,53 struct device_attribute *attr,54 char *buf)55{56 int result;57 int ret;58 struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);59 struct iio_hwmon_state *state = dev_get_drvdata(dev);60 struct iio_channel *chan = &state->channels[sattr->index];61 enum iio_chan_type type;62 63 ret = iio_get_channel_type(chan, &type);64 if (ret < 0)65 return ret;66 67 if (type == IIO_POWER)68 /* mili-Watts to micro-Watts conversion */69 ret = iio_read_channel_processed_scale(chan, &result, 1000);70 else71 ret = iio_read_channel_processed(chan, &result);72 if (ret < 0)73 return ret;74 75 return sprintf(buf, "%d\n", result);76}77 78static int iio_hwmon_probe(struct platform_device *pdev)79{80 struct device *dev = &pdev->dev;81 struct iio_hwmon_state *st;82 struct sensor_device_attribute *a;83 int ret, i, attr = 0;84 int in_i = 1, temp_i = 1, curr_i = 1, humidity_i = 1, power_i = 1;85 enum iio_chan_type type;86 struct iio_channel *channels;87 struct device *hwmon_dev;88 char *sname;89 void *buf;90 91 channels = devm_iio_channel_get_all(dev);92 if (IS_ERR(channels)) {93 ret = PTR_ERR(channels);94 if (ret == -ENODEV)95 ret = -EPROBE_DEFER;96 return dev_err_probe(dev, ret,97 "Failed to get channels\n");98 }99 100 st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);101 buf = (void *)devm_get_free_pages(dev, GFP_KERNEL, 0);102 if (!st || !buf)103 return -ENOMEM;104 105 st->channels = channels;106 107 /* count how many channels we have */108 while (st->channels[st->num_channels].indio_dev)109 st->num_channels++;110 111 st->attrs = devm_kcalloc(dev,112 2 * st->num_channels + 1, sizeof(*st->attrs),113 GFP_KERNEL);114 if (st->attrs == NULL)115 return -ENOMEM;116 117 for (i = 0; i < st->num_channels; i++) {118 const char *prefix;119 int n;120 121 a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);122 if (a == NULL)123 return -ENOMEM;124 125 sysfs_attr_init(&a->dev_attr.attr);126 ret = iio_get_channel_type(&st->channels[i], &type);127 if (ret < 0)128 return ret;129 130 switch (type) {131 case IIO_VOLTAGE:132 n = in_i++;133 prefix = "in";134 break;135 case IIO_TEMP:136 n = temp_i++;137 prefix = "temp";138 break;139 case IIO_CURRENT:140 n = curr_i++;141 prefix = "curr";142 break;143 case IIO_POWER:144 n = power_i++;145 prefix = "power";146 break;147 case IIO_HUMIDITYRELATIVE:148 n = humidity_i++;149 prefix = "humidity";150 break;151 default:152 return -EINVAL;153 }154 155 a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,156 "%s%d_input",157 prefix, n);158 if (a->dev_attr.attr.name == NULL)159 return -ENOMEM;160 161 a->dev_attr.show = iio_hwmon_read_val;162 a->dev_attr.attr.mode = 0444;163 a->index = i;164 st->attrs[attr++] = &a->dev_attr.attr;165 166 /* Let's see if we have a label... */167 if (iio_read_channel_label(&st->channels[i], buf) < 0)168 continue;169 170 a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);171 if (a == NULL)172 return -ENOMEM;173 174 sysfs_attr_init(&a->dev_attr.attr);175 a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,176 "%s%d_label",177 prefix, n);178 if (!a->dev_attr.attr.name)179 return -ENOMEM;180 181 a->dev_attr.show = iio_hwmon_read_label;182 a->dev_attr.attr.mode = 0444;183 a->index = i;184 st->attrs[attr++] = &a->dev_attr.attr;185 }186 187 devm_free_pages(dev, (unsigned long)buf);188 189 st->attr_group.attrs = st->attrs;190 st->groups[0] = &st->attr_group;191 192 if (dev_fwnode(dev)) {193 sname = devm_kasprintf(dev, GFP_KERNEL, "%pfwP", dev_fwnode(dev));194 if (!sname)195 return -ENOMEM;196 strreplace(sname, '-', '_');197 } else {198 sname = "iio_hwmon";199 }200 201 hwmon_dev = devm_hwmon_device_register_with_groups(dev, sname, st,202 st->groups);203 return PTR_ERR_OR_ZERO(hwmon_dev);204}205 206static const struct of_device_id iio_hwmon_of_match[] = {207 { .compatible = "iio-hwmon", },208 { }209};210MODULE_DEVICE_TABLE(of, iio_hwmon_of_match);211 212static struct platform_driver iio_hwmon_driver = {213 .driver = {214 .name = "iio_hwmon",215 .of_match_table = iio_hwmon_of_match,216 },217 .probe = iio_hwmon_probe,218};219 220module_platform_driver(iio_hwmon_driver);221 222MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");223MODULE_DESCRIPTION("IIO to hwmon driver");224MODULE_LICENSE("GPL v2");225