--- /dev/null
+/* 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");
Code Review / kvmfornfv.git / blobdiff