drivers/regulator/fixed.c - third_party/linux - Git at Google

 // 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/of_device.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/regulator/machine.h>
 #include <linux/clk.h>


 struct fixed_voltage_data {
 	struct regulator_desc desc;
 	struct regulator_dev *dev;

 	struct clk *enable_clock;
 	unsigned int clk_enable_counter;
 };

 struct fixed_dev_type {
 	bool has_enable_clock;
 };

 static const struct fixed_dev_type fixed_voltage_data = {
 	.has_enable_clock = false,
 };

 static const struct fixed_dev_type fixed_clkenable_data = {
 	.has_enable_clock = true,
 };

 static int reg_clock_enable(struct regulator_dev *rdev)
 {
 	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
 	int ret = 0;

 	ret = clk_prepare_enable(priv->enable_clock);
 	if (ret)
 		return ret;

 	priv->clk_enable_counter++;

 	return ret;
 }

 static int reg_clock_disable(struct regulator_dev *rdev)
 {
 	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);

 	clk_disable_unprepare(priv->enable_clock);
 	priv->clk_enable_counter--;

 	return 0;
 }

 static int reg_clock_is_enabled(struct regulator_dev *rdev)
 {
 	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);

 	return priv->clk_enable_counter > 0;
 }


 /**
  * 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 struct regulator_ops fixed_voltage_clkenabled_ops = {
 	.enable = reg_clock_enable,
 	.disable = reg_clock_disable,
 	.is_enabled = reg_clock_is_enabled,
 };

 static int reg_fixed_voltage_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct fixed_voltage_config *config;
 	struct fixed_voltage_data *drvdata;
 	const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
 	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;

 	if (drvtype && drvtype->has_enable_clock) {
 		drvdata->desc.ops = &fixed_voltage_clkenabled_ops;

 		drvdata->enable_clock = devm_clk_get(dev, NULL);
 		if (IS_ERR(drvdata->enable_clock)) {
 			dev_err(dev, "Can't get enable-clock from devicetree\n");
 			return PTR_ERR(drvdata->enable_clock);
 		}
 	} else {
 		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",
 		.data = &fixed_voltage_data,
 	},
 	{
 		.compatible = "regulator-fixed-clock",
 		.data = &fixed_clkenable_data,
 	},
 	{
 	},
 };
 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(&regulator_fixed_voltage_driver);
 }
 subsys_initcall(regulator_fixed_voltage_init);

 static void __exit regulator_fixed_voltage_exit(void)
 {
 	platform_driver_unregister(&regulator_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");
	// 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/of_device.h>
	#include <linux/regulator/of_regulator.h>
	#include <linux/regulator/machine.h>
	#include <linux/clk.h>


	struct fixed_voltage_data {
	struct regulator_desc desc;
	struct regulator_dev *dev;

	struct clk *enable_clock;
	unsigned int clk_enable_counter;
	};

	struct fixed_dev_type {
	bool has_enable_clock;
	};

	static const struct fixed_dev_type fixed_voltage_data = {
	.has_enable_clock = false,
	};

	static const struct fixed_dev_type fixed_clkenable_data = {
	.has_enable_clock = true,
	};

	static int reg_clock_enable(struct regulator_dev *rdev)
	{
	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);
	int ret = 0;

	ret = clk_prepare_enable(priv->enable_clock);
	if (ret)
	return ret;

	priv->clk_enable_counter++;

	return ret;
	}

	static int reg_clock_disable(struct regulator_dev *rdev)
	{
	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);

	clk_disable_unprepare(priv->enable_clock);
	priv->clk_enable_counter--;

	return 0;
	}

	static int reg_clock_is_enabled(struct regulator_dev *rdev)
	{
	struct fixed_voltage_data *priv = rdev_get_drvdata(rdev);

	return priv->clk_enable_counter > 0;
	}


	/**
	* 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 struct regulator_ops fixed_voltage_clkenabled_ops = {
	.enable = reg_clock_enable,
	.disable = reg_clock_disable,
	.is_enabled = reg_clock_is_enabled,
	};

	static int reg_fixed_voltage_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct fixed_voltage_config *config;
	struct fixed_voltage_data *drvdata;
	const struct fixed_dev_type *drvtype = of_device_get_match_data(dev);
	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;

	if (drvtype && drvtype->has_enable_clock) {
	drvdata->desc.ops = &fixed_voltage_clkenabled_ops;

	drvdata->enable_clock = devm_clk_get(dev, NULL);
	if (IS_ERR(drvdata->enable_clock)) {
	dev_err(dev, "Can't get enable-clock from devicetree\n");
	return PTR_ERR(drvdata->enable_clock);
	}
	} else {
	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",
	.data = &fixed_voltage_data,
	},
	{
	.compatible = "regulator-fixed-clock",
	.data = &fixed_clkenable_data,
	},
	{
	},
	};
	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(&regulator_fixed_voltage_driver);
	}
	subsys_initcall(regulator_fixed_voltage_init);

	static void __exit regulator_fixed_voltage_exit(void)
	{
	platform_driver_unregister(&regulator_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");