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/abx500.c b/drivers/hwmon/abx500.c
new file mode 100644
index 0000000..d87cae8
--- /dev/null
+++ b/drivers/hwmon/abx500.c
@@ -0,0 +1,491 @@
+/*
+ * Copyright (C) ST-Ericsson 2010 - 2013
+ * Author: Martin Persson <martin.persson@stericsson.com>
+ *         Hongbo Zhang <hongbo.zhang@linaro.org>
+ * License Terms: GNU General Public License v2
+ *
+ * ABX500 does not provide auto ADC, so to monitor the required temperatures,
+ * a periodic work is used. It is more important to not wake up the CPU than
+ * to perform this job, hence the use of a deferred delay.
+ *
+ * A deferred delay for thermal monitor is considered safe because:
+ * If the chip gets too hot during a sleep state it's most likely due to
+ * external factors, such as the surrounding temperature. I.e. no SW decisions
+ * will make any difference.
+ */
+
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/workqueue.h>
+#include "abx500.h"
+
+#define DEFAULT_MONITOR_DELAY	HZ
+#define DEFAULT_MAX_TEMP	130
+
+static inline void schedule_monitor(struct abx500_temp *data)
+{
+	data->work_active = true;
+	schedule_delayed_work(&data->work, DEFAULT_MONITOR_DELAY);
+}
+
+static void threshold_updated(struct abx500_temp *data)
+{
+	int i;
+	for (i = 0; i < data->monitored_sensors; i++)
+		if (data->max[i] != 0 || data->min[i] != 0) {
+			schedule_monitor(data);
+			return;
+		}
+
+	dev_dbg(&data->pdev->dev, "No active thresholds.\n");
+	cancel_delayed_work_sync(&data->work);
+	data->work_active = false;
+}
+
+static void gpadc_monitor(struct work_struct *work)
+{
+	int temp, i, ret;
+	char alarm_node[30];
+	bool updated_min_alarm, updated_max_alarm;
+	struct abx500_temp *data;
+
+	data = container_of(work, struct abx500_temp, work.work);
+	mutex_lock(&data->lock);
+
+	for (i = 0; i < data->monitored_sensors; i++) {
+		/* Thresholds are considered inactive if set to 0 */
+		if (data->max[i] == 0 && data->min[i] == 0)
+			continue;
+
+		if (data->max[i] < data->min[i])
+			continue;
+
+		ret = data->ops.read_sensor(data, data->gpadc_addr[i], &temp);
+		if (ret < 0) {
+			dev_err(&data->pdev->dev, "GPADC read failed\n");
+			continue;
+		}
+
+		updated_min_alarm = false;
+		updated_max_alarm = false;
+
+		if (data->min[i] != 0) {
+			if (temp < data->min[i]) {
+				if (data->min_alarm[i] == false) {
+					data->min_alarm[i] = true;
+					updated_min_alarm = true;
+				}
+			} else {
+				if (data->min_alarm[i] == true) {
+					data->min_alarm[i] = false;
+					updated_min_alarm = true;
+				}
+			}
+		}
+		if (data->max[i] != 0) {
+			if (temp > data->max[i]) {
+				if (data->max_alarm[i] == false) {
+					data->max_alarm[i] = true;
+					updated_max_alarm = true;
+				}
+			} else if (temp < data->max[i] - data->max_hyst[i]) {
+				if (data->max_alarm[i] == true) {
+					data->max_alarm[i] = false;
+					updated_max_alarm = true;
+				}
+			}
+		}
+
+		if (updated_min_alarm) {
+			ret = sprintf(alarm_node, "temp%d_min_alarm", i + 1);
+			sysfs_notify(&data->pdev->dev.kobj, NULL, alarm_node);
+		}
+		if (updated_max_alarm) {
+			ret = sprintf(alarm_node, "temp%d_max_alarm", i + 1);
+			sysfs_notify(&data->pdev->dev.kobj, NULL, alarm_node);
+		}
+	}
+
+	schedule_monitor(data);
+	mutex_unlock(&data->lock);
+}
+
+/* HWMON sysfs interfaces */
+static ssize_t show_name(struct device *dev, struct device_attribute *devattr,
+			 char *buf)
+{
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	/* Show chip name */
+	return data->ops.show_name(dev, devattr, buf);
+}
+
+static ssize_t show_label(struct device *dev,
+			  struct device_attribute *devattr, char *buf)
+{
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	/* Show each sensor label */
+	return data->ops.show_label(dev, devattr, buf);
+}
+
+static ssize_t show_input(struct device *dev,
+			  struct device_attribute *devattr, char *buf)
+{
+	int ret, temp;
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	u8 gpadc_addr = data->gpadc_addr[attr->index];
+
+	ret = data->ops.read_sensor(data, gpadc_addr, &temp);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%d\n", temp);
+}
+
+/* Set functions (RW nodes) */
+static ssize_t set_min(struct device *dev, struct device_attribute *devattr,
+		       const char *buf, size_t count)
+{
+	unsigned long val;
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	int res = kstrtol(buf, 10, &val);
+	if (res < 0)
+		return res;
+
+	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);
+
+	mutex_lock(&data->lock);
+	data->min[attr->index] = val;
+	threshold_updated(data);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t set_max(struct device *dev, struct device_attribute *devattr,
+		       const char *buf, size_t count)
+{
+	unsigned long val;
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	int res = kstrtol(buf, 10, &val);
+	if (res < 0)
+		return res;
+
+	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);
+
+	mutex_lock(&data->lock);
+	data->max[attr->index] = val;
+	threshold_updated(data);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t set_max_hyst(struct device *dev,
+			    struct device_attribute *devattr,
+			    const char *buf, size_t count)
+{
+	unsigned long val;
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	int res = kstrtoul(buf, 10, &val);
+	if (res < 0)
+		return res;
+
+	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);
+
+	mutex_lock(&data->lock);
+	data->max_hyst[attr->index] = val;
+	threshold_updated(data);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+/* Show functions (RO nodes) */
+static ssize_t show_min(struct device *dev,
+			struct device_attribute *devattr, char *buf)
+{
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+	return sprintf(buf, "%lu\n", data->min[attr->index]);
+}
+
+static ssize_t show_max(struct device *dev,
+			struct device_attribute *devattr, char *buf)
+{
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+	return sprintf(buf, "%lu\n", data->max[attr->index]);
+}
+
+static ssize_t show_max_hyst(struct device *dev,
+			     struct device_attribute *devattr, char *buf)
+{
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+	return sprintf(buf, "%lu\n", data->max_hyst[attr->index]);
+}
+
+static ssize_t show_min_alarm(struct device *dev,
+			      struct device_attribute *devattr, char *buf)
+{
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+	return sprintf(buf, "%d\n", data->min_alarm[attr->index]);
+}
+
+static ssize_t show_max_alarm(struct device *dev,
+			      struct device_attribute *devattr, char *buf)
+{
+	struct abx500_temp *data = dev_get_drvdata(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+	return sprintf(buf, "%d\n", data->max_alarm[attr->index]);
+}
+
+static umode_t abx500_attrs_visible(struct kobject *kobj,
+				   struct attribute *attr, int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct abx500_temp *data = dev_get_drvdata(dev);
+
+	if (data->ops.is_visible)
+		return data->ops.is_visible(attr, n);
+
+	return attr->mode;
+}
+
+/* Chip name, required by hwmon */
+static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, 0);
+
+/* GPADC - SENSOR1 */
+static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_min, set_min, 0);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_max, set_max, 0);
+static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
+			  show_max_hyst, set_max_hyst, 0);
+static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_min_alarm, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_max_alarm, NULL, 0);
+
+/* GPADC - SENSOR2 */
+static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min, 1);
+static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max, 1);
+static SENSOR_DEVICE_ATTR(temp2_max_hyst, S_IWUSR | S_IRUGO,
+			  show_max_hyst, set_max_hyst, 1);
+static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_min_alarm, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_max_alarm, NULL, 1);
+
+/* GPADC - SENSOR3 */
+static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, show_label, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min, 2);
+static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max, 2);
+static SENSOR_DEVICE_ATTR(temp3_max_hyst, S_IWUSR | S_IRUGO,
+			  show_max_hyst, set_max_hyst, 2);
+static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_min_alarm, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_max_alarm, NULL, 2);
+
+/* GPADC - SENSOR4 */
+static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, show_label, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_input, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp4_min, S_IWUSR | S_IRUGO, show_min, set_min, 3);
+static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_max, set_max, 3);
+static SENSOR_DEVICE_ATTR(temp4_max_hyst, S_IWUSR | S_IRUGO,
+			  show_max_hyst, set_max_hyst, 3);
+static SENSOR_DEVICE_ATTR(temp4_min_alarm, S_IRUGO, show_min_alarm, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_max_alarm, NULL, 3);
+
+static struct attribute *abx500_temp_attributes[] = {
+	&sensor_dev_attr_name.dev_attr.attr,
+
+	&sensor_dev_attr_temp1_label.dev_attr.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_min.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_temp2_label.dev_attr.attr,
+	&sensor_dev_attr_temp2_input.dev_attr.attr,
+	&sensor_dev_attr_temp2_min.dev_attr.attr,
+	&sensor_dev_attr_temp2_max.dev_attr.attr,
+	&sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_temp3_label.dev_attr.attr,
+	&sensor_dev_attr_temp3_input.dev_attr.attr,
+	&sensor_dev_attr_temp3_min.dev_attr.attr,
+	&sensor_dev_attr_temp3_max.dev_attr.attr,
+	&sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_temp4_label.dev_attr.attr,
+	&sensor_dev_attr_temp4_input.dev_attr.attr,
+	&sensor_dev_attr_temp4_min.dev_attr.attr,
+	&sensor_dev_attr_temp4_max.dev_attr.attr,
+	&sensor_dev_attr_temp4_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group abx500_temp_group = {
+	.attrs = abx500_temp_attributes,
+	.is_visible = abx500_attrs_visible,
+};
+
+static irqreturn_t abx500_temp_irq_handler(int irq, void *irq_data)
+{
+	struct platform_device *pdev = irq_data;
+	struct abx500_temp *data = platform_get_drvdata(pdev);
+
+	data->ops.irq_handler(irq, data);
+	return IRQ_HANDLED;
+}
+
+static int setup_irqs(struct platform_device *pdev)
+{
+	int ret;
+	int irq = platform_get_irq_byname(pdev, "ABX500_TEMP_WARM");
+
+	if (irq < 0) {
+		dev_err(&pdev->dev, "Get irq by name failed\n");
+		return irq;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+		abx500_temp_irq_handler, 0, "abx500-temp", pdev);
+	if (ret < 0)
+		dev_err(&pdev->dev, "Request threaded irq failed (%d)\n", ret);
+
+	return ret;
+}
+
+static int abx500_temp_probe(struct platform_device *pdev)
+{
+	struct abx500_temp *data;
+	int err;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->pdev = pdev;
+	mutex_init(&data->lock);
+
+	/* Chip specific initialization */
+	err = abx500_hwmon_init(data);
+	if (err	< 0 || !data->ops.read_sensor || !data->ops.show_name ||
+			!data->ops.show_label)
+		return err;
+
+	INIT_DEFERRABLE_WORK(&data->work, gpadc_monitor);
+
+	platform_set_drvdata(pdev, data);
+
+	err = sysfs_create_group(&pdev->dev.kobj, &abx500_temp_group);
+	if (err < 0) {
+		dev_err(&pdev->dev, "Create sysfs group failed (%d)\n", err);
+		return err;
+	}
+
+	data->hwmon_dev = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		dev_err(&pdev->dev, "Class registration failed (%d)\n", err);
+		goto exit_sysfs_group;
+	}
+
+	if (data->ops.irq_handler) {
+		err = setup_irqs(pdev);
+		if (err < 0)
+			goto exit_hwmon_reg;
+	}
+	return 0;
+
+exit_hwmon_reg:
+	hwmon_device_unregister(data->hwmon_dev);
+exit_sysfs_group:
+	sysfs_remove_group(&pdev->dev.kobj, &abx500_temp_group);
+	return err;
+}
+
+static int abx500_temp_remove(struct platform_device *pdev)
+{
+	struct abx500_temp *data = platform_get_drvdata(pdev);
+
+	cancel_delayed_work_sync(&data->work);
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&pdev->dev.kobj, &abx500_temp_group);
+
+	return 0;
+}
+
+static int abx500_temp_suspend(struct platform_device *pdev,
+			       pm_message_t state)
+{
+	struct abx500_temp *data = platform_get_drvdata(pdev);
+
+	if (data->work_active)
+		cancel_delayed_work_sync(&data->work);
+
+	return 0;
+}
+
+static int abx500_temp_resume(struct platform_device *pdev)
+{
+	struct abx500_temp *data = platform_get_drvdata(pdev);
+
+	if (data->work_active)
+		schedule_monitor(data);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id abx500_temp_match[] = {
+	{ .compatible = "stericsson,abx500-temp" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, abx500_temp_match);
+#endif
+
+static struct platform_driver abx500_temp_driver = {
+	.driver = {
+		.name = "abx500-temp",
+		.of_match_table = of_match_ptr(abx500_temp_match),
+	},
+	.suspend = abx500_temp_suspend,
+	.resume = abx500_temp_resume,
+	.probe = abx500_temp_probe,
+	.remove = abx500_temp_remove,
+};
+
+module_platform_driver(abx500_temp_driver);
+
+MODULE_AUTHOR("Martin Persson <martin.persson@stericsson.com>");
+MODULE_DESCRIPTION("ABX500 temperature driver");
+MODULE_LICENSE("GPL");