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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* fixed.c
*
* Copyright 2008 Wolfson Microelectronics PLC.
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*
* Copyright (c) 2009 Nokia Corporation
* Roger Quadros <ext-roger.quadros@nokia.com>
*
* This is useful for systems with mixed controllable and
* non-controllable regulators, as well as for allowing testing on
* systems with no controllable regulators.
*/
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/fixed.h>
#include <linux/gpio/consumer.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/machine.h>
struct fixed_voltage_data {
struct regulator_desc desc;
struct regulator_dev *dev;
};
/**
* of_get_fixed_voltage_config - extract fixed_voltage_config structure info
* @dev: device requesting for fixed_voltage_config
* @desc: regulator description
*
* Populates fixed_voltage_config structure by extracting data from device
* tree node, returns a pointer to the populated structure of NULL if memory
* alloc fails.
*/
static struct fixed_voltage_config *
of_get_fixed_voltage_config(struct device *dev,
const struct regulator_desc *desc)
{
struct fixed_voltage_config *config;
struct device_node *np = dev->of_node;
struct regulator_init_data *init_data;
config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
GFP_KERNEL);
if (!config)
return ERR_PTR(-ENOMEM);
config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
if (!config->init_data)
return ERR_PTR(-EINVAL);
init_data = config->init_data;
init_data->constraints.apply_uV = 0;
config->supply_name = init_data->constraints.name;
if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
config->microvolts = init_data->constraints.min_uV;
} else {
dev_err(dev,
"Fixed regulator specified with variable voltages\n");
return ERR_PTR(-EINVAL);
}
if (init_data->constraints.boot_on)
config->enabled_at_boot = true;
of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
if (of_find_property(np, "vin-supply", NULL))
config->input_supply = "vin";
return config;
}
static struct regulator_ops fixed_voltage_ops = {
};
static int reg_fixed_voltage_probe(struct platform_device *pdev)
{
struct fixed_voltage_config *config;
struct fixed_voltage_data *drvdata;
struct regulator_config cfg = { };
enum gpiod_flags gflags;
int ret;
drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
if (pdev->dev.of_node) {
config = of_get_fixed_voltage_config(&pdev->dev,
&drvdata->desc);
if (IS_ERR(config))
return PTR_ERR(config);
} else {
config = dev_get_platdata(&pdev->dev);
}
if (!config)
return -ENOMEM;
drvdata->desc.name = devm_kstrdup(&pdev->dev,
config->supply_name,
GFP_KERNEL);
if (drvdata->desc.name == NULL) {
dev_err(&pdev->dev, "Failed to allocate supply name\n");
return -ENOMEM;
}
drvdata->desc.type = REGULATOR_VOLTAGE;
drvdata->desc.owner = THIS_MODULE;
drvdata->desc.ops = &fixed_voltage_ops;
drvdata->desc.enable_time = config->startup_delay;
if (config->input_supply) {
drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
config->input_supply,
GFP_KERNEL);
if (!drvdata->desc.supply_name) {
dev_err(&pdev->dev,
"Failed to allocate input supply\n");
return -ENOMEM;
}
}
if (config->microvolts)
drvdata->desc.n_voltages = 1;
drvdata->desc.fixed_uV = config->microvolts;
/*
* The signal will be inverted by the GPIO core if flagged so in the
* decriptor.
*/
if (config->enabled_at_boot)
gflags = GPIOD_OUT_HIGH;
else
gflags = GPIOD_OUT_LOW;
/*
* Some fixed regulators share the enable line between two
* regulators which makes it necessary to get a handle on the
* same descriptor for two different consumers. This will get
* the GPIO descriptor, but only the first call will initialize
* it so any flags such as inversion or open drain will only
* be set up by the first caller and assumed identical on the
* next caller.
*
* FIXME: find a better way to deal with this.
*/
gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
/*
* Do not use devm* here: the regulator core takes over the
* lifecycle management of the GPIO descriptor.
*/
cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags);
if (IS_ERR(cfg.ena_gpiod))
return PTR_ERR(cfg.ena_gpiod);
cfg.dev = &pdev->dev;
cfg.init_data = config->init_data;
cfg.driver_data = drvdata;
cfg.of_node = pdev->dev.of_node;
drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
&cfg);
if (IS_ERR(drvdata->dev)) {
ret = PTR_ERR(drvdata->dev);
dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, drvdata);
dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
drvdata->desc.fixed_uV);
return 0;
}
#if defined(CONFIG_OF)
static const struct of_device_id fixed_of_match[] = {
{ .compatible = "regulator-fixed", },
{},
};
MODULE_DEVICE_TABLE(of, fixed_of_match);
#endif
static struct platform_driver regulator_fixed_voltage_driver = {
.probe = reg_fixed_voltage_probe,
.driver = {
.name = "reg-fixed-voltage",
.of_match_table = of_match_ptr(fixed_of_match),
},
};
static int __init regulator_fixed_voltage_init(void)
{
return platform_driver_register(®ulator_fixed_voltage_driver);
}
subsys_initcall(regulator_fixed_voltage_init);
static void __exit regulator_fixed_voltage_exit(void)
{
platform_driver_unregister(®ulator_fixed_voltage_driver);
}
module_exit(regulator_fixed_voltage_exit);
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("Fixed voltage regulator");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:reg-fixed-voltage");
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