--- /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/hwmon-sysfs.h>
+#include "consumer.h"
+#include "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;
+ 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)
+{
+ long result;
+ int val, ret, scaleint, scalepart;
+ struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
+ struct iio_hwmon_state *state = dev_get_drvdata(dev);
+
+ /*
+ * No locking between this pair, so theoretically possible
+ * the scale has changed.
+ */
+ ret = iio_st_read_channel_raw(&state->channels[sattr->index],
+ &val);
+ if (ret < 0)
+ return ret;
+
+ ret = iio_st_read_channel_scale(&state->channels[sattr->index],
+ &scaleint, &scalepart);
+ if (ret < 0)
+ return ret;
+ switch (ret) {
+ case IIO_VAL_INT:
+ result = val * scaleint;
+ break;
+ case IIO_VAL_INT_PLUS_MICRO:
+ result = (s64)val * (s64)scaleint +
+ div_s64((s64)val * (s64)scalepart, 1000000LL);
+ break;
+ case IIO_VAL_INT_PLUS_NANO:
+ result = (s64)val * (s64)scaleint +
+ div_s64((s64)val * (s64)scalepart, 1000000000LL);
+ break;
+ default:
+ return -EINVAL;
+ }
+ return sprintf(buf, "%ld\n", result);
+}
+
+static void iio_hwmon_free_attrs(struct iio_hwmon_state *st)
+{
+ int i;
+ struct sensor_device_attribute *a;
+ for (i = 0; i < st->num_channels; i++)
+ if (st->attrs[i]) {
+ a = to_sensor_dev_attr(
+ container_of(st->attrs[i],
+ struct device_attribute,
+ attr));
+ kfree(a);
+ }
+}
+
+static int __devinit iio_hwmon_probe(struct platform_device *pdev)
+{
+ struct iio_hwmon_state *st;
+ struct sensor_device_attribute *a;
+ int ret, i;
+ int in_i = 1, temp_i = 1, curr_i = 1;
+ enum iio_chan_type type;
+
+ st = kzalloc(sizeof(*st), GFP_KERNEL);
+ if (st == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ st->channels = iio_st_channel_get_all(dev_name(&pdev->dev));
+ if (IS_ERR(st->channels)) {
+ ret = PTR_ERR(st->channels);
+ goto error_free_state;
+ }
+
+ /* count how many attributes we have */
+ while (st->channels[st->num_channels].indio_dev)
+ st->num_channels++;
+
+ st->attrs = kzalloc(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 = kzalloc(sizeof(*a), GFP_KERNEL);
+ if (a == NULL) {
+ ret = -ENOMEM;
+ goto error_free_attrs;
+ }
+
+ sysfs_attr_init(&a->dev_attr.attr);
+ ret = iio_st_get_channel_type(&st->channels[i], &type);
+ if (ret < 0) {
+ kfree(a);
+ goto error_free_attrs;
+ }
+ 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;
+ default:
+ ret = -EINVAL;
+ kfree(a);
+ goto error_free_attrs;
+ }
+ if (a->dev_attr.attr.name == NULL) {
+ kfree(a);
+ ret = -ENOMEM;
+ goto error_free_attrs;
+ }
+ 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;
+ platform_set_drvdata(pdev, st);
+ ret = sysfs_create_group(&pdev->dev.kobj, &st->attr_group);
+ if (ret < 0)
+ goto error_free_attrs;
+
+ st->hwmon_dev = hwmon_device_register(&pdev->dev);
+ if (IS_ERR(st->hwmon_dev)) {
+ ret = PTR_ERR(st->hwmon_dev);
+ goto error_remove_group;
+ }
+ return 0;
+
+error_remove_group:
+ sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
+error_free_attrs:
+ iio_hwmon_free_attrs(st);
+ kfree(st->attrs);
+error_release_channels:
+ iio_st_channel_release_all(st->channels);
+error_free_state:
+ kfree(st);
+error_ret:
+ return ret;
+}
+
+static int __devexit iio_hwmon_remove(struct platform_device *pdev)
+{
+ struct iio_hwmon_state *st = platform_get_drvdata(pdev);
+
+ hwmon_device_unregister(st->hwmon_dev);
+ sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
+ iio_hwmon_free_attrs(st);
+ kfree(st->attrs);
+ iio_st_channel_release_all(st->channels);
+
+ return 0;
+}
+
+static struct platform_driver __refdata iio_hwmon_driver = {
+ .driver = {
+ .name = "iio_hwmon",
+ .owner = THIS_MODULE,
+ },
+ .probe = iio_hwmon_probe,
+ .remove = __devexit_p(iio_hwmon_remove),
+};
+
+static int iio_inkern_init(void)
+{
+ return platform_driver_register(&iio_hwmon_driver);
+}
+module_init(iio_inkern_init);
+
+static void iio_inkern_exit(void)
+{
+ platform_driver_unregister(&iio_hwmon_driver);
+}
+module_exit(iio_inkern_exit);
+
+MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
+MODULE_DESCRIPTION("IIO to hwmon driver");
+MODULE_LICENSE("GPL v2");
projects / ~andy / linux / commitdiff