diff options
Diffstat (limited to 'drivers/regulator/virtual.c')
| -rw-r--r-- | drivers/regulator/virtual.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/drivers/regulator/virtual.c b/drivers/regulator/virtual.c new file mode 100644 index 000000000..a6f1c7a99 --- /dev/null +++ b/drivers/regulator/virtual.c @@ -0,0 +1,349 @@ +/* + * 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"); |