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>

1 files changed, 345 insertions, 0 deletions

diff --git a/drivers/regulator/virtual.c b/drivers/regulator/virtual.c
new file mode 100644
index 000000000000..5ddb464b1c3f
--- /dev/null
+++ b/drivers/regulator/virtual.c
@@ -0,0 +1,345 @@
+/*
+ * 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");