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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* reg-virtual-consumer.c
*
* Copyright 2008 Wolfson Microelectronics PLC.
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*/
#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>
#include <linux/of.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,
};
#ifdef CONFIG_OF
static const struct of_device_id regulator_virtual_consumer_of_match[] = {
{ .compatible = "regulator-virtual-consumer" },
{},
};
MODULE_DEVICE_TABLE(of, regulator_virtual_consumer_of_match);
#endif
static int regulator_virtual_probe(struct platform_device *pdev)
{
char *reg_id = dev_get_platdata(&pdev->dev);
struct virtual_consumer_data *drvdata;
static bool warned;
int ret;
if (!warned) {
warned = true;
pr_warn("**********************************************************\n");
pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
pr_warn("** **\n");
pr_warn("** regulator-virtual-consumer is only for testing and **\n");
pr_warn("** debugging. Do not use it in a production kernel. **\n");
pr_warn("** **\n");
pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
pr_warn("**********************************************************\n");
}
drvdata = devm_kzalloc(&pdev->dev, sizeof(struct virtual_consumer_data),
GFP_KERNEL);
if (drvdata == NULL)
return -ENOMEM;
/*
* This virtual consumer does not have any hardware-defined supply
* name, so just allow the regulator to be specified in a property
* named "default-supply" when we're being probed from devicetree.
*/
if (!reg_id && pdev->dev.of_node)
reg_id = "default";
mutex_init(&drvdata->lock);
drvdata->regulator = devm_regulator_get(&pdev->dev, reg_id);
if (IS_ERR(drvdata->regulator))
return dev_err_probe(&pdev->dev, PTR_ERR(drvdata->regulator),
"Failed to obtain supply '%s'\n",
reg_id);
ret = sysfs_create_group(&pdev->dev.kobj,
&regulator_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, &regulator_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",
.of_match_table = of_match_ptr(regulator_virtual_consumer_of_match),
},
};
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");