File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/hwmon/vexpress.c b/drivers/hwmon/vexpress.c
new file mode 100644
index 0000000..8ba419d
--- /dev/null
+++ b/drivers/hwmon/vexpress.c
@@ -0,0 +1,259 @@
+/*
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2012 ARM Limited
+ */
+
+#define DRVNAME "vexpress-hwmon"
+#define pr_fmt(fmt) DRVNAME ": " fmt
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/vexpress.h>
+
+struct vexpress_hwmon_data {
+	struct device *hwmon_dev;
+	struct regmap *reg;
+};
+
+static ssize_t vexpress_hwmon_label_show(struct device *dev,
+		struct device_attribute *dev_attr, char *buffer)
+{
+	const char *label = of_get_property(dev->of_node, "label", NULL);
+
+	return snprintf(buffer, PAGE_SIZE, "%s\n", label);
+}
+
+static ssize_t vexpress_hwmon_u32_show(struct device *dev,
+		struct device_attribute *dev_attr, char *buffer)
+{
+	struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
+	int err;
+	u32 value;
+
+	err = regmap_read(data->reg, 0, &value);
+	if (err)
+		return err;
+
+	return snprintf(buffer, PAGE_SIZE, "%u\n", value /
+			to_sensor_dev_attr(dev_attr)->index);
+}
+
+static ssize_t vexpress_hwmon_u64_show(struct device *dev,
+		struct device_attribute *dev_attr, char *buffer)
+{
+	struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
+	int err;
+	u32 value_hi, value_lo;
+
+	err = regmap_read(data->reg, 0, &value_lo);
+	if (err)
+		return err;
+
+	err = regmap_read(data->reg, 1, &value_hi);
+	if (err)
+		return err;
+
+	return snprintf(buffer, PAGE_SIZE, "%llu\n",
+			div_u64(((u64)value_hi << 32) | value_lo,
+			to_sensor_dev_attr(dev_attr)->index));
+}
+
+static umode_t vexpress_hwmon_attr_is_visible(struct kobject *kobj,
+		struct attribute *attr, int index)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct device_attribute *dev_attr = container_of(attr,
+				struct device_attribute, attr);
+
+	if (dev_attr->show == vexpress_hwmon_label_show &&
+			!of_get_property(dev->of_node, "label", NULL))
+		return 0;
+
+	return attr->mode;
+}
+
+struct vexpress_hwmon_type {
+	const char *name;
+	const struct attribute_group **attr_groups;
+};
+
+#if !defined(CONFIG_REGULATOR_VEXPRESS)
+static DEVICE_ATTR(in1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, vexpress_hwmon_u32_show,
+		NULL, 1000);
+static struct attribute *vexpress_hwmon_attrs_volt[] = {
+	&dev_attr_in1_label.attr,
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	NULL
+};
+static struct attribute_group vexpress_hwmon_group_volt = {
+	.is_visible = vexpress_hwmon_attr_is_visible,
+	.attrs = vexpress_hwmon_attrs_volt,
+};
+static struct vexpress_hwmon_type vexpress_hwmon_volt = {
+	.name = "vexpress_volt",
+	.attr_groups = (const struct attribute_group *[]) {
+		&vexpress_hwmon_group_volt,
+		NULL,
+	},
+};
+#endif
+
+static DEVICE_ATTR(curr1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
+static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, vexpress_hwmon_u32_show,
+		NULL, 1000);
+static struct attribute *vexpress_hwmon_attrs_amp[] = {
+	&dev_attr_curr1_label.attr,
+	&sensor_dev_attr_curr1_input.dev_attr.attr,
+	NULL
+};
+static struct attribute_group vexpress_hwmon_group_amp = {
+	.is_visible = vexpress_hwmon_attr_is_visible,
+	.attrs = vexpress_hwmon_attrs_amp,
+};
+static struct vexpress_hwmon_type vexpress_hwmon_amp = {
+	.name = "vexpress_amp",
+	.attr_groups = (const struct attribute_group *[]) {
+		&vexpress_hwmon_group_amp,
+		NULL
+	},
+};
+
+static DEVICE_ATTR(temp1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, vexpress_hwmon_u32_show,
+		NULL, 1000);
+static struct attribute *vexpress_hwmon_attrs_temp[] = {
+	&dev_attr_temp1_label.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	NULL
+};
+static struct attribute_group vexpress_hwmon_group_temp = {
+	.is_visible = vexpress_hwmon_attr_is_visible,
+	.attrs = vexpress_hwmon_attrs_temp,
+};
+static struct vexpress_hwmon_type vexpress_hwmon_temp = {
+	.name = "vexpress_temp",
+	.attr_groups = (const struct attribute_group *[]) {
+		&vexpress_hwmon_group_temp,
+		NULL
+	},
+};
+
+static DEVICE_ATTR(power1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
+static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, vexpress_hwmon_u32_show,
+		NULL, 1);
+static struct attribute *vexpress_hwmon_attrs_power[] = {
+	&dev_attr_power1_label.attr,
+	&sensor_dev_attr_power1_input.dev_attr.attr,
+	NULL
+};
+static struct attribute_group vexpress_hwmon_group_power = {
+	.is_visible = vexpress_hwmon_attr_is_visible,
+	.attrs = vexpress_hwmon_attrs_power,
+};
+static struct vexpress_hwmon_type vexpress_hwmon_power = {
+	.name = "vexpress_power",
+	.attr_groups = (const struct attribute_group *[]) {
+		&vexpress_hwmon_group_power,
+		NULL
+	},
+};
+
+static DEVICE_ATTR(energy1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
+static SENSOR_DEVICE_ATTR(energy1_input, S_IRUGO, vexpress_hwmon_u64_show,
+		NULL, 1);
+static struct attribute *vexpress_hwmon_attrs_energy[] = {
+	&dev_attr_energy1_label.attr,
+	&sensor_dev_attr_energy1_input.dev_attr.attr,
+	NULL
+};
+static struct attribute_group vexpress_hwmon_group_energy = {
+	.is_visible = vexpress_hwmon_attr_is_visible,
+	.attrs = vexpress_hwmon_attrs_energy,
+};
+static struct vexpress_hwmon_type vexpress_hwmon_energy = {
+	.name = "vexpress_energy",
+	.attr_groups = (const struct attribute_group *[]) {
+		&vexpress_hwmon_group_energy,
+		NULL
+	},
+};
+
+static const struct of_device_id vexpress_hwmon_of_match[] = {
+#if !defined(CONFIG_REGULATOR_VEXPRESS)
+	{
+		.compatible = "arm,vexpress-volt",
+		.data = &vexpress_hwmon_volt,
+	},
+#endif
+	{
+		.compatible = "arm,vexpress-amp",
+		.data = &vexpress_hwmon_amp,
+	}, {
+		.compatible = "arm,vexpress-temp",
+		.data = &vexpress_hwmon_temp,
+	}, {
+		.compatible = "arm,vexpress-power",
+		.data = &vexpress_hwmon_power,
+	}, {
+		.compatible = "arm,vexpress-energy",
+		.data = &vexpress_hwmon_energy,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, vexpress_hwmon_of_match);
+
+static int vexpress_hwmon_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct vexpress_hwmon_data *data;
+	const struct vexpress_hwmon_type *type;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, data);
+
+	match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
+	if (!match)
+		return -ENODEV;
+	type = match->data;
+
+	data->reg = devm_regmap_init_vexpress_config(&pdev->dev);
+	if (IS_ERR(data->reg))
+		return PTR_ERR(data->reg);
+
+	data->hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
+			type->name, data, type->attr_groups);
+
+	return PTR_ERR_OR_ZERO(data->hwmon_dev);
+}
+
+static struct platform_driver vexpress_hwmon_driver = {
+	.probe = vexpress_hwmon_probe,
+	.driver	= {
+		.name = DRVNAME,
+		.of_match_table = vexpress_hwmon_of_match,
+	},
+};
+
+module_platform_driver(vexpress_hwmon_driver);
+
+MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
+MODULE_DESCRIPTION("Versatile Express hwmon sensors driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:vexpress-hwmon");