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/*
* 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 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.
*
* 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.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_gpio.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
*
* 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)
{
struct fixed_voltage_config *config;
struct device_node *np = dev->of_node;
const __be32 *delay;
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);
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;
config->gpio = of_get_named_gpio(np, "gpio", 0);
/*
* of_get_named_gpio() currently returns ENODEV rather than
* EPROBE_DEFER. This code attempts to be compatible with both
* for now; the ENODEV check can be removed once the API is fixed.
* of_get_named_gpio() doesn't differentiate between a missing
* property (which would be fine here, since the GPIO is optional)
* and some other error. Patches have been posted for both issues.
* Once they are check in, we should replace this with:
* if (config->gpio < 0 && config->gpio != -ENOENT)
*/
if ((config->gpio == -ENODEV) || (config->gpio == -EPROBE_DEFER))
return ERR_PTR(-EPROBE_DEFER);
delay = of_get_property(np, "startup-delay-us", NULL);
if (delay)
config->startup_delay = be32_to_cpu(*delay);
if (of_find_property(np, "enable-active-high", NULL))
config->enable_high = true;
if (of_find_property(np, "gpio-open-drain", NULL))
config->gpio_is_open_drain = true;
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 = { };
int ret;
if (pdev->dev.of_node) {
config = of_get_fixed_voltage_config(&pdev->dev);
if (IS_ERR(config))
return PTR_ERR(config);
} else {
config = dev_get_platdata(&pdev->dev);
}
if (!config)
return -ENOMEM;
drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
GFP_KERNEL);
if (drvdata == NULL) {
dev_err(&pdev->dev, "Failed to allocate device data\n");
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;
if (config->gpio >= 0)
cfg.ena_gpio = config->gpio;
cfg.ena_gpio_invert = !config->enable_high;
if (config->enabled_at_boot) {
if (config->enable_high)
cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
else
cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
} else {
if (config->enable_high)
cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
else
cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
}
if (config->gpio_is_open_drain)
cfg.ena_gpio_flags |= GPIOF_OPEN_DRAIN;
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",
.owner = THIS_MODULE,
.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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