regulator: regulator test harness

This provides a virtual regulator test harness which exposes a sysfs
interface for setting power requirements, intended for test purposes only.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>

drivers/regulator/virtual.c

+/*
+ * reg-virtual-consumer.c
+ *
+ * Copyright 2008 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ */
+
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+struct virtual_consumer_data {
+	struct mutex lock;
+	struct regulator *regulator;
+	int enabled;
+	int min_uV;
+	int max_uV;
+	int min_uA;
+	int max_uA;
+	unsigned int mode;
+};
+
+static void update_voltage_constraints(struct virtual_consumer_data *data)
+{
+	int ret;
+
+	if (data->min_uV && data->max_uV
+	    && data->min_uV <= data->max_uV) {
+		ret = regulator_set_voltage(data->regulator,
+					    data->min_uV, data->max_uV);
+		if (ret != 0) {
+			printk(KERN_ERR "regulator_set_voltage() failed: %d\n",
+			       ret);
+			return;
+		}
+	}
+
+	if (data->min_uV && data->max_uV && !data->enabled) {
+		ret = regulator_enable(data->regulator);
+		if (ret == 0)
+			data->enabled = 1;
+		else
+			printk(KERN_ERR "regulator_enable() failed: %d\n",
+				ret);
+	}
+
+	if (!(data->min_uV && data->max_uV) && data->enabled) {
+		ret = regulator_disable(data->regulator);
+		if (ret == 0)
+			data->enabled = 0;
+		else
+			printk(KERN_ERR "regulator_disable() failed: %d\n",
+				ret);
+	}
+}
+
+static void update_current_limit_constraints(struct virtual_consumer_data
+						*data)
+{
+	int ret;
+
+	if (data->max_uA
+	    && data->min_uA <= data->max_uA) {
+		ret = regulator_set_current_limit(data->regulator,
+					data->min_uA, data->max_uA);
+		if (ret != 0) {
+			pr_err("regulator_set_current_limit() failed: %d\n",
+			       ret);
+			return;
+		}
+	}
+
+	if (data->max_uA && !data->enabled) {
+		ret = regulator_enable(data->regulator);
+		if (ret == 0)
+			data->enabled = 1;
+		else
+			printk(KERN_ERR "regulator_enable() failed: %d\n",
+				ret);
+	}
+
+	if (!(data->min_uA && data->max_uA) && data->enabled) {
+		ret = regulator_disable(data->regulator);
+		if (ret == 0)
+			data->enabled = 0;
+		else
+			printk(KERN_ERR "regulator_disable() failed: %d\n",
+				ret);
+	}
+}
+
+static ssize_t show_min_uV(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", data->min_uV);
+}
+
+static ssize_t set_min_uV(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	long val;
+
+	if (strict_strtol(buf, 10, &val) != 0)
+		return count;
+
+	mutex_lock(&data->lock);
+
+	data->min_uV = val;
+	update_voltage_constraints(data);
+
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_max_uV(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", data->max_uV);
+}
+
+static ssize_t set_max_uV(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	long val;
+
+	if (strict_strtol(buf, 10, &val) != 0)
+		return count;
+
+	mutex_lock(&data->lock);
+
+	data->max_uV = val;
+	update_voltage_constraints(data);
+
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_min_uA(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", data->min_uA);
+}
+
+static ssize_t set_min_uA(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	long val;
+
+	if (strict_strtol(buf, 10, &val) != 0)
+		return count;
+
+	mutex_lock(&data->lock);
+
+	data->min_uA = val;
+	update_current_limit_constraints(data);
+
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_max_uA(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	return sprintf(buf, "%d\n", data->max_uA);
+}
+
+static ssize_t set_max_uA(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	long val;
+
+	if (strict_strtol(buf, 10, &val) != 0)
+		return count;
+
+	mutex_lock(&data->lock);
+
+	data->max_uA = val;
+	update_current_limit_constraints(data);
+
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_mode(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+
+	switch (data->mode) {
+	case REGULATOR_MODE_FAST:
+		return sprintf(buf, "fast\n");
+	case REGULATOR_MODE_NORMAL:
+		return sprintf(buf, "normal\n");
+	case REGULATOR_MODE_IDLE:
+		return sprintf(buf, "idle\n");
+	case REGULATOR_MODE_STANDBY:
+		return sprintf(buf, "standby\n");
+	default:
+		return sprintf(buf, "unknown\n");
+	}
+}
+
+static ssize_t set_mode(struct device *dev, struct device_attribute *attr,
+			const char *buf, size_t count)
+{
+	struct virtual_consumer_data *data = dev_get_drvdata(dev);
+	unsigned int mode;
+	int ret;
+
+	if (strncmp(buf, "fast", strlen("fast")) == 0)
+		mode = REGULATOR_MODE_FAST;
+	else if (strncmp(buf, "normal", strlen("normal")) == 0)
+		mode = REGULATOR_MODE_NORMAL;
+	else if (strncmp(buf, "idle", strlen("idle")) == 0)
+		mode = REGULATOR_MODE_IDLE;
+	else if (strncmp(buf, "standby", strlen("standby")) == 0)
+		mode = REGULATOR_MODE_STANDBY;
+	else {
+		dev_err(dev, "Configuring invalid mode\n");
+		return count;
+	}
+
+	mutex_lock(&data->lock);
+	ret = regulator_set_mode(data->regulator, mode);
+	if (ret == 0)
+		data->mode = mode;
+	else
+		dev_err(dev, "Failed to configure mode: %d\n", ret);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static DEVICE_ATTR(min_microvolts, 0666, show_min_uV, set_min_uV);
+static DEVICE_ATTR(max_microvolts, 0666, show_max_uV, set_max_uV);
+static DEVICE_ATTR(min_microamps, 0666, show_min_uA, set_min_uA);
+static DEVICE_ATTR(max_microamps, 0666, show_max_uA, set_max_uA);
+static DEVICE_ATTR(mode, 0666, show_mode, set_mode);
+
+struct device_attribute *attributes[] = {
+	&dev_attr_min_microvolts,
+	&dev_attr_max_microvolts,
+	&dev_attr_min_microamps,
+	&dev_attr_max_microamps,
+	&dev_attr_mode,
+};
+
+static int regulator_virtual_consumer_probe(struct platform_device *pdev)
+{
+	char *reg_id = pdev->dev.platform_data;
+	struct virtual_consumer_data *drvdata;
+	int ret, i;
+
+	drvdata = kzalloc(sizeof(struct virtual_consumer_data), GFP_KERNEL);
+	if (drvdata == NULL) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mutex_init(&drvdata->lock);
+
+	drvdata->regulator = regulator_get(&pdev->dev, reg_id);
+	if (IS_ERR(drvdata->regulator)) {
+		ret = PTR_ERR(drvdata->regulator);
+		goto err;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(attributes); i++) {
+		ret = device_create_file(&pdev->dev, attributes[i]);
+		if (ret != 0)
+			goto err;
+	}
+
+	drvdata->mode = regulator_get_mode(drvdata->regulator);
+
+	platform_set_drvdata(pdev, drvdata);
+
+	return 0;
+
+err:
+	for (i = 0; i < ARRAY_SIZE(attributes); i++)
+		device_remove_file(&pdev->dev, attributes[i]);
+	kfree(drvdata);
+	return ret;
+}
+
+static int regulator_virtual_consumer_remove(struct platform_device *pdev)
+{
+	struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(attributes); i++)
+		device_remove_file(&pdev->dev, attributes[i]);
+	if (drvdata->enabled)
+		regulator_disable(drvdata->regulator);
+	regulator_put(drvdata->regulator);
+
+	kfree(drvdata);
+
+	return 0;
+}
+
+static struct platform_driver regulator_virtual_consumer_driver = {
+	.probe		= regulator_virtual_consumer_probe,
+	.remove		= regulator_virtual_consumer_remove,
+	.driver		= {
+		.name		= "reg-virt-consumer",
+	},
+};
+
+
+static int __init regulator_virtual_consumer_init(void)
+{
+	return platform_driver_register(&regulator_virtual_consumer_driver);
+}
+module_init(regulator_virtual_consumer_init);
+
+static void __exit regulator_virtual_consumer_exit(void)
+{
+	platform_driver_unregister(&regulator_virtual_consumer_driver);
+}
+module_exit(regulator_virtual_consumer_exit);
+
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("Virtual regulator consumer");
+MODULE_LICENSE("GPL");