|  | /* | 
|  | * 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> | 
|  | #include <linux/module.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 (kstrtol(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 (kstrtol(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 (kstrtol(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 (kstrtol(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, 0664, show_min_uV, set_min_uV); | 
|  | static DEVICE_ATTR(max_microvolts, 0664, show_max_uV, set_max_uV); | 
|  | static DEVICE_ATTR(min_microamps, 0664, show_min_uA, set_min_uA); | 
|  | static DEVICE_ATTR(max_microamps, 0664, show_max_uA, set_max_uA); | 
|  | static DEVICE_ATTR(mode, 0664, 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 regulator_virtual_probe(struct platform_device *pdev) | 
|  | { | 
|  | char *reg_id = dev_get_platdata(&pdev->dev); | 
|  | struct virtual_consumer_data *drvdata; | 
|  | int ret; | 
|  |  | 
|  | drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data), | 
|  | GFP_KERNEL); | 
|  | if (drvdata == NULL) | 
|  | return -ENOMEM; | 
|  |  | 
|  | mutex_init(&drvdata->lock); | 
|  |  | 
|  | drvdata->regulator = devm_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); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | 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); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | drvdata->mode = regulator_get_mode(drvdata->regulator); | 
|  |  | 
|  | platform_set_drvdata(pdev, drvdata); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int 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); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static struct platform_driver regulator_virtual_consumer_driver = { | 
|  | .probe		= regulator_virtual_probe, | 
|  | .remove		= regulator_virtual_remove, | 
|  | .driver		= { | 
|  | .name		= "reg-virt-consumer", | 
|  | }, | 
|  | }; | 
|  |  | 
|  | module_platform_driver(regulator_virtual_consumer_driver); | 
|  |  | 
|  | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); | 
|  | MODULE_DESCRIPTION("Virtual regulator consumer"); | 
|  | MODULE_LICENSE("GPL"); | 
|  | MODULE_ALIAS("platform:reg-virt-consumer"); |