drivers/regulator/fixed.c - kernel/msm - Gitiles

 /*
  * 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/platform_device.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/fixed.h>
 #include <linux/gpio.h>
 #include <linux/delay.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;
 	int microvolts;
 	int gpio;
 	unsigned startup_delay;
 	bool enable_high;
 	bool is_enabled;
 };


 /**
  * 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.
  */
 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 NULL;

 	config->init_data = of_get_regulator_init_data(dev);
 	init_data = config->init_data;

 	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 NULL;
 	}

 	if (init_data->constraints.boot_on)
 		config->enabled_at_boot = true;

 	config->gpio = of_get_named_gpio(np, "gpio", 0);
 	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;

 	return config;
 }

 static int fixed_voltage_is_enabled(struct regulator_dev *dev)
 {
 	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

 	return data->is_enabled;
 }

 static int fixed_voltage_enable(struct regulator_dev *dev)
 {
 	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

 	if (gpio_is_valid(data->gpio)) {
 		gpio_set_value_cansleep(data->gpio, data->enable_high);
 		data->is_enabled = true;
 	}

 	return 0;
 }

 static int fixed_voltage_disable(struct regulator_dev *dev)
 {
 	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

 	if (gpio_is_valid(data->gpio)) {
 		gpio_set_value_cansleep(data->gpio, !data->enable_high);
 		data->is_enabled = false;
 	}

 	return 0;
 }

 static int fixed_voltage_enable_time(struct regulator_dev *dev)
 {
 	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

 	return data->startup_delay;
 }

 static int fixed_voltage_get_voltage(struct regulator_dev *dev)
 {
 	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

 	return data->microvolts;
 }

 static int fixed_voltage_list_voltage(struct regulator_dev *dev,
 				      unsigned selector)
 {
 	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

 	if (selector != 0)
 		return -EINVAL;

 	return data->microvolts;
 }

 static struct regulator_ops fixed_voltage_ops = {
 	.is_enabled = fixed_voltage_is_enabled,
 	.enable = fixed_voltage_enable,
 	.disable = fixed_voltage_disable,
 	.enable_time = fixed_voltage_enable_time,
 	.get_voltage = fixed_voltage_get_voltage,
 	.list_voltage = fixed_voltage_list_voltage,
 };

 static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
 {
 	struct fixed_voltage_config *config = pdev->dev.platform_data;
 	struct fixed_voltage_data *drvdata;
 	int ret;

 	if (pdev->dev.of_node)
 		config = of_get_fixed_voltage_config(&pdev->dev);

 	drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
 	if (drvdata == NULL) {
 		dev_err(&pdev->dev, "Failed to allocate device data\n");
 		ret = -ENOMEM;
 		goto err;
 	}

 	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
 	if (drvdata->desc.name == NULL) {
 		dev_err(&pdev->dev, "Failed to allocate supply name\n");
 		ret = -ENOMEM;
 		goto err;
 	}
 	drvdata->desc.type = REGULATOR_VOLTAGE;
 	drvdata->desc.owner = THIS_MODULE;
 	drvdata->desc.ops = &fixed_voltage_ops;
 	drvdata->desc.n_voltages = 1;

 	drvdata->microvolts = config->microvolts;
 	drvdata->gpio = config->gpio;
 	drvdata->startup_delay = config->startup_delay;

 	if (gpio_is_valid(config->gpio)) {
 		drvdata->enable_high = config->enable_high;

 		/* FIXME: Remove below print warning
 		 *
 		 * config->gpio must be set to -EINVAL by platform code if
 		 * GPIO control is not required. However, early adopters
 		 * not requiring GPIO control may forget to initialize
 		 * config->gpio to -EINVAL. This will cause GPIO 0 to be used
 		 * for GPIO control.
 		 *
 		 * This warning will be removed once there are a couple of users
 		 * for this driver.
 		 */
 		if (!config->gpio)
 			dev_warn(&pdev->dev,
 				"using GPIO 0 for regulator enable control\n");

 		ret = gpio_request(config->gpio, config->supply_name);
 		if (ret) {
 			dev_err(&pdev->dev,
 			   "Could not obtain regulator enable GPIO %d: %d\n",
 							config->gpio, ret);
 			goto err_name;
 		}

 		/* set output direction without changing state
 		 * to prevent glitch
 		 */
 		drvdata->is_enabled = config->enabled_at_boot;
 		ret = drvdata->is_enabled ?
 				config->enable_high : !config->enable_high;

 		ret = gpio_direction_output(config->gpio, ret);
 		if (ret) {
 			dev_err(&pdev->dev,
 			   "Could not configure regulator enable GPIO %d direction: %d\n",
 							config->gpio, ret);
 			goto err_gpio;
 		}

 	} else {
 		/* Regulator without GPIO control is considered
 		 * always enabled
 		 */
 		drvdata->is_enabled = true;
 	}

 	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
 					  config->init_data, drvdata, NULL);
 	if (IS_ERR(drvdata->dev)) {
 		ret = PTR_ERR(drvdata->dev);
 		dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
 		goto err_gpio;
 	}

 	platform_set_drvdata(pdev, drvdata);

 	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
 		drvdata->microvolts);

 	return 0;

 err_gpio:
 	if (gpio_is_valid(config->gpio))
 		gpio_free(config->gpio);
 err_name:
 	kfree(drvdata->desc.name);
 err:
 	kfree(drvdata);
 	return ret;
 }

 static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
 {
 	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);

 	regulator_unregister(drvdata->dev);
 	if (gpio_is_valid(drvdata->gpio))
 		gpio_free(drvdata->gpio);
 	kfree(drvdata->desc.name);
 	kfree(drvdata);

 	return 0;
 }

 #if defined(CONFIG_OF)
 static const struct of_device_id fixed_of_match[] __devinitconst = {
 	{ .compatible = "regulator-fixed", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, fixed_of_match);
 #else
 #define fixed_of_match NULL
 #endif

 static struct platform_driver regulator_fixed_voltage_driver = {
 	.probe		= reg_fixed_voltage_probe,
 	.remove		= __devexit_p(reg_fixed_voltage_remove),
 	.driver		= {
 		.name		= "reg-fixed-voltage",
 		.owner		= THIS_MODULE,
 		.of_match_table = 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");
	/*
	* 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/platform_device.h>
	#include <linux/regulator/driver.h>
	#include <linux/regulator/fixed.h>
	#include <linux/gpio.h>
	#include <linux/delay.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;
	int microvolts;
	int gpio;
	unsigned startup_delay;
	bool enable_high;
	bool is_enabled;
	};


	/**
	* 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.
	*/
	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 NULL;

	config->init_data = of_get_regulator_init_data(dev);
	init_data = config->init_data;

	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 NULL;
	}

	if (init_data->constraints.boot_on)
	config->enabled_at_boot = true;

	config->gpio = of_get_named_gpio(np, "gpio", 0);
	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;

	return config;
	}

	static int fixed_voltage_is_enabled(struct regulator_dev *dev)
	{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	return data->is_enabled;
	}

	static int fixed_voltage_enable(struct regulator_dev *dev)
	{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	if (gpio_is_valid(data->gpio)) {
	gpio_set_value_cansleep(data->gpio, data->enable_high);
	data->is_enabled = true;
	}

	return 0;
	}

	static int fixed_voltage_disable(struct regulator_dev *dev)
	{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	if (gpio_is_valid(data->gpio)) {
	gpio_set_value_cansleep(data->gpio, !data->enable_high);
	data->is_enabled = false;
	}

	return 0;
	}

	static int fixed_voltage_enable_time(struct regulator_dev *dev)
	{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	return data->startup_delay;
	}

	static int fixed_voltage_get_voltage(struct regulator_dev *dev)
	{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	return data->microvolts;
	}

	static int fixed_voltage_list_voltage(struct regulator_dev *dev,
	unsigned selector)
	{
	struct fixed_voltage_data *data = rdev_get_drvdata(dev);

	if (selector != 0)
	return -EINVAL;

	return data->microvolts;
	}

	static struct regulator_ops fixed_voltage_ops = {
	.is_enabled = fixed_voltage_is_enabled,
	.enable = fixed_voltage_enable,
	.disable = fixed_voltage_disable,
	.enable_time = fixed_voltage_enable_time,
	.get_voltage = fixed_voltage_get_voltage,
	.list_voltage = fixed_voltage_list_voltage,
	};

	static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
	{
	struct fixed_voltage_config *config = pdev->dev.platform_data;
	struct fixed_voltage_data *drvdata;
	int ret;

	if (pdev->dev.of_node)
	config = of_get_fixed_voltage_config(&pdev->dev);

	drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
	if (drvdata == NULL) {
	dev_err(&pdev->dev, "Failed to allocate device data\n");
	ret = -ENOMEM;
	goto err;
	}

	drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
	if (drvdata->desc.name == NULL) {
	dev_err(&pdev->dev, "Failed to allocate supply name\n");
	ret = -ENOMEM;
	goto err;
	}
	drvdata->desc.type = REGULATOR_VOLTAGE;
	drvdata->desc.owner = THIS_MODULE;
	drvdata->desc.ops = &fixed_voltage_ops;
	drvdata->desc.n_voltages = 1;

	drvdata->microvolts = config->microvolts;
	drvdata->gpio = config->gpio;
	drvdata->startup_delay = config->startup_delay;

	if (gpio_is_valid(config->gpio)) {
	drvdata->enable_high = config->enable_high;

	/* FIXME: Remove below print warning
	*
	* config->gpio must be set to -EINVAL by platform code if
	* GPIO control is not required. However, early adopters
	* not requiring GPIO control may forget to initialize
	* config->gpio to -EINVAL. This will cause GPIO 0 to be used
	* for GPIO control.
	*
	* This warning will be removed once there are a couple of users
	* for this driver.
	*/
	if (!config->gpio)
	dev_warn(&pdev->dev,
	"using GPIO 0 for regulator enable control\n");

	ret = gpio_request(config->gpio, config->supply_name);
	if (ret) {
	dev_err(&pdev->dev,
	"Could not obtain regulator enable GPIO %d: %d\n",
	config->gpio, ret);
	goto err_name;
	}

	/* set output direction without changing state
	* to prevent glitch
	*/
	drvdata->is_enabled = config->enabled_at_boot;
	ret = drvdata->is_enabled ?
	config->enable_high : !config->enable_high;

	ret = gpio_direction_output(config->gpio, ret);
	if (ret) {
	dev_err(&pdev->dev,
	"Could not configure regulator enable GPIO %d direction: %d\n",
	config->gpio, ret);
	goto err_gpio;
	}

	} else {
	/* Regulator without GPIO control is considered
	* always enabled
	*/
	drvdata->is_enabled = true;
	}

	drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
	config->init_data, drvdata, NULL);
	if (IS_ERR(drvdata->dev)) {
	ret = PTR_ERR(drvdata->dev);
	dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
	goto err_gpio;
	}

	platform_set_drvdata(pdev, drvdata);

	dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
	drvdata->microvolts);

	return 0;

	err_gpio:
	if (gpio_is_valid(config->gpio))
	gpio_free(config->gpio);
	err_name:
	kfree(drvdata->desc.name);
	err:
	kfree(drvdata);
	return ret;
	}

	static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
	{
	struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);

	regulator_unregister(drvdata->dev);
	if (gpio_is_valid(drvdata->gpio))
	gpio_free(drvdata->gpio);
	kfree(drvdata->desc.name);
	kfree(drvdata);

	return 0;
	}

	#if defined(CONFIG_OF)
	static const struct of_device_id fixed_of_match[] __devinitconst = {
	{ .compatible = "regulator-fixed", },
	{},
	};
	MODULE_DEVICE_TABLE(of, fixed_of_match);
	#else
	#define fixed_of_match NULL
	#endif

	static struct platform_driver regulator_fixed_voltage_driver = {
	.probe = reg_fixed_voltage_probe,
	.remove = __devexit_p(reg_fixed_voltage_remove),
	.driver = {
	.name = "reg-fixed-voltage",
	.owner = THIS_MODULE,
	.of_match_table = 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");