/* * 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> #include <linux/slab.h> struct virtual_consumer_data { struct mutex lock; struct regulator *regulator; bool enabled; int min_uV; int max_uV; int min_uA; int max_uA; unsigned int mode; }; static void update_voltage_constraints(struct device *dev, struct virtual_consumer_data *data) { int ret; if (data->min_uV && data->max_uV && data->min_uV <= data->max_uV) { dev_dbg(dev, "Requesting %d-%duV\n", data->min_uV, data->max_uV); ret = regulator_set_voltage(data->regulator, data->min_uV, data->max_uV); if (ret != 0) { dev_err(dev, "regulator_set_voltage() failed: %d\n", ret); return; } } if (data->min_uV && data->max_uV && !data->enabled) { dev_dbg(dev, "Enabling regulator\n"); ret = regulator_enable(data->regulator); if (ret == 0) data->enabled = true; else dev_err(dev, "regulator_enable() failed: %d\n", ret); } if (!(data->min_uV && data->max_uV) && data->enabled) { dev_dbg(dev, "Disabling regulator\n"); ret = regulator_disable(data->regulator); if (ret == 0) data->enabled = false; else dev_err(dev, "regulator_disable() failed: %d\n", ret); } } static void update_current_limit_constraints(struct device *dev, struct virtual_consumer_data *data) { int ret; if (data->max_uA && data->min_uA <= data->max_uA) { dev_dbg(dev, "Requesting %d-%duA\n", data->min_uA, data->max_uA); ret = regulator_set_current_limit(data->regulator, data->min_uA, data->max_uA); if (ret != 0) { dev_err(dev, "regulator_set_current_limit() failed: %d\n", ret); return; } } if (data->max_uA && !data->enabled) { dev_dbg(dev, "Enabling regulator\n"); ret = regulator_enable(data->regulator); if (ret == 0) data->enabled = true; else dev_err(dev, "regulator_enable() failed: %d\n", ret); } if (!(data->min_uA && data->max_uA) && data->enabled) { dev_dbg(dev, "Disabling regulator\n"); ret = regulator_disable(data->regulator); if (ret == 0) data->enabled = false; else dev_err(dev, "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(dev, 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(dev, 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(dev, 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(dev, 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; /* * sysfs_streq() doesn't need the \n's, but we add them so the strings * will be shared with show_mode(), above. */ if (sysfs_streq(buf, "fast\n")) mode = REGULATOR_MODE_FAST; else if (sysfs_streq(buf, "normal\n")) mode = REGULATOR_MODE_NORMAL; else if (sysfs_streq(buf, "idle\n")) mode = REGULATOR_MODE_IDLE; else if (sysfs_streq(buf, "standby\n")) 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); static struct attribute *regulator_virtual_attributes[] = { &dev_attr_min_microvolts.attr, &dev_attr_max_microvolts.attr, &dev_attr_min_microamps.attr, &dev_attr_max_microamps.attr, &dev_attr_mode.attr, NULL }; static const struct attribute_group regulator_virtual_attr_group = { .attrs = regulator_virtual_attributes, }; static int __devinit regulator_virtual_probe(struct platform_device *pdev) { char *reg_id = pdev->dev.platform_data; struct virtual_consumer_data *drvdata; int ret; drvdata = kzalloc(sizeof(struct virtual_consumer_data), GFP_KERNEL); if (drvdata == NULL) return -ENOMEM; mutex_init(&drvdata->lock); drvdata->regulator = regulator_get(&pdev->dev, reg_id); if (IS_ERR(drvdata->regulator)) { ret = PTR_ERR(drvdata->regulator); dev_err(&pdev->dev, "Failed to obtain supply '%s': %d\n", reg_id, ret); goto err; } ret = sysfs_create_group(&pdev->dev.kobj, ®ulator_virtual_attr_group); if (ret != 0) { dev_err(&pdev->dev, "Failed to create attribute group: %d\n", ret); goto err_regulator; } drvdata->mode = regulator_get_mode(drvdata->regulator); platform_set_drvdata(pdev, drvdata); return 0; err_regulator: regulator_put(drvdata->regulator); err: kfree(drvdata); return ret; } static int __devexit regulator_virtual_remove(struct platform_device *pdev) { struct virtual_consumer_data *drvdata = platform_get_drvdata(pdev); sysfs_remove_group(&pdev->dev.kobj, ®ulator_virtual_attr_group); if (drvdata->enabled) regulator_disable(drvdata->regulator); regulator_put(drvdata->regulator); kfree(drvdata); platform_set_drvdata(pdev, NULL); return 0; } static struct platform_driver regulator_virtual_consumer_driver = { .probe = regulator_virtual_probe, .remove = __devexit_p(regulator_virtual_remove), .driver = { .name = "reg-virt-consumer", .owner = THIS_MODULE, }, }; static int __init regulator_virtual_consumer_init(void) { return platform_driver_register(®ulator_virtual_consumer_driver); } module_init(regulator_virtual_consumer_init); static void __exit regulator_virtual_consumer_exit(void) { platform_driver_unregister(®ulator_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"); MODULE_ALIAS("platform:reg-virt-consumer");