231 lines
6.4 KiB
C
231 lines
6.4 KiB
C
/*
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* fixed.c
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*
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* Copyright 2008 Wolfson Microelectronics PLC.
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*
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* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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*
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* Copyright (c) 2009 Nokia Corporation
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* Roger Quadros <ext-roger.quadros@nokia.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This is useful for systems with mixed controllable and
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* non-controllable regulators, as well as for allowing testing on
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* systems with no controllable regulators.
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*/
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/driver.h>
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#include <linux/regulator/fixed.h>
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#include <linux/gpio.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include <linux/of_gpio.h>
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#include <linux/regulator/of_regulator.h>
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#include <linux/regulator/machine.h>
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struct fixed_voltage_data {
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struct regulator_desc desc;
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struct regulator_dev *dev;
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};
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/**
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* of_get_fixed_voltage_config - extract fixed_voltage_config structure info
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* @dev: device requesting for fixed_voltage_config
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*
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* Populates fixed_voltage_config structure by extracting data from device
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* tree node, returns a pointer to the populated structure of NULL if memory
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* alloc fails.
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*/
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static struct fixed_voltage_config *
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of_get_fixed_voltage_config(struct device *dev)
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{
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struct fixed_voltage_config *config;
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struct device_node *np = dev->of_node;
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struct regulator_init_data *init_data;
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config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
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GFP_KERNEL);
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if (!config)
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return ERR_PTR(-ENOMEM);
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config->init_data = of_get_regulator_init_data(dev, dev->of_node);
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if (!config->init_data)
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return ERR_PTR(-EINVAL);
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init_data = config->init_data;
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init_data->constraints.apply_uV = 0;
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config->supply_name = init_data->constraints.name;
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if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
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config->microvolts = init_data->constraints.min_uV;
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} else {
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dev_err(dev,
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"Fixed regulator specified with variable voltages\n");
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return ERR_PTR(-EINVAL);
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}
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if (init_data->constraints.boot_on)
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config->enabled_at_boot = true;
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config->gpio = of_get_named_gpio(np, "gpio", 0);
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/*
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* of_get_named_gpio() currently returns ENODEV rather than
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* EPROBE_DEFER. This code attempts to be compatible with both
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* for now; the ENODEV check can be removed once the API is fixed.
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* of_get_named_gpio() doesn't differentiate between a missing
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* property (which would be fine here, since the GPIO is optional)
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* and some other error. Patches have been posted for both issues.
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* Once they are check in, we should replace this with:
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* if (config->gpio < 0 && config->gpio != -ENOENT)
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*/
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if ((config->gpio == -ENODEV) || (config->gpio == -EPROBE_DEFER))
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return ERR_PTR(-EPROBE_DEFER);
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of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
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config->enable_high = of_property_read_bool(np, "enable-active-high");
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config->gpio_is_open_drain = of_property_read_bool(np,
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"gpio-open-drain");
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if (of_find_property(np, "vin-supply", NULL))
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config->input_supply = "vin";
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return config;
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}
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static struct regulator_ops fixed_voltage_ops = {
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};
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static int reg_fixed_voltage_probe(struct platform_device *pdev)
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{
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struct fixed_voltage_config *config;
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struct fixed_voltage_data *drvdata;
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struct regulator_config cfg = { };
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int ret;
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if (pdev->dev.of_node) {
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config = of_get_fixed_voltage_config(&pdev->dev);
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if (IS_ERR(config))
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return PTR_ERR(config);
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} else {
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config = dev_get_platdata(&pdev->dev);
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}
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if (!config)
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return -ENOMEM;
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drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
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GFP_KERNEL);
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if (!drvdata)
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return -ENOMEM;
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drvdata->desc.name = devm_kstrdup(&pdev->dev,
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config->supply_name,
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GFP_KERNEL);
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if (drvdata->desc.name == NULL) {
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dev_err(&pdev->dev, "Failed to allocate supply name\n");
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return -ENOMEM;
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}
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drvdata->desc.type = REGULATOR_VOLTAGE;
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drvdata->desc.owner = THIS_MODULE;
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drvdata->desc.ops = &fixed_voltage_ops;
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drvdata->desc.enable_time = config->startup_delay;
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if (config->input_supply) {
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drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
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config->input_supply,
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GFP_KERNEL);
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if (!drvdata->desc.supply_name) {
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dev_err(&pdev->dev,
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"Failed to allocate input supply\n");
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return -ENOMEM;
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}
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}
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if (config->microvolts)
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drvdata->desc.n_voltages = 1;
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drvdata->desc.fixed_uV = config->microvolts;
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if (config->gpio >= 0)
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cfg.ena_gpio = config->gpio;
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cfg.ena_gpio_invert = !config->enable_high;
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if (config->enabled_at_boot) {
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if (config->enable_high)
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cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
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else
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cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
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} else {
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if (config->enable_high)
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cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
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else
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cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
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}
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if (config->gpio_is_open_drain)
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cfg.ena_gpio_flags |= GPIOF_OPEN_DRAIN;
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cfg.dev = &pdev->dev;
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cfg.init_data = config->init_data;
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cfg.driver_data = drvdata;
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cfg.of_node = pdev->dev.of_node;
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drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
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&cfg);
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if (IS_ERR(drvdata->dev)) {
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ret = PTR_ERR(drvdata->dev);
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dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
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return ret;
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}
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platform_set_drvdata(pdev, drvdata);
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dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
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drvdata->desc.fixed_uV);
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return 0;
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}
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#if defined(CONFIG_OF)
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static const struct of_device_id fixed_of_match[] = {
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{ .compatible = "regulator-fixed", },
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{},
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};
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MODULE_DEVICE_TABLE(of, fixed_of_match);
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#endif
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static struct platform_driver regulator_fixed_voltage_driver = {
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.probe = reg_fixed_voltage_probe,
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.driver = {
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.name = "reg-fixed-voltage",
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.owner = THIS_MODULE,
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.of_match_table = of_match_ptr(fixed_of_match),
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},
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};
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static int __init regulator_fixed_voltage_init(void)
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{
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return platform_driver_register(®ulator_fixed_voltage_driver);
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}
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subsys_initcall(regulator_fixed_voltage_init);
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static void __exit regulator_fixed_voltage_exit(void)
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{
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platform_driver_unregister(®ulator_fixed_voltage_driver);
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}
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module_exit(regulator_fixed_voltage_exit);
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MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
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MODULE_DESCRIPTION("Fixed voltage regulator");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:reg-fixed-voltage");
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