Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 172 insertions, 0 deletions

diff --git a/drivers/hwmon/iio_hwmon.c b/drivers/hwmon/iio_hwmon.c
new file mode 100644
index 000000000..2f3f875c0
--- /dev/null
+++ b/drivers/hwmon/iio_hwmon.c
@@ -0,0 +1,172 @@
+/* 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)
+ * @attr_group:		the group of attributes
+ * @groups:		null terminated array of attribute groups
+ * @attrs:		null terminated array of attribute pointers.
+ */
+struct iio_hwmon_state {
+	struct iio_channel *channels;
+	int num_channels;
+	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";
+	struct device *hwmon_dev;
+	char *sname;
+
+	if (dev->of_node && dev->of_node->name)
+		name = dev->of_node->name;
+
+	channels = devm_iio_channel_get_all(dev);
+	if (IS_ERR(channels)) {
+		if (PTR_ERR(channels) == -ENODEV)
+			return -EPROBE_DEFER;
+		return PTR_ERR(channels);
+	}
+
+	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
+	if (st == NULL)
+		return -ENOMEM;
+
+	st->channels = channels;
+
+	/* count how many attributes we have */
+	while (st->channels[st->num_channels].indio_dev)
+		st->num_channels++;
+
+	st->attrs = devm_kcalloc(dev,
+				 st->num_channels + 1, sizeof(*st->attrs),
+				 GFP_KERNEL);
+	if (st->attrs == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < st->num_channels; i++) {
+		a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
+		if (a == NULL)
+			return -ENOMEM;
+
+		sysfs_attr_init(&a->dev_attr.attr);
+		ret = iio_get_channel_type(&st->channels[i], &type);
+		if (ret < 0)
+			return ret;
+
+		switch (type) {
+		case IIO_VOLTAGE:
+			a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
+							       "in%d_input",
+							       in_i++);
+			break;
+		case IIO_TEMP:
+			a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
+							       "temp%d_input",
+							       temp_i++);
+			break;
+		case IIO_CURRENT:
+			a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
+							       "curr%d_input",
+							       curr_i++);
+			break;
+		case IIO_HUMIDITYRELATIVE:
+			a->dev_attr.attr.name = devm_kasprintf(dev, GFP_KERNEL,
+							       "humidity%d_input",
+							       humidity_i++);
+			break;
+		default:
+			return -EINVAL;
+		}
+		if (a->dev_attr.attr.name == NULL)
+			return -ENOMEM;
+
+		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;
+
+	sname = devm_kstrdup(dev, name, GFP_KERNEL);
+	if (!sname)
+		return -ENOMEM;
+
+	strreplace(sname, '-', '_');
+	hwmon_dev = devm_hwmon_device_register_with_groups(dev, sname, st,
+							   st->groups);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+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,
+};
+
+module_platform_driver(iio_hwmon_driver);
+
+MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
+MODULE_DESCRIPTION("IIO to hwmon driver");
+MODULE_LICENSE("GPL v2");